This Amendment No. 3 to Schedule 14D-9 (this
“Amendment”) amends and supplements the Solicitation/Recommendation Statement on Schedule 14D-9 previously filed by Apellis Pharmaceuticals, Inc., a Delaware corporation
(“Apellis”), with the U.S. Securities and Exchange Commission (the “SEC”) on April 14, 2026 (together with any exhibits and annexes thereto and as amended or supplemented from time to time, the “Schedule 14D-9”). The Schedule 14D-9 relates to the Tender Offer Statement on Schedule TO filed with the SEC on April 14, 2026 (together with any
amendments and supplements thereto, the “Schedule TO”) by Biogen Inc., a Delaware corporation (“Biogen”), and Aspen Purchaser Sub, Inc., a Delaware corporation and wholly owned subsidiary of Biogen (“Purchaser”).
The Schedule TO relates to the tender offer by Purchaser to purchase all of the outstanding shares of common stock, par value $0.0001 per share (“Shares”), of Apellis in exchange for (i) $41.00 per Share, net to the seller in cash,
without interest and subject to reduction for any applicable tax withholding, plus (ii) one contractual, non-transferable contingent value right per Share representing the right
to receive contingent cash payments of up to an aggregate of $4.00 in cash, without interest and subject to reduction for any applicable tax withholding, upon the achievement of certain specified milestones in accordance with the terms and
conditions of a contingent value rights agreement to be entered into by and among Biogen, Apellis and a rights agent mutually acceptable to Biogen and Apellis, in each case, upon the terms and subject to the conditions set forth in the Offer to
Purchase dated April 14, 2026 (together with any amendments and supplements thereto, the “offer to purchase”) and in the related Letter of Transmittal (as it may be amended or supplemented from time to time), copies of which were
incorporated by reference into the Schedule 14D-9 as Exhibits (a)(1)(A) and (a)(1)(B), respectively. Terms used, but not otherwise defined, in this Amendment shall have the meanings ascribed to them in the
Schedule 14D-9.
Except as set forth below, the information set forth in the Schedule 14D-9 remains unchanged
and is incorporated herein by reference as relevant to the items in this Amendment.
Item 8. Additional Information.
Item 8 of the Schedule 14D-9 is hereby amended and supplemented by adding the following text immediately before the
section entitled “—Cautionary Note Regarding Forward-Looking Statements”:
“Final Results of the Offer
The offer and related withdrawal rights expired as scheduled at one minute after 11:59 p.m., Eastern Time, on May 13, 2026 (the “expiration
time”), and the offer was not extended. Equiniti Trust Company, LLC, the depositary for the offer, advised Purchaser that, immediately prior to the expiration time, a total of 105,687,831 Shares were validly tendered (and not validly
withdrawn) pursuant to the offer, representing approximately 82.4% of the Shares outstanding immediately prior to the expiration time.
As of the
expiration time, the number of Shares validly tendered (and not validly withdrawn) pursuant to the offer (excluding Shares tendered pursuant to guaranteed delivery procedures that have not yet been “received”, as such term is defined by
Section 251(h)(6)(f) of the DGCL), together with any Shares beneficially owned by Biogen or any of its subsidiaries, satisfied the minimum condition that, immediately prior to the expiration time, the number of Shares validly tendered and not
validly withdrawn (excluding shares tendered pursuant to guaranteed delivery procedures that have not yet been “received,” as such term is defined by Section 251(h)(6)(f) of the DGCL), together with any Shares beneficially owned by
Biogen or any of its subsidiaries, equaled at least one share more than fifty percent (50%) of the Shares then outstanding. All other conditions to the consummation of the offer having been satisfied or waived, on May 14, 2026, Purchaser
irrevocably accepted for payment all Shares that were validly tendered (and not validly withdrawn) pursuant to the offer, and payment for such Shares will be made promptly in accordance with the terms of the offer and the merger agreement.
Following the expiration time and acceptance for payment of the Shares, the remaining conditions to the merger set forth in the merger agreement were
satisfied or waived, and Purchaser expects to consummate the merger on May 14, 2026 in accordance with Section 251(h) of the DGCL without a vote of the stockholders of Apellis. At the effective time, Purchaser will merge with and into
Apellis, the separate existence of Purchaser will cease and Apellis will continue as the surviving corporation in the merger and a wholly owned subsidiary of Biogen. Pursuant to the merger agreement, at the effective time, each Share issued and
outstanding immediately prior to the effective time (other than Shares that are (i) held in the treasury of Apellis, (ii) irrevocably accepted for purchase in the offer by Purchaser and “received” (as such term is defined by
Section 251(h)(6)(f) of the DGCL) by Purchaser, (iii) held by Biogen, Purchaser or any other wholly owned subsidiary of Biogen as of both the commencement of the offer and immediately prior to the effective time or (iv) held by
stockholders who were entitled to, and properly demanded, appraisal for such Shares in accordance with Section 262 of the DGCL) will be converted into the right to receive the merger consideration, without interest and subject to reduction for
any applicable withholding taxes.
