OS Therapies Incorporated (OSTX)

OS Therapies Appoints Dr. Craig Eagle to Board of DirectorsJuly 2, 2026 7:30 AM
NewsfileCompany secures $10 million line of credit supported by OS Therapies UK tax creditsNew York, New York and Rockville, Maryland--(Newsfile Corp. - July 2, 2026) - OS Therapies, Inc. (NYSE American: OSTX) ("OS Therapies" or "the Company"), the world leader in gene-edited, Listeria-based cancer immunotherapies, today announced that it has appointed Dr. Craig Eagle to the Company's Board of Directors. Dr. Eagle currently serves as the Company's Chief Medical Advisor. The Company also thanks Karim Galzahr for his service to the Board of Directors and will continue as a member of the Company's advisory board."Having enjoyed participating in recent U.S., European and U.K. regulatory meetings as we prepare for a late third quarter initiation of the confirmatory Phase 3 study for OST-HER2 in the prevention or delay of recurrence of fully resected, pulmonary metastatic osteosarcoma, we have now reached consensus on the vast majority of key items that pave the way for potential early market authorizations in late 2026," said Dr. Craig Eagle, Chief Medical Advisor and Board Member of OS Therapies. "The progress made on the sustained OST-HER2 overall survival benefit compared with historical control at the 2.5-year timepoint, the unique biomarker signature that predicts that overall survival benefit, as well as critical mass now having been reached in the recruitment into OST-400 all give me confidence as we prepare for U.S. Food & Drug Administration (FDA) Type B Statistical Methods and, thereafter, Type B Pre-BLA meetings to gain full regulatory alignment prior to completing the submission of our ongoing Biologics License Application submission under the Accelerated Approval Program. We are hopeful for decisions on Rolling Review, Regenerative Medicine Advanced Therapy (RMAT) and Breakthrough Therapy designations following the Type B Statistical Methods Meeting."Dr. Eagle most recently served as Guardant Health's Chief Medical Officer. Prior to joining Guardant Health, Dr. Eagle served as Vice President of Medical Affairs Oncology for Genentech, where he oversaw the medical programs across the oncology portfolio and developed innovative cancer trials and strategies in personalized health care. Prior to Genentech, Dr. Eagle held several leadership roles at Pfizer, including oncology business lead for the United Kingdom and Canada, global lead for Oncology Strategic Alliances and Partnerships, and global head of the Oncology Therapeutic Area Global Medical and Outcomes Group, where he oversaw the U.S. oncology business. Dr. Eagle attended medical school at the University of New South Wales in Sydney, Australia and received his general internist training at Royal North Shore Hospital in Sydney."We are thrilled to have Dr. Eagle join our Board of Directors as we look to transition from a development-stage company into a commercial healthcare organization over the next year," said Paul Romness, MPH, Chairman & CEO of OS Therapies.Concurrent with this announcement, the Company announced a $10 million line of credit (LOC) supported by the Company's wholly-owned subsidiary OS Therapies U.K. tax credits. The Company will receive an initial draw of $1.6 million that primarily supported the second phase OST-HER2 commercial manufacturing following the receipt of global regulatory alignment on the commercial manufacturing pathway for OST-HER2. OS Therapies UK currently has accumulated approximately $5.86 million in pending tax credit refunds and expects to have accumulated a total of $10.2 million through year-end 2026. The Company did not provide security interest in its intellectual property as part of the LOC agreements. "With a reliable way to monetize the significant R&D investments we made in the fourth quarter of 2025 and the first quarter in the U.K. subsidiary, combined with significantly reduced expenses projected for the third quarter, the Company reiterates that it expects to have sufficient cash and cash resources to provide runway into 2027," said Chris Acevedo, CPA, Chief Financial Officer of OS Therapies. OST-HER2 has received Orphan Drug Designation (ODD), Fast Track Designation (FTD) and Rare Pediatric Disease Designation (RPDD) from the FDA, and ODD, FTD and ATMP from the EMA. Under the RPDD program, if the Company receives a BLA in the United States, it will become eligible to receive a Priority Review Voucher (PRV) that it intends to sell. The Company is seeking to obtain a BLA under the Accelerated Approval Program for OST-HER2 in osteosarcoma by year-end 2026 in the U.S., in addition to conditional Marketing Authorisation Applications in Europe, the U.K. and Australia.About OS TherapiesOS Therapies is a clinical stage oncology company focused on the identification, development, and commercialization of treatments for Osteosarcoma (OS) and other solid tumors. The Company is the world leader in gene-edited, Listeria-based cancer immunotherapies. OST-HER2, the Company's lead asset, is an immunotherapy leveraging the immune-stimulatory effects of Listeria bacteria to initiate a strong immune response targeting the HER2 protein. OST-HER2 is designed to target two mutated extracellular epitopes and one mutated intracellular epitope of the HER2 oncogene, requiring only one of these three epitopes to be present in a tumor (or micro-metastasis) to trigger the desired immune response. OST-HER2 has received Orphan Drug Designation (ODD), Fast Track Designation (FTD) and Rare Pediatric Disease Designation (RPDD) from the U.S. Food & Drug Administration and has received ODD, FTD and ATMP from the European Medicines Agency. The Company reported positive data in its Phase 2b clinical trial of OST-HER2 in recurrent, fully resected, lung metastatic osteosarcoma, demonstrating clinically significant benefit in the 12-month event free survival (EFS) primary endpoint of the study and the overall survival (OS) secondary endpoint. The Company is seeking a Biologics License Application (BLA) from the U.S. FDA for OST-HER2 in osteosarcoma in 2026 and, if approved, would become eligible to receive a Priority Review Voucher that it could then sell. The Company also anticipates receiving Conditional Marketing Authorisation Applications from the U.K.'s Medicines and Healthcare products Regulatory Agency and the EMA for OST-HER2 in 2026. OST-HER2 has completed a Phase 1 clinical study primarily in breast cancer patients, in addition to showing preclinical efficacy data in various models of breast cancer. OST-HER2 has been conditionally approved by the U.S. Department of Agriculture for the treatment of canines with osteosarcoma. The Company has also completed dosing in a Phase 1 study of OST-504 for castration-resistant prostate cancer. In addition, OS Therapies is advancing its next-generation Antibody Drug Conjugate (ADC) and Drug Conjugates (DC), known as tunable ADC (tADC), which features tunable, tailored antibody-linker-payload candidates. This platform leverages the Company's proprietary silicone Si-Linker and Conditionally Active Payload (CAP) technology, enabling the delivery of multiple payloads per linker. For more information, please visit www.ostherapies.com. Forward-Looking StatementsStatements in this press release about future expectations, plans and prospects, as well as any other statements regarding matters that are not historical facts, may constitute forward-looking statements within the meaning of the federal securities laws. These forward-looking statements and terms such as "anticipate," "expect," "intend," "may," "will," "should" or other comparable terms involve risks and uncertainties because they relate to events and depend on circumstances that will occur in the future. Those statements include statements regarding the intent, belief or current expectations of OS Therapies and members of its management, as well as the assumptions on which such statements are based. OS Therapies cautions readers that forward-looking statements are based on management's expectations and assumptions as of the date of this press release and are subject to certain risks and uncertainties that could cause actual results to differ materially, including, but not limited to the potential approval of OST-HER2 by the U.S. FDA and other risks and uncertainties described in "Risk Factors" in the Company's most recent Annual Report on Form 10-K and other subsequent documents the Company files with the Securities and Exchange Commission. Any forward-looking statements contained in this press release speak only as of the date hereof, and, except as required by the federal securities laws, OS Therapies specifically disclaims any obligation to update any forward-looking statement, whether as a result of new information, future events or otherwise.OS Therapies Contact Information:Investor Relations
Harrison Seidner, PhD
WaterSeid Partners
OSTX@waterseid.com Public Relations
Stephanie Chen
Elev8 New Media
media@ostherapies.com https://x.com/OSTherapies
https://www.instagram.com/ostherapies/
https://www.facebook.com/OSTherapies/
https://www.linkedin.com/company/os-therapies/To view the source version of this press release, please visit https://www.newsfilecorp.com/release/303725 Original: OS Therapies Appoints Dr. Craig Eagle to Board of Directors

Agree it’s sucks I has planning on an Uncy pop and I could sell some at a nice profit and load up more of my Ostx holdings….oh well….3 or 4 Uncy guys have bought Ostx recently

Up in the air- had my finger on the button to buy more Uncy today but I am hesitant because there are so many variables now- might drop it into OSTX as it seems there is a better chance of the share price going up dramatically in the next few months here compared to waiting for UNCY to get its act together.

OS Therapies Provides U.S. Regulatory UpdateJune 30, 2026 7:40 AM
NewsfileType B Meeting requested to follow up on September 2025 End of Phase 2 FDA Meeting guidance on statistical methods to be used for BLA SubmissionSeeking to align FDA with MHRA & EMA on 3-year overall survival as approval endpointBiomarker data submitted to FDA BEST program as surrogate clinical efficacy dataSynthetic historical control arm OST-400 recruitment potentially adds comparator for BLA submission under the Accelerated ApprovalReview of Rolling Review, RMAT & Breakthrough Therapy designation requests soughtNew York, New York and Rockville, Maryland--(Newsfile Corp. - June 30, 2026) - OS Therapies, Inc. (NYSE American: OSTX) ("OS Therapies" or "the Company"), the world leader in gene-edited, Listeria-based cancer immunotherapies, today provided regulatory update on the Company's interactions with the U.S. Food and Drug Administration (FDA) in its pursuit of a Biologics License Application (BLA) under the Accelerated Approval Program (Accelerated Approval) for OST-HER2 in the prevention or delay of recurrence in fully resected, pulmonary metastatic osteosarcoma (the "Metastatic Osteosarcoma Program"). OS Therapies has requested a Type B Meeting to review the Company's 2.5-year overall survival data and to confirm alignment that 3-year overall survival data is an approvable clinical efficacy endpoint. The Company recently aligned with the U.K.'s Medicines and Healthcare products Regulatory Agency (MHRA) and the European Medicines Agency on 3-year overall survival as the proposed approvable clinical endpoint to support Conditional Marketing Authorisations. The Company has also submitted its pharmacodynamic response biomarker data to the FDA's Biomarkers, Endpoints, and other Tools (BEST) program for evaluation as a surrogate clinical efficacy data. FDA and EMA have begun joint coordination on the OST-HER2 regulatory dossier to evaluate early market access.OS Therapies intends to review with FDA the potential inclusion of concurrent natural history control database OST-400, "Recurrent Osteosarcoma after Resection in Children and Young Adults: A Retrospective Longitudinal Study," as an added synthetic control comparator arm at the meeting. The Company recently made significant progress with recruitment for OST-400 that now allows the Company to respond to June 2025 Breakthrough Therapy Designation (BTD) request feedback and September 2025 End of Phase 2 Meeting guidance provided by FDA on OST-400's development. OS Therapies also expects to review outstanding Rolling Review, Regenerative Medicine Advanced Therapy (RMAT) designation and BTD requests with FDA at the meeting. The potential suitability of OST-400 as a second supportive comparator arm for Accelerated Approval is in addition to the suitability of pooled historical control data already shared with FDA to support Accelerated Approval."We look forward to reviewing our overall survival data with FDA as we seek to gain the same alignment we now have with MHRA and EMA on the use of 3-year overall survival clinical efficacy data together with pharmacodynamic biomarker surrogate clinical efficacy data to support early market access of OST-HER2 for patients in the U.S.," said Paul Romness, MHP, Chairman and CEO of OS Therapies. "With significant progress having now been made with recruitment for OST-400, we believe we are in a strong position to gain alignment on the proposed statistical analysis methods to be used to confirm clinical results in the upcoming 3-year overall survival data readout early in the fall. We are hopeful that this upcoming meeting will allow us to align FDA with the EMA and MHRA on rolling review and regenerative medicine status now that joint dossier coordination has begun between the three agencies."About OST-400OST-400 is a natural history study entitled "Recurrent Osteosarcoma after Resection in Children and Young Adults: A Retrospective Longitudinal Study". Data is being sourced primarily from US and international oncology research institutions. OST-400 database is being assembled in order to be able to develop a synthetic control arm suitable to support a randomization process that could serve as comparator arm in the event FDA relies upon its 2023 Rare Diseases guidance. Various FDA-accepted statistical analysis methods reviewed in this Guidance allow for randomization after treatment in single-arm trials.About OS TherapiesOS Therapies is a clinical stage oncology company focused on the identification, development, and commercialization of treatments for Osteosarcoma (OS) and other solid tumors. The Company is the world leader in gene-edited, Listeria-based cancer immunotherapies. OST-HER2, the Company's lead asset, is an immunotherapy leveraging the immune-stimulatory effects of Listeria bacteria to initiate a strong immune response targeting the HER2 protein. OST-HER2 is designed to target two mutated extracellular epitopes and one mutated intracellular epitope of the HER2 oncogene, requiring only one of these three epitopes to be present in a tumor (or micro-metastasis) to trigger the desired immune response. OST-HER2 has received Orphan Drug Designation (ODD), Fast Track Designation (FTD) and Rare Pediatric Disease Designation (RPDD) from the U.S. Food & Drug Administration and has received ODD, FTD and ATMP from the European Medicines Agency. The Company reported positive data in its Phase 2b clinical trial of OST-HER2 in recurrent, fully resected, lung metastatic osteosarcoma, demonstrating clinically significant benefit in the 12-month event free survival (EFS) primary endpoint of the study and the overall survival (OS) secondary endpoint. The Company is seeking a Biologics License Application (BLA) from the U.S. FDA for OST-HER2 in osteosarcoma in 2026 and, if approved, would become eligible to receive a Priority Review Voucher that it could then sell. The Company also anticipates receiving Conditional Marketing Authorisation Applications from the U.K.'s Medicines and Healthcare products Regulatory Agency and the EMA for OST-HER2 in 2026. OST-HER2 has completed a Phase 1 clinical study primarily in breast cancer patients, in addition to showing preclinical efficacy data in various models of breast cancer. OST-HER2 has been conditionally approved by the U.S. Department of Agriculture for the treatment of canines with osteosarcoma. In addition, OS Therapies is advancing its next-generation Antibody Drug Conjugate (ADC) and Drug Conjugates (DC), known as tunable ADC (tADC), which features tunable, tailored antibody-linker-payload candidates. This platform leverages the Company's proprietary silicone Si-Linker and Conditionally Active Payload (CAP) technology, enabling the delivery of multiple payloads per linker. For more information, please visit www.ostherapies.com. Forward-Looking StatementsStatements in this press release about future expectations, plans and prospects, as well as any other statements regarding matters that are not historical facts, may constitute forward-looking statements within the meaning of the federal securities laws. These forward-looking statements and terms such as "anticipate," "expect," "intend," "may," "will," "should" or other comparable terms involve risks and uncertainties because they relate to events and depend on circumstances that will occur in the future. Those statements include statements regarding the intent, belief or current expectations of OS Therapies and members of its management, as well as the assumptions on which such statements are based. OS Therapies cautions readers that forward-looking statements are based on management's expectations and assumptions as of the date of this press release and are subject to certain risks and uncertainties that could cause actual results to differ materially, including, but not limited to the potential approval of OST-HER2 by the U.S. FDA and other risks and uncertainties described in "Risk Factors" in the Company's most recent Annual Report on Form 10-K and other subsequent documents the Company files with the Securities and Exchange Commission. Any forward-looking statements contained in this press release speak only as of the date hereof, and, except as required by the federal securities laws, OS Therapies specifically disclaims any obligation to update any forward-looking statement, whether as a result of new information, future events or otherwise.OS Therapies Contact Information:Investor Relations
Harrison Seidner, PhD
WaterSeid Partners
OSTX@waterseid.com Public Relations
Stephanie Chen
Elev8 New Media
media@ostherapies.com https://x.com/OSTherapies
https://www.instagram.com/ostherapies/
https://www.facebook.com/OSTherapies/
https://www.linkedin.com/company/os-therapies/To view the source version of this press release, please visit https://www.newsfilecorp.com/release/303383 Original: OS Therapies Provides U.S. Regulatory Update

Lot of the UNCY crew is buying OSTX now 💰💵

OS Animal Health Announces Peer-Reviewed Publication of Clinical Trial Data for OST-HER2 Plus Palliative Radiation as Frontline Treatment in Canine OsteosarcomaJune 26, 2026 7:40 AM
Newsfile20% of OST-HER2 treated dogs survived 2-year vs. 1% in control group (p = 0.00995)Over 15,000 dogs per year diagnosed with osteosarcomaCompany expects to submit U.S. Department of Agriculture meeting request to gain alignment on regulatory path towards conditional approval in the third quarter of 2026OS Therapies reiterates plan to distribute OS Animal Health shares to shareholdersOS Animal Health plans crowdfunding to expand shareholder base to meet U.S. national exchange initial listing standards, with indications of interest now being receivedRockville, Maryland--(Newsfile Corp. - June 26, 2026) - OS Animal Health, Inc. ("OS Animal Health" or "the Company"), the wholly-owned animal health subsidiary of OS Therapies, Inc. (NYSE American: OSTX) ("OS Therapies"), the world leader in gene-edited, Listeria-based cancer immunotherapies, today announced the peer-reviewed publication of data from the Phase 2 clinical trial of OST-HER2, together with palliative radiation therapy ("RT"), aimed at preventing amputation in frontline canine osteosarcoma. The median overall survival time in the OST-HER2 +RT treated dogs was 159 days vs. 124 days in the RT-alone control group (p = 0.0237). Survival at 2 years significantly favors OST-HER2+RT treated dogs when compared with RT-alone 0.00995. The Company intends to meet with the U.S. Department of Agriculture, the regulatory agency that governs the licensure of biologic drugs for companion animals, in the third quarter to align on a regulatory path to market for OST-HER2 in canines now that there is alignment with global regulators on manufacturing requirements for OST-HER2 in humans. A link to the publication can be found at: https://www.cell.com/molecular-therapy-family/oncology/fulltext/S2950-3299(26)00119-0. Survival for OST-HER2+radiation vs. radiation-alone in frontline canine osteosarcoma
Survival to 1 year Survival to 500 daySurvival to 2 yearOverall Survival Median
Survival Time (days) OST-HER2+Radiation33% (5/15)27% (4/15)20% (3/15)159 Radiation-alone13% (11/83)2% (2/83)1% (1/83)124 p-value0.07250.01080.009950.0237 OS Therapies reiterates its plan to distribute OS Animal Health shares to OS Therapies shareholders following OS Animal Health's previously proposed 'go-public' transaction for which a Form S-1 offering was filed confidentially in the first quarter of 2026. The Company has been advised by potential underwriters to expand the Company's shareholder base while still private in preparation for the transaction. OS Animal Health plans to initiate a crowdfunding in the third quarter of 2026 to expand its shareholder base in order to meet the initial listing standards for a U.S. national stock exchange. Indications of interest from potential investors in the proposed crowdfunding are being received at: https://www.mrcrowd.com/ttw/osah "The data from this pilot study is very exciting and represents the first evidence that it may be possible for some dogs to avoid amputation and survive with adequate limb function and good quality of life beyond what is expected with palliative radiation alone," said Dr. Nicola J. Mason, the Paul A. James and Charles A. Gilmore Endowed Chair Professor and Professor of Medicine and Pathobiology at the University of Pennsylvania School of Veterinary Medicine and lead author of the study. "Although many dogs do extremely well physically with amputation, there is often a reluctance to amputate especially in large breeds given their size and the almost inevitable development of metastases and associated poor prognosis. While small, this study shows that a subset of immunotherapy treated dogs can control their primary disease, and experience delay in development of metastases without amputation and opens the door to a potential change in the standard of care (SOC) in the treatment of osteosarcoma. We believe that recent data showing improved antigen presentation and anti-cancer cellular immune activity in treated dogs and humans, combined with clinical data showing increased survival in various disease settings, support the concept that OST-HER2 may represent a breakthrough treatment for all stages of osteosarcoma. We intend to continue to study OST-HER2 alone, as well as in combination with potential complementary therapies, to find the best solution for canine patients dealing with this deadly disease in the hope that future findings may be translated into further human clinical development."Over 15,000 dogs per year are diagnosed with osteosarcoma in the United States. Despite the introduction of amputation, chemotherapy and radiation therapy into the treatment paradigm, prognosis remains extremely poor. Comparative Oncology, the field in which naturally-occurring cancers in animals are studied to identify whether progress could be translated to human cancers, has identified canine osteosarcoma as the most promising area where translation of advancements in dogs may be possible to humans due to high genetic homology of the cancers, shared environment, congruent immune system responses and near-identical clinical disease-course."The field of canine oncology treatment is gaining significant momentum as the large animal health companies begin to launch molecularly-targeted therapies for dogs," said Edward Robb, DVT, President of OS Animal Health. "OST-HER2 is the anchor product candidate from the listeria platform that can potentially begin to make a near-term commercial impact in osteosarcoma. However, the opportunity for OS Animal Health is much broader than that. With the advent of molecularly targeted therapies gaining traction in animal health, the idea that OST-HER2 could become the standard for all HER2 positive canine cancers is something we will begin to look at closely. If that translates into clinical success, we could then advance listeria product candidates from that platform that target other cancer antigens. We believe this platform is ideally suited as the 'go-to' molecularly targeted immunotherapy for veterinarians."About OS Animal HealthOS Animal Health (OSAH) is a wholly owned subsidiary of OS Therapies, Inc. (NYSE American: OSTX) dedicated to improving outcomes for pets with cancer. The Company is focused on developing and commercializing OST-HER2, an off-the-shelf immunotherapy candidate for canine osteosarcoma that has previously received conditional approval from the USDA for the treatment of this aggressive bone cancer in dogs. Operating with a separate, animal-health-focused strategy and capital structure, OS Animal Health is working to re-establish USDA conditional approval and bring innovative immunotherapies to the veterinary oncology market, with the goal of extending and improving the lives of dogs living with osteosarcoma, and animals living with other HER2 positive cancers.About Our Intended OfferingOS Animal Health is "testing the waters" to gauge investor interest in an offering under Regulation Crowdfunding. No money or other consideration is being solicited - if sent, it will not be accepted. No offer to buy securities will be accepted, and no part of the purchase price will be received until a Form C offering statement is filed with the SEC and through an approved intermediary platform. Any indication of interest involves no obligation or commitment of any kind.About OS TherapiesOS Therapies is a clinical stage oncology company focused on the identification, development, and commercialization of treatments for Osteosarcoma (OS) and other solid tumors. The Company is the world leader in gene-edited, Listeria-based cancer immunotherapies. OST-HER2, the Company's lead asset, is an immunotherapy leveraging the immune-stimulatory effects of Listeria bacteria to initiate a strong immune response targeting the HER2 protein. OST-HER2 is designed to target two mutated extracellular epitopes and one mutated intracellular epitope of the HER2 oncogene, requiring only one of these three epitopes to be present in a tumor (or micro-metastasis) to trigger the desired immune response. OST-HER2 has received Orphan Drug Designation (ODD), Fast Track Designation (FTD) and Rare Pediatric Disease Designation (RPDD) from the U.S. Food & Drug Administration and has received ODD, FTD and ATMP from the European Medicines Agency. The Company reported positive data in its Phase 2b clinical trial of OST-HER2 in recurrent, fully resected, lung metastatic osteosarcoma, demonstrating clinically significant benefit in the 12-month event free survival (EFS) primary endpoint of the study and the overall survival (OS) secondary endpoint. The Company is seeking a Biologics License Application (BLA) from the U.S. FDA for OST-HER2 in osteosarcoma in 2026 and, if approved, would become eligible to receive a Priority Review Voucher that it could then sell. The Company also anticipates receiving Conditional Marketing Authorisation Applications from the U.K.'s Medicines and Healthcare products Regulatory Agency and the EMA for OST-HER2 in 2026. OST-HER2 has completed a Phase 1 clinical study primarily in breast cancer patients, in addition to showing preclinical efficacy data in various models of breast cancer. OST-HER2 has been conditionally approved by the U.S. Department of Agriculture for the treatment of canines with osteosarcoma. In addition, OS Therapies is advancing its next-generation Antibody Drug Conjugate (ADC) and Drug Conjugates (DC), known as tunable ADC (tADC), which features tunable, tailored antibody-linker-payload candidates. This platform leverages the Company's proprietary silicone Si-Linker and Conditionally Active Payload (CAP) technology, enabling the delivery of multiple payloads per linker. For more information, please visit www.ostherapies.com. Forward-Looking StatementsStatements in this press release about future expectations, plans and prospects, as well as any other statements regarding matters that are not historical facts, may constitute forward-looking statements within the meaning of the federal securities laws. These forward-looking statements and terms such as "anticipate," "expect," "intend," "may," "will," "should" or other comparable terms involve risks and uncertainties because they relate to events and depend on circumstances that will occur in the future. Those statements include statements regarding the intent, belief or current expectations of OS Therapies and members of its management, as well as the assumptions on which such statements are based. OS Therapies cautions readers that forward-looking statements are based on management's expectations and assumptions as of the date of this press release and are subject to certain risks and uncertainties that could cause actual results to differ materially, including, but not limited to the potential approval of OST-HER2 by the U.S. FDA, licensure by the U.S. Department of Agriculture and other risks and uncertainties described in "Risk Factors" in the Company's most recent Annual Report on Form 10-K and other subsequent documents the Company files with the Securities and Exchange Commission. The proposal for a future distribution of OS Animal Health shares and national market listing are preliminary and not assured. Any forward-looking statements contained in this press release speak only as of the date hereof, and, except as required by the federal securities laws, OS Therapies specifically disclaims any obligation to update any forward-looking statement, whether as a result of new information, future events or otherwise.OS Therapies Contact Information:Investor Relations
Harrison Seidner, PhD
WaterSeid Partners
OSTX@waterseid.com Public Relations
Stephanie Chen
Elev8 New Media
media@ostherapies.com https://x.com/OSTherapies
https://www.instagram.com/ostherapies/
https://www.facebook.com/OSTherapies/
https://www.linkedin.com/company/os-therapies/To view the source version of this press release, please visit https://www.newsfilecorp.com/release/302971 Original: OS Animal Health Announces Peer-Reviewed Publication of Clinical Trial Data for OST-HER2 Plus Palliative Radiation as Frontline Treatment in Canine Osteosarcoma

