SOUTH SAN FRANCISCO, Calif.,
April 27, 2020 /PRNewswire/ -- Sutro
Biopharma, Inc. (NASDAQ: STRO), a clinical-stage drug discovery,
development and manufacturing company focused on the application of
precise protein engineering and rational design to create
next-generation oncology therapeutics, today announced updated
interim data regarding safety and anti-tumor activity results in
heavily pre-treated patients with ovarian cancer from its on-going
Phase 1 clinical trial (dose escalation phase) evaluating its
folate receptor alpha (FolRα) antibody drug-conjugate (ADC) STRO-002. Sutro will host a conference call
and live audio webcast on Monday, April
27, at 8 a.m. EDT to discuss
the STRO-002 data.
"We designed STRO-002 to have a wider therapeutic window, with
the potential for improved tumor control and better patient
tolerability, than other FolRα targeted therapies," said
Bill Newell, CEO of Sutro Biopharma.
"The data we present today from this all-comers trial suggest that
our optimally designed ADC can achieve these objectives. In 75% (15
of 20) of ovarian cancer patients at STRO-002 dose levels of 2.9
milligrams per kilogram (mpk) or higher, we saw in the initial
post-baseline scans one partial response and 14 stable disease.
This level of tumor control is typically very difficult to achieve
in these patients who have been heavily pre-treated, with a median
of five prior lines of other therapies, and who have such advanced
disease. Equally encouraging are the data showing that 13 patients
had a ≥50% reduction or normalization of CA-125, including six
confirmed responses, six unconfirmed responses and one prolonged
CA-125 normalization. Of these 13 patients, one patient is not yet
evaluable under RECIST criteria. All of the other 12 patients
(100%) have also achieved stable disease (confirmed or unconfirmed)
or a confirmed partial response. With 89% of adverse events (AEs)
reported to be grade 1 or 2, we believe the emerging safety profile
reflects our optimized design approach."
The interim clinical data for STRO-002 in patients treated at
dose levels of 2.9 mpk or higher include: one patient with an
ongoing confirmed partial response (36 weeks); five patients with
confirmed stable disease (three up to 18 weeks, two up to 27
weeks); and seven ongoing patients who have unconfirmed stable
disease at the six-week assessment point.
STRO-002 was generally well-tolerated and was mostly associated
with mild AEs. Eighty-nine percent (89%) of AEs were grade 1 or
grade 2 and prophylactic corticosteroid eye drops have not been
necessary. Grade 3 treatment emergent AEs included fatigue,
neutropenia, arthralgia, diarrhea, peripheral neuropathy and
myalgia, with the only grade 4 treatment emergent AE being
neutropenia; all neutropenias were reversible within one week.
"The preliminary evidence of anti-tumor activity we observed is
encouraging, particularly in this heavily pre-treated patient
population," said Wendel Naumann,
MD, gynecologic oncologist at Levine Cancer Institute and a
principal investigator on the STRO-002 study. "With limited
therapeutic options for these patients, we are excited to continue
to advance this clinical program to further investigate its
therapeutic potential."
"These data support Sutro's continued development of targeted
therapies for cancer patients and joins two other Sutro-developed
and manufactured ADCs in clinical trials, including our
BCMA-targeted ADC which is in a Phase 1 trial being conducted by
our collaborator Bristol Myers Squibb," said Arturo Molina, MD, Sutro's Chief Medical
Officer. "It is extremely encouraging that we see this preliminary
evidence of anti-tumor activity at this stage of development. As we
advance STRO-002 in the clinic, we plan to share additional data on
the efficacy and safety of STRO-002 by the end of 2020 and we look
forward to the potential to bring a new treatment option to ovarian
cancer patients."
Through April 20, 2020, the Phase
1 trial of STRO-002 has enrolled 30 patients with recurrent
platinum resistant or refractory ovarian cancer, without regard to
FolRα expression levels. A dose expansion phase of this trial is
planned to commence in the second half of 2020. Although maximum
tolerated dose (MTD) has not been reached, Sutro is continuing to
actively explore the 5.2 mpk to 6.0 mpk dose levels as it seeks to
determine the recommended Phase 2 dose.
The ongoing Phase 1, open-label, multicenter, dose escalation
trial with dose expansion of STRO-002 is designed to identify the
MTD, the recommended Phase 2 clinical dose and to evaluate the
safety, tolerability, and preliminary anti-tumor activity of
STRO-002 in adults with advanced epithelial ovarian cancer,
including fallopian or primary peritoneal cancer, and endometrial
cancer. This trial is registered with clinicaltrials.gov identifier
NCT03748186. Sutro discovered, developed and manufactures STRO-002
using its proprietary XpressCF+™ cell-free protein synthesis
technology.
Conference Call Information:
To access the conference call and live audio webcast on
Monday, April 27, at 8 a.m. EDT, please dial (833) 729-4781 (domestic)
or (830) 213-7705 (international) and refer to conference ID
2699785.
The conference call will be webcast via the Investors page on
the company's website at ir.sutrobio.com. Approximately two hours
following the live event, a webcast replay of the conference call
will be available through the Company Presentation page of the
Investor section of the company's website at
www.sutrobio.com for approximately 30 days.
