Notice of Delisting or Failure to Satisfy a Continued Listing Rule or Standard; Transfer of Listing. The disclosures in the Introductory Note are incorporated herein by reference. On September 3, 2026, the Company (i) notified the Nasdaq Global Market (“Nasdaq”) of the consummation of the Merger and its intent to remove all Company Common Stock from Nasdaq and (ii) requested that Nasdaq (A) maintain the halt in trading of Company Common Stock, which was effective following the closing of afte…

Changes in Control of Registrant. The disclosures under the Introductory Note, Item 2.01, Item 3.01, Item 3.03,

are incorporated herein by reference. In connection with the Merger and effective as of, and contingent upon, the Effective Time, all of the Company’s directors (Michael Henderson, M.D., Mark C. McKenna, Lisa Bollinger, M.D., Jennifer Fox, William (BJ) Jones, Jr., Tomas Kiselak and Nimish Shah) voluntarily resigned from the Company’s board of directors and the directors of Merger Sub immediately prior to the Effective Time became the directors of the Company. In addition, as of the Effective…

Termination of a Material Definitive Agreement. Effective as of the Effective Time, the Company terminated the Company’s 2023 Equity Incentive Plan and 2023 Employee Stock Purchase Plan.

Material Modification to Rights of Security Holders. The disclosures under the Introductory Note, Item 3.01,

The provided text is only the standard Item 5.02 header and introductory fragment, containing no specific details about a person, role, or action to classify.

Director: The resignations are routine and conditioned on the consummation of a previously announced merger, not a sudden departure or disagreement.

Results of Operations and Financial Condition. On August 10, 2026, Apogee Therapeutics, Inc. (the “Company”) issued a press release providing a business update and announcing its financial results for the quarter ended June 30, 2026 (the “Earnings Press Release”). A copy of the Earnings Press Release is furnished as Exhibit 99.1 to this Current Report on Form 8-K (the “Form 8-K”) and is incorporated by reference herein. The exhibit furnished under

Entry into a Material Definitive Agreement. IL-31R Antibody Discovery Agreement On June 17, 2026, Apogee Therapeutics, Inc. (the “Company”) entered into an antibody discovery agreement with Paragon Therapeutics, Inc. (“Paragon,” and the antibody discovery agreement between the Company and Paragon, the “IL-31R Discovery Agreement”). Under the terms of the IL-31R Discovery Agreement, Paragon generates and characterizes monospecific antibody candidates directed to interleukin 31 receptor (IL-31R…

Entry into a Material Definitive Agreement. Agreement and Plan of Merger On June 18, 2026, Apogee Therapeutics, Inc. (the “Company” or “Apogee”) entered into an Agreement and Plan of Merger (the “Merger Agreement”) with Andor LLC, a Delaware limited liability company and a wholly owned subsidiary of Guarantor (“Parent”), Andor Merger Co., a Delaware corporation and a wholly owned subsidiary of Parent (“Merger Sub”), and solely for the limited purposes set forth therein, AbbVie Inc., a Delawar…

Entry into a Material Definitive Agreement. Revenue Participation Right Purchase and Sale Agreement On May 26, 2026 (the “Effective Date”), Apogee Therapeutics, Inc. (the “Company”) entered into a revenue participation right purchase and sale agreement (the “Revenue Share Agreement”) with Annapurna Aggregator L.P., an affiliate of funds managed by Blackstone Life Sciences (“BXLS”). Pursuant to the Revenue Share Agreement, in exchange for an upfront payment of $100.0 million (the “Tranche 1 Fu…

Results of Operations and Financial Condition. On May 11, 2026, Apogee Therapeutics, Inc. (the “Company”) issued a press release providing a business update and announcing its financial results for the quarter ended March 31, 2026 (the “Earnings Press Release”). A copy of the Earnings Press Release is furnished as Exhibit 99.1 to this Current Report on Form 8-K (the “Form 8-K”) and is incorporated by reference herein. The exhibit furnished under

Director — Andrew Gottesdiener, M.D., Peter Harwin: Dr. Gottesdiener and Mr. Harwin resigned from the Board of Directors.