I'm going to buy a little today with the intention of helping someone someday survive this disease. Until you know of someone in the refractory stage in osteosarcoma, you really don't understand how badly a successful drug therapy is needed right now. From what I've learned, this is a very aggressive form of cancer. And when it is detected late, the medical teams are playing catch up. It's like trying to stop a freight train with a with a piece of thread and the train is 100 miles ahead of you and you're on foot. Can't be done. I don't know if OTSX has the answer for refractory cases in such a late stage, but if they can help save anyone this is a feel good investment I feel good about even with a few hundred shares. It appears there are 5 or 6 other companies working on this too, but OSTX seems to be the only pure play on osteosarcoma. As always, do your own due diligence.

OS Therapies Achieves Global Regulatory Alignment on Design of Phase 3 Trial of OST-HER2 in Fully Resected, Pulmonary Metastatic OsteosarcomaJune 8, 2026 6:00 AM
NewsfileConfirmatory Phase 3 trial to commence prior to BLA grant under Accelerated Approval Program in the U.S. and Conditional MAA in the U.K., Europe and AustraliaPatent pending pharmacodynamic response biomarker accepted as surrogate clinical efficacy endpointTGA and MHRA agree to allow utilization of remaining Phase 2b drug product for initiation of confirmatory Phase 3FDA and EMA fully align with Company on Chemistry, Manufacturing and Controls (CMC)Market access process initiated with UK NICE and EU JCANew York, New York and Rockville, Maryland--(Newsfile Corp. - June 8, 2026) - OS Therapies, Inc. (NYSE American: OSTX) ("OS Therapies" or "the Company"), the world leader in gene-edited, Listeria-based cancer immunotherapies, today announced that it achieved alignment on the design of its pending Phase 3 study of OST-HER2 in the prevention or delay of recurrence in fully resected, pulmonary metastatic osteosarcoma with the U.S. Food & Drug Administration (FDA) and the U.K. Medicines and Healthcare products Regulatory Agency (MHRA). A confirmatory Phase 3 study is required to have commenced prior to the grant of a Biologics License Application (BLA) under the Accelerated Approval Program in the U.S. and Conditional Marketing Authorisation Applications (CMAAs) in the U.K., Europe and Australia. The Phase 3 study has received substantial support from international KOLs as part of regulatory meetings and is expected to commence late in the third quarter in Australia making the Company eligible for regulatory decisions in the fourth quarter. "This alignment amongst each of the four key regulatory agencies where we are seeking early market access allows us to move forward with confidence as we prepare the Clinical Trial Notification (CTN) scheme submission to the Australian Therapeutic Goods Administration (TGA) to gain authorization to initiate the Phase 3 study," said Dr. Craig Eagle, Chief Medical Advisor of OS Therapies. "Australia has a very attractive R&D tax incentive program complementing the company's existing UK R&D tax credit strategy to incentivize the initiation of global clinical trials, allowing us to initiate the Phase 3 with minimal cost. MHRA and TGA are allowing us to initiate the Phase 3 trial with the same drug product used in the Phase 2b trial, positioning the Phase 3 trial to open in the third quarter of 2026. FDA, MHRA, EMA and TGA have now aligned with the Company on the CMC plan and potency assays for commercial drug product. These alignments allow the Company to be positioned for potential year-end regulatory decisions and 2027 patient access."Dr. Eagle continued, "Both FDA and MHRA also aligned with the EMA and TGA to include the pharmacodynamic biomarker signature as a surrogate clinical efficacy endpoint in the Phase 3. EMA has already begun rolling review of the regulatory dossier and we expect decisions regarding rolling review and Regenerative Medicine Advanced Therapy (RMAT) designation in the United States following our upcoming Type B Pre-BLA Meeting following the successful Type C Phase 3 Design Meeting last week."OST-HER2 has received Orphan Drug Designation (ODD), Fast Track Designation (FTD) and Rare Pediatric Disease Designation (RPDD) from the FDA, and ODD, FTD and Advanced Therapeutic Medicinal Product (ATMP) designation from the EMA and MHRA. Under the RPDD program, if the Company is granted a BLA in the United States, it will become eligible to receive a Priority Review Voucher (PRV) that it intends to sell. The Company has begun filing a BLA for osteosarcoma with FDA and has received rolling review from the EMA. About OS TherapiesOS Therapies is a clinical stage oncology company focused on the identification, development, and commercialization of treatments for Osteosarcoma (OS) and other solid tumors. The Company is the world leader in gene-edited, Listeria-based cancer immunotherapies. OST-HER2, the Company's lead asset, is an immunotherapy leveraging the immune-stimulatory effects of Listeria bacteria to initiate a strong immune response targeting the HER2 protein. OST-HER2 is designed to target two mutated extracellular epitopes and one mutated intracellular epitope of the HER2 oncogene, requiring only one of these three epitopes to be present in a tumor (or micro-metastasis) to trigger the desired immune response. OST-HER2 has received Orphan Drug Designation (ODD), Fast Track Designation (FTD) and Rare Pediatric Disease Designation (RPDD) from the U.S. Food & Drug Administration and has received ODD, FTD and ATMP from the European Medicines Agency. The Company reported positive data in its Phase 2b clinical trial of OST-HER2 in recurrent, fully resected, lung metastatic osteosarcoma, demonstrating clinically significant benefit in the 12-month event free survival (EFS) primary endpoint of the study and the overall survival (OS) secondary endpoint. The Company is seeking a Biologics License Application (BLA) from the U.S. FDA for OST-HER2 in osteosarcoma in 2026 and, if approved, would become eligible to receive a Priority Review Voucher that it could then sell. The Company also anticipates receiving Conditional Marketing Authorisation Applications from the U.K.'s Medicines and Healthcare products Regulatory Agency and the EMA for OST-HER2 in 2026. OST-HER2 has completed a Phase 1 clinical study primarily in breast cancer patients, in addition to showing preclinical efficacy data in various models of breast cancer. OST-HER2 has been conditionally approved by the U.S. Department of Agriculture for the treatment of canines with osteosarcoma. In addition, OS Therapies is advancing its next-generation Antibody Drug Conjugate (ADC) and Drug Conjugates (DC), known as tunable ADC (tADC), which features tunable, tailored antibody-linker-payload candidates. This platform leverages the Company's proprietary silicone Si-Linker and Conditionally Active Payload (CAP) technology, enabling the delivery of multiple payloads per linker. For more information, please visit www.ostherapies.com. Forward-Looking StatementsStatements in this press release about future expectations, plans and prospects, as well as any other statements regarding matters that are not historical facts, may constitute forward-looking statements within the meaning of the federal securities laws. These forward-looking statements and terms such as "anticipate," "expect," "intend," "may," "will," "should" or other comparable terms involve risks and uncertainties because they relate to events and depend on circumstances that will occur in the future. Those statements include statements regarding the intent, belief or current expectations of OS Therapies and members of its management, as well as the assumptions on which such statements are based. OS Therapies cautions readers that forward-looking statements are based on management's expectations and assumptions as of the date of this press release and are subject to certain risks and uncertainties that could cause actual results to differ materially, including, but not limited to the potential approval of OST-HER2 by the U.S. FDA and other risks and uncertainties described in "Risk Factors" in the Company's most recent Annual Report on Form 10-K and other subsequent documents the Company files with the Securities and Exchange Commission. Any forward-looking statements contained in this press release speak only as of the date hereof, and, except as required by the federal securities laws, OS Therapies specifically disclaims any obligation to update any forward-looking statement, whether as a result of new information, future events or otherwise.OS Therapies Contact Information:Investor Relations
Harrison Seidner, PhD
WaterSeid Partners
OSTX@waterseid.com Public Relations
Stephanie Chen
Elev8 New Media
media@ostherapies.comhttps://x.com/OSTherapies
https://www.instagram.com/ostherapies/
https://www.facebook.com/OSTherapies/
https://www.linkedin.com/company/os-therapies/To view the source version of this press release, please visit https://www.newsfilecorp.com/release/300469 Original: OS Therapies Achieves Global Regulatory Alignment on Design of Phase 3 Trial of OST-HER2 in Fully Resected, Pulmonary Metastatic Osteosarcoma

OS Therapies Achieves Statistically Significant 2.5-Year Overall Survival in Phase 2b Trial of OST-HER2 in Fully Resected Pulmonary Metastatic OsteosarcomaJune 2, 2026 6:00 AM
Newsfile75% 2.5-year overall survival for OST-HER2 vs. 47% pooled historical control (p = 0.003), with no new patient deaths reported since the 2-year overall survival data (75% vs. 60%, p = 0.034)Updated clinical efficacy data being added to regulatory dossiers as Company seeks early market authorizations in U.S., U.K., Europe and Australia in 2nd half of 2026EMA and Australia TGA (TGA) alignment achieved on early Q4-2026 3-year overall survival data, supported by biomarker data, as key approvable clinical efficacy endpointUpcoming U.S. FDA and U.K. MHRA meetings seek alignment with EMA and TGA on Phase 2b 3-year overall survival and biomarker data to support early market access Confirmatory Phase 3 study, required to have commenced prior to grant of early market access in U.S., U.K., Europe or Australia, expected to initiate in late Q3-2026 in AustraliaNew York and Rockville, Maryland--(Newsfile Corp. - June 2, 2026) - OS Therapies, Inc. (NYSE American: OSTX) ("OS Therapies" or "the Company"), the world leader in gene-edited, Listeria-based cancer immunotherapies, today announced that its Phase 2b trial of OST-HER2 in the prevention or delay of recurrence in fully resected, pulmonary metastatic osteosarcoma (the "Metastatic Osteosarcoma") achieved statistically significant benefit for OST-HER2 treated patients in overall survival at the 2.5-year timepoint (75% vs. 47%, p = 0.003, Figure 1 OST-HER2 vs. pooled historical control). The topline data shows improving OST-HER2 survival benefit when compared with the 2-year data (2-year overall survival was 75% vs. 60%, p = 0.034). No new patient deaths were reported between the 2 and 2.5-year timepoints in the OST-HER2 treated group. OST-HER2 data is supported by a unique, patent pending pharmacodynamic immune response biomarker signature (Antigen Presentation, NK Cell Activation, T Cell Activation, etc.) that was developed as a surrogate clinical efficacy endpoint. The Company intends to present detailed data results during the MIB Agents Factor 2026 Osteosarcoma Conference being held June 25-27, 2026 in Columbus, OH. "The osteosarcoma community is eagerly awaiting its first approved immunotherapy that has a strong safety profile and activates the immune system to surveil against pulmonary recurrence," said Dr. Peter Anderson, pediatric oncologist at Cleveland Clinic Children's and member of the scientific advisory board for OS Therapies. "New treatments are needed for metastatic osteosarcoma, so I am hopeful OST-HER2 could become an option in the near future."Figure 1 - Overall Survival Kaplan-Meier Curve To view an enhanced version of this graphic, please visit:
https://images.newsfilecorp.com/files/11596/299769_os-therapies.jpgOS Therapies is now updating its ongoing U.S. and international regulatory market authorization submissions for OST-HER2 in Metastatic Osteosarcoma with this new clinical efficacy data. The European Medicines Agency (EMA) and the Australian Therapeutic Goods Administration (TGA) have already aligned on the use of 3-year overall survival data that will be available in early Q4-2026 as the key clinical efficacy data to support the Company's conditional Marketing Authorisation Applications (cMAAs), with rolling review already underway in Europe. The Company has an upcoming Type B Pre-BLA Meeting with the U.S. Food & Drug Administration (FDA) to gain alignment on use of the forthcoming 3-year overall survival to support a Biologics Licensing Application (BLA) under the Accelerated Approval Program. "The sustained survival benefit for patients treated with our immunotherapy, with no new deaths reported between the 2-year and 2.5-year timepoints, demonstrates potential durability of OST-HER2's clinical benefit for metastatic osteosarcoma patients," said Dr. Craig Eagle, Chief Medical Advisor of OS Therapies. "As we engage further with regulators on the risk-benefit of OST-HER2 treatment for patients likely to experience metastatic osteosarcoma recurrence, we believe that sustained overall survival benefit, when coupled with the biomarker data, will support early market access authorizations in late 2026. With 3-year survival data on the horizon in early Q4-2026 to support our FDA, EMA, MHRA and TGA filings for early market access, we anticipate receiving authorizations in late Q4-2026."OS Therapies also has an upcoming Type C Meeting with FDA, and a separate Scientific Advice Meeting (SAM) with the U.K.'s Medicines and Healthcare products Regulatory Agency (MHRA), both being held in early June 2026, to confirm each agency's alignment with the key design parameters already agreed upon with EMA and TGA for the confirmatory Phase 3 protocol. OST-HER2 has received Orphan Drug Designation (ODD), Fast Track Designation (FTD) and Rare Pediatric Disease Designation (RPDD) from the FDA, and ODD, FTD and ATMP from the EMA. Under the RPDD program, if the Company is granted a BLA in the United States, it will become eligible to receive a Priority Review Voucher (PRV) which it intends to sell. The Company has begun filing a BLA for OST-HER2 in pulmonary metastatic osteosarcoma with FDA under the Accelerated Approval Program for OST-HER2 and has received rolling review from the EMA. The Company also anticipates CMA decisions in Europe, the U.K. and Australia in late 2026.About OS TherapiesOS Therapies is a clinical stage oncology company focused on the identification, development, and commercialization of treatments for Osteosarcoma (OS) and other solid tumors. The Company is the world leader in gene-edited, Listeria-based cancer immunotherapies. OST-HER2, the Company's lead asset, is an immunotherapy leveraging the immune-stimulatory effects of Listeria bacteria to initiate a strong immune response targeting the HER2 protein. OST-HER2 is designed to target two mutated extracellular epitopes and one mutated intracellular epitope of the HER2 oncogene, requiring only one of these three epitopes to be present in a tumor (or micro-metastasis) to trigger the desired immune response. OST-HER2 has received Orphan Drug Designation (ODD), Fast Track Designation (FTD) and Rare Pediatric Disease Designation (RPDD) from the U.S. Food & Drug Administration and has received ODD, FTD and ATMP from the European Medicines Agency. The Company reported positive data in its Phase 2b clinical trial of OST-HER2 in recurrent, fully resected, lung metastatic osteosarcoma, demonstrating clinically significant benefit in the 12-month event free survival (EFS) primary endpoint of the study and the overall survival (OS) secondary endpoint. The Company is seeking a Biologics License Application (BLA) from the U.S. FDA for OST-HER2 in osteosarcoma in 2026 and, if approved, would become eligible to receive a Priority Review Voucher that it could then sell. The Company also anticipates receiving Conditional Marketing Authorisations from the U.K.'s Medicines and Healthcare products Regulatory Agency and the EMA for OST-HER2 in 2026. OST-HER2 has completed a Phase 1 clinical study primarily in breast cancer patients, in addition to showing preclinical efficacy data in various models of breast cancer. OST-HER2 has been conditionally approved by the U.S. Department of Agriculture for the treatment of canines with osteosarcoma. The Company also anticipates reading out data from a Phase 1b study of OST-504 in castration resistant prostate cancer in the first half of 2026.In addition, OS Therapies is advancing its next-generation Antibody Drug Conjugate (ADC) and Drug Conjugates (DC), known as tunable ADC (tADC), which features tunable, tailored antibody-linker-payload candidates. This platform leverages the Company's proprietary silicone Si-Linker and Conditionally Active Payload (CAP) technology, enabling the delivery of multiple payloads per linker. For more information, please visit www.ostherapies.com. Forward-Looking StatementsStatements in this press release about future expectations, plans and prospects, as well as any other statements regarding matters that are not historical facts, may constitute forward-looking statements within the meaning of the federal securities laws. These forward-looking statements and terms such as "anticipate," "expect," "intend," "may," "will," "should" or other comparable terms involve risks and uncertainties because they relate to events and depend on circumstances that will occur in the future. Those statements include statements regarding the intent, belief or current expectations of OS Therapies and members of its management, as well as the assumptions on which such statements are based. OS Therapies cautions readers that forward-looking statements are based on management's expectations and assumptions as of the date of this press release and are subject to certain risks and uncertainties that could cause actual results to differ materially, including, but not limited to our expectations regarding cash runway into 2027, the potential approval of OST-HER2 by the U.S. FDA and other risks and uncertainties described in "Risk Factors" in the Company's most recent Annual Report on Form 10-K and other subsequent documents the Company files with the Securities and Exchange Commission. Any forward-looking statements contained in this press release speak only as of the date hereof, and, except as required by the federal securities laws, OS Therapies specifically disclaims any obligation to update any forward-looking statement, whether because of new information, future events or otherwise.OS Therapies Contact Information:Investor Relations
Harrison Seidner, PhD
WaterSeid Partners
OSTX@waterseid.com Public Relations
Stephanie Chen
Elev8 New Media
media@ostherapies.comhttps://x.com/OSTherapies
https://www.instagram.com/ostherapies/
https://www.facebook.com/OSTherapies/
https://www.linkedin.com/company/os-therapies/1 Chen F, et al. Repeat resection of pulmonary metastasis is beneficial for patients with osteosarcoma of the extremities. Interact Cardiovasc Thorac Surg. 2009 Oct;9(4):649-53.
2 Carola A.S. Arndt, et al; Inhaled Granulocyte-Macrophage Colony Stimulating Factor for First Pulmonary Recurrence of Osteosarcoma: Effects on Disease-Free Survival and Immunomodulation. A Report From the Children's Oncology Group. Clin Cancer Res 1 August 2010; 16 (15): 4024-4030.
3 Hingorani P, et al. Phase 2 study of anti-disialoganglioside antibody, dinutuximab, in combination with GM-CSF in patients with recurrent osteosarcoma: A report from the Children's Oncology Group. Eur J Cancer. 2022;172:264-275.
4 Kempf-Bielack B, et al. Osteosarcoma relapse after combined modality therapy: an analysis of unselected patients in the Cooperative Osteosarcoma Study Group (COSS). J Clin Oncol. 2005;23(3):559-568.
5 Janeway KA, et al. A Phase 2 Trial of RANKL Antibody, Denosumab, in Two Cohorts of Patients with Recurrent/Refractory Osteosarcoma, a Report from the Children's Oncology Group. Clin Cancer Res. 2026;32(1):36-44.
6 Leary SE, et al. Survival of pediatric patients after relapsed osteosarcoma: the St. Jude Children's Research Hospital experience. Cancer. 2013;119(14):2645-2653.
7 Chou AJ, et al. Treatment of osteosarcoma at first recurrence after contemporary therapy: the Memorial Sloan-Kettering Cancer Center experience. Cancer. 2005;104(10):2214-2221. To view the source version of this press release, please visit https://www.newsfilecorp.com/release/299769 Original: OS Therapies Achieves Statistically Significant 2.5-Year Overall Survival in Phase 2b Trial of OST-HER2 in Fully Resected Pulmonary Metastatic Osteosarcoma

