Amendment: SEC Form SCHEDULE 13D/A filed by Apogee Therapeutics Inc.

Item 4 of the Schedule 13D is hereby amended and supplemented by adding the following at the end thereof: Merger Agreement and Voting Agreement On June 18, 2026, Andor LLC ("Parent"), a Delaware limited liability company and a wholly owned subsidiary of AbbVie Inc. ("Guarantor"), Andor Merger Co. ("Merger Sub"), a Delaware corporation and a wholly owned subsidiary of Parent, the Company and Guarantor (solely for limited purposes) entered into an Agreement and Plan of Merger (the "Merger Agreement"), pursuant to which Merger Sub will merge with and into the Company (the "Merger"), with the Company surviving the Merger as a wholly owned subsidiary of Parent. Pursuant to the Merger Agreement, at the effective time of the Merger (the "Effective Time"), each share of Common Stock issued and outstanding immediately prior to the effective time of the Merger (other than certain excluded shares) will be cancelled and converted into the right to receive $135.11 per Share in cash, without interest (the "Merger Consideration"). The consummation of the Merger is subject to customary conditions, including (a) the affirmative vote of the holders of a majority of the outstanding shares of Common Stock, par value $0.00001 per share the ("Required Company Voting Stockholder Approval"), and (b) for so long as at least 6,061,821 shares of Non-Voting Common Stock, par value $0.00001 per share remain issued and outstanding, the affirmative vote or written consent of the holders of a majority of the outstanding shares of Non-Voting Common Stock, (the "Required Non-Voting Stockholder Approval", together with the Required Company Voting Stockholder Approval, the "Required Company Stockholder Approvals"). Concurrently with the execution of the Merger Agreement, on June 18, 2026, Fund II entered into a Voting Agreement (the "Voting Agreement") with Guarantor, Parent and Merger Sub. Pursuant to the Voting Agreement, Fund II agreed, among other things, to: (a) vote (or cause to be voted) all of its Subject Shares (as defined in the Voting Agreement) (i) in favor of (A) the adoption of the Merger Agreement and approval of the Merger, (B) any proposal to adjourn or postpone any meeting of stockholders at which the Merger Agreement is submitted for approval, (C) any other proposal necessary for consummation of the Merger, and (ii) against (A) any alternative acquisition transaction, (B) any action that would result in a breach of the Company's obligations under the Merger Agreement, (C) any change in the membership of the Company's board of directors not recommended by the Company's board, and (D) any other action intended or expected to impede the Merger; (b) grant an irrevocable proxy to Parent as attorney-in-fact in the event Fund II fails to deliver a proxy card at least two (2) business days prior to the applicable meeting of stockholders; (c) not Transfer (as defined in the Voting Agreement) any Subject Shares, create any encumbrances on the Subject Shares, enter into any derivative arrangement with respect to the Subject Shares, grant any proxy or power-of-attorney with respect to the Subject Shares, deposit the Subject Shares into a voting trust, or take any other action that would reasonably be expected to prevent Fund II from performing its obligations under the Voting Agreement, subject to limited exceptions for Transfers to controlled Affiliates (provided such transferees execute a counterpart of the Voting Agreement); (d) not take any actions the Company is prohibited from taking under Section 5.3(a) of the Merger Agreement (relating to non-solicitation of alternative transactions); and (e) waive any appraisal or dissenters' rights (including under Section 262 of the DGCL) with respect to the Subject Shares in connection with the Merger. The Voting Agreement terminates automatically upon the first to occur of: (a) the valid termination of the Merger Agreement in accordance with its terms; (b) the Effective Time; (c) receipt of the Required Company Stockholder Approvals; (d) the End Date (as defined in the Voting Agreement); (e) any modification or amendment to the Merger Agreement that reduces the amount, changes the form or otherwise adversely affects the Merger Consideration; or (f) the mutual written consent of all parties thereto. In addition, concurrently with the execution of the Merger Agreement, Fund II delivered a written consent (the "Written Consent") approving the Merger for purposes of Section 4.2(b) of the Company's Certificate of Incorporation, which requires approval from the holders of a majority of the outstanding Non-Voting Common Stock for certain fundamental transactions. The foregoing descriptions of the Merger Agreement and the Voting Agreement do not purport to be complete and are qualified in their entirety by reference to the full text of the Merger Agreement and the Voting Agreement. The Voting Agreement is filed as Exhibit 99.2 to this Amendment No. 6 and is incorporated herein by reference. On June 22, 2026, the Company filed the Merger Agreement as an exhibit to a Current Report on Form 8-K. Resignation of Peter Harwin On May 11, 2026, Peter Harwin resigned from the Board of Directors of the Company. Mr. Harwin's resignation was not the result of any disagreement with the Company on any matter relating to the Company's operations, policies or practices.

The information in rows 11 and 13 of each of the cover pages (including the explanatory note in the "Comments") of this Amendment No. 6 is incorporated by reference herein.

The information in rows 7 through 10 of each of the cover pages of this Amendment No. 6 is incorporated by reference herein. In the aggregate, the Reporting Persons have voting and dispositive power over 6,790,369 shares of Common Stock, which is comprised of the following: (i) 298,647 shares of Common Stock held by Fund II; (ii) 6,274,593 shares of Common Stock issuable upon conversion of 6,274,593 shares of Non-Voting Common Stock, held by Fund II, reflecting the beneficial ownership limitation of 9.99% of the outstanding Common Stock; (iii) 51,166 shares of Common Stock held by Mr. Harwin; (iv) 42,208 shares of Common Stock underlying vested options held by Mr. Harwin; (v) 51,166 shares of Common Stock held by Mr. Kiselak; and (vi) 72,589 shares of Common Stock underlying vested options held by Mr. Kiselak. In total, Fund II currently owns 6,743,321 shares of Non-Voting Common Stock.

On June 17, 2026, Mr. Kiselak's stock options to purchase 14,461 shares of Common Stock at an exercise price of $41.66 per share, received as compensation for his service as a director of the Company, vested in full and became exercisable.

The information set forth and/or incorporated by reference in Item 4 is hereby incorporated by reference into this Item 6.

99.1 Joint Filing Agreement (incorporated by reference to Exhibit 99.1 to the Schedule 13D filed with the SEC on October 14, 2025) 99.2 Voting Agreement, dated June 18, 2026, by and among AbbVie Inc., Andor LLC, Andor Merger Co. and Fairmount Healthcare Fund II, L.P. (incorporated by reference to Exhibit 99.2 to the Company's Form 8-K filed with the SEC on June 22, 2026)