Werewolf Therapeutics SEC filings document material events, operating results, governance matters, and capital-structure disclosures for a Delaware biopharmaceutical company developing conditionally activated immune therapeutics. Recent 8-K filings furnish quarterly financial results, press-release exhibits, and updates tied to the company’s PREDATOR, INDUKINE, and INDUCER programs.
The filings also cover Nasdaq continued-listing matters, audit committee composition, exit and disposal activities, emerging growth company status, common stock registered under the HOWL symbol, shareholder voting matters, clinical and regulatory disclosures, and risk language related to strategy, operations, development plans, and corporate alternatives.
Werewolf Therapeutics, Inc. (HOWL) reported insider stock sales by an affiliated director and 10% owner. Investment entities associated with MPM BioImpact LLC filed a Form 4 showing automatic sales of common stock under a Rule 10b5-1 trading plan dated September 24, 2025. On November 13, 2025, they sold 90,951 shares at a weighted average price of $0.98 per share, followed by 61,640 shares at $0.93 on November 14 and 57,061 shares at $0.95 on November 17. After these transactions, the group reported indirect beneficial ownership of 5,481,539 shares held across several MPM-managed funds, while disclaiming beneficial ownership beyond their economic interest. This filing is one of two identical submissions due to limits on the number of reporting persons.
Werewolf Therapeutics, Inc. (HOWL) director and 10% owner affiliated with MPM BioImpact reported planned insider stock sales. The filing covers three open‑market sales of Werewolf common stock executed under a Rule 10b5-1 trading plan dated September 24, 2025.
On November 13, 2025, the reporting group sold 90,951 shares at a weighted average price of $0.98. On November 14, 2025, they sold 61,640 shares at a weighted average price of $0.93, and on November 17, 2025, they sold 57,061 shares at a weighted average price of $0.95. Each day’s trades occurred across multiple prices within disclosed ranges.
After these transactions, the group reports indirect beneficial ownership of 5,481,539 Werewolf shares held through several affiliated investment vehicles, including MPM Asset Management LLC, MPM BioVentures 2014 funds, MPM Oncology Innovations Fund, and UBS Oncology Impact Fund.
Werewolf Therapeutics (HOWL) — Form 4 insider activity: Director Luke Evnin reported open‑market sales of company common stock executed under a Rule 10b5‑1 trading plan dated September 24, 2025. Sales occurred on four dates: 11/07/2025 (43,950 shares at a weighted average price of $1.11), 11/10/2025 (31,172 at $1.18), 11/11/2025 (35,818 at $1.14), and 11/12/2025 (26,101 at $1.09).
Following these transactions, the reported indirect beneficial holdings were updated to 3,743,524; 3,712,352; 3,676,534; and 3,650,433 shares, respectively. The holdings are indirect through affiliated entities (including AM LLC, BV 2014, BV 2014(B), AM BV2014, and MPM OIF), with a stated disclaimer of beneficial ownership beyond pecuniary interest.
Werewolf Therapeutics (HOWL): affiliated reporting persons led by MPM entities, identified as a director and 10% owner, reported open‑market sales executed under a Rule 10b5‑1 plan dated September 24, 2025. Sales occurred on November 7–12, 2025 across four days totaling 213,529 shares.
Disclosed transactions: 68,480 shares on 11/07 at a weighted average price of $1.11; 48,570 on 11/10 at $1.18; 55,810 on 11/11 at $1.14; and 40,669 on 11/12 at $1.09. Following these trades, the group reported 5,691,191 shares beneficially owned, held indirectly across multiple MPM-managed entities. Price ranges for the weighted averages were provided for each day, and the filing notes it is one of two identical filings due to reporting person limits.
Werewolf Therapeutics (HOWL): A director and 10% owner affiliated with MPM entities reported open‑market sales totaling 213,529 shares across 11/07–11/12/2025 under a Rule 10b5‑1 plan dated September 24, 2025. Weighted average prices by day were $1.11, $1.18, $1.14 and $1.09, with disclosed trade ranges spanning $1.065 to $1.21. Following these transactions, indirect beneficial ownership was 5,691,191 shares.
Werewolf Therapeutics (HOWL) director Luke Evnin reported open‑market sales totaling 155,885 shares on November 4–6, 2025 under a Rule 10b5‑1 trading plan established on September 24, 2025.
Weighted‑average sale prices were $1.22 on Nov 4 (range $1.17–$1.30), $1.22 on Nov 5 (range $1.19–$1.25), and $1.21 on Nov 6 (range $1.185–$1.27). Following these transactions, indirect beneficial holdings were 3,787,474 shares, held across multiple MPM‑affiliated entities. The filing notes the reporting person disclaims beneficial ownership except to the extent of pecuniary interest.
Werewolf Therapeutics (HOWL): Insider transactions disclosed. An affiliated group led by MPM BioImpact reported open‑market sales of common stock on three dates under a Rule 10b5‑1 plan dated September 24, 2025.
Across 11/04/2025, 11/05/2025, and 11/06/2025, the group sold a combined 242,890 shares, at weighted‑average prices of $1.22, $1.22, and $1.21, respectively. Reported price ranges were $1.17–$1.30, $1.19–$1.25, and $1.185–$1.27. Following these transactions, the reporting persons indirectly beneficially owned 5,904,720 shares.
The filing notes the reporting person is a director and 10% owner, and that sales were allocated among affiliated entities including MPM Asset Management LLC, MPM BioVentures 2014, L.P., MPM BioVentures 2014(B), L.P., MPM Asset Management Investors BV2014 LLC, MPM Oncology Innovations Fund, L.P., and UBS Oncology Impact Fund L.P.
Werewolf Therapeutics (HOWL) reported insider stock sales by affiliated reporting persons. The group executed open‑market sales under a Rule 10b5‑1 plan dated September 24, 2025. Transactions included 140,488 shares on November 4 at a weighted average price of $1.22, 47,950 shares on November 5 at $1.22, and 54,452 shares on November 6 at $1.21.
Following these trades, the reporting persons collectively reported 5,904,720 shares beneficially owned on an indirect basis. The filing indicates the reporting persons are a director and 10% owner, and that the submission was made by more than one reporting person.
Werewolf Therapeutics (HOWL) filed its Q3 2025 report, highlighting continued operating losses and a liquidity warning. The company reported a Q3 net loss of $16.4 million and a nine‑month net loss of $52.4 million. Revenue was $0 for the quarter and year‑to‑date, following prior collaboration revenue in 2024.
Cash and cash equivalents were $65.7 million as of September 30, 2025, down from $111.0 million at year‑end 2024, after $49.3 million used in operating activities year‑to‑date. Management states there is substantial doubt about the company’s ability to continue as a going concern and is evaluating options to raise additional capital. The company sold 2,360,186 shares via its ATM for net proceeds of $3.6 million in the first nine months.
R&D expense was $11.6 million and G&A was $4.1 million in Q3. Debt includes a $30.0 million K2HV term loan at a coupon of 10.3% (effective rate disclosed at 19.24%) and a related derivative liability of $2.6 million. Clinical programs continue: WTX‑124 is in Phase 1/1b with planned interim data in Q4 2025, and WTX‑330 has advanced to Phase 1b/2 with an update also planned in Q4 2025.
Werewolf Therapeutics furnished a press release announcing financial results for the quarter ended September 30, 2025.
The company reported this under Item 2.02 of an 8-K on November 4, 2025, and stated the information, including Exhibit 99.1, is furnished and not deemed filed under the Exchange Act.
The filing also includes a caution regarding forward-looking statements.