Ostx starting to gain attention

Could see a new 52 week high soon

OS Therapies Announces the Publication of Four Articles on OST-HER2 and Osteosarcoma in Drug Discovery WorldMay 29, 2026 7:20 AM
NewsfileThe Company confirms that it will release 2.5 year overall survival data from Phase 2b clinical trial OST-HER2 in the prevention or delay of recurrence in fully-resected pulmonary metastatic osteosarcoma during the 2026 American Society of Clinical Oncologists (ASCO) Annual Meeting being held from May 28, 2026 to June 2, 2026.New York, New York and Rockville, Maryland--(Newsfile Corp. - May 29, 2026) - OS Therapies, Inc. (NYSE American: OSTX) ("OS Therapies" or "the Company"), the world leader in gene-edited, listeria-based cancer immunotherapies, today announced the publication of four articles related to OST-HER2 and/or Osteosarcoma in Drug Discovery World.Looking back to see forward: The future of osteosarcoma treatment
Publication Date: December 8, 2025Comparative Oncology in Osteosarcoma: leveraging canine disease to drive drug discovery and validation of biomarkers and accelerate the pathway to new therapies
Publication Date: February 23, 2026Novel regulatory science considerations in osteosarcoma: the imperative for regulatory flexibility to meet critical unmet patient and clinical needs
Publication Date: May 21, 2026The case for accelerated approval in recurrent osteosarcoma
Publication Date: May 29, 2026Concurrent with this announcement, the Company reiterated that it will release 2.5 year overall survival data from Phase 2b clinical trial OST-HER2 in the prevention or delay of recurrence in fully-resected pulmonary metastatic osteosarcoma during the 2026 ASCO Annual Meeting being held from May 28, 2026 to June 2, 2026.OST-HER2 has received Orphan Drug Designation (ODD), Fast Track Designation (FTD) and Rare Pediatric Disease Designation (RPDD) from the FDA, and ODD, FTD and ATMP from the EMA. Under the RPDD program, if the Company receives a BLA in the United States, it will become eligible to receive a Priority Review Voucher (PRV) that it intends to sell. The Company is seeking to obtain a BLA under the Accelerated Approval Program in U.S. for OST-HER2 in osteosarcoma in the second half of 2026, in addition to CMAs in Europe, the U.K. and Australia.About OS TherapiesOS Therapies is a clinical stage oncology company focused on the identification, development, and commercialization of treatments for Osteosarcoma (OS) and other solid tumors. The Company is the world leader in listeria-based cancer immunotherapies. OST-HER2, the Company's lead asset, is an immunotherapy leveraging the immune-stimulatory effects of Listeria bacteria to initiate a strong immune response targeting the HER2 protein. OST-HER2 is designed to target two mutated extracellular epitopes and one mutated intracellular epitope of the HER2 oncogene, requiring only one of these three epitopes to be present in a tumor (or micro-metastasis) to trigger the desired immune response. OST-HER2 has received Orphan Drug Designation (ODD), Fast Track Designation (FTD) and Rare Pediatric Disease Designation (RPDD) from the U.S. Food & Drug Administration and has received ODD, FTD and ATMP from the European Medicines Agency. The Company reported positive data in its Phase 2b clinical trial of OST-HER2 in recurrent, fully resected, lung metastatic osteosarcoma, demonstrating clinically significant benefit in the 12-month event free survival (EFS) primary endpoint of the study and the overall survival (OS) secondary endpoint. The Company anticipates receiving a Biologics License Application (BLA) from the U.S. FDA for OST-HER2 in osteosarcoma in 2026 and, if approved, would become eligible to receive a Priority Review Voucher that it could then sell. The Company also anticipates receiving Conditional Marketing Authorisations from the U.K.'s Medicines and Healthcare products Regulatory Agency and the EMA for OST-HER2 in 2026. OST-HER2 has completed a Phase 1 clinical study primarily in breast cancer patients, in addition to showing preclinical efficacy data in various models of breast cancer. OST-HER2 has been conditionally approved by the U.S. Department of Agriculture for the treatment of canines with osteosarcoma. The Company also anticipates reading out data from a Phase 1b study of OST-504 in castration resistant prostate cancer in the first half of 2026.In addition, OS Therapies is advancing its next-generation Antibody Drug Conjugate (ADC) and Drug Conjugates (DC), known as tunable ADC (tADC), which features tunable, tailored antibody-linker-payload candidates. This platform leverages the Company's proprietary silicone Si-Linker and Conditionally Active Payload (CAP) technology, enabling the delivery of multiple payloads per linker. For more information, please visit www.ostherapies.com. Forward-Looking StatementsStatements in this press release about future expectations, plans and prospects, as well as any other statements regarding matters that are not historical facts, may constitute forward-looking statements within the meaning of the federal securities laws. These forward-looking statements and terms such as "anticipate," "expect," "intend," "may," "will," "should" or other comparable terms involve risks and uncertainties because they relate to events and depend on circumstances that will occur in the future. Those statements include statements regarding the intent, belief or current expectations of OS Therapies and members of its management, as well as the assumptions on which such statements are based. OS Therapies cautions readers that forward-looking statements are based on management's expectations and assumptions as of the date of this press release and are subject to certain risks and uncertainties that could cause actual results to differ materially, including, but not limited to our expected to provide cash runway into 2027, the intended use of net proceeds from the offering, the potential approval of OST-HER2 by the U.S. FDA and other risks and uncertainties described in "Risk Factors" in the Company's most recent Annual Report on Form 10-K and other subsequent documents the Company files with the Securities and Exchange Commission. Any forward-looking statements contained in this press release speak only as of the date hereof, and, except as required by the federal securities laws, OS Therapies specifically disclaims any obligation to update any forward-looking statement, whether as a result of new information, future events or otherwise.OS Therapies Contact Information:Investor Relations
Harrison Seidner, PhD
WaterSeid Partners
OSTX@waterseid.com Public Relations
Stephanie Chen
Elev8 New Media
media@ostherapies.com https://x.com/OSTherapies
https://www.instagram.com/ostherapies/
https://www.facebook.com/OSTherapies/
https://www.linkedin.com/company/os-therapies/To view the source version of this press release, please visit https://www.newsfilecorp.com/release/299365 Original: OS Therapies Announces the Publication of Four Articles on OST-HER2 and Osteosarcoma in Drug Discovery World

Hope you’ve been accumulating 💵💰….only a matter of time

OS Therapies to Attend Upcoming Medical, Financial and Industry ConferencesMay 26, 2026 7:40 AM
NewsfileASCO 2026: 2.5-Year Overall Survival DataJefferies Healthcare Conference: Partnering & Investor meetingsBIO International Convention: Panel ParticipationMIB Agents Factor Osteosarcoma Conference: Data PresentationNew York, New York and Rockville, Maryland--(Newsfile Corp. - May 26, 2026) - OS Therapies, Inc. (NYSE American: OSTX) ("OS Therapies" or "the Company"), the world leader in gene-edited, listeria-based cancer immunotherapies, announced that it will attend upcoming medical, financial and scientific conferences:American Society of Clinical Oncologists 2026
Where: Chicago, IL
When: May 29, 2026 to June 2, 2026
What: 2.5-year overall survival data announcementJefferies Global Healthcare Conference 2026
Where: New York, NY
When: June 2, 2026 to June 4, 2026
What: Partnering meetings and select investor meetingsBIO International Convention 2026
Where: San Diego, CA
When: June 22, 2026 to June 25, 2026
What: Partnering meetings and panel participation - "ADCs: How can we make bringing ADCs to market a faster, simpler, and more collaborative process?"MIB Agents: Factor Osteosarcoma Conference 2026
Where: Columbus, OH
When: June 25, 2026 to June 27, 2026
What: Data PresentationAbout OS TherapiesOS Therapies is a clinical stage oncology company focused on the identification, development, and commercialization of treatments for Osteosarcoma (OS) and other solid tumors. The Company is the world leader in listeria-based cancer immunotherapies. OST-HER2, the Company's lead asset, is an immunotherapy leveraging the immune-stimulatory effects of Listeria bacteria to initiate a strong immune response targeting the HER2 protein. OST-HER2 is designed to target two mutated extracellular epitopes and one mutated intracellular epitope of the HER2 oncogene, requiring only one of these three epitopes to be present in a tumor (or micro-metastasis) to trigger the desired immune response. OST-HER2 has received Orphan Drug Designation (ODD), Fast Track Designation (FTD) and Rare Pediatric Disease Designation (RPDD) from the U.S. Food & Drug Administration and has received ODD, FTD and ATMP from the European Medicines Agency. The Company reported positive data in its Phase 2b clinical trial of OST-HER2 in recurrent, fully resected, lung metastatic osteosarcoma, demonstrating clinically significant benefit in the 12-month event free survival (EFS) primary endpoint of the study and the overall survival (OS) secondary endpoint. The Company anticipates receiving a Biologics License Application (BLA) from the U.S. FDA for OST-HER2 in osteosarcoma in 2026 and, if approved, would become eligible to receive a Priority Review Voucher that it could then sell. The Company also anticipates receiving Conditional Marketing Authorisations from the U.K.'s Medicines and Healthcare products Regulatory Agency and the EMA for OST-HER2 in 2026. OST-HER2 has completed a Phase 1 clinical study primarily in breast cancer patients, in addition to showing preclinical efficacy data in various models of breast cancer. OST-HER2 has been conditionally approved by the U.S. Department of Agriculture for the treatment of canines with osteosarcoma. The Company also anticipates reading out data from a Phase 1b study of OST-504 in castration resistant prostate cancer in the first half of 2026.In addition, OS Therapies is advancing its next-generation Antibody Drug Conjugate (ADC) and Drug Conjugates (DC), known as tunable ADC (tADC), which features tunable, tailored antibody-linker-payload candidates. This platform leverages the Company's proprietary silicone Si-Linker and Conditionally Active Payload (CAP) technology, enabling the delivery of multiple payloads per linker. For more information, please visit www.ostherapies.com. Forward-Looking StatementsStatements in this press release about future expectations, plans and prospects, as well as any other statements regarding matters that are not historical facts, may constitute forward-looking statements within the meaning of the federal securities laws. These forward-looking statements and terms such as "anticipate," "expect," "intend," "may," "will," "should" or other comparable terms involve risks and uncertainties because they relate to events and depend on circumstances that will occur in the future. Those statements include statements regarding the intent, belief or current expectations of OS Therapies and members of its management, as well as the assumptions on which such statements are based. OS Therapies cautions readers that forward-looking statements are based on management's expectations and assumptions as of the date of this press release and are subject to certain risks and uncertainties that could cause actual results to differ materially, including, but not limited to our expected to provide cash runway into 2027, the intended use of net proceeds from the offering, the potential approval of OST-HER2 by the U.S. FDA and other risks and uncertainties described in "Risk Factors" in the Company's most recent Annual Report on Form 10-K and other subsequent documents the Company files with the Securities and Exchange Commission. Any forward-looking statements contained in this press release speak only as of the date hereof, and, except as required by the federal securities laws, OS Therapies specifically disclaims any obligation to update any forward-looking statement, whether as a result of new information, future events or otherwise.OS Therapies Contact Information:Investor Relations
Harrison Seidner, PhD
WaterSeid Partners
OSTX@waterseid.com Public Relations
Stephanie Chen
Elev8 New Media
media@ostherapies.com https://x.com/OSTherapies
https://www.instagram.com/ostherapies/
https://www.facebook.com/OSTherapies/
https://www.linkedin.com/company/os-therapies/To view the source version of this press release, please visit https://www.newsfilecorp.com/release/298851 Original: OS Therapies to Attend Upcoming Medical, Financial and Industry Conferences

OS Therapies Reports First Quarter 2026 Financials and Provides Business UpdateMay 18, 2026 6:30 AM
Newsfile$5.5 million financing that closed on April 2, 2026 together with $5.7 million in capital raised in Q1-2026, expected to provide Company with cash runway into 2027$4.5 million of accrued VAT refunds and R&D refundable tax credits from UK subsidiary begin maturing, including $1.9 million VAT cash refund expected in June 2026Successful EMA and Australia TGA (ATGA) meetings aligned around use of existing biomarker and pending release of 3-year overall survival data to support Conditional Marketing Authorisations (CMAs) for OST-HER2 in prevention or delay of recurrence in fully-resected, pulmonary metastatic osteosarcoma ("Metastatic Osteosarcoma")2.5-year overall survival data expected to be released during ASCO 2026EMA and ATGA have aligned on key design aspects of confirmatory Phase 3 Metastatic Osteosarcoma protocol required to have commenced prior to grant of CMAs or FDA BLA, including alignment on 3-year overall survival as a primary clinical efficacy endpointUpcoming U.S. FDA Type C meeting and U.K. MHRA SAM meeting to align with EMA & ATGA prior to Australia Clinical Trial Notification submission for Phase 3, including alignment on 3-year overall survival as a primary clinical efficacy endpoint. U.S. FDA ("FDA") Pre-BLA meeting to confirm alignment on surrogate and primary clinical efficacy endpoints with EMA/ATGA, including alignment on 3-year overall survival as a primary clinical efficacy endpoint, and seek decisions on rolling review acceptance and RMAT designation following the EMA and U.K. MHRA granting ATMP designation (EMA/MHRA RMAT equivalent) for OST-HER2 in Metastatic OsteosarcomaOS Animal Health S-1 filing for proposed 'Go-Public' transaction and receipt of SEC commentsNew York, New York and Rockville, Maryland--(Newsfile Corp. - May 18, 2026) - OS Therapies, Inc. (NYSE American: OSTX) ("OS Therapies" or "the Company"), the world leader in gene-edited, listeria-based cancer immunotherapies, reported first quarter 2026 financial results and provided a business update centered on the Company's lead program for OST-HER2 in the prevention or delay of recurrence in fully-resected, pulmonary metastatic osteosarcoma ("Metastatic Osteosarcoma"). "In the first quarter of 2026 we successfully implemented our international research & development approach, aligning regulatory and tax strategies via our wholly-owned U.K.-based subsidiary OS Therapies UK Ltd. We made significant investments in order to be able to benefit from return of cash via value-added tax (VAT) reimbursements and refundable research & development tax credits ("R&D Tax Credits")," said Chris Acevedo, CPA, Chief Financial Officer of OS Therapies. "With approximately $2 million in non-dilutive cash expected to be returned to the Company in June 2026, together with the $5.5 million registered direct offering that closed on April 2, 2026, as well as the aggregate $5.7 million of proceeds from the January 2026 Warrant Inducement & Exchange Offering and March 2026 bridge financing, each with pre-existing high net worth investors, we believe the Company is well positioned financially as we approach critical clinical and regulatory milestones. In addition, the April 2, 2026 registered direct offering resulted in the full conversion into common stock and warrants of the convertible debt issued in the March 2026 bridge financing, which had been reflected as outstanding in the Company's Quarterly Report Form 10-Q for the first quarter of 2026." Mr. Acevedo continued, "As we continue with our tax strategy in the U.K. - a jurisdiction that provides attractive incentives for developers of treatments for orphan diseases - we have accrued an additional $2.5 million in cash expected to be returned to the Company through VAT reimbursement and R&D Tax Credits beginning in July 2026. We expect this strategy to continue generating recurring non-dilutive cash inflows driven by our planned monthly R&D expenditures." First Quarter 2026 Corporate HighlightsCompleted submissions to FDA of clinical efficacy and biomarker surrogate clinical efficacy data for OST-HER2 in Metastatic Osteosarcoma in preparation for the Company's upcoming Type B Pre-Biologics License Application (BLA) Meeting (the "Pre-BLA Meeting") following U.S. Food & Drug Administration's (FDA) elevation of the initially-granted Type D meeting into a Type B Pre-BLA Meeting, and concurrent request that the related clinical and biomarker data be submitted in advance to facilitate alignment prior to formal submission as the BLA clinical moduleNon-clinical and chemistry, manufacturing and controls (CMC) BLA module submissions to FDA completed alongside request for rolling reviewU.S. government reauthorization of Pediatric Priority Review Voucher (PRV) programCompelling OST-HER2 pharmacodynamic response biomarker Metastatic Osteosarcoma dataFiling of a patent application covering a novel immune biomarker signature of seroconversion in response to OST-HER2 treatment that is predictive of survivalGranted Advanced Therapy Medicinal Product (ATMP) designation granted by EMA and MHRA; European equivalent of FDA's Regeneration Medicine Advanced Therapy (RMAT)Submitted RMAT designation request submitted to FDAFiling of Form S-1 with the U.S. Securities Exchange Commission (SEC) for the proposed 'Go-Public' transaction of wholly-owned subsidiary OS Animal Health, Inc. and received initial SEC commentsCompleted January 2026 warrant inducement and exchange offering and March 2026 bridge financing that provided an aggregate of $5.7 million in cash proceeds to the Company for the quarter ended March 30, 2026Implementation of U.K. tax strategy via wholly-owned subsidiary expected to provide approximately $2 million of non-dilutive cash returns to the Company"The first quarter was a period of intense biomarker, clinical and regulatory execution for the Company as we initiated filing of our BLA for OST-HER2, completed biomarker analyses from the OST-HER Metastatic Osteosarcoma Phase 2b trial showing strong correlation between seroconversion and survival," said Paul Romness, MPH, Chair & CEO of OS Therapies. "We also received ATMP status in Europe, raised the capital needed into 2027 and formally began preparations for the Go-Public transaction of OS Animal Health that has now been pushed into the second half of 2026 in order to allow for a planned regulatory meeting with the U.S. Department of Agriculture (USDA) to define the regulatory path forward for OST-HER2 in canine osteosarcoma, including the potential expansion of therapeutic uses into frontline treatment, that we believe is important before setting a valuation for the transaction. We expect clinical data on OST-HER2's potential in frontline canine osteosarcoma, initially reported in April 2025, to be published in the near future in a peer-reviewed journal that will further underscore the tremendous potential for OST-HER2 to change the standard of care for canine patients."Mr. Romness continued, "We are actively preparing for upcoming meetings with FDA and U.K. Medicines and Healthcare products Regulatory Agency (MHRA) following successful meetings with the European Medicines Agency (EMA) and Australia's Therapeutic Goods Administration (ATGA). There we gained alignment on the clinical efficacy and surrogate clinical efficacy endpoints required to support early market access for of OST-HER2 under upcoming conditional MAA requests, as well as alignment on the provisional design of our confirmatory Phase 3 OST-HER2 Metastatic Osteosarcoma trial. EMA has now initiated rolling review of our conditional MAA, which is also a major regulatory milestone."Second Quarter 2026 Highlights to Date and Upcoming MilestonesHighlights to dateEMA initiation of rolling review for the Company's conditional MAA requestAppointment of industry leader Dr. Craig Eagle as Chief Medical AdvisorAppointment of biotech luminary Dr. Robert Langer as strategic advisor$5.5 million registered direct offering and conversion of all outstanding debtConference call reviewed biomarker pharmacodynamic response data that is being used as a surrogate clinical efficacy endpoint to support conditional MAAs and BLA requestsUpcoming milestones2.5-year overall survival data expected to be released during the meeting of the American Society of Clinical Oncology (ASCO) FDA Type B meeting to gain alignment on the confirmatory Phase 3 OST-HER2 Metastatic Osteosarcoma trial design that is a pre-requisite to being granted a BLA under the Accelerated Approval ProgramMHRA Scientific Advice Meeting to gain alignment on confirmatory Phase 3 OST-HER2 Metastatic Osteosarcoma trial design that is a pre-requisite to being granted a conditional MAA in the U.K.Completion of BLA filing with 2.5-year overall survival dataCompletion of conditional MAA request to MHRA with 2.5-year overall survival dataUpdate conditional MAA request to EMA with 2.5-year overall survival dataSubmission of the Clinical Trial Notification (CTN) to ATGA in preparation for initiation of the confirmatory Phase 3 Metastatic Osteosarcoma trial Receipt of approximately $2 million expected in cash VAT refund to U.K. subsidiaryData from Phase 1b trial of OST-503 in castration-resistant prostate cancerPublication of OST-HER2 clinical data in frontline canine osteosarcomaKey Second Half of 2026 MilestonesComplete submission of conditional MAA request to ATGAInitiation of confirmatory Phase 3 trial in Australia 3-year overall survival dataFDA decision on BLA request under Accelerated Approval ProgramEMA decision on conditional MAA requestMHRA decision on conditional MAA requestATGA decision on conditional MAA requestOST-HER2 has received Orphan Drug Designation (ODD), Fast Track Designation (FTD) and Rare Pediatric Disease Designation (RPDD) from the FDA, and ODD, FTD and ATMP from the EMA. Under the RPDD program, if the Company receives a BLA in the United States, it will become eligible to receive a Priority Review Voucher (PRV) that it intends to sell. The most recent PRV sale occurred in April 2026 for $195 million. However, there can be no assurance that the Company would realize a comparable value, if any, in connection with any future PRV sale. The Company is seeking to obtain a BLA under the Accelerated Approval Program for OST-HER2 in osteosarcoma in the second half of 2026, in addition to CMAs in Europe, the U.K. and Australia.Loss from Operations:The Company recorded a net operating loss of $10.396 million in the quarter ended March 30, 2026 compared with a net operating loss of $3.876 million in the quarter March 30, 2025. The increase in net loss was largely due to the expenses associated with biomarker research & development and regulatory activities in the Company's newly formed wholly-owned subsidiary OS Therapies UK Ltd. and general and administrative expenses. Net loss per share in the quarter ended March 30, 2026 was $0.27 on 38.674 million weighted average shares outstanding compared to the quarter ended March 30, 2025 where the Company delivered a loss of $0.18 per share on 21.249 million weighted average shares outstanding.This press release shall not constitute an offer to sell or the solicitation of an offer to buy any securities.About OS TherapiesOS Therapies is a clinical stage oncology company focused on the identification, development, and commercialization of treatments for Osteosarcoma (OS) and other solid tumors. The Company is the world leader in listeria-based cancer immunotherapies. OST-HER2, the Company's lead asset, is an immunotherapy leveraging the immune-stimulatory effects of Listeria bacteria to initiate a strong immune response targeting the HER2 protein. OST-HER2 is designed to target two mutated extracellular epitopes and one mutated intracellular epitope of the HER2 oncogene, requiring only one of these three epitopes to be present in a tumor (or micro-metastasis) to trigger the desired immune response. OST-HER2 has received Orphan Drug Designation (ODD), Fast Track Designation (FTD) and Rare Pediatric Disease Designation (RPDD) from the U.S. Food & Drug Administration and has received ODD, FTD and ATMP from the European Medicines Agency. The Company reported positive data in its Phase 2b clinical trial of OST-HER2 in recurrent, fully resected, lung metastatic osteosarcoma, demonstrating clinically significant benefit in the 12-month event free survival (EFS) primary endpoint of the study and the overall survival (OS) secondary endpoint. The Company anticipates receiving a Biologics License Application (BLA) from the U.S. FDA for OST-HER2 in osteosarcoma in 2026 and, if approved, would become eligible to receive a Priority Review Voucher that it could then sell. The Company also anticipates receiving Conditional Marketing Authorisations from the U.K.'s Medicines and Healthcare products Regulatory Agency and the EMA for OST-HER2 in 2026. OST-HER2 has completed a Phase 1 clinical study primarily in breast cancer patients, in addition to showing preclinical efficacy data in various models of breast cancer. OST-HER2 has been conditionally approved by the U.S. Department of Agriculture for the treatment of canines with osteosarcoma. The Company also anticipates reading out data from a Phase 1b study of OST-504 in castration resistant prostate cancer in the first half of 2026.In addition, OS Therapies is advancing its next-generation Antibody Drug Conjugate (ADC) and Drug Conjugates (DC), known as tunable ADC (tADC), which features tunable, tailored antibody-linker-payload candidates. This platform leverages the Company's proprietary silicone Si-Linker and Conditionally Active Payload (CAP) technology, enabling the delivery of multiple payloads per linker. For more information, please visit www.ostherapies.com. Forward-Looking StatementsStatements in this press release about future expectations, plans and prospects, as well as any other statements regarding matters that are not historical facts, may constitute forward-looking statements within the meaning of the federal securities laws. These forward-looking statements and terms such as "anticipate," "expect," "intend," "may," "will," "should" or other comparable terms involve risks and uncertainties because they relate to events and depend on circumstances that will occur in the future. Those statements include statements regarding the intent, belief or current expectations of OS Therapies and members of its management, as well as the assumptions on which such statements are based. OS Therapies cautions readers that forward-looking statements are based on management's expectations and assumptions as of the date of this press release and are subject to certain risks and uncertainties that could cause actual results to differ materially, including, but not limited to our cash runway expectations, our expected cash returns through VAT reimbursement and R&D Credits, the potential approval of OST-HER2 by the U.S. FDA and foreign regulatory agencies, and other risks and uncertainties described in "Risk Factors" in the Company's most recent Annual Report on Form 10-K and other subsequent documents the Company files with the Securities and Exchange Commission. Any forward-looking statements contained in this press release speak only as of the date hereof, and, except as required by the federal securities laws, OS Therapies specifically disclaims any obligation to update any forward-looking statement, whether as a result of new information, future events or otherwise.OS Therapies Contact Information:Investor Relations
Harrison Seidner, PhD
WaterSeid Partners
OSTX@waterseid.com Public Relations
Stephanie Chen
Elev8 New Media
media@ostherapies.com https://x.com/OSTherapies
https://www.instagram.com/ostherapies/
https://www.facebook.com/OSTherapies/
https://www.linkedin.com/company/os-therapies/To view the source version of this press release, please visit https://www.newsfilecorp.com/release/297769 Original: OS Therapies Reports First Quarter 2026 Financials and Provides Business Update