Poster Presentation Details:
STRO-002-GM1, a First in Human, Phase 1 Study of STRO-002, an
anti-Folate Receptor-alpha (FRα) Antibody Drug Conjugate (ADC), in
Patients with Advanced Platinum-Resistant/Refractory Epithelial
Ovarian Cancer (OC), including Fallopian Tube or Primary Peritoneal
Cancers
Date &
Time:
|
Monday, April 27,
2020, 9 a.m. to 6 p.m. EDT
|
Location:
|
The AACR Virtual
Meeting at aacr.org
|
Poster
Number:
|
CT125
|
The poster will be accessible through the Clinical/Scientific
Presentation and Publication Highlights page of the News section of
the company's website at www.sutrobio.com.
About Sutro Biopharma
Sutro Biopharma, Inc., located
in South San Francisco, is a
clinical-stage drug discovery, development and manufacturing
company. Using precise protein engineering and rational design,
Sutro is advancing next-generation oncology therapeutics.
Sutro's proprietary and integrated cell-free protein synthesis
platform XpressCF® and site-specific conjugation platform,
XpressCF+™, led to the discovery of STRO-001 and STRO-002, Sutro's
first two internally-developed ADCs. STRO-001 is a CD74-targeting
ADC currently being investigated in a Phase 1 clinical trial of
patients with advanced B-cell malignancies, including multiple
myeloma and non-Hodgkin lymphoma. STRO-001 was granted Orphan Drug
Designation by the FDA for multiple myeloma in October 2018. STRO-002 is a folate receptor alpha
(FolRα)-targeting ADC, currently being investigated in a Phase 1
clinical trial of patients with ovarian and endometrial cancers.
This is the second product candidate to be evaluated in clinical
trials resulting from Sutro's XpressCF® and XpressCF+™ technology
platforms. A third program, CC-99712 (BCMA-targeting ADC), which is
part of Sutro's collaboration with Bristol Myers Squibb (formerly
Celgene Corporation), is enrolling patients for its Phase 1
clinical trial of patients with multiple myeloma. Sutro's
proprietary technology was responsible for the discovery and
manufacturing of CC-99712, for which Bristol Myers Squibb has
worldwide development and commercialization rights. Sutro is
entitled to development and regulatory milestone payments and
tiered royalties from Bristol Myers Squibb for this BCMA ADC. Sutro
is dedicated to transforming the lives of cancer patients by
creating medicines with improved therapeutic profiles for areas of
unmet need.
To date, Sutro has designed cytokine-based immuno-oncology
therapies, ADCs, vaccines and bispecific antibodies primarily
directed at clinically-validated targets for which the current
standard of care is suboptimal.
Sutro's platform allows it to accelerate discovery and
development of potential first-in-class and best-in-class molecules
through rapid and systematic evaluation of protein
structure-activity relationships to create optimized homogeneous
product candidates.
In addition to developing its own oncology pipeline, Sutro is
collaborating with select pharmaceutical and biotech companies to
discover and develop novel, next-generation therapeutics. As the
pace of clinical development accelerates, Sutro and its partners
are developing therapeutics designed to more efficiently kill
tumors without harming healthy cells.
Additional multimedia content from Sutro regarding STRO-001 and
STRO-002 can be found here and here.
Follow Sutro on Twitter, @Sutrobio, and at www.sutrobio.com to
learn more about our passion for changing the future of
oncology.
Forward-Looking Statements
This press release contains forward-looking statements within
the meaning of the "safe harbor" provisions of the Private
Securities Litigation Reform Act of 1995, including, but not
limited to, anticipated preclinical and clinical development
activities, timing of announcements of clinical results, potential
benefits of the company's product candidates and platform and
potential market opportunities for the company's product
candidates. All statements other than statements of historical fact
are statements that could be deemed forward-looking statements.
Although the company believes that the expectations reflected in
such forward-looking statements are reasonable, the company cannot
guarantee future events, results, actions, levels of activity,
performance or achievements, and the timing and results of
biotechnology development and potential regulatory approval is
inherently uncertain. Forward-looking statements are subject to
risks and uncertainties that may cause the company's actual
activities or results to differ significantly from those expressed
in any forward-looking statement, including risks and uncertainties
related to the company's ability to advance its product candidates,
the receipt and timing of potential regulatory designations,
approvals and commercialization of product candidates, the impact
of the COVID-19 pandemic on the Company's business, clinical trial
sites, supply chain and manufacturing facilities, the Company's
ability to maintain and recognize the benefits of certain
designations received by product candidates, the timing and results
of preclinical and clinical trials, the company's ability to fund
development activities and achieve development goals, the company's
ability to protect intellectual property, and the Company's
commercial collaborations with third parties and other risks and
uncertainties described under the heading "Risk Factors" in
documents the company files from time to time with the Securities
and Exchange Commission. These forward-looking statements speak
only as of the date of this press release, and the company
undertakes no obligation to revise or update any forward-looking
statements to reflect events or circumstances after the date
hereof.
Investor Contacts
John Graziano
Solebury Trout
+1 646-378-2942
jgraziano@soleburytrout.com
Xuan Yang
Solebury Trout
+1 646-378-2975
xyang@soleburytrout.com
Media Contacts
David Schull
Russo Partners
(212) 845-4271
david.schull@russopartnersllc.com
Travis Kruse
Russo Partners
(212) 845-4272
travis.kruse@russopartnersllc.com
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SOURCE Sutro Biopharma