Entry into a Material Definitive Agreement Merger Agreement On August 21, 2026, Werewolf Therapeutics, Inc., a Delaware corporation (“Werewolf”), entered into an Agreement and Plan of Merger (the “Merger Agreement”) by and among Ambros Therapeutics, Inc., a Delaware corporation (“Ambros”), Werewolf, and Wave Atlantis Merger Sub, Inc., a Delaware corporation and a direct, wholly owned subsidiary of Werewolf (“Merger Sub”). Pursuant to the Merger Agreement, and upon the terms and subject to the…

Unregistered Sales of Equity Securities To the extent required by this Item, the information included in

Entry into a Material Definitive Agreement. On August 14, 2026 (the “Closing”), Werewolf Therapeutics, Inc. (the “Company”) entered into an asset purchase agreement (the “Purchase Agreement”) with EMD Serono Research & Development Institute Inc. (“EMD”), pursuant to which, and subject to the terms and conditions thereof, the Company sold to EMD (the “Asset Sale”) technology comprising (i) its pre-clinical INDUCER platform, including all patents and know-how related thereto, pre-clinical compo…

in this Current Report on Form 8-K, including Exhibit 99.1, shall not be deemed “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 Securities Act of 1933, as amended, or the Exchange Act, except as expressly set forth by specific reference in such a filing.

in this Current Report on Form 8-K, including Exhibit 99.1, shall not be deemed “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 Securities Act of 1933, as amended, or the Exchange Act, except as expressly set forth by specific reference in such a filing.

in this Current Report on Form 8-K, including Exhibit 99.1, shall not be deemed “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 Securities Act of 1933, as amended, or the Exchange Act, except as expressly set forth by specific reference in such a filing.

Chief Financial Officer and Chief Medical Officer — Timothy W. Trost and Dr. Randi Isaacs: The CFO and CMO resigned as part of a reduction, with severance benefits and consulting agreements.

is being furnished and shall not be deemed “filed” for the purposes of Section 18 of 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 Securities Act of 1933, as amended, or the Exchange Act, except as expressly set forth by specific reference in such a filing. Cautionary Note Regarding Forward-Looking Statements This Current Report on Form 8-K contains forward-looking statements that involve sub…

Costs Associated with Exit or Disposal Activities. On February 9, 2026, the board of directors (the “Board”) of Werewolf Therapeutics, Inc. (the “Company”) approved a reduction in force, representing 64% of the Company’s workforce (the “Reduction”). The Company expects the Reduction to be substantially completed by February 13, 2026. The Company is undertaking the Reduction to decrease operating expenses. As a result of the Reduction, the Company estimates that it will record a one-time charg…

Notice of Delisting or Failure to Satisfy a Continued Listing Rule or Standard; Transfer of Listing. On February 4, 2026, Werewolf Therapeutics, Inc. (the “Company”) received a deficiency letter (the “Notice”) from the Listing Qualifications Department (the “Staff”) of the Nasdaq Stock Market, LLC (“Nasdaq”) notifying the Company that, for the last 30 consecutive business days, the bid price for the Company’s common stock had closed below $1.00 per share, which is the minimum bid price requir…

Other Events. Press Release On December 18, 2025, Werewolf Therapeutics, Inc. (the “Company” or “Werewolf”) issued a press release announcing a pipeline update, including a review of recent data for its INDUKINE ™ programs, and a business overview of its priorities for 2026 that includes a focus on the Company’s highly differentiated INDUCER T-cell engager platform. The Company is seeking strategic partnerships for further development of the promising WTX-124 and WTX-330 INDUKINE programs, in…

in this Current Report on Form 8-K, including Exhibit 99.1, shall not be deemed “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 Securities Act of 1933, as amended, or the Exchange Act, except as expressly set forth by specific reference in such a filing.

Notice of Delisting or Failure to Satisfy a Continued Listing Rule or Standard; Transfer of Listing. Werewolf Therapeutics, Inc. (the “Company”) is saddened to report that Dr. Alon Lazarus, Ph.D., a member of the Company’s Board of Directors (the “Board”), passed away on September 30, 2025. Dr. Lazarus joined the Company’s Board in August 2019 and served as Chair of the Compensation Committee and as a member of the Audit Committee. The Company is grateful for Dr. Lazarus’s dedication and serv…

in this Current Report on Form 8-K, including Exhibit 99.1, shall not be deemed “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 Securities Act of 1933, as amended, or the Exchange Act, except as expressly set forth by specific reference in such a filing.

Notice of Delisting or Failure to Satisfy a Continued Listing Rule or Standard; Transfer of Listing. On May 13, 2025, Werewolf Therapeutics, Inc. (the “Company”) received a deficiency letter (the “Notice”) from the Listing Qualifications Department (the “Staff”) of the Nasdaq Stock Market, LLC (“Nasdaq”) notifying the Company that, for the last 30 consecutive business days, the bid price for the Company’s common stock had closed below $1.00 per share, which is the minimum bid price required t…

in this Current Report on Form 8-K, including Exhibit 99.1, shall not be deemed “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 Securities Act of 1933, as amended, or the Exchange Act, except as expressly set forth by specific reference in such a filing.

in this Current Report on Form 8-K (including Exhibit 99.1) shall not be deemed “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 Securities Act of 1933, as amended, or the Exchange Act, except as expressly set forth by specific reference in such a filing.

Director — Derek DiRocco, M.D.: Dr. DiRocco resigned from the Board of Directors.

in this Current Report on Form 8-K (including Exhibit 99.1) shall not be deemed “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 Securities Act of 1933, as amended, or the Exchange Act, except as expressly set forth by specific reference in such a filing.

in this Current Report on Form 8-K (including Exhibit 99.1) shall not be deemed “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 Securities Act of 1933, as amended, or the Exchange Act, except as expressly set forth by specific reference in such a filing.

in this Current Report on Form 8-K (including Exhibit 99.1) shall not be deemed “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 Securities Act of 1933, as amended, or the Exchange Act, except as expressly set forth by specific reference in such a filing.

Chief Scientific Officer — Cynthia Seidel-Dugan, Ph.D.: Dr. Cynthia Seidel-Dugan retired from her position as Chief Scientific Officer.

in this Current Report on Form 8-K (including Exhibit 99.1) shall not be deemed “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 Securities Act of 1933, as amended, or the Exchange Act, except as expressly set forth by specific reference in such a filing.

Other Events. Prospectus Supplement Filing On February 9, 2024, Werewolf Therapeutics, Inc. (the “Company”) filed a prospectus supplement (the “Prospectus Supplement”) under the Company’s universal shelf registration statement on Form S-3 (File No. 333-264844) that was originally filed with the Securities and Exchange Commission (the “SEC”) on May 10, 2022 and declared effective by the SEC on May 20, 2022 (the “Registration Statement”), relating to the offer and sale of a total of up to $25.0…

Director — Michael B. Atkins, M.D.: Dr. Michael B. Atkins was appointed as a director and member of the Nominating and Corporate Governance Committee.