OS Therapies to Announce First Quarter 2026 Financials on Monday, May 18, 2026May 15, 2026 4:05 PM
NewsfileNew York, New York and Rockville, Maryland--(Newsfile Corp. - May 15, 2026) - OS Therapies, Inc. (NYSE American: OSTX) ("OS Therapies" or "the Company"), the world leader in gene-edited, listeria-based cancer immunotherapies, announced that it will announce first quarter 2026 financials and provide a business update on the morning of Monday May 18, 2026. About OS TherapiesOS Therapies is a clinical stage oncology company focused on the identification, development, and commercialization of treatments for Osteosarcoma (OS) and other solid tumors. The Company is the world leader in listeria-based cancer immunotherapies. OST-HER2, the Company's lead asset, is an immunotherapy leveraging the immune-stimulatory effects of Listeria bacteria to initiate a strong immune response targeting the HER2 protein. OST-HER2 is designed to target two mutated extracellular epitopes and one mutated intracellular epitope of the HER2 oncogene, requiring only one of these three epitopes to be present in a tumor (or micro-metastasis) to trigger the desired immune response. OST-HER2 has received Orphan Drug Designation (ODD), Fast Track Designation (FTD) and Rare Pediatric Disease Designation (RPDD) from the U.S. Food & Drug Administration and has received ODD, FTD and ATMP from the European Medicines Agency. The Company reported positive data in its Phase 2b clinical trial of OST-HER2 in recurrent, fully resected, lung metastatic osteosarcoma, demonstrating clinically significant benefit in the 12-month event free survival (EFS) primary endpoint of the study and the overall survival (OS) secondary endpoint. The Company anticipates receiving a Biologics License Application (BLA) from the U.S. FDA for OST-HER2 in osteosarcoma in 2026 and, if approved, would become eligible to receive a Priority Review Voucher that it could then sell. The Company also anticipates receiving Conditional Marketing Authorisations from the U.K.'s Medicines and Healthcare products Regulatory Agency and the EMA for OST-HER2 in 2026. OST-HER2 has completed a Phase 1 clinical study primarily in breast cancer patients, in addition to showing preclinical efficacy data in various models of breast cancer. OST-HER2 has been conditionally approved by the U.S. Department of Agriculture for the treatment of canines with osteosarcoma. The Company also anticipates reading out data from a Phase 1b study of OST-504 in castration resistant prostate cancer in the first half of 2026.In addition, OS Therapies is advancing its next-generation Antibody Drug Conjugate (ADC) and Drug Conjugates (DC), known as tunable ADC (tADC), which features tunable, tailored antibody-linker-payload candidates. This platform leverages the Company's proprietary silicone Si-Linker and Conditionally Active Payload (CAP) technology, enabling the delivery of multiple payloads per linker. For more information, please visit www.ostherapies.com. Forward-Looking StatementsStatements in this press release about future expectations, plans and prospects, as well as any other statements regarding matters that are not historical facts, may constitute forward-looking statements within the meaning of the federal securities laws. These forward-looking statements and terms such as "anticipate," "expect," "intend," "may," "will," "should" or other comparable terms involve risks and uncertainties because they relate to events and depend on circumstances that will occur in the future. Those statements include statements regarding the intent, belief or current expectations of OS Therapies and members of its management, as well as the assumptions on which such statements are based. OS Therapies cautions readers that forward-looking statements are based on management's expectations and assumptions as of the date of this press release and are subject to certain risks and uncertainties that could cause actual results to differ materially, including, but not limited to our expected to provide cash runway into 2027, the intended use of net proceeds from the offering, the potential approval of OST-HER2 by the U.S. FDA and other risks and uncertainties described in "Risk Factors" in the Company's most recent Annual Report on Form 10-K and other subsequent documents the Company files with the Securities and Exchange Commission. Any forward-looking statements contained in this press release speak only as of the date hereof, and, except as required by the federal securities laws, OS Therapies specifically disclaims any obligation to update any forward-looking statement, whether as a result of new information, future events or otherwise.OS Therapies Contact Information:Investor Relations
Harrison Seidner, PhD
WaterSeid Partners
OSTX@waterseid.com Public Relations
Stephanie Chen
Elev8 New Media
media@ostherapies.com https://x.com/OSTherapies
https://www.instagram.com/ostherapies/
https://www.facebook.com/OSTherapies/
https://www.linkedin.com/company/os-therapies/To view the source version of this press release, please visit https://www.newsfilecorp.com/release/297679 Original: OS Therapies to Announce First Quarter 2026 Financials on Monday, May 18, 2026

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Stonegate Capital Partners Updates Coverage on OS Therapies Inc. (OSTX)May 12, 2026 2:35 PM
NewsfileDallas, Texas--(Newsfile Corp. - May 12, 2026) - OS Therapies Inc. (NYSE American: OSTX): Stonegate Capital Partners updates their coverage on OS Therapies Inc. (NYSE American: OSTX). OS Therapies advanced materially through late-stage regulatory and commercialization preparation as OST-HER2 moved from Phase 2bsupported planning toward a more defined global approval pathway in recurrent, fully resected, pulmonary metastatic osteosarcoma. The key change is greater regulatory clarity: EMA initiated rolling review of the OSTHER2 Conditional Marketing Authorization dossier, while EMA and Australia's TGA aligned on 3-year overall survival as the approvable efficacy endpoint. Management also positioned seroconversion biomarker data as supportive surrogate efficacy evidence, shifting the investment debate from early proof-of-concept toward execution across a dense 2026 catalyst calendar. Key milestones include 2.5-year OS data in mid-2Q26, FDA/MHRA meetings in 2Q26, Phase 3 initiation in Australia in 3Q26, 3-year OS data in early 4Q26, and a potential EMA CMA decision in 4Q26. To view the full announcement, including downloadable images, bios, and more, click here. Key Takeaways: Regulatory clarity is the core value inflection. EMA rolling review, TGA endpoint alignment, MHRA ATMP designation, and 2026 FDA/MHRA meetings shift OST-HER2 from Phase 2b validation toward an executable global approval pathway. Survival data remain the key catalyst stack. Mid-2Q26 2.5-year OS data and early-4Q26 3-year OS data should determine whether OSTX can complete EMA CMA submission and sustain accelerated-access momentum. Financing/PRV optionality bridges the regulatory window. The $5.25M raise plus expected $4.0M non-dilutive funding supports 2026 catalysts, while a potential PRV remains a meaningful approval-contingent valuation lever, with the latest public transaction at $205M. Click image above to view full announcement. About Stonegate
Stonegate Capital Partners is a leading capital markets advisory firm providing investor relations, equity research, and institutional investor outreach services for public companies. Our affiliate, Stonegate Capital Markets (member FINRA) provides a full spectrum of investment banking services for public and private companies. Contacts: Stonegate Capital Partners
(214) 987-4121
info@stonegateinc.com Source: Stonegate, Inc. To view the source version of this press release, please visit https://www.newsfilecorp.com/release/297183 Original: Stonegate Capital Partners Updates Coverage on OS Therapies Inc. (OSTX)

OS Therapies Announces EMA Initiates Rolling Review of Conditional Marketing Authorization Application for OST-HER2 in the Prevention or Delay of Recurrence in Fully Resected Pulmonary Metastatic OsteosarcomaApril 30, 2026 6:00 AM
NewsfileConference call scheduled for Thursday, April 30, 2026, at 8:30 am ET to review new OST-HER2 immune pharmacodynamic biomarker response (seroconversion) data and review regulatory successes validating the OST-HER2 approach. Participants will include strategic advisors Dr. Craig Eagle and Dr. Bob Langer, and Osteosarcoma key opinion leader Dr. Peter Anderson from Cleveland Clinic.EMA and Australia TGA (ATGA) align on 3-year overall survival as the approvable clinical efficacy endpoint for Conditional Marketing Authorizations (CMAs), with alignment also achieved on confirmatory Phase 3 initiation, initially only in Australia, planned for Q3 2026 to meet regulatory requirement to support early approvals in the U.S., U.K., Europe and Australia Alignment achieved with EMA and ATGA on Seroconversion data serving as surrogate clinical efficacy data to support CMAs for early market access and eligibility for a Priority Review Voucher (PRV) under Rare Pediatric Disease Designation (RPDD)Alignment achieved with EMA and ATGA on non-clinical, CMC and safety dataAlignment achieved with ATGA on existing drug product being used to initiate Phase 3EMA selects Company into Raw Data Pilot ProgramOST-HER2 granted ATMP designation by U.K. MHRACompany forecasts European peak OST-HER2 osteosarcoma sales exceeding $300 million following ATMP designation grant, with over $50 million in sales expected in 2027 Upcoming U.S. FDA and U.K MHRA meetings scheduled in 2nd quarter of 2026 OST-504 Phase 1b castrate resistant prostate cancer trial biomarker analysis to mirror OST-HER2 Phase 2b osteosarcoma biomarker analysis OST-503 Phase 2 non-small cell lung cancer candidate indications expanded to include pancreatic cancer following review of target vector antigens include all KRAS G12 position mutations, which represents 76% of all KRAS mutations in cancerNew York, New York--(Newsfile Corp. - April 30, 2026) - OS Therapies, Inc. (NYSE American: OSTX) ("OS Therapies" or "the Company"), the world leader in gene-edited, listeria-based cancer immunotherapies, today announced that the European Medicines Agency (EMA)'s Committee for Advanced Therapy (CAT), in conjunction with the Committee for Medicinal Products for Human Use (CHMP) and Pharmacovigilance Risk Assessment Committee (PRAC), has initiated Continuous Evaluation ("Rolling Review") of the OST-HER2 Conditional Marketing Authorisation (CMA) request regulatory dossier for the prevention of recurrence in fully resected, pulmonary metastatic osteosarcoma.1 The Company also announced that it was selected into EMA's Raw Data Pilot programme. Concurrent with this announcement, the This effort will be done in concert with the EMA Scientific Advice Working Party (SAWP). TGA has also invited the OS Therapies to make an application for Provisional Determination, the Australian equivalent of a Conditional Marketing Authorisation of the OST-HER2 regulatory dossier, and is expected to make a decision on rolling review following the receipt of the Clinical Trial Notification (CTN) for the confirmatory Phase 3 trial later this quarter that will position the OS Therapies to initiate the confirmatory Phase 3 in the third quarter of 2026."I am delighted with the regulatory interactions OS Therapies has had to date, and I look forward to supporting OS Therapies in upcoming meetings with U.S. and U.K regulators," said Dr. Craig Eagle, strategic advisor for OS Therapies.OST-HER2 Immune Pharmacodynamic Biomarkers Conference Call DetailsTitle: OS Therapies (NYSE: OSTX) | Conference Call: OST-HER2 immune pharmacodynamic response biomarkers
Date: April 30th, 2026
Time: 8:30 AM Eastern Time
Registration Link: https://zoom.us/webinar/register/WN_Xlmj7kdNTH6C0MA_xdwiiQ EMA OST-HER2 Rolling Review StatusOS Therapies and EMA have agreed that 3-year overall survival data will serve as the basis to complete evaluation of the CMA request. The Company's recently submitted clinical efficacy data includes 2-year overall survival data, with EMA requesting updated 2.5-year overall survival data that will be available by the middle of the second quarter of 2026, and 3-year overall survival data that will become available early in the fourth quarter of 2026, which will complete the CMA submission. The Company anticipates a potential CMA decision by EMA in the fourth quarter of 2026. Market access interactions related to reimbursement with the UK's NICE and EMA Health Technology Assessment (HTA) processes have commenced simultaneously to minimize the time between regulatory approval(s) and patient access to treatment. International regulatory coordination has also commenced under the EMA FDA Information Sharing programme2. Additionally, the Company has been granted Advanced Therapy Medicinal Product designation from the U.K. Medicines and Healthcare products Regulatory Agency (MHRA)3 by virtue of its reciprocal designation agreement with EMA. "We are grateful for EMA and ATGA's strong support of our OST-HER2 program as we urgently work to improve outcomes for patients facing this rare and deadly pediatric cancer," said Paul Romness, Chair and Chief Executive Officer of OS Therapies. "With all currently available data submitted and key regulatory alignment achieved, we are advancing toward early market access via Conditional Marketing Authorizations in Europe, the U.K., and Australia, as well as a U.S. Biologics License Application (BLA) under Accelerated Approval. Following our recent ATMP designation in Europe, we believe peak European sales could exceed $300 million annually, with the potential to generate more than $50 million in sales beginning in 2027." Mr. Romness continued: "We have aligned with EMA and ATGA on the provisional design of our global confirmatory Phase 3 trial that is required to be initiated prior to being granted early market access, including 3-year overall survival as the primary efficacy endpoint. 3-year overall survival will also be the efficacy endpoint that will serve as the basis for potential early market access in the U.S., U.K., Europe, and Australia. This gives us strong confidence as we head into upcoming FDA and MHRA meetings, while reinforcing the growing recognition of our pharmacodynamic biomarker response seroconversion data as a meaningful surrogate for the key overall survival efficacy endpoint, further supporting our global regulatory pathway. We are delighted that immunotherapies are becoming more central in the approach to treating cancers globally, which bolsters OST-HER2 and the rest of our attenuated listeria monocytogenes platform candidates." "With the significant momentum we now have surrounding OST-HER2 in osteosarcoma, we are actively working to be prepared for the time when resources become available to advance our exciting listeria monocytogenes platform pipeline," said Robert Petit, PhD, Chief Medical and Scientific Officer at OS Therapies. "Based upon the extensive biomarker work we have done to date on the OST-HER2 osteosarcoma program, we are now positioned to generate congruent data for the OST-504 castration-resistant prostate cancer program. Additionally, following significant advancement in the exciting KRAS-targeted antibody pancreatic cancer field with important clinical data showing significant survival benefit, we have identified that our promising Phase 2 non-small cell lung cancer (NSCLC) candidate OST-503 was constructed to target all KRAS G12 position-related antigen mutations, which represents 76% of all KRAS mutations in cancer. As a result, we believe OST-503 could represent a highly complementary approach to KRAS-target antibodies currently in development."OST-HER2 has received Orphan Drug Designation (ODD), Fast Track Designation (FTD) and Rare Pediatric Disease Designation (RPDD) from the FDA, and ODD, FTD and ATMP from the EMA. Under the RPDD program, if the Company receives a BLA in the United States, it will become eligible to receive a Priority Review Voucher (PRV) that it intends to sell. The Company is seeking to obtain a BLA under the Accelerated Approval Program for OST-HER2 in osteosarcoma in the second half of 2026, in addition to CMAs in Europe, the U.K. and Australia.Upcoming 2nd Quarter Milestones2.5-year overall survival dataFDA Pre-BLA Type B meeting to gain alignment on surrogate clinical efficacy endpoints based on most up-to-date Phase 2b clinical, biomarker and CMC, following the December 2025 alignment achieved non-clinical and safety dataRegenerative Medicine Advanced Therapy designation ("RMAT" - FDA equivalent to EMA ATMP designation) decision to be based upon preliminary evidence of efficacy supported by clinical and biomarker data metrics aligned uponFDA rolling review decision based upon pre-BLA meeting outcome FDA Type C meeting to gain alignment on the design of the confirmatory Phase 3 study Submission of the Accelerated Approval BLA request to FDA MHRA meeting to gain alignment on the design of the confirmatory Phase 3 study Submission of CMA request to MHRA MHRA rolling review decision based on Phase 3 confirmatory study design alignment Submission of CMA request to Australia in conjunction with Clinical Trial Notification (CTN) request for confirmatory Phase 3 study Receipt of approximately 1.45 million GBP in non-dilutive cash VAT tax refund About OS TherapiesOS Therapies is a clinical stage oncology company focused on the identification, development, and commercialization of treatments for Osteosarcoma (OS) and other solid tumors. The Company is the world leader in listeria-based cancer immunotherapies. OST-HER2, the Company's lead asset, is an immunotherapy leveraging the immune-stimulatory effects of Listeria bacteria to initiate a strong immune response targeting the HER2 protein. OST-HER2 is designed to target two mutated extracellular epitopes and one mutated intracellular epitope of the HER2 oncogene, requiring only one of these three epitopes to be present in a tumor (or micro-metastasis) to trigger the desired immune response. OST-HER2 has received Orphan Drug Designation (ODD), Fast Track Designation (FTD) and Rare Pediatric Disease Designation (RPDD) from the U.S. Food & Drug Administration and has received ODD, FTD and ATMP from the European Medicines Agency. The Company reported positive data in its Phase 2b clinical trial of OST-HER2 in recurrent, fully resected, lung metastatic osteosarcoma, demonstrating clinically significant benefit in the 12-month event free survival (EFS) primary endpoint of the study and the overall survival (OS) secondary endpoint. The Company anticipates receiving a Biologics License Application (BLA) from the U.S. FDA for OST-HER2 in osteosarcoma in 2026 and, if approved, would become eligible to receive a Priority Review Voucher that it could then sell. The Company also anticipates receiving Conditional Marketing Authorisations from the U.K.'s Medicines and Healthcare products Regulatory Agency and the EMA for OST-HER2 in 2026. OST-HER2 has completed a Phase 1 clinical study primarily in breast cancer patients, in addition to showing preclinical efficacy data in various models of breast cancer. OST-HER2 has been conditionally approved by the U.S. Department of Agriculture for the treatment of canines with osteosarcoma. The Company also anticipates reading out data from a Phase 1b study of OST-504 in castration resistant prostate cancer in the first half of 2026.In addition, OS Therapies is advancing its next-generation Antibody Drug Conjugate (ADC) and Drug Conjugates (DC), known as tunable ADC (tADC), which features tunable, tailored antibody-linker-payload candidates. This platform leverages the Company's proprietary silicone Si-Linker and Conditionally Active Payload (CAP) technology, enabling the delivery of multiple payloads per linker. For more information, please visit www.ostherapies.com. Forward-Looking StatementsStatements in this press release about future expectations, plans and prospects, as well as any other statements regarding matters that are not historical facts, may constitute forward-looking statements within the meaning of the federal securities laws. These forward-looking statements and terms such as "anticipate," "expect," "intend," "may," "will," "should" or other comparable terms involve risks and uncertainties because they relate to events and depend on circumstances that will occur in the future. Those statements include statements regarding the intent, belief or current expectations of OS Therapies and members of its management, as well as the assumptions on which such statements are based. OS Therapies cautions readers that forward-looking statements are based on management's expectations and assumptions as of the date of this press release and are subject to certain risks and uncertainties that could cause actual results to differ materially, including, but not limited to our expected to provide cash runway into 2027, the intended use of net proceeds from the offering, the potential approval of OST-HER2 by the U.S. FDA and other risks and uncertainties described in "Risk Factors" in the Company's most recent Annual Report on Form 10-K and other subsequent documents the Company files with the Securities and Exchange Commission. Any forward-looking statements contained in this press release speak only as of the date hereof, and, except as required by the federal securities laws, OS Therapies specifically disclaims any obligation to update any forward-looking statement, whether as a result of new information, future events or otherwise.OS Therapies Contact Information:Investor Relations
Harrison Seidner, PhD
WaterSeid Partners
OSTX@waterseid.com Public Relations
Stephanie Chen
Elev8 New Media
media@ostherapies.com https://x.com/OSTherapies
https://www.instagram.com/ostherapies/
https://www.facebook.com/OSTherapies/
https://www.linkedin.com/company/os-therapies/ 1 https://www.ema.europa.eu/en/about-us/how-we-work/data-regulation-big-data-other-sources/use-clinical-study-data-medicine-evaluation
2 https://www.fda.gov/drugs/cder-international-program/international-agreements-information-sharing
3 https://www.gov.uk/guidance/advanced-therapy-medicinal-products-regulation-and-licensing To view the source version of this press release, please visit https://www.newsfilecorp.com/release/295127
Original: OS Therapies Announces EMA Initiates Rolling Review of Conditional Marketing Authorization Application for OST-HER2 in the Prevention or Delay of Recurrence in Fully Resected Pulmonary Metastatic Osteosarcoma