Entry into a Material Definitive Agreement. On March 24, 2026, Apogee Therapeutics, Inc. (the “Company”) entered into an underwriting agreement (“Underwriting Agreement”) with Jefferies LLC, TD Securities (USA) LLC, Stifel, Nicolaus & Company, Incorporated and Guggenheim Securities, LLC, as the representatives of the Underwriters named therein (the “Underwriters”), to issue and sell 5,000,000 shares of the Company’s common stock at a public offering price of $70.00 per share (the “Offering”).…

Results of Operations and Financial Condition. On March 2, 2026, Apogee Therapeutics, Inc. (the “Company”) issued a press release providing a business update and announcing its financial results for the year ended December 31, 2025 (the “Earnings Press Release”). A copy of the Earnings Press Release is furnished as Exhibit 99.1 to this Current Report on Form 8-K (the “Form 8-K”) and is incorporated by reference herein. The exhibit furnished under

Results of Operations and Financial Condition. On November 10, 2025, Apogee Therapeutics, Inc. (the “Company”) issued a press release announcing its financial results for the quarter ended September 30, 2025 (the “Earnings Press Release”). A copy of the Earnings Press Release is furnished as Exhibit 99.1 to this Current Report on Form 8-K (the “Form 8-K”) and is incorporated by reference herein. The exhibit furnished under

Entry into a Material Definitive Agreement. On October 8, 2025, Apogee Therapeutics, Inc. (the “Company”) entered into an underwriting agreement (“Underwriting Agreement”) with Jefferies LLC, BofA Securities, Inc., Guggenheim Securities, LLC and TD Securities (USA) LLC, as the representatives of the underwriters named therein (the “Underwriters”), to issue and sell 6,951,221 shares of the Company’s common stock at a public offering price of $41.00 per share and, in lieu of common stock to cer…

of this Form 8-K shall not be deemed to be “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), or otherwise subject to the liabilities of that section, nor shall it be deemed incorporated by reference in any filing under the Exchange Act or the Securities Act of 1933, as amended (the “Securities Act”), regardless of any general incorporation language in such filing.

Other Events. On July 7, 2025, the Company announced (1) positive 16-week data from Part A of the Phase 2 APEX clinical trial of APG777, its potentially best-in-class anti-IL-13 antibody, in patients with moderate-to-severe AD, and (2) that the first patient has been dosed in its Phase 1b head-to-head trial of APG279 (IL-13 + OX40L) in patients with moderate-to-severe AD, in comparison to DUPIXENT, with readout expected in the second half of 2026. APEX Phase 2 Part A Key 16-Week Results The P…

of this Form 8-K shall not be deemed to be “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), or otherwise subject to the liabilities of that section, nor shall it be deemed incorporated by reference in any filing under the Exchange Act or the Securities Act of 1933, as amended (the “Securities Act”), regardless of any general incorporation language in such filing.

Entry into a Material Definitive Agreement. On March 10, 2025, Apogee Therapeutics, Inc. (the “Company” or “Apogee”) entered into a Master Services Agreement (“MSA”), made effective as of February 28, 2025, with Samsung Biologics Co., Ltd. (“Samsung”), pursuant to which Samsung will manufacture and supply Apogee with APG777 drug substance (“Product”) for clinical development and commercial sale, if approved. The Company is obligated to pay Samsung service fees for each manufactured batch, as…

of this Current Report on Form 8-K shall not be deemed to be “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), or otherwise subject to the liabilities of that section, nor shall it be deemed incorporated by reference in any filing under the Exchange Act or the Securities Act of 1933, as amended (the “Securities Act”), regardless of any general incorporation language in such filing.

Other Events On February 3, 2025, the Company announced that the first patient has been dosed in the Part B portion of the Phase 2 APEX clinical trial of APG777 in patients with moderate-to-severe AD, and that enrollment has been completed in the Part A portion of the trial. APEX is a Phase 2 randomized, placebo-controlled clinical trial evaluating APG777, a novel, subcutaneous extended half-life monoclonal antibody targeting IL-13 – a critical cytokine in inflammation and a primary driver of…

Other Events. On December 10, 2024, the Company announced that it has initiated dosing of healthy volunteers in its clinical trial for APG333, a novel, subcutaneous half-life extended monoclonal antibody targeting thymic stromal lymphopoietin, which is being evaluated initially as a treatment for people living with asthma, COPD and broader I&I conditions. The APG333 Phase 1 clinical trial is designed as a double-blind, placebo controlled, first-in-human, single-ascending dose trial in healthy…

of this Current Report on Form 8-K shall not be deemed to be “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), or otherwise subject to the liabilities of that section, nor shall it be deemed incorporated by reference in any filing under the Exchange Act or the Securities Act of 1933, as amended, regardless of any general incorporation language in such filing.