This Amendment No. 1 (this Amendment) amends and supplements the Tender Offer Statement on
Schedule TO filed with the Securities and Exchange Commission on February 1, 2022 (together with any subsequent amendments and supplements thereto, the Schedule TO), by Zinc Merger Sub, Inc., a Delaware corporation
(Purchaser) and an indirect wholly owned subsidiary of UCB S.A., a société anonyme formed under the laws of Belgium (Parent), and Parent. The Schedule TO relates to the offer by Purchaser to purchase all
of the outstanding shares of common stock, par value $0.001 per share (the Shares), of Zogenix, Inc., a Delaware corporation (Zogenix), in exchange for (i) $26.00 per Share, net to the seller in cash, without interest and
less any applicable withholding taxes (the Cash Amount), plus (ii) one non-transferable contingent value right per Share (each, a CVR), which CVR represents the right to
receive a contingent payment of $2.00, net to the seller in cash, without interest and less any applicable tax withholding, which amount will become payable, if at all, if a specified milestone is achieved on or prior to December 31, 2023 (the
Cash Amount plus one CVR, collectively, or any greater amount per Share that may be paid pursuant to the Offer, being hereinafter referred to as the Offer Price), upon the terms and subject to the conditions set forth in the Offer to
Purchase and in the related Letter of Transmittal, copies of which are attached to the Schedule TO as Exhibits (a)(1)(A) and (a)(1)(B), respectively.
Except as otherwise set forth in this Amendment, the information set forth in the Schedule TO remains unchanged and is incorporated herein by reference to the
extent relevant to the items in this Amendment. Capitalized terms used but not defined herein have the meanings ascribed to them in the Schedule TO.
Items 1 through 9; and Item 11
(a) The disclosure
in the Offer to Purchase and Item 11 of the Schedule TO is hereby amended and supplemented by deleting the second sentence of the first paragraph under Section 16Certain Legal Matters; Regulatory Approvals Antitrust
Compliance of the Offer to Purchase and replacing it with the following paragraph:
Parent and Zogenix filed their
respective Premerger Notification and Report Forms with the FTC and the Antitrust Division on February 1, 2022. The waiting period applicable to the purchase of the Shares pursuant to the Offer will expire at 11:59 p.m., Eastern Time, on
March 3, 2022. This period may change if the FTC or the Antitrust Division, as applicable, grants earlier termination of the waiting period, Parent voluntarily withdraws and refiles its Premerger Notification and Report Form, or the FTC or the
Antitrust Division, as applicable, issues a request for additional information or documentary material prior to that time.
(b) The disclosure in the
Offer to Purchase and Item 11 of the Schedule TO is hereby amended and supplemented by deleting the fourth and fifth sentences of the first paragraph in Section 16Certain Legal Matters; Regulatory Approvals Antitrust
Compliance Foreign Antitrust Filings in Germany of the Offer to Purchase and replacing such sentences with the following two sentences:
On February 23, 2022, the FCO issued an unconditional phase 1 clearance letter with respect to the Offer and the Merger.
Accordingly, the condition to the Offer relating to the receipt of any clearance, approval or consent under applicable antitrust laws, to the extent relating to such clearances, approvals or consents under the German Act Against Restraints of
Competition, has been satisfied.
(c) The disclosure in the Offer to Purchase and Item 11 of the Schedule TO is hereby amended and supplemented by
adding the following sub-heading and paragraphs at the end of Section 16Certain Legal Matters; Regulatory Approvals of the Offer to Purchase:
Certain Litigation
Between February 2, 2022 and the time of filing of this Amendment No. 1, 10 complaints were filed in the United States District Court for
the Southern District of New York, the United States District Court for the Northern District of California, the United States District Court for the Eastern District of New York, the United States District Court for the District of Delaware and the
United States District Court for the Eastern District of Pennsylvania by putative stockholders of Zogenix: Wang v. Zogenix, Inc., No. 1:22-cv-00900 (S.D.N.Y.);
Barman v. Zogenix, Inc., No. 4:22-cv-00719 (N.D. Cal.); Finuliar v. Zogenix, Inc., No.
1:22-cv-01051 (S.D.N.Y.) (the Finuliar Action); Hansen v. Zogenix, Inc., No.
1:22-cv-00679 (E.D.N.Y.); Ciccotelli v. Zogenix, Inc., No. 1:22-cv-00172 (D. Del.)
(the Ciccotelli Action); Eiden v. Zogenix, Inc., No. 1:22-cv-01108 (S.D.N.Y.); Wheeler v. Zogenix, Inc., No. 1:22-cv-00183 (D. Del.); Wilhelm v. Zogenix, Inc., No. 1:22-cv-00185 (D. Del.); Justice v. Zogenix, Inc., No. 2:22-cv-00545 (E.D. Pa.); and Kelly v. Zogenix, Inc., No. 1:22-cv-01184 (S.D.N.Y.)
(collectively, the Complaints). All of the Complaints name Zogenix and the members of the Zogenix Board as defendants, and the complaint in the Ciccotelli Action also names Parent and Purchaser as defendants. The Complaints assert
violations of Sections 14 and 20(a) of the Securities Exchange
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