OS Therapies Schedules OST-HER2 Pharmacodynamic Response Biomarker Conference Call on April 30, 2026 at 8:30am ETApril 27, 2026 4:01 PM
NewsfileRegulatory feedback recent from April 2026 EU EMA and Australian TGA meetingsRemaining Q2-2026 regulatory meetings include two U.S. FDA meetings and one UK MHRA meeting, in addition to follow-up meetings with EU EMA and Australian TGANew York, New York--(Newsfile Corp. - April 27, 2026) - OS Therapies, Inc. (NYSE American: OSTX) ("OS Therapies" or "the Company"), the world leader in gene-edited, listeria-based cancer immunotherapies, today announced that it will be hosting a conference call on Thursday April 30, 2026 at 8:30am ET to review the data that supported the recent Patent Cooperation Treaty (PCT) international application for a OST-HER2 pharmacodynamic biomarker1 (the "OST-HER2 Immune Signature") as a surrogate clinical efficacy endpoint. The OST-HER2 Immune Signature is expected to be used to support early market access in the second half of 2026 in the U.S via a Biologics License Application ("BLA") under the Accelerated Approval Program2 (Accelerated Approval), in addition to Europe, the UK and Australia via Conditional Marketing Authorisations3 (CMAs). Conference Call Details
Title: OS Therapies (NYSE American: OSTX) | Conference Call: OST-HER2 immune pharmacodynamic response biomarkers
Date: April 30th, 2026
Time: 8:30 AM Eastern Time
Registration Link: https://zoom.us/webinar/register/WN_Xlmj7kdNTH6C0MA_xdwiiQOST-HER2 has received Orphan Drug Designation (ODD), Fast Track Designation (FTD) and Rare Pediatric Disease Designation (RPDD) from the FDA, and ODD, FTD and ATMP from the EMA. Under the RPDD program, if the Company receives a BLA in the United States, it will become eligible to receive a Priority Review Voucher (PRV) that it intends to sell. The most recent publicly disclosed PRV transaction occurred in February 2026 at a reported value of $205 million. The Company is seeking to obtain a BLA under the Accelerated Approval Program for OST-HER2 in osteosarcoma in the second half of 2026, in addition to CMAs in Europe, the U.K. and Australia.About OS TherapiesOS Therapies is a clinical stage oncology company focused on the identification, development, and commercialization of treatments for Osteosarcoma (OS) and other solid tumors. The Company is the world leader in listeria-based cancer immunotherapies. OST-HER2, the Company's lead asset, is an immunotherapy leveraging the immune-stimulatory effects of Listeria bacteria to initiate a strong immune response targeting the HER2 protein. OST-HER2 has received Orphan Drug Designation (ODD), Fast Track Designation (FTD) and Rare Pediatric Disease Designation (RPDD) from the U.S. Food & Drug Administration and has received ODD, FTD and ATMP from the European Medicines Agency. The Company reported positive data in its Phase 2b clinical trial of OST-HER2 in recurrent, fully resected, lung metastatic osteosarcoma, demonstrating clinically significant benefit in the 12-month event free survival (EFS) primary endpoint of the study and the overall survival (OS) secondary endpoint. The Company anticipates receiving a Biologics License Application (BLA) from the U.S. FDA for OST-HER2 in osteosarcoma in 2026 and, if approved, would become eligible to receive a Priority Review Voucher that it could then sell. The Company also anticipates receiving Conditional Marketing Authorisations from the U.K.'s Medicines and Healthcare products Regulatory Agency and the EMA for OST-HER2 in 2026. OST-HER2 has completed a Phase 1 clinical study primarily in breast cancer patients, in addition to showing preclinical efficacy data in various models of breast cancer. OST-HER2 has been conditionally approved by the U.S. Department of Agriculture for the treatment of canines with osteosarcoma. The Company also anticipates reading out data from a Phase 1b study of OST-504 in castration resistant prostate cancer in the first half of 2026.In addition, OS Therapies is advancing its next-generation Antibody Drug Conjugate (ADC) and Drug Conjugates (DC), known as tunable ADC (tADC), which features tunable, tailored antibody-linker-payload candidates. This platform leverages the Company's proprietary silicone Si-Linker and Conditionally Active Payload (CAP) technology, enabling the delivery of multiple payloads per linker. For more information, please visit www.ostherapies.com. Forward-Looking StatementsStatements in this press release about future expectations, plans and prospects, as well as any other statements regarding matters that are not historical facts, may constitute forward-looking statements within the meaning of the federal securities laws. These forward-looking statements and terms such as "anticipate," "expect," "intend," "may," "will," "should" or other comparable terms involve risks and uncertainties because they relate to events and depend on circumstances that will occur in the future. Those statements include statements regarding the intent, belief or current expectations of OS Therapies and members of its management, as well as the assumptions on which such statements are based. OS Therapies cautions readers that forward-looking statements are based on management's expectations and assumptions as of the date of this press release and are subject to certain risks and uncertainties that could cause actual results to differ materially, including, but not limited to our expected to provide cash runway into 2027, the intended use of net proceeds from the offering, the potential approval of OST-HER2 by the U.S. FDA and other risks and uncertainties described in "Risk Factors" in the Company's most recent Annual Report on Form 10-K and other subsequent documents the Company files with the Securities and Exchange Commission. Any forward-looking statements contained in this press release speak only as of the date hereof, and, except as required by the federal securities laws, OS Therapies specifically disclaims any obligation to update any forward-looking statement, whether as a result of new information, future events or otherwise.OS Therapies Contact Information:Investor Relations
Harrison Seidner, PhD
WaterSeid Partners
OSTX@waterseid.com Public Relations
Stephanie Chen
Elev8 New Media
media@ostherapies.com  https://x.com/OSTherapies 
https://www.instagram.com/ostherapies/ 
https://www.facebook.com/OSTherapies/ 
https://www.linkedin.com/company/os-therapies/ 1 https://www.ncbi.nlm.nih.gov/books/NBK338448/
2 https://www.fda.gov/drugs/nda-and-bla-approvals/accelerated-approval-program
3 https://www.ema.europa.eu/en/human-regulatory-overview/marketing-authorisation/conditional-marketing-authorisation To view the source version of this press release, please visit https://www.newsfilecorp.com/release/294409
Original: OS Therapies Schedules OST-HER2 Pharmacodynamic Response Biomarker Conference Call on April 30, 2026 at 8:30am ET

OS Therapies Files New Patent Application Covering Biomarkers of the Immune Response to Listeria MonocytogenesApril 16, 2026 7:20 AM
NewsfileNew patent application covers treatment-emergent immune signature related to 'turning cold tumors hot' and the activation of targeted cytotoxic cellular immune responses Company to host conference call later in April 2026 to review new biomarker signatureBiomarker signature meets pharmacodynamic/response criteria established by FDA's Biomarkers, EndpointS and other Tools (BEST) program for use as a surrogate clinical endpoint of 1-year event free survival and 2-year overall survival in OST-HER2's Phase 2b trial in the prevention of delay of recurrent, fully-resected, pulmonary metastatic osteosarcoma to support a BLA submission under FDA's Accelerated Approval ProgramNew York, New York--(Newsfile Corp. - April 16, 2026) - OS Therapies, Inc. (NYSE American: OSTX) ("OS Therapies" or "the Company"), the world leader in gene-edited, listeria-based cancer immunotherapies, today announced that it has filed a new patent application covering a unique immune signature in response to treatment with therapeutic candidates developed from the Company's proprietary Listeria monocytogenes platform ('Listeria') based on new biomarker data from the Company's Phase 2b trial of OST-HER2 in the prevention or delay of recurrent, fully-resected, pulmonary metastatic osteosarcoma. Filed claims include treatment with Listeria leading to the downregulation of genes associated with tumor and circulating tumor cell immune evasion in combination with the upregulation of genes associated with cytotoxic cellular immune activation leads to improved anti-tumor cellular immunity activation. The Company will host a conference call later in April 2026 to review OST-HER2 Phase 2b's new treatment response biomarker signature data showing correlation with clinical outcomes, and its regulatory implications in upcoming Q2-2026 meetings and regulatory submissions with the U.S. Food & Drug Administration (FDA), the European Medicines Agency (EMA), the U.K. Medicines and Healthcare products Regulatory Agency (MHRA) and the Australian Therapeutic Goods Administration (TGA). The Company will complete the first complete OST-HER2 regulatory market access filing in the world to the EMA, at its request, on April 30, 2026."The biomarker data from patients who responded to OST-HER2 treatment shows tremendous innate and adaptive immune responses that result in a significantly improved ability to fight cancer," said Paul Romness, MPH, Chair & CEO of OS Therapies. "While not all metastatic osteosarcoma is HER2 positive, a recently published study reported that over 80% of the patients were found to have HER2 positive metastatic lesions[1]. In our Phase 2b trial, 100% of the patients that did achieve 1-year event free survival (EFS) exhibited the distinct immune signature covered in our patent application and went of to achieve 2-year overall survival. We believe this meets the pharmacodynamic/response biomarker criteria outlined in the U.S. Food & Drug Administration's (FDA)'s Biomarkers, EndpointS, and other Tools (BEST)[2] glossary as a surrogate clinical endpoint to support a Biologics License Application under the Accelerated Approval Program[3]. This pharmacodynamic/response biomarker also provides us with a strong basis to think about additional clinical applications of OST-HER2 beyond osteosarcoma, such as in HER2 positive breast cancer and bladder cancer. Mr. Romness continued, "Notwithstanding the potential for future indication expansion, we are now laser focused on our packed Q2-2026 regulatory meeting schedule with FDA, EMA, MHRA and TGA in preparation for gaining accelerated market access for OST-HER2 in the fully-resected pulmonary metastatic setting later this year in the U.S., Europe and the U.K. with the potential to expand beyond these jurisdictions in 2027."OST-HER2 has received Orphan Drug Designation (ODD), Fast Track Designation (FTD) and Rare Pediatric Disease Designation (RPDD) from the FDA, and ODD, FTD and ATMP from the EMA. Under the RPDD program, if the Company receives a Biologics License Application (BLA) in the United States, it will become eligible to receive a Priority Review Voucher (PRV) that it intends to sell. The most recent publicly disclosed PRV transaction occurred in February 2026 at a reported value of $205 million. The Company is seeking to obtain a BLA under the Accelerated Approval Program for OST-HER2 in osteosarcoma in the second half of 2026.About OS TherapiesOS Therapies is a clinical stage oncology company focused on the identification, development, and commercialization of treatments for Osteosarcoma (OS) and other solid tumors. The Company is the world leader in listeria-based cancer immunotherapies. OST-HER2, the Company's lead asset, is an immunotherapy leveraging the immune-stimulatory effects of Listeria bacteria to initiate a strong immune response targeting the HER2 protein. OST-HER2 has received Orphan Drug Designation (ODD), Fast Track Designation (FTD) and Rare Pediatric Disease Designation (RPDD) from the U.S. Food & Drug Administration and has received ODD, FTD and ATMP from the European Medicines Agency. The Company reported positive data in its Phase 2b clinical trial of OST-HER2 in recurrent, fully resected, lung metastatic osteosarcoma, demonstrating statistically significant benefit in the 12-month event free survival (EFS) primary endpoint of the study and the overall survival (OS) secondary endpoint. The Company anticipates receiving a Biologics License Application (BLA) from the U.S. FDA for OST-HER2 in osteosarcoma in 2026 and, if approved, would become eligible to receive a Priority Review Voucher that it could then sell. The Company also anticipates receiving Conditional Marketing Authorisations from the U.K.'s Medicines and Healthcare products Regulatory Agency and the EMA for OST-HER2 in 2026. OST-HER2 has completed a Phase 1 clinical study primarily in breast cancer patients, in addition to showing preclinical efficacy data in various models of breast cancer. OST-HER2 has been conditionally approved by the U.S. Department of Agriculture for the treatment of canines with osteosarcoma. The Company also anticipates reading out data from a Phase 1b study of OST-504 in castration resistant prostate cancer in the first half of 2026.In addition, OS Therapies is advancing its next-generation Antibody Drug Conjugate (ADC) and Drug Conjugates (DC), known as tunable ADC (tADC), which features tunable, tailored antibody-linker-payload candidates. This platform leverages the Company's proprietary silicone Si-Linker and Conditionally Active Payload (CAP) technology, enabling the delivery of multiple payloads per linker. For more information, please visit www.ostherapies.com. Forward-Looking StatementsStatements in this press release about future expectations, plans and prospects, as well as any other statements regarding matters that are not historical facts, may constitute forward-looking statements within the meaning of the federal securities laws. These forward-looking statements and terms such as "anticipate," "expect," "intend," "may," "will," "should" or other comparable terms involve risks and uncertainties because they relate to events and depend on circumstances that will occur in the future. Those statements include statements regarding the intent, belief or current expectations of OS Therapies and members of its management, as well as the assumptions on which such statements are based. OS Therapies cautions readers that forward-looking statements are based on management's expectations and assumptions as of the date of this press release and are subject to certain risks and uncertainties that could cause actual results to differ materially, including, but not limited to our expected to provide cash runway into 2027, the intended use of net proceeds from the offering, the potential approval of OST-HER2 by the U.S. FDA and other risks and uncertainties described in "Risk Factors" in the Company's most recent Annual Report on Form 10-K and other subsequent documents the Company files with the Securities and Exchange Commission. Any forward-looking statements contained in this press release speak only as of the date hereof, and, except as required by the federal securities laws, OS Therapies specifically disclaims any obligation to update any forward-looking statement, whether as a result of new information, future events or otherwise.OS Therapies Contact Information:Investor Relations
Harrison Seidner, PhD
WaterSeid Partners
OSTX@waterseid.com Public Relations
Stephanie Chen
Elev8 New Media
media@ostherapies.com https://x.com/OSTherapies
https://www.instagram.com/ostherapies/
https://www.facebook.com/OSTherapies/
https://www.linkedin.com/company/os-therapies/[1] https://ascopubs.org/doi/10.1200/OA-25-00094 [2] https://www.fda.gov/drugs/biomarker-qualification-program/about-biomarkers-and-qualification [3] https://www.fda.gov/drugs/nda-and-bla-approvals/accelerated-approval-program To view the source version of this press release, please visit https://www.newsfilecorp.com/release/292852
Original: OS Therapies Files New Patent Application Covering Biomarkers of the Immune Response to Listeria Monocytogenes

OS Therapies Appoints Biotech Industry Luminary Robert "Bob" S. Langer, PhD as Strategic AdvisorApril 13, 2026 6:00 AM
NewsfileCo-founder of more than 40 biotechnology companies, including 16 IPOs and 19 successful acquisitions Scientific and medical titan focused on driving innovation for human healthWill assist with listeria oncology pipeline prioritization, combinations with other oncology-focused biotechnologies and tADC candidate selection for further developmentNew York, New York--(Newsfile Corp. - April 13, 2026) - OS Therapies, Inc. (NYSE American: OSTX) ("OS Therapies" or "the Company"), the world leader in gene-edited, listeria-based cancer immunotherapies, announced today that Dr. Robert "Bob" S. Langer, co-founder of Moderna, was appointed to the Company's strategic advisory board. Dr. Langer will assist management with listeria oncology pipeline prioritization, combinations of listeria product candidates with other oncology-focused biotechnologies, as well as tunable Antibody Drug Conjugate (tADC) candidate selection for further development. Dr. Langer is a luminary in the field of biotechnology, having developed core technologies used ubiquitously throughout the field for drug discovery and development, improving the health of millions worldwide."The use of listeria monocytogenes as a vehicle to activate the immune system to kill cancer has been studied for decades but may soon become a medical reality thanks to OS Therapies," said Dr. Langer, newly-appointed member of the Company's strategic advisory board. "Listeria's unique properties as an intracellular bacterium create major opportunities both to treat cancers which have not responded to existing immunotherapies and to enhance outcomes for patients already receiving other anti-cancer agents, given the strong safety profile exhibited in the Phase 2b study of OST-HER2 and the more than one thousand patients treated with the platform. I will be working with the OS Therapies team implement a robust pipeline development strategy for both standalone and combination product development. Moreover, the unique proprieties of silicone dioxide that underlie the tADC linker/cap technology present tremendous opportunities to design more comprehensive and efficacious candidates which can deliver combinations of cytotoxic and immune stimulatory compounds in a targeted way: this means we can more effectively treat solid tumors and ultimately aim to improve patient outcomes."Dr. Bob Langer is one of nine Institute Professors at the Massachusetts Institute of Technology (MIT), MIT's highest faculty honor. His pioneering work includes isolating the first angiogenesis inhibitors (with Dr. Judah Folkman) leading to new treatments for cancer and blindness. He also created the first nanoparticles and microparticles for delivering large molecules, including nucleic acids, and helped establish the field of tissue engineering which enabled artificial skin for burn victims and organ-on-a-chip technology. Dr. Langer has authored more than 1,600 papers, cited more than 473,000 times. With an h-index of 336, Langer is the most cited engineer in history. His patents have been licensed or sublicensed to over 400 companies, and he has co-founded more than 40 ventures, including Moderna. Dr. Langer chaired the FDA's Science Board, the agency's highest advisory board, from 1999-2002 and has received over 220 awards, including the U.S. National Medal of Science and the National Medal of Technology and Innovation (one of only three living individuals to receive both). His accolades include the Draper Prize (considered engineering's Nobel Prize), Queen Elizabeth Prize for Engineering, Albany Medical Center Prize, Breakthrough Prize in Life Sciences, Kyoto Prize, Wolf Prize in Chemistry, Millennium Technology Prize, and the Kavli Prize in Nanoscience. He holds 44 honorary doctorates from institutions such as Harvard, Yale, Columbia, and Oxford, and has been elected to the National Academies of Medicine, Engineering, and Sciences, as well as the National Academy of Inventors. "It is a tremendous honor to have a biotechnologist of Dr. Langer's distinction join our fight against cancer," said Paul Romness, MPH, Chair & CEO of OS Therapies. "Taken together with Dr. Craig Eagle's appointment last week, these recent additions to our strategic advisory board elevate the Company's standing in the biotechnology community, sending a powerful vote of confidence in our core technologies and the Company's future. We now have a tremendous opportunity to leverage Dr. Langer's unique expertise and vast network to help drive our mission forward as we engage with international regulators and potential industry partners regarding OST-HER2's potential in osteosarcoma and beyond. In the near-term, we are continuing to focus on regulatory execution surrounding gaining market access for OST-HER2 in the prevention or delay of recurrent, fully resected, pulmonary metastatic osteosarcoma in the U.S., U.K. and Europe, as well as countries with regulatory reciprocity with these jurisdictions. We will now begin working more closely with our strategic advisory board to fully build out our strategy for the diligent development of our pipeline as resources become available from product revenues, partnership agreements and/or the sale of a potential priority review voucher following approval in the U.S."OST-HER2 has received Orphan Drug Designation (ODD), Fast Track Designation (FTD) and Rare Pediatric Disease Designation (RPDD) from the FDA, and ODD, FTD and ATMP from the EMA. Under the RPDD program, if the Company receives a Biologics License Application (BLA) in the United States, it will become eligible to receive a Priority Review Voucher (PRV) that it intends to sell. The most recent publicly disclosed PRV transaction occurred in February 2026 at a reported value of $205 million. The Company is seeking to obtain a BLA under the Accelerated Approval Program for OST-HER2 in osteosarcoma in the second half of 2026.About OS TherapiesOS Therapies is a clinical stage oncology company focused on the identification, development, and commercialization of treatments for Osteosarcoma (OS) and other solid tumors. The Company is the world leader in listeria-based cancer immunotherapies. OST-HER2, the Company's lead asset, is an immunotherapy leveraging the immune-stimulatory effects of Listeria bacteria to initiate a strong immune response targeting the HER2 protein. OST-HER2 has received Orphan Drug Designation (ODD), Fast Track Designation (FTD) and Rare Pediatric Disease Designation (RPDD) from the U.S. Food & Drug Administration and has received ODD, FTD and ATMP from the European Medicines Agency. The Company reported positive data in its Phase 2b clinical trial of OST-HER2 in recurrent, fully resected, lung metastatic osteosarcoma, demonstrating statistically significant benefit in the 12-month event free survival (EFS) primary endpoint of the study and the overall survival (OS) secondary endpoint. The Company anticipates receiving a Biologics License Application (BLA) from the U.S. FDA for OST-HER2 in osteosarcoma in 2026 and, if approved, would become eligible to receive a Priority Review Voucher that it could then sell. The Company also anticipates receiving Conditional Marketing Authorisations from the U.K.'s Medicines and Healthcare products Regulatory Agency and the EMA for OST-HER2 in 2026. OST-HER2 has completed a Phase 1 clinical study primarily in breast cancer patients, in addition to showing preclinical efficacy data in various models of breast cancer. OST-HER2 has been conditionally approved by the U.S. Department of Agriculture for the treatment of canines with osteosarcoma. The Company also anticipates reading out data from a Phase 1b study of OST-504 in castration resistant prostate cancer in the first half of 2026.In addition, OS Therapies is advancing its next-generation Antibody Drug Conjugate (ADC) and Drug Conjugates (DC), known as tunable ADC (tADC), which features tunable, tailored antibody-linker-payload candidates. This platform leverages the Company's proprietary silicone Si-Linker and Conditionally Active Payload (CAP) technology, enabling the delivery of multiple payloads per linker. For more information, please visit www.ostherapies.com. Forward-Looking Statements
Statements in this press release about future expectations, plans and prospects, as well as any other statements regarding matters that are not historical facts, may constitute forward-looking statements within the meaning of the federal securities laws. These forward-looking statements and terms such as "anticipate," "expect," "intend," "may," "will," "should" or other comparable terms involve risks and uncertainties because they relate to events and depend on circumstances that will occur in the future. Those statements include statements regarding the intent, belief or current expectations of OS Therapies and members of its management, as well as the assumptions on which such statements are based. OS Therapies cautions readers that forward-looking statements are based on management's expectations and assumptions as of the date of this press release and are subject to certain risks and uncertainties that could cause actual results to differ materially, including, but not limited to our expected to provide cash runway into 2027, the intended use of net proceeds from the offering, the potential approval of OST-HER2 by the U.S. FDA and other risks and uncertainties described in "Risk Factors" in the Company's most recent Annual Report on Form 10-K and other subsequent documents the Company files with the Securities and Exchange Commission. Any forward-looking statements contained in this press release speak only as of the date hereof, and, except as required by the federal securities laws, OS Therapies specifically disclaims any obligation to update any forward-looking statement, whether as a result of new information, future events or otherwise.OS Therapies Contact Information:Investor Relations
Harrison Seidner, PhD
WaterSeid Partners
OSTX@waterseid.com Public Relations
Stephanie Chen
Elev8 New Media
media@ostherapies.com https://x.com/OSTherapies
https://www.instagram.com/ostherapies/
https://www.facebook.com/OSTherapies/
https://www.linkedin.com/company/os-therapies/To view the source version of this press release, please visit https://www.newsfilecorp.com/release/292132
Original: OS Therapies Appoints Biotech Industry Luminary Robert "Bob" S. Langer, PhD as Strategic Advisor

OS Therapies Appoints Craig Eagle, MD as Strategic AdvisorApril 8, 2026 11:38 AM
NewsfileSenior leadership roles at Guardant Health, Genentech and PfizerRegulatory, clinical and commercial expertise in therapeutics and biomarkersWill assist with osteosarcoma regulatory advice and oncology pipeline prioritizationNew York, New York--(Newsfile Corp. - April 8, 2026) - OS Therapies, Inc. (NYSE American: OSTX) ("OS Therapies" or "the Company"), the world leader in gene-edited, listeria-based cancer immunotherapies, today announced that Craig Eagle, MD, was appointed to the Company's newly-formed strategic advisory board. The Company's strategic advisory board is being formed to assist the Company in fine-tuning its osteosarcoma regulatory execution plan and to help develop a detailed pipeline development plan to prioritize the highest value opportunities beyond osteosarcoma. The Company currently has clinical-stage pipeline assets in breast cancer, colorectal cancer, non-small cell lung cancer, prostate cancer, HPV-related cancers, as well as several other oncology indications."I am excited to help advise OS Therapies at this crucial time in the Company's life cycle," said Craig Eagle, MD, inaugural member of the Company's strategic advisory board. "I have been following the listeria-based immuno-oncology field for well over a decade. With OS Therapies' focus on an ultra-rare pediatric cancer where other immunotherapy assets have faced significant challenges, they are showing the value of this more comprehensive listeria-based immunostimulatory approach. Having been privy to the biomarker data from the Phase 2b trial, I am confident in the direction the Company is going and its prospects in osteosarcoma and beyond."Dr. Craig Eagle currently serves as Guardant Health's Chief Medical Officer. Prior to joining Guardant Health, Dr. Eagle served as Vice President of Medical Affairs Oncology for Genentech, where he oversaw the medical programs across the oncology portfolio and developed innovative cancer trials and strategies in personalized health care. Prior to Genentech, Dr. Eagle held several leadership roles at Pfizer, including oncology business lead for the United Kingdom and Canada, global lead for Oncology Strategic Alliances and Partnerships, and global head of the Oncology Therapeutic Area Global Medical and Outcomes Group, where he oversaw the U.S. oncology business, an extensive clinical trial program, health outcomes assessments, and scientific collaborations. Dr. Eagle attended medical school at the University of New South Wales in Sydney, Australia and received his general internist training at Royal North Shore Hospital in Sydney. Dr. Eagle completed his specialist training in hemato-oncology and laboratory hematology at Royal Prince Alfred Hospital in Sydney and was granted a Fellowship in the Royal Australasian College of Physicians (FRACP) and the Royal College of Pathologists Australasia (FRCPA)."Given Dr. Eagle's expertise in oncology therapeutic and biomarker development, we are very pleased to be able to leverage his experience as we engage with global regulators on the utility of our biomarker data to drive the regulatory process forward, as well as thinking through prioritization of our pipeline to create maximum shareholder value once the Company is commercial," said Paul Romness, MPH, Chair & CEO of OS Therapies.About OS TherapiesOS Therapies is a clinical stage oncology company focused on the identification, development, and commercialization of treatments for Osteosarcoma (OS) and other solid tumors. The Company is the world leader in listeria-based cancer immunotherapies. OST-HER2, the Company's lead asset, is an immunotherapy leveraging the immune-stimulatory effects of Listeria bacteria to initiate a strong immune response targeting the HER2 protein. OST-HER2 has received Orphan Drug Designation (ODD), Fast Track Designation (FTD) and Rare Pediatric Disease Designation (RPDD) from the U.S. Food & Drug Administration and has received ODD, FTD and ATMP from the European Medicines Agency. The Company reported positive data in its Phase 2b clinical trial of OST-HER2 in recurrent, fully resected, lung metastatic osteosarcoma, demonstrating statistically significant benefit in the 12-month event free survival (EFS) primary endpoint of the study and the overall survival (OS) secondary endpoint. The Company anticipates receiving a Biologics License Application (BLA) from the U.S. FDA for OST-HER2 in osteosarcoma in 2026 and, if approved, would become eligible to receive a Priority Review Voucher that it could then sell. The Company also anticipates receiving Conditional Marketing Authorisations from the U.K.'s Medicines and Healthcare products Regulatory Agency and the EMA for OST-HER2 in 2026. OST-HER2 has completed a Phase 1 clinical study primarily in breast cancer patients, in addition to showing preclinical efficacy data in various models of breast cancer. OST-HER2 has been conditionally approved by the U.S. Department of Agriculture for the treatment of canines with osteosarcoma. The Company also anticipates reading out data from a Phase 1b study of OST-504 in castration resistant prostate cancer in the first half of 2026.In addition, OS Therapies is advancing its next-generation Antibody Drug Conjugate (ADC) and Drug Conjugates (DC), known as tunable ADC (tADC), which features tunable, tailored antibody-linker-payload candidates. This platform leverages the Company's proprietary silicone Si-Linker and Conditionally Active Payload (CAP) technology, enabling the delivery of multiple payloads per linker. For more information, please visit www.ostherapies.com. Forward-Looking StatementsStatements in this press release about future expectations, plans and prospects, as well as any other statements regarding matters that are not historical facts, may constitute forward-looking statements within the meaning of the federal securities laws. These forward-looking statements and terms such as "anticipate," "expect," "intend," "may," "will," "should" or other comparable terms involve risks and uncertainties because they relate to events and depend on circumstances that will occur in the future. Those statements include statements regarding the intent, belief or current expectations of OS Therapies and members of its management, as well as the assumptions on which such statements are based. OS Therapies cautions readers that forward-looking statements are based on management's expectations and assumptions as of the date of this press release and are subject to certain risks and uncertainties that could cause actual results to differ materially, including, but not limited to our expected to provide cash runway into 2027, the intended use of net proceeds from the offering, the potential approval of OST-HER2 by the U.S. FDA and other risks and uncertainties described in "Risk Factors" in the Company's most recent Annual Report on Form 10-K and other subsequent documents the Company files with the Securities and Exchange Commission. Any forward-looking statements contained in this press release speak only as of the date hereof, and, except as required by the federal securities laws, OS Therapies specifically disclaims any obligation to update any forward-looking statement, whether as a result of new information, future events or otherwise.OS Therapies Contact Information:Investor Relations
Harrison Seidner, PhD
WaterSeid Partners
OSTX@waterseid.com Public Relations
Stephanie Chen
Elev8 New Media
media@ostherapies.comhttps://x.com/OSTherapies
https://www.instagram.com/ostherapies/
https://www.facebook.com/OSTherapies/
https://www.linkedin.com/company/os-therapies/To view the source version of this press release, please visit https://www.newsfilecorp.com/release/291627
Original: OS Therapies Appoints Craig Eagle, MD as Strategic Advisor

OS Therapies Completes $5.25M Registered Direct Offering Primarily with Pre-Existing High-Net-Worth InvestorsApril 2, 2026 5:15 PM
NewsfileCompany expects approximately $2 million in non-dilutive VAT refunds from wholly owned U.K. subsidiary in 2Q-26Company expects to receive approximately $2 million in non-dilutive R&D tax credits repayable to the company in cash from its U.K. subsidiary in 2H-26Offering net proceeds, together with funds expected to be received via U.K. subsidiary, expected to provide cash runway into 2027Company expects to receive approvals in the U.S., U.K. and Europe for OST-HER2 in the prevention of delay of recurrent, fully resected, pulmonary metastatic osteosarcoma in the second half of 2026 New York, New York--(Newsfile Corp. - April 2, 2026) - OS Therapies, Inc. (NYSE American: OSTX) ("OS Therapies" or "the Company"), the world leader in gene-edited, listeria-based cancer immunotherapies, today announced it that it has completed a $5.25 million registered direct offering of common stock (or pre-funded warrants in lieu thereof) and warrants, with participation primarily from high-net-worth investors who have invested in several of the Company's prior financing rounds. Each investor was issued either shares of common stock at a purchase price of $1.40 per share or, in lieu thereof, pre-funded warrants at a purchase price of $1.399 per pre-funded warrant, together with one warrant to purchase one share of common stock at an exercise price of $1.40 per share for each share of common stock issued or issuable upon exercise of the pre-funded warrants. Additional details related to the offering are included in the Company's Current Report on Form 8-K filed with the U.S. Securities and Exchange Commission (the "SEC") on April 2, 2026. Ceros Financial Services, Inc. acted as the exclusive placement agent for the offering.Additionally, the Company announced that it expects to receive approximately $4 million in additional non-dilutive funds from VAT refunds and R&D reclaim funds via its wholly owned U.K. subsidiary that was established in 2025 for the purpose of conducting research & development."This capital raise, together with the non-dilutive funding we expect to receive from our U.K. subsidiary, is expected to support our operations as we advance toward crucial anticipated 2026 regulatory milestones for OST-HER2 in the U.S., U.K. and Europe, including early market access authorizations and potential eligibility for a Priority Review Voucher (PRV) under our Rare Pediatric Disease Designation (RPDD)," said Paul Romness, President & CEO of OS Therapies. "We are now focused on our upcoming regulatory interactions, including planned meetings later this quarter with the U.S. Food & Drug Administration (FDA), the European Medicines Agency (EMA), the U.K. Medicines and Healthcare products Regulatory Agency (MHRA) and the Australian Therapeutic Goods Administration (TGA) to review our clinical and biomarker data, as well as our proposed confirmatory Phase 3 trial design. We are hopeful these interactions will support market access for osteosarcoma patients beginning in 2027. This funding is also expected to support the initiation of a Phase 3 confirmatory trial, including the planned activation of an initial trial site in Australia, which is part of the requirements for a Biologics License Application (BLA) under the U.S. Accelerated Approval Program (Accelerated Approval) and for Conditional Marketing Authorisations (CMAs) in the U.K. and Europe."OST-HER2 has received Orphan Drug Designation (ODD), Fast Track Designation (FTD) and RPDD from the FDA, and ODD, FTD and ATMP from the EMA. Under the RPDD program, if the Company receives a BLA in the United States, it will become eligible to receive a PRV that it intends to sell, subject to market conditions. The most recent publicly disclosed PRV transaction occurred in February 2026 at a reported value of $205 million; however, there can be no assurance that the Company would realize a comparable value, if any, in connection with any future PRV sale. The Company is seeking to obtain a BLA under the Accelerated Approval Program for OST-HER2 in osteosarcoma in the second half of 2026.The securities described above were offered pursuant to a "shelf" registration statement on Form S-3 (File No. 333-289443) filed by the Company with the SEC on August 8, 2025 and declared effective by the SEC on August 25, 2025. The offering was made only by means of a prospectus, including a prospectus supplement, forming a part of the effective registration statement. The prospectus supplement and the accompanying prospectus relating to the securities being offered were filed with the SEC and are available at the SEC's website at www.sec.gov. Electronic copies of the prospectus supplement and the accompanying prospectus relating to the securities being offered may also be obtained by contacting Ceros Financial Services, Inc. at 1445 Research Boulevard, Rockville, Maryland 20850, or e-mail Ahmed Gheith, Managing Director at Ceros at agheith@cerosfs.com. No Offer to Sell or SolicitThis press release is for informational purposes only and does not constitute an offer to sell or the solicitation of an offer to buy any of the securities described herein, nor shall there be any sale of these securities in any state or jurisdiction in which such offer, solicitation or sale would be unlawful prior to the registration or qualification under the securities laws of any such state or jurisdiction.About OS TherapiesOS Therapies is a clinical stage oncology company focused on the identification, development, and commercialization of treatments for Osteosarcoma (OS) and other solid tumors. The Company is the world leader in listeria-based cancer immunotherapies. OST-HER2, the Company's lead asset, is an immunotherapy leveraging the immune-stimulatory effects of Listeria bacteria to initiate a strong immune response targeting the HER2 protein. OST-HER2 has received Orphan Drug Designation (ODD), Fast Track Designation (FTD) and Rare Pediatric Disease Designation (RPDD) from the U.S. Food & Drug Administration and has received ODD, FTD and ATMP from the European Medicines Agency. The Company reported positive data in its Phase 2b clinical trial of OST-HER2 in recurrent, fully resected, lung metastatic osteosarcoma, demonstrating statistically significant benefit in the 12-month event free survival (EFS) primary endpoint of the study and the overall survival (OS) secondary endpoint. The Company anticipates receiving a Biologics License Application (BLA) from the U.S. FDA for OST-HER2 in osteosarcoma in 2026 and, if approved, would become eligible to receive a Priority Review Voucher that it could then sell. The Company also anticipates receiving Conditional Marketing Authorisations from the U.K.'s Medicines and Healthcare products Regulatory Agency and the EMA for OST-HER2 in 2026. OST-HER2 has completed a Phase 1 clinical study primarily in breast cancer patients, in addition to showing preclinical efficacy data in various models of breast cancer. OST-HER2 has been conditionally approved by the U.S. Department of Agriculture for the treatment of canines with osteosarcoma. The Company also anticipates reading out data from a Phase 1b study of OST-504 in castration resistant prostate cancer in the first half of 2026.In addition, OS Therapies is advancing its next-generation Antibody Drug Conjugate (ADC) and Drug Conjugates (DC), known as tunable ADC (tADC), which features tunable, tailored antibody-linker-payload candidates. This platform leverages the Company's proprietary silicone Si-Linker and Conditionally Active Payload (CAP) technology, enabling the delivery of multiple payloads per linker. For more information, please visit www.ostherapies.com. Forward-Looking Statements
Statements in this press release about future expectations, plans and prospects, as well as any other statements regarding matters that are not historical facts, may constitute forward-looking statements within the meaning of the federal securities laws. These forward-looking statements and terms such as "anticipate," "expect," "intend," "may," "will," "should" or other comparable terms involve risks and uncertainties because they relate to events and depend on circumstances that will occur in the future. Those statements include statements regarding the intent, belief or current expectations of OS Therapies and members of its management, as well as the assumptions on which such statements are based. OS Therapies cautions readers that forward-looking statements are based on management's expectations and assumptions as of the date of this press release and are subject to certain risks and uncertainties that could cause actual results to differ materially, including, but not limited to our expected to provide cash runway into 2027, the intended use of net proceeds from the offering, the potential approval of OST-HER2 by the U.S. FDA and other risks and uncertainties described in "Risk Factors" in the Company's most recent Annual Report on Form 10-K and other subsequent documents the Company files with the Securities and Exchange Commission. Any forward-looking statements contained in this press release speak only as of the date hereof, and, except as required by the federal securities laws, OS Therapies specifically disclaims any obligation to update any forward-looking statement, whether as a result of new information, future events or otherwise.OS Therapies Contact Information:Investor Relations
Harrison Seidner, PhD
WaterSeid Partners
OSTX@waterseid.com Public Relations
Stephanie Chen
Elev8 New Media
media@ostherapies.com
https://x.com/OSTherapies
https://www.instagram.com/ostherapies/
https://www.facebook.com/OSTherapies/
https://www.linkedin.com/company/os-therapies/To view the source version of this press release, please visit https://www.newsfilecorp.com/release/291086
Original: OS Therapies Completes $5.25M Registered Direct Offering Primarily with Pre-Existing High-Net-Worth Investors

OS Therapies Completes Submission of Biomarker & Clinical Data for U.S. FDA Pre-BLA Meeting, Reports Full Year 2025 Financial Results and Provides Business UpdateMarch 31, 2026 7:40 AM
NewsfileDecember 2025 Type C Meeting confirmed immune biomarkers suitability to establish surrogate clinical efficacy that could support BLA under Accelerated Approval PathwayPre-specified clinical outcomes data correlates with Immune biomarker signatureCompany positioned to review completed Phase 2b clinical & biomarker data and confirmatory Phase 3 trial protocol with U.S. FDA, EMA and U.K. MHRA in 2Q/26Company expects to initiate confirmatory Phase 3 trial in Australia in 3Q/26Company anticipates receiving a BLA under Accelerated Approval Program in the U.S. and Conditional Marketing Authorizations in Europe and in the U.K. in 2H/26New York, New York--(Newsfile Corp. - March 31, 2026) - OS Therapies, Inc. (NYSE American: OSTX) ("OS Therapies" or "the Company"), the world leader in listeria-based cancer immunotherapies, today announced that it has completed the submission on clinical and biomarker data from the Company's Phase 2b clinical trial of OST-HER2 in the prevention of delay of recurrent, fully resected, pulmonary metastatic osteosarcoma to the U.S. Food & Drug Administration in preparation for the Company's upcoming Pre-BLA Meeting, reported full-year 2025 financial results for the period ended December 31, 2025 and provided a business update. The Company expects the Pre-BLA Meeting to occur in May 2026."The biomarker and clinical data packages are now with FDA as we begin preparations for our upcoming Pre-BLA Meeting with FDA," said Robert Petit, PhD, Chief Medical & Scientific Officer of OS Therapies. "In December 2025, FDA agreed that OST-HER2 had a strong safety profile and further aligned with the Company around pre-specified immune biomarker strategies being suitable to serve as surrogate clinical efficacy endpoints based upon well-established science. Now that the data is with FDA, we are focused on completing our pending Marketing Authorization Application requests to U.K.'s Medicines and Healthcare products Regulatory Agency and the European Medicines Agency in April 2026 with the expectation that we will receive approval decisions in each of these three jurisdictions in the second half of 2026."2025 Year in Review"2025 marked a year of focused regulatory alignment and strong operational execution at OS Therapies," said Paul Romness, MPH, CEO of OS Therapies. "We began the year by reporting highly encouraging 12-month event free survival data (EFS) in January of 2025 from our Phase 2b trial of OST-HER2 in the prevention of delay of recurrent, fully resected, pulmonary metastatic osteosarcoma that met the pre-specified threshold to be eligible for further assessment. Shortly thereafter, we announced the acquisition of the entire listeria monocytogenes cancer immunotherapy platform from Ayala Pharmaceuticals, thus eliminating $20 million in development and commercial milestone payments while reducing net royalties owed to 1.5%. Following the FDA Oncology Center of Excellence's August 2025 elevation of Overall Survival (OS) to a primary endpoint in many oncology clinical trial settings via new guidance, the Company reported 75% 2-year overall survival in October of 2025."Mr. Romness continued, "On the heels of FDA and Osteosarcoma Institute's October 2025 workshop reviewing the current status of osteosarcoma research, particularly the strong utility of spontaneous canine osteosarcoma as a predictive model for human disease, the Company aligned with FDA on the use of biomarkers identified in clinical trials of OST-HER2 in canine osteosarcoma as pre-specified surrogate clinical efficacy endpoints for efficacy assessment of the Phase 2b trial data, for the purposes of assessing a Biologics License Application (BLA) under the Accelerated Approval Program (Accelerated Approval). Additionally, we made significant progress with the European Medicines Agency (EMA) and the U.K.'s Medicines and Healthcare products Regulatory Agency (MHRA) on the path to gaining Conditional Marketing Authorisations (CMAs) in those jurisdictions. As we also update on the progress made throughout the first quarter of 2026, we have now completed the clinical and biomarker study reports from the Phase 2b trial in preparation for upcoming meetings with FDA, EMA, MHRA and the Australian Therapeutics Goods Administration (TGA) to evaluate the safety and efficacy of OST-HER2, as well as upcoming meetings to review the proposed Phase 3 clinical protocol that we intend to initiate in Australia in the third quarter." OST-HER2 has received Orphan Drug Designation (ODD), Fast Track Designation (FTD) and Rare Pediatric Disease Designation (RPDD) from the FDA, and ODD, FTD and ATMP from the EMA. Under the RPDD program, if the Company receives a Biologics License Application (BLA) in the United States, it will become eligible to receive a Priority Review Voucher (PRV) that it intends to sell, subject to market conditions. The most recent publicly disclosed PRV transaction occurred in February 2026 at a reported value of $205 million; however, there can be no assurance that the Company would realize a comparable value, if any, in connection with any future PRV sale. The Company is seeking to obtain a BLA under the Accelerated Approval Program for OST-HER2 in osteosarcoma in the second half of 2026.Full-Year 2025 Corporate Highlights:Phase 2b clinical trial of OST-HER2 achieves EFS with statistical significancePhase 2b clinical trial of OST-HER2 achieves elevated Overall Survival (OS) endpoint with statistical significanceSuccessful Type C, End of Phase 2 and 2nd Type C Meetings with U.S. FDASuccessful Scientific Advice Meetings (SAMs) and Pre-Marketing Authorisation Application (MAA) meetings with EMA and MHRAU.S. OST-HER2 commercialization partnership with EversanaAcquisition of listeria monocytogenes assets from Ayala PharmaceuticalsIssuance of patents covering commercial manufacturing of OST-HER2 and rest of listeria monocytogenes platform, extending patent runway into 2040Documentary 'Shelter Me: Cancer Pioneers' featuring OST-HER2-treated human and canine patients nominated for 2 Daytime Emmy AwardsPositive data for OST-HER2 in fully resected metastatic osteosarcoma, unresectable pulmonary osteosarcoma and unresected primary osteosarcomaNon-proprietary name for OST-HER2 granted by World Health OrganizationFDA PDUFA fee waiver grantedFirst Quarter 2026 Highlights to Date:Raised $5.5 million in capitalReauthorization of Pediatric Priority Review Voucher (PRV) program Positive pre-specified biomarker data from Phase 2b clinical trialInitiation and completion of BLA filing with FDA for OST-HER2EMA grants OST-HER2 Advanced Therapy Medicinal Product (ATMP) designationOS Animal Health subsidiary files Form S-1 for spinoff transaction to fund commercialization of OST-HER2 in canine osteosarcomaPositive Patient Advocacy and Key Opinion Leader (KOL) Meetings aligning around regulatory and clinical pathwaysPending 2026 Milestones:April 2026 meeting TAG to review Phase 2b data and Phase 3 protocol design2Q/26 meetings with FDA, EMA and MHRA to review safety & efficacy data for OST-HER2 Phase 2b clinical trial to support accelerated market access requests (BLA in U.S., CMAs in Europe & U.K.)2Q/26 meetings with FDA, EMA and MHRA to review proposed confirmatory Phase 3 protocol2Q/26 complete OST-HER2 submissions of BLA for Accelerated Approval in U.S. and MAAs for CMAs in Europe and U.K.2H/26 gain accelerated market access for OST-HER2 in the U.S. (BLA), Europe (CMA) and the U.K. (CMA)Loss from Operations:The Company recorded a net operating loss of $28.75 million in the year ended 2025 compared with a net operating loss of $8.82 million in 2024. The increase in net loss was largely due to the expenses associated with research and development, and general and administrative expenses. Net loss per share in the full year 2025 was $0.98 on 290235 million weighted average shares outstanding compared to full year 2024 where the Company delivered a loss of $1.28 per share on 6.950 million weighted average shares outstanding.This press release shall not constitute an offer to sell or the solicitation of an offer to buy any securities.About OS TherapiesOS Therapies is a clinical stage oncology company focused on the identification, development, and commercialization of treatments for Osteosarcoma (OS) and other solid tumors. The Company is the world leader in listeria-based cancer immunotherapies. OST-HER2, the Company's lead asset, is an immunotherapy leveraging the immune-stimulatory effects of Listeria bacteria to initiate a strong immune response targeting the HER2 protein. OST-HER2 has received Orphan Drug Designation (ODD), Fast Track Designation (FTD) and Rare Pediatric Disease Designation (RPDD) from the U.S. Food & Drug Administration and has received ODD, FTD and ATMP from the European Medicines Agency. The Company reported positive data in its Phase 2b clinical trial of OST-HER2 in recurrent, fully resected, lung metastatic osteosarcoma, demonstrating statistically significant benefit in the 12-month event free survival (EFS) primary endpoint of the study and the overall survival (OS) secondary endpoint. The Company anticipates receiving a Biologics License Application (BLA) from the U.S. FDA for OST-HER2 in osteosarcoma in 2026 and, if approved, would become eligible to receive a Priority Review Voucher that it could then sell. The Company also anticipates receiving Conditional Marketing Authorisations from the U.K.'s Medicines and Healthcare products Regulatory Agency and the EMA for OST-HER2 in 2026. OST-HER2 has completed a Phase 1 clinical study primarily in breast cancer patients, in addition to showing preclinical efficacy data in various models of breast cancer. OST-HER2 has been conditionally approved by the U.S. Department of Agriculture for the treatment of canines with osteosarcoma. The Company also anticipates reading out data from a Phase 1b study of OST-504 in castration resistant prostate cancer in the first half of 2026.In addition, OS Therapies is advancing its next-generation Antibody Drug Conjugate (ADC) and Drug Conjugates (DC), known as tunable ADC (tADC), which features tunable, tailored antibody-linker-payload candidates. This platform leverages the Company's proprietary silicone Si-Linker and Conditionally Active Payload (CAP) technology, enabling the delivery of multiple payloads per linker. For more information, please visit www.ostherapies.com. Forward-Looking StatementsStatements in this press release about future expectations, plans and prospects, as well as any other statements regarding matters that are not historical facts, may constitute forward-looking statements within the meaning of the federal securities laws. These forward-looking statements and terms such as "anticipate," "expect," "intend," "may," "will," "should" or other comparable terms involve risks and uncertainties because they relate to events and depend on circumstances that will occur in the future. Those statements include statements regarding the intent, belief or current expectations of OS Therapies and members of its management, as well as the assumptions on which such statements are based. OS Therapies cautions readers that forward-looking statements are based on management's expectations and assumptions as of the date of this press release and are subject to certain risks and uncertainties that could cause actual results to differ materially, including, but not limited to the approval of OST-HER2 by the U.S. FDA and other risks and uncertainties described in "Risk Factors" in the Company's most recent Annual Report on Form 10-K, most recent Quarterly Report on Form 10-Q and other subsequent documents the Company files with the Securities and Exchange Commission. Any forward-looking statements contained in this press release speak only as of the date hereof, and, except as required by the federal securities laws, OS Therapies specifically disclaims any obligation to update any forward-looking statement, whether as a result of new information, future events or otherwise.OS Therapies Contact Information:Investor Relations
Harrison Seidner, PhD
WaterSeid Partners
OSTX@waterseid.comPublic Relations
Stephanie Chen
Elev8 New Media
media@ostherapies.comhttps://x.com/OSTherapies
https://www.instagram.com/ostherapies/
https://www.facebook.com/OSTherapies/
https://www.linkedin.com/company/os-therapies/To view the source version of this press release, please visit https://www.newsfilecorp.com/release/290639
Original: OS Therapies Completes Submission of Biomarker & Clinical Data for U.S. FDA Pre-BLA Meeting, Reports Full Year 2025 Financial Results and Provides Business Update

Thanks

Yes I am and still adding…..possible end of year fda approval

Hey Stumble, are you still in this one. Looking at again here.

OS Therapies Granted Meetings with U.S. FDA, U.K. MHRA, EMA and Australian Therapeutic Goods Administration to Review Global Confirmatory Phase 3 Trial for OST-HER2 in Metastatic OsteosarcomaMarch 27, 2026 6:00 AM
NewsfileMeetings with all four regulatory agencies scheduled to occur in the second quarter of 2026, with expected Phase 3 commencement in the third quarter of 2026 initially in Australia Commencing the Phase 3 confirmatory study is a pre-requisite to being granted a Biologics License Application (BLA) under the Accelerated Approval Program in the U.S. and Conditional Marketing Authorisations (CMAs) in the U.K. & EuropeNew York, New York--(Newsfile Corp. - March 27, 2026) - OS Therapies, Inc. (NYSE American: OSTX) ("OS Therapies" or "the Company"), the world leader in listeria-based cancer immunotherapies, today announced that it has been granted meetings with the U.S. Food & Drug Administration (FDA), the U.K. Medicines and Healthcare products Regulatory Agency (MHRA), the European Medicines Agency (EMA) and the Australian Therapeutic Goods Administration (TGA) to review the design of the proposed global confirmatory Phase 3 trial for OST-HER2 in metastatic osteosarcoma. Meetings with each of these four regulatory agencies are expected to occur in the second quarter of 2026, with trial enrollment expected to begin in the third quarter of 2026 initially in Australia. Commencing the Phase 3 trial is a requirement to be granted a Biologics License Application (BLA) under the Accelerated Approval Program in the U.S. and Conditional Marketing Authorisation (CMA) in the U.K. and in Europe. The Company is seeking to receive a BLA in the U.S. and CMAs in the U.K. & in Europe in the second half of 2026. The Company remains on track to deliver to FDA the clinical and biomarker data it requested in preparation for the Company's upcoming Type B Pre-BLA Meeting by the end of the first quarter of 2026. The company has also commenced preparatory market access activities in Europe, including the Health Technology Assessment (HTA) process. "We are very pleased to see coordination between these global regulatory agencies as it relates to the proposed design of our planned global confirmatory Phase 3 trial design," said Paul Romness, MPH, Chairman & CEO of OS Therapies. "Patients with metastatic osteosarcoma have significant mortality risk and have seen no improvements in the standard of care in over forty years. The immune system activation mechanism OST-HER2 candidate is very well tolerated. We believe the clinical and biomarker data that we have generated are more than sufficient to justify early market access for patients who have no alternatives with this deadly childhood cancer. We look forward to engaging with the regulators on our path to gaining market access in 2026."OST-HER2 has received Orphan Drug Designation (ODD), Fast Track Designation (FTD) and Rare Pediatric Disease Designation (RPDD) from the FDA, and ODD, FTD and ATMP from the EMA. Under the RPDD program, if the Company receives a Biologics License Application (BLA) in the United States, it will become eligible to receive a Priority Review Voucher (PRV) that it intends to sell. The most recent publicly disclosed PRV transaction occurred in February 2026 at a reported value of $205 million. The Company is seeking to obtain a BLA under the Accelerated Approval Program for OST-HER2 in osteosarcoma in the second half of 2026.About OS Therapies
OS Therapies is a clinical stage oncology company focused on the identification, development, and commercialization of treatments for Osteosarcoma (OS) and other solid tumors. The Company is the world leader in listeria-based cancer immunotherapies. OST-HER2, the Company's lead asset, is an immunotherapy leveraging the immune-stimulatory effects of Listeria bacteria to initiate a strong immune response targeting the HER2 protein. OST-HER2 has received Orphan Drug Designation (ODD), Fast Track Designation (FTD) and Rare Pediatric Disease Designation (RPDD) from the U.S. Food & Drug Administration and has received ODD, FTD and ATMP from the European Medicines Agency. The Company reported positive data in its Phase 2b clinical trial of OST-HER2 in recurrent, fully resected, lung metastatic osteosarcoma, demonstrating statistically significant benefit in the 12-month event free survival (EFS) primary endpoint of the study and the overall survival (OS) secondary endpoint. The Company anticipates receiving a Biologics License Application (BLA) from the U.S. FDA for OST-HER2 in osteosarcoma in 2026 and, if approved, would become eligible to receive a Priority Review Voucher that it could then sell. The Company also anticipates receiving Conditional Marketing Authorisations from the U.K.'s Medicines and Healthcare products Regulatory Agency and the EMA for OST-HER2 in 2026. OST-HER2 has completed a Phase 1 clinical study primarily in breast cancer patients, in addition to showing preclinical efficacy data in various models of breast cancer. OST-HER2 has been conditionally approved by the U.S. Department of Agriculture for the treatment of canines with osteosarcoma. The Company also anticipates reading out data from a Phase 1b study of OST-504 in castration resistant prostate cancer in the first half of 2026.In addition, OS Therapies is advancing its next-generation Antibody Drug Conjugate (ADC) and Drug Conjugates (DC), known as tunable ADC (tADC), which features tunable, tailored antibody-linker-payload candidates. This platform leverages the Company's proprietary silicone Si-Linker and Conditionally Active Payload (CAP) technology, enabling the delivery of multiple payloads per linker. For more information, please visit www.ostherapies.com. Forward-Looking Statements
Statements in this press release about future expectations, plans and prospects, as well as any other statements regarding matters that are not historical facts, may constitute forward-looking statements within the meaning of the federal securities laws. These forward-looking statements and terms such as "anticipate," "expect," "intend," "may," "will," "should" or other comparable terms involve risks and uncertainties because they relate to events and depend on circumstances that will occur in the future. Those statements include statements regarding the intent, belief or current expectations of OS Therapies and members of its management, as well as the assumptions on which such statements are based. OS Therapies cautions readers that forward-looking statements are based on management's expectations and assumptions as of the date of this press release and are subject to certain risks and uncertainties that could cause actual results to differ materially, including, but not limited to the approval of OST-HER2 by the U.S. FDA and other risks and uncertainties described in "Risk Factors" in the Company's most recent Annual Report on Form 10-K, most recent Quarterly Report on Form 10-Q and other subsequent documents the Company files with the Securities and Exchange Commission. Any forward-looking statements contained in this press release speak only as of the date hereof, and, except as required by the federal securities laws, OS Therapies specifically disclaims any obligation to update any forward-looking statement, whether as a result of new information, future events or otherwise.OS Therapies Contact Information:Investor Relations
Harrison Seidner, PhD
WaterSeid Partners
OSTX@waterseid.com Public Relations
Stephanie Chen
Elev8 New Media
media@ostherapies.comhttps://x.com/OSTherapies
https://www.instagram.com/ostherapies/
https://www.facebook.com/OSTherapies/
https://www.linkedin.com/company/os-therapies/To view the source version of this press release, please visit https://www.newsfilecorp.com/release/290189
Original: OS Therapies Granted Meetings with U.S. FDA, U.K. MHRA, EMA and Australian Therapeutic Goods Administration to Review Global Confirmatory Phase 3 Trial for OST-HER2 in Metastatic Osteosarcoma

OS Therapies Granted EMA's Advanced Therapy Medicinal Product (ATMP) Designation for OST-HER2 in the Treatment of Pulmonary Recurrence in Resected OsteosarcomaMarch 25, 2026 6:00 AM
NewsfileATMP benefits include access to the Conditional Marketing Authorisation accelerated market access pathway in Europe, significantly reduced user fees for small and medium-sized enterprises (SMEs), tailored regulatory assessment via Committee for Advanced Therapies (CAT) and increased pricing power New York, New York--(Newsfile Corp. - March 25, 2026) - OS Therapies, Inc. (NYSE American: OSTX) ("OS Therapies" or "the Company"), the world leader in listeria-based cancer immunotherapies, today announced that the European Medicines Agency's (EMA) Committee for Advanced Therapies (CAT) granted OST-HER2 Advanced Therapy Medicinal Product designation (ATMP) for the treatment of pulmonary recurrence in resected osteosarcoma in the European Union (EU) at CAT's 18-20th March 2026 meeting. ATMP benefits include opening of the Conditional Marketing Authorisation (CMA) accelerated market access pathway in Europe, significantly reduced user fees for small and medium-sized enterprises (SMEs), tailored regulatory assessment via Committee for Advanced Therapies (CAT) and increased reimbursement pathways & reimbursement codes. The Company is finalizing the preparation of a CMA submission to EMA for OST-HER2 in the prevention or delay of recurrent, fully-resected, pulmonary metastatic osteosarcoma. ATMP designation is the European equivalent of the Regenerative Medicine Advanced Therapy (RMAT) designation with the U.S. Food & Drug Administration."ATMP designation marks a significant milestone along OST-HER2's path toward becoming the standard of care in Europe," said Paul Romness, MPH, Chairman & CEO of OS Therapies. "We believe this increases the likelihood that we will receive conditional marketing authorisation later this year, which would help us establish a significant revenue stream for the Company projected to begin in 2027. We look forward to continued engagement with the EMA in the months ahead and are pleased that EMA has begun coordinating with the U.K. Medicines and Healthcare products Regulatory Agency (MHRA) and U.S. Food & Drug Administration (FDA) on the product candidate evaluation process. We will deliver regulatory dossiers to each of these agencies in the weeks ahead and look forward to upcoming meetings where we will review the clinical data, biomarker data, manufacturing data, non-clinical data and proposed confirmatory study designs that would position OST-HER2 for market access in the U.S., U.K. and Europe later this year."OST-HER2 has received Orphan Drug Designation (ODD), Fast Track Designation (FTD) and Rare Pediatric Disease Designation (RPDD) from the FDA, and ODD, FTD and ATMP from the EMA. Under the RPDD program, if the Company receives a Biologics License Application (BLA) in the United States, it will become eligible to receive a Priority Review Voucher (PRV) that it intends to sell. The most recent publicly disclosed PRV transaction occurred in February 2026 at a reported value of $205 million. The Company is seeking to obtain a BLA under the Accelerated Approval Program for OST-HER2 in osteosarcoma in the second half of 2026.About OS TherapiesOS Therapies is a clinical stage oncology company focused on the identification, development, and commercialization of treatments for Osteosarcoma (OS) and other solid tumors. The Company is the world leader in listeria-based cancer immunotherapies. OST-HER2, the Company's lead asset, is an immunotherapy leveraging the immune-stimulatory effects of Listeria bacteria to initiate a strong immune response targeting the HER2 protein. OST-HER2 has received Orphan Drug Designation (ODD), Fast Track Designation (FTD) and Rare Pediatric Disease Designation (RPDD) from the U.S. Food & Drug Administration and has received ODD, FTD and ATMP from the European Medicines Agency. The Company reported positive data in its Phase 2b clinical trial of OST-HER2 in recurrent, fully resected, lung metastatic osteosarcoma, demonstrating statistically significant benefit in the 12-month event free survival (EFS) primary endpoint of the study and the overall survival (OS) secondary endpoint. The Company anticipates receiving a Biologics License Application (BLA) from the U.S. FDA for OST-HER2 in osteosarcoma in 2026 and, if approved, would become eligible to receive a Priority Review Voucher that it could then sell. The Company also anticipates receiving Conditional Marketing Authorisations from the U.K.'s Medicines and Healthcare products Regulatory Agency and the EMA for OST-HER2 in 2026. OST-HER2 has completed a Phase 1 clinical study primarily in breast cancer patients, in addition to showing preclinical efficacy data in various models of breast cancer. OST-HER2 has been conditionally approved by the U.S. Department of Agriculture for the treatment of canines with osteosarcoma. The Company also anticipates reading out data from a Phase 1b study of OST-504 in castration resistant prostate cancer in the first half of 2026.In addition, OS Therapies is advancing its next-generation Antibody Drug Conjugate (ADC) and Drug Conjugates (DC), known as tunable ADC (tADC), which features tunable, tailored antibody-linker-payload candidates. This platform leverages the Company's proprietary silicone Si-Linker and Conditionally Active Payload (CAP) technology, enabling the delivery of multiple payloads per linker. For more information, please visit www.ostherapies.com. Forward-Looking StatementsStatements in this press release about future expectations, plans and prospects, as well as any other statements regarding matters that are not historical facts, may constitute forward-looking statements within the meaning of the federal securities laws. These forward-looking statements and terms such as "anticipate," "expect," "intend," "may," "will," "should" or other comparable terms involve risks and uncertainties because they relate to events and depend on circumstances that will occur in the future. Those statements include statements regarding the intent, belief or current expectations of OS Therapies and members of its management, as well as the assumptions on which such statements are based. OS Therapies cautions readers that forward-looking statements are based on management's expectations and assumptions as of the date of this press release and are subject to certain risks and uncertainties that could cause actual results to differ materially, including, but not limited to the approval of OST-HER2 by the U.S. FDA and other risks and uncertainties described in "Risk Factors" in the Company's most recent Annual Report on Form 10-K, most recent Quarterly Report on Form 10-Q and other subsequent documents the Company files with the Securities and Exchange Commission. Any forward-looking statements contained in this press release speak only as of the date hereof, and, except as required by the federal securities laws, OS Therapies specifically disclaims any obligation to update any forward-looking statement, whether as a result of new information, future events or otherwise.OS Therapies Contact Information:Investor Relations
Harrison Seidner, PhD
WaterSeid Partners
OSTX@waterseid.com Public Relations
Stephanie Chen
Elev8 New Media
media@ostherapies.comhttps://x.com/OSTherapies
https://www.instagram.com/ostherapies/
https://www.facebook.com/OSTherapies/
https://www.linkedin.com/company/os-therapies/To view the source version of this press release, please visit https://www.newsfilecorp.com/release/289799
Original: OS Therapies Granted EMA's Advanced Therapy Medicinal Product (ATMP) Designation for OST-HER2 in the Treatment of Pulmonary Recurrence in Resected Osteosarcoma

OS Therapies Announces FDA OST-HER2 Type D Meeting Elevated to Type B Pre-BLA MeetingMarch 9, 2026 7:40 AM
NewsfileFDA's elevated meeting status signals transition from biomarker data discussions to Accelerated Approval discussionsOS Therapies on track to complete clinical data submission by the end of Q1 2026New York, New York--(Newsfile Corp. - March 9, 2026) - OS Therapies Inc. (NYSE American: OSTX) ("OS Therapies" or "the Company"), the world leader in listeria-based cancer immunotherapies, today provided an update regarding ongoing conversations with the United States Food & Drug Administration (FDA) with regards to its ongoing Biologics License Application (BLA) submission under the Accelerated Approval Program (Accelerated Approval) for OST-HER2 in the prevention or delay of recurrent, fully resected, pulmonary metastatic osteosarcoma. FDA elevated OS Therapies' Type D Biomarker Meeting to a Type B pre-BLA Meeting, expected to occur shortly after the Company completes submission of its clinical data package to the agency, targeted for the end of the first quarter of 2026."We credit FDA with taking decisive action to help advance Accelerated Approval discussions regarding OST-HER2 for pediatric cancer patients with osteosarcoma," said Paul Romness, MPH, Chairman & CEO of OS Therapies. "With the biomarker analysis complete, and patent filings in process, we are poised to deliver data to the agency that we believe represents surrogate clinical efficacy sufficient to enable our ongoing BLA submission. Following key meetings with Key Opinion Leaders over the last few weeks, many of whom treated patients in our clinical trial, we believe we now have a clear path forward to establish confirmatory randomized Phase 3 trial that is required to have a commenced prior to being granted Accelerated Approval in the United States."OST-HER2 has received FDA Orphan Drug Designation (ODD) and Fast Track Designation from the FDA & EMA and has also received Rare Pediatric Disease Designation (RPDD) from the FDA. Under the RPDD program, if the Company receives Accelerated Approval in the United States, it will become eligible to receive a Priority Review Voucher (PRV) that it intends to sell. The most recent publicly disclosed PRV transaction occurred in February 2026 at a reported value of $205 million. The Company is seeking to get Accelerated Approval for OST-HER2 in osteosarcoma in the second half of 2026.About OS TherapiesOS Therapies is a clinical stage oncology company focused on the identification, development, and commercialization of treatments for Osteosarcoma (OS) and other solid tumors. The Company is the world leader in listeria-based cancer immunotherapies. OST-HER2, the Company's lead asset, is an immunotherapy leveraging the immune-stimulatory effects of Listeria bacteria to initiate a strong immune response targeting the HER2 protein. OST-HER2 has received Rare Pediatric Disease Designation (RPDD) from the U.S. Food & Drug Administration and Fast-Track and Orphan Drug designations from the U.S. FDA and European Medicines Agency. The Company reported positive data in its Phase 2b clinical trial of OST-HER2 in recurrent, fully resected, lung metastatic osteosarcoma, demonstrating statistically significant benefit in the 12-month event free survival (EFS) primary endpoint of the study. The Company anticipates receiving a Biologics Licensing Application (BLA) from the U.S. FDA for OST-HER2 in osteosarcoma in 2026 and, if approved, would become eligible to receive a Priority Review Voucher that it could then sell. The Company also anticipates receiving conditional Marketing Authorisations from the U.K.'s Medicines and Healthcare products Regulatory Agency and the European Medicines Agency for OST-HER2 in 2026. OST-HER2 has completed a Phase 1 clinical study primarily in breast cancer patients, in addition to showing preclinical efficacy data in various models of breast cancer. OST-HER2 has been conditionally approved by the U.S. Department of Agriculture for the treatment of canines with osteosarcoma. The Company also anticipates reading out data from a Phase 1b study of OST-504 in castration resistant prostate cancer in the first half of 2026.In addition, OS Therapies is advancing its next-generation Antibody Drug Conjugate (ADC) and Drug Conjugates (DC), known as tunable ADC (tADC), which features tunable, tailored antibody-linker-payload candidates. This platform leverages the Company's proprietary silicone Si-Linker and Conditionally Active Payload (CAP) technology, enabling the delivery of multiple payloads per linker. For more information, please visit www.ostherapies.com. Forward-Looking StatementsStatements in this press release about future expectations, plans and prospects, as well as any other statements regarding matters that are not historical facts, may constitute forward-looking statements within the meaning of the federal securities laws. These forward-looking statements and terms such as "anticipate," "expect," "intend," "may," "will," "should" or other comparable terms involve risks and uncertainties because they relate to events and depend on circumstances that will occur in the future. Those statements include statements regarding the intent, belief or current expectations of OS Therapies and members of its management, as well as the assumptions on which such statements are based. OS Therapies cautions readers that forward-looking statements are based on management's expectations and assumptions as of the date of this press release and are subject to certain risks and uncertainties that could cause actual results to differ materially, including, but not limited to the approval of OST-HER2 by the U.S. FDA and other risks and uncertainties described in "Risk Factors" in the Company's most recent Annual Report on Form 10-K, most recent Quarterly Report on Form 10-Q and other subsequent documents the Company files with the Securities and Exchange Commission. Any forward-looking statements contained in this press release speak only as of the date hereof, and, except as required by the federal securities laws, OS Therapies specifically disclaims any obligation to update any forward-looking statement, whether as a result of new information, future events or otherwise.OS Therapies Contact Information:Investor Relations
Harrison Seidner, PhD
WaterSeid Partners
OSTX@waterseid.com Public Relations
Stephanie Chen
Elev8 New Media
media@ostherapies.comhttps://x.com/OSTherapies
https://www.instagram.com/ostherapies/
https://www.facebook.com/OSTherapies/
https://www.linkedin.com/company/os-therapies/To view the source version of this press release, please visit https://www.newsfilecorp.com/release/287699
Original: OS Therapies Announces FDA OST-HER2 Type D Meeting Elevated to Type B Pre-BLA Meeting

OS Therapies Provides Global Regulatory Update for OST-HER2 in Recurrent, Fully Resected, Pulmonary Metstatic OsteosarcomaFebruary 17, 2026 6:00 AM
NewsfileAdditional forthcoming biomarker data from human trial expected to further characterize immune pathway activation and its relationship to clinical outcomesU.S., U.K. and European osteosarcoma key opinion leaders assembling to review clinical & biomarker trial data, and comment on proposed confirmatory trial designAyala Pharmaceuticals announces dissolution following liquidation of assetsNew York, New York--(Newsfile Corp. - February 17, 2026) - OS Therapies Inc. (NYSE American: OSTX) ("OS Therapies" or "the Company"), the world leader in listeria-based cancer immunotherapies, today provided a global regulatory update for OST-HER2 in the prevention or delay of recurrent, fully resected, pulmonary metastatic osteosarcoma (the "Human Metastatic Osteosarcoma Program"). Following the submission of the Non-Clinical and Chemistry, Manufacturing & Controls (CMC) modules of its Biologics License Application (BLA) to U.S. Food & Drug Administration (FDA) at the end of January 2026, the Company anticipates releasing additional biomarker data from its Human Metastatic Osteosarcoma Program in the first quarter of 2026. These analyses are intended to further characterize immune pathway activation and evaluate the relationship between biomarker expression and observed clinical outcomes.The Company expects to complete conditional Marketing Authorisation Application (MAA) submissions to both the U.K.'s Medicines and Healthcare products Regulatory Agency (MHRA) and the European Medicines Agency (EMA) by the end of the first quarter of 2026. The Company remains on track to submit the Clinical BLA module to the FDA following an anticipated Type D meeting expected to occur in March 2026."We continue to advance our global regulatory strategy following previously reported pre-specified biomarker analyses demonstrating concordant immune pathway activation signatures and clinical outcomes in both human and canine elite responders (long term survivors) when compared with patients who showed no clinical benefit," said Paul Romness, MPH, CEO of OS Therapies. "We have now nearly completed additional follow-on biomarker analyses designed to further elucidate the drug's treatment effect and its relationship to clinical outcomes. We are hopeful the data will provide further support for the use of these biomarkers as surrogate endpoints of clinical efficacy. We expect to share this data in the coming weeks."Concurrent with this announcement, the Company disclosed that it is assembling a meeting of U.S., U.K. and European osteosarcoma key opinion leaders to review the clinical and biomarker data from the Human Metastatic Osteosarcoma Program and provide input on proposed confirmatory trial designs for the Company's confirmatory clinical development program. The Company is seeking a BLA under the Accelerated Approval Program ('Accelerated Approval') in the U.S. and conditional MAAs in the U.K. and Europe, which all require confirmatory studies to be initiated prior to approval. The Company anticipates initiating the confirmatory trial in the third quarter of 2026 with the opening of a single site that allows it to meet the Accelerated Approval statutory requirement, with broader site activation expected following regulatory approval. OST-HER2 has received FDA Orphan Drug Designation (ODD) and Fast Track Designation from the FDA & EMA and has received Rare Pediatric Disease Designation (RPDD) from the FDA. Under the RPDD program, if the Company receives Accelerated Approval in the United States, it will become eligible to receive a Priority Review Voucher (PRV) that it intends to sell. The most recent publicly disclosed PRV transaction occurred in January 2026 at a reported value of $200 million.Additionally, the Company announced that it has been informed that Ayala Pharmaceuticals, Inc. ('Ayala') has informed its shareholders that Ayala is dissolving. The Company acquired all listeria-based clinical, pre-clinical and intellectual property assets from Ayala in April 2025, issuing to Ayala the equivalent of 4.8 million shares of OS Therapies common stock that became eligible for trading on October 9, 2025. The Company was informed by Ayala representatives that Ayala completed the liquidation of its OS Therapies common stock on February 9, 2026, and no longer holds any securities in the Company.About OS Therapies
OS Therapies is a clinical stage oncology company focused on the identification, development, and commercialization of treatments for Osteosarcoma (OS) and other solid tumors. The Company is the world leader in listeria-based cancer immunotherapies. OST-HER2, the Company's lead asset, is an immunotherapy leveraging the immune-stimulatory effects of Listeria bacteria to initiate a strong immune response targeting the HER2 protein. OST-HER2 has received Rare Pediatric Disease Designation (RPDD) from the U.S. Food & Drug Administration and Fast-Track and Orphan Drug designations from the U.S. FDA and European Medicines Agency. The Company reported positive data in its Phase 2b clinical trial of OST-HER2 in recurrent, fully resected, lung metastatic osteosarcoma, demonstrating statistically significant benefit in the 12-month event free survival (EFS) primary endpoint of the study. The Company anticipates receiving a Biologics Licensing Application (BLA) from the U.S. FDA for OST-HER2 in osteosarcoma in 2026 and, if approved, would become eligible to receive a Priority Review Voucher that it could then sell. The Company also anticipates receiving conditional Marketing Authorisations from the U.K.'s Medicines and Healthcare products Regulatory Agency and the European Medicines Agency for OST-HER2 in 2026. OST-HER2 has completed a Phase 1 clinical study primarily in breast cancer patients, in addition to showing preclinical efficacy data in various models of breast cancer. OST-HER2 has been conditionally approved by the U.S. Department of Agriculture for the treatment of canines with osteosarcoma. The Company also anticipates reading out data from a Phase 1b study of OST-504 in castration resistant prostate cancer in the first half of 2026. In addition, OS Therapies is advancing its next-generation Antibody Drug Conjugate (ADC) and Drug Conjugates (DC), known as tunable ADC (tADC), which features tunable, tailored antibody-linker-payload candidates. This platform leverages the Company's proprietary silicone Si-Linker and Conditionally Active Payload (CAP) technology, enabling the delivery of multiple payloads per linker. For more information, please visit www.ostherapies.com. Forward-Looking Statements
Statements in this press release about future expectations, plans and prospects, as well as any other statements regarding matters that are not historical facts, may constitute forward-looking statements within the meaning of the federal securities laws. These forward-looking statements and terms such as "anticipate," "expect," "intend," "may," "will," "should" or other comparable terms involve risks and uncertainties because they relate to events and depend on circumstances that will occur in the future. Those statements include statements regarding the intent, belief or current expectations of OS Therapies and members of its management, as well as the assumptions on which such statements are based. OS Therapies cautions readers that forward-looking statements are based on management's expectations and assumptions as of the date of this press release and are subject to certain risks and uncertainties that could cause actual results to differ materially, including, but not limited to the approval of OST-HER2 by the U.S. FDA and other risks and uncertainties described in "Risk Factors" in the Company's most recent Annual Report on Form 10-K, most recent Quarterly Report on Form 10-Q and other subsequent documents the Company files with the Securities and Exchange Commission. Any forward-looking statements contained in this press release speak only as of the date hereof, and, except as required by the federal securities laws, OS Therapies specifically disclaims any obligation to update any forward-looking statement, whether as a result of new information, future events or otherwise. OS Therapies Contact Information:Investor Relations
Harrison Seidner, PhD
WaterSeid Partners
OSTX@waterseid.com Public Relations
Stephanie Chen
Elev8 New Media
media@ostherapies.comhttps://x.com/OSTherapies
https://www.instagram.com/ostherapies/
https://www.facebook.com/OSTherapies/
https://www.linkedin.com/company/os-therapies/To view the source version of this press release, please visit https://www.newsfilecorp.com/release/284086
Original: OS Therapies Provides Global Regulatory Update for OST-HER2 in Recurrent, Fully Resected, Pulmonary Metstatic Osteosarcoma

Based on recent analyst ratings, clinical progress, and market commentary, OS Therapies (OSTX) is considered a potential biotech acquisition target, with analysts highlighting significant upside potential.
Arguments Supporting Potential Buyout Status:
Strong Analyst Consensus: Analysts have a "Strong Buy" consensus rating on the stock. As of early 2026, 80% to 100% of covering analysts recommend buying or holding the stock.
High Price Targets: Analysts have projected aggressive price targets, with average forecasts suggesting an upside of over 700% to 1,200% from early 2026 price levels (e.g., $18.50–$20.00 range).
Key Clinical Data: The company has reported positive 2-year overall survival data for its lead program, OST-HER2, for treating osteosarcoma.
Regulatory Alignment: OS Therapies has had productive meetings with the FDA regarding the OST-HER2 program and is moving toward a Biologics Licensing Application (BLA).
Small Market Cap: With a market cap in the range of $50–$70 million (as of late 2025/early 2026), it is considered a small, accessible target for larger pharmaceutical companies.

Started a position today and will be adding for the near future

Prv is fantastic

Latest news sounds encouraging

OS Therapies Applauds Reauthorization of Pediatric Priority Review Voucher Program to Advance Breakthrough Osteosarcoma ImmunotherapiesFebruary 4, 2026 12:45 PM
NewsfileNew York, New York--(Newsfile Corp. - February 4, 2026) - OS Therapies Inc. (NYSE American: OSTX) ("OS Therapies" or "the Company"), the world leader in listeria-based cancer immunotherapies, is honored to celebrate the passage of the Mikaela Naylon Give Kids A Chance Act. Mikaela, like so many other children, courageously battled pediatric cancer - specifically Osteosarcoma. Her legacy through this legislation will accelerate critical opportunities for research and therapeutic access for other children and teens currently living with pediatric cancers. Innovation is urgent and direly needed as pediatric cancers remain the leading disease-based cause of pediatric death in the United States. OS Therapies is empowered to continue its groundbreaking work combating osteosarcoma, where there is still significant unmet need for patients - primarily children and teens. Through the reauthorization of the Rare Pediatric Disease Designation (RPDD) Priority Review Voucher (PRV) program, OS Therapies can continue their dedicated efforts with an extended deadline for the Company to receive a Biologics License Application (BLA) for OST-HER2 in the prevention or delay of recurrent, fully resected, pulmonary metastatic osteosarcoma. The Company will now remain eligible to receive a PRV from September 30, 2026, to September 30, 2029. The reauthorization of the program also incentivizes OS Therapies to re-evaluate the development of other pipeline products across its listeria-based cancer immunotherapy platform in the context of potential additional PRV opportunities, and benefits afforded by the FDA Platform Technology Designation Program for Drug Development. The Company will provide further details regarding the outcome of this evaluation process after the current sequence of marketing authorization submissions for its lead osteosarcoma candidate is completed. OS Therapies is grateful for the positive impact of Mikaela's and some many other patients' legacy, and the Company is committed to building upon it to transform the lives of children and teens living with osteosarcoma and other rare cancers. OST-HER2 has received FDA Orphan Disease Designation (ODD) and Fast Track Designation from FDA & EMA and has received Rare Pediatric Disease Designation (RPDD) from FDA. Under the RPDD program, if the Company receives Accelerated Approval prior to September 30, 2029, it will become eligible to receive a Priority Review Voucher (PRV).About OS TherapiesOS Therapies is a clinical stage oncology company focused on the identification, development, and commercialization of treatments for Osteosarcoma (OS) and other solid tumors. The Company is the world leader in listeria-based cancer immunotherapies. OST-HER2, the Company's lead asset, is an immunotherapy leveraging the immune-stimulatory effects of Listeria bacteria to initiate a strong immune response targeting the HER2 protein. OST-HER2 has received Rare Pediatric Disease Designation (RPDD) from the U.S. Food & Drug Administration and Fast-Track and Orphan Drug designations from the U.S. FDA and European Medicines Agency. The Company reported positive data in its Phase 2b clinical trial of OST-HER2 in recurrent, fully resected, lung metastatic osteosarcoma, demonstrating statistically significant benefit in the 12-month event free survival (EFS) primary endpoint of the study. The Company is submitting a Biologics Licensing Application (BLA) to the U.S. FDA for OST-HER2 in osteosarcoma and, if approved, would become eligible to receive a Priority Review Voucher that it could then sell. OST-HER2 has completed a Phase 1 clinical study primarily in breast cancer patients, in addition to showing preclinical efficacy data in various models of breast cancer. OST-HER2 has been conditionally approved by the U.S. Department of Agriculture for the treatment of canines with osteosarcoma.In addition, OS Therapies is advancing its next-generation Antibody Drug Conjugate (ADC) and Drug Conjugates (DC), known as tunable ADC (tADC), which features tunable, tailored antibody-linker-payload candidates. This platform leverages the Company's proprietary silicone Si-Linker and Conditionally Active Payload (CAP) technology, enabling the delivery of multiple payloads per linker. For more information, please visit www.ostherapies.com. Forward-Looking StatementsStatements in this press release about future expectations, plans and prospects, as well as any other statements regarding matters that are not historical facts, may constitute forward-looking statements within the meaning of the federal securities laws. These forward-looking statements and terms such as "anticipate," "expect," "intend," "may," "will," "should" or other comparable terms involve risks and uncertainties because they relate to events and depend on circumstances that will occur in the future. Those statements include statements regarding the intent, belief or current expectations of OS Therapies and members of its management, as well as the assumptions on which such statements are based. OS Therapies cautions readers that forward-looking statements are based on management's expectations and assumptions as of the date of this press release and are subject to certain risks and uncertainties that could cause actual results to differ materially, including, but not limited to the approval of OST-HER2 by the U.S. FDA and other risks and uncertainties described in "Risk Factors" in the Company's most recent Annual Report on Form 10-K, most recent Quarterly Report on Form 10-Q and other subsequent documents the Company files with the Securities and Exchange Commission. Any forward-looking statements contained in this press release speak only as of the date hereof, and, except as required by the federal securities laws, OS Therapies specifically disclaims any obligation to update any forward-looking statement, whether as a result of new information, future events or otherwise.OS Therapies Contact Information:Investor Relations
Harrison Seidner, PhD
WaterSeid Partners
OSTX@waterseid.com Public Relations
Stephanie Chen
Elev8 New Media
media@ostherapies.com

https://x.com/OSTherapies
https://www.instagram.com/ostherapies/
https://www.facebook.com/OSTherapies/
https://www.linkedin.com/company/os-therapies/To view the source version of this press release, please visit https://www.newsfilecorp.com/release/282703
Original: OS Therapies Applauds Reauthorization of Pediatric Priority Review Voucher Program to Advance Breakthrough Osteosarcoma Immunotherapies

OS Therapies Initiates US FDA BLA Filing for OST-HER2 in the Prevention or Delay of Recurrent, Fully Resected, Pulmonary Metastatic OsteosarcomaFebruary 2, 2026 6:00 AM
NewsfileRequest for FDA Rolling Review submitted to FDA on January 30, 2026Non-Clinical and CMC BLA modules submitted to FDAAt FDA's request, Type D Meeting expected in March 2026 to review Comparative Oncology biomarker data from patients treated in OST-HER2 Phase 2b human clinical trial and OST-HER2 trial in spontaneous osteosarcoma in caninesFinal BLA clinical module expected to be submitted to FDA by end of March 2026 after Type D Meeting Regenerative Medicine Advanced Therapy (RMAT) designation requests update submitted to FDA with recent biomarker dataCompany remains on track to be eligible to receive Priority Review Voucher under Rare Pediatric Disease Designation (RPDD) with approval anticipated by September 30, 2026New York, New York--(Newsfile Corp. - February 2, 2026) - OS Therapies Inc. (NYSE American: OSTX) ("OS Therapies" or "the Company"), the world leader in listeria-based cancer immunotherapies, today announced that it has formally initiated a Biologics License Application (BLA) submission to the U.S. Food & Drug Administration (FDA) for OST-HER2 in the prevention or delay of recurrent, fully resected, pulmonary metastatic osteosarcoma ("Human Metastatic Osteosarcoma"). The Company has submitted the Non-Clinical and the Chemistry, Manufacturing, and Controls (CMC) modules of the BLA to FDA, along with a request for Rolling Review. At FDA's invitation following a December 2025 Type C Meeting, the Company has requested a Type D Meeting to review new Comparative Oncology OST-HER2 biomarker data generated from the Company's Phase 2b human clinical trial in Human Metastatic Osteosarcoma and a similar trial of OST-HER2 in spontaneous osteosarcoma in canines (the "OST-HER2 Comparative Oncology Data"). The Company expects to submit the clinical BLA module that will rely upon the OST-HER2 Comparative Oncology Data by the end of March 2026, keeping it on schedule to be eligible to receive approval by September 30, 2026."We are delighted in the FDA's interest in reviewing OST-HER2 Comparative Oncology Data," said Paul Romness, MPH, Chairman & CEO of OS Therapies. "There is strong demand for compassionate use of OST-HER2 from the patient community, underscoring the urgent need for new therapies in Human Metastatic Osteosarcoma. We remain committed to bringing OST-HER2 to market as expeditiously as possible and are grateful for FDA's engagement as we finalize the biomarker data package that will be submitted as part of Type D meeting preparations to support our request for a BLA under the Accelerated Approval Program."Concurrent with this announcement, the Company announced it has updated its Regenerative Medicine Advanced Therapy (RMAT) designation requests to FDA with recent biomarker data. RMAT designation typically shortens the timeframe granted for review of a BLA submission significantly from the standard timelines, expediting the time to patient access. OST-HER2 has received FDA Orphan Disease Designation (ODD) and Fast Track Designation from FDA & EMA and has received Rare Pediatric Disease Designation (RPDD) from FDA. Under the RPDD program, if the Company receives Accelerated Approval prior to September 30, 2026, it will become eligible to receive a Priority Review Voucher (PRV) that it intends to sell. The most recent PRV sale, valued at $200 million, occurred in January 2026.About OS Therapies OS Therapies is a clinical stage oncology company focused on the identification, development, and commercialization of treatments for Osteosarcoma (OS) and other solid tumors. The Company is the world leader in listeria-based cancer immunotherapies. OST-HER2, the Company's lead asset, is an immunotherapy leveraging the immune-stimulatory effects of Listeria bacteria to initiate a strong immune response targeting the HER2 protein. OST-HER2 has received Rare Pediatric Disease Designation (RPDD) from the U.S. Food & Drug Administration and Fast-Track and Orphan Drug designations from the U.S. FDA and European Medicines Agency. The Company reported positive data in its Phase 2b clinical trial of OST-HER2 in recurrent, fully resected, lung metastatic osteosarcoma, demonstrating statistically significant benefit in the 12-month event free survival (EFS) primary endpoint of the study. The Company anticipates completing submission of a BLA to the U.S. FDA for OST-HER2 in osteosarcoma in March 2026 and, if approved, would become eligible to receive a Priority Review Voucher that it could then sell. OST-HER2 has completed a Phase 1 clinical study primarily in breast cancer patients, in addition to showing preclinical efficacy data in various models of breast cancer. OST-HER2 has been conditionally approved by the U.S. Department of Agriculture for the treatment of canines with osteosarcoma. In addition, OS Therapies is advancing its next-generation Antibody Drug Conjugate (ADC) and Drug Conjugates (DC), known as tunable ADC (tADC), which features tunable, tailored antibody-linker-payload candidates. This platform leverages the Company's proprietary silicone Si-Linker and Conditionally Active Payload (CAP) technology, enabling the delivery of multiple payloads per linker. For more information, please visit www.ostherapies.com. Forward-Looking Statements Statements in this press release about future expectations, plans and prospects, as well as any other statements regarding matters that are not historical facts, may constitute forward-looking statements within the meaning of the federal securities laws. These forward-looking statements and terms such as "anticipate," "expect," "intend," "may," "will," "should" or other comparable terms involve risks and uncertainties because they relate to events and depend on circumstances that will occur in the future. Those statements include statements regarding the intent, belief or current expectations of OS Therapies and members of its management, as well as the assumptions on which such statements are based. OS Therapies cautions readers that forward-looking statements are based on management's expectations and assumptions as of the date of this press release and are subject to certain risks and uncertainties that could cause actual results to differ materially, including, but not limited to the approval of OST-HER2 by the U.S. FDA and other risks and uncertainties described in "Risk Factors" in the Company's most recent Annual Report on Form 10-K, most recent Quarterly Report on Form 10-Q and other subsequent documents the Company files with the Securities and Exchange Commission. Any forward-looking statements contained in this press release speak only as of the date hereof, and, except as required by the federal securities laws, OS Therapies specifically disclaims any obligation to update any forward-looking statement, whether as a result of new information, future events or otherwise. OS Therapies Contact Information:Investor Relations
Harrison Seidner, PhD
WaterSeid Partners
OSTX@waterseid.com Public Relations
Stephanie ChenElev8 New Media
media@ostherapies.com https://x.com/OSTherapies
https://www.instagram.com/ostherapies/
https://www.facebook.com/OSTherapies/
https://www.linkedin.com/company/os-therapies/To view the source version of this press release, please visit https://www.newsfilecorp.com/release/282344
Original: OS Therapies Initiates US FDA BLA Filing for OST-HER2 in the Prevention or Delay of Recurrent, Fully Resected, Pulmonary Metastatic Osteosarcoma

OS Therapies Incorporated (NYSE American: OSTX): Virtual Investor Conferences



Weekly Chart
https://schrts.co/grBiVdCr

OSTX $1.85 ,BLA fling for Cancer drug in the coming weeks , the under radar gem has low valuation of 63 million dollar and could receive priority review voucher upon FDA approval which is worh 150million+ this could be a 10 bagger opportunity

company presentation
https://d1io3yog0oux5.cloudfront.net/_bff678b5554d5fc4f771a03521120b45/ostherapies/db/2484/23354/pdf/OSTX+Investor+Presentation+October+2025.pdf

OS Therapies eyes global osteosarcoma vaccine approvals after Phase IIb win

“We remain on track to file a conditional Marketing Authorisation Application (MAA) to Medicines and Healthcare products Regulatory Agency (MHRA) in December 2025, a Biologics Licensing Application (BLA) under the Accelerated Approval Program to the FDA in January 2026, and an MAA to the EMA in the first quarter of 2026,” Petit clarified.

If OST-HER2 were to get the US Food and Drug Administration (FDA) green light, it would become the first targeted treatment available for metastatic osteosarcoma.

https://www.clinicaltrialsarena.com/news/os-therapies-ost-her2-cancer-vaccine-mets-osteosarcoma-phase-iib/?cf-view

RADAR

Johnny, we've got to wonder how such a rotten financial manager as GC can keep landing on his feet.
Hard luck research companies need people like GC with a good line of quality horse manure.
Learning what doesn't work creates more opportunity for the next experiment.

OSTX under $2

OSTX being promoted by some pr firm called RedChip on Bloomberg. 

$1.92 ..The Company recently completed a $7.1 millionfinancing in January 2025 and has sufficient capital into mid 2026..
(2) sell the Priority Review Voucher (PRV) it would receive from the FDA BLA approval prior to the September 30, 2026 PRV deadline to a larger pharmaceutical company at prevailing market prices (most recent PRV sale transaction was $150 million), (3) commercialize OST-HER2 in osteosarcoma and (4) then expand the clinical development of OST-HER2 into breast cancer and other larger solid tumor indications for additional revenue potential.

too much debt AND the CBO is a lying POS shyster who destroys SH value



C-Suites my royal right butt cheek ...!

just look at what Gerald Commissiong did to AMBS and TOMDF

drove both into insolvency and stole everything he could via serial dilution from his SH's

its just that plain and simple...!



Gerald Commissiong - WAPOS

Yes only played premarket to much debt here 

OSTX under $3

don't touch it...

unless you're Jack be nimble Jack be quick...

AJMHO

I'm seeing 1.6m float