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 reported new data from its INDUKINE™ pipeline and outlined priorities for 2026. For WTX-124, Phase 1/1b data as of October 2025 showed objective, durable responses as a monotherapy in several solid tumors and in combination with pembrolizumab. In heavily pretreated advanced cutaneous melanoma, monotherapy delivered a 21% objective response rate, rising to 30% in patients who had previously responded to immunotherapy, with no vascular leak syndrome and limited high-grade side effects. The FDA accepted 18 mg as the recommended dose and provided initial guidance for a monotherapy registration path in relapsed or refractory melanoma after immune checkpoint inhibitors.
For WTX-330, Phase 1b/2 data in the first twelve patients showed favorable tolerability and antitumor activity using an optimized manufacturing process that improved safety, pharmacokinetics, and therapeutic index. At 0.024 mg/kg IV twice weekly, WTX-330 reached a 17-fold higher Cmax than published rhIL-12 with only 0.12% free IL-12, and there was a confirmed partial response in metastatic gall bladder cancer with a 45% tumor reduction. Werewolf plans additional WTX-124 and WTX-330 data in the first half of 2026, is seeking strategic partnerships, and notes that further development and planned INDs for INDUCER T-cell engager candidates WTX-1011 and WTX-2022 will require additional funding.
Werewolf Therapeutics director Luke Evnin reported selling shares of the company’s common stock in three transactions carried out under a Rule 10b5-1 trading plan dated September 24, 2025. On December 15, 2025, affiliated investment entities sold a total of 23,640 shares at a weighted average price of $1.07. On December 16, 2025, they sold 14,548 shares at a weighted average price of $1.05, and on December 17, 2025, they sold 9,983 shares at a weighted average price of $1.14. Following these sales, Evnin reported 2,841,957 shares of Werewolf Therapeutics common stock beneficially owned indirectly through several MPM-managed entities.
Werewolf Therapeutics director Luke Evnin reported insider sales of the company’s common stock in mid-December 2025. On December 10, he reported selling 37,104 shares at a weighted average price of $1.06 per share through MPM-affiliated investment entities. On December 11 and 12, he reported additional sales of 28,009 and 17,858 shares at weighted average prices of $1.07 and $1.08, respectively, each executed in multiple trades within disclosed price ranges. These transactions were carried out under a Rule 10b5-1 trading plan dated September 24, 2025, and after the reported sales he indicated indirect beneficial ownership of 2,890,128 shares held across several MPM-managed funds.
Werewolf Therapeutics director reports planned stock sales
Luke Evnin, a director of Werewolf Therapeutics, Inc. (HOWL), reported three sales of common stock made under a Rule 10b5-1 trading plan dated September 24, 2025. On November 21, 2025, affiliated investment entities sold a total of 41,287 shares at a weighted average price of $0.83 per share. On November 24, 2025, they sold 56,992 shares at a weighted average price of $0.98 per share, and on November 25, 2025, they sold 27,297 shares at a weighted average price of $0.92 per share.
After these transactions, entities associated with Evnin beneficially owned a total of 3,287,551 HOWL shares across several MPM-managed funds and vehicles. The filing states that Evnin disclaims beneficial ownership of these securities except to the extent of his pecuniary interest.
Werewolf Therapeutics, Inc. (HOWL) reported insider stock sales by entities affiliated with MPM BioImpact, which is identified as a director and 10% owner group. On 11/21/2025, these affiliated funds sold 64,331 shares of common stock at a weighted average price of $0.83. On 11/24/2025, they sold another 88,802 shares at a weighted average price of $0.98, and on 11/25/2025 they sold 42,533 shares at a weighted average price of $0.92. The filing states that these trades were made under a Rule 10b5-1 trading plan dated September 24, 2025. After these transactions, the reporting group collectively held 5,125,770 shares of Werewolf Therapeutics common stock through various affiliated investment vehicles.
Werewolf Therapeutics, Inc. (HOWL) insider filing shows planned share sales by MPM-affiliated funds. A reporting group connected to MPM BioImpact and related investment vehicles sold 64,331 shares of common stock on 11/21/2025 at a weighted average price of $0.83, 88,802 shares on 11/24/2025 at $0.98, and 42,533 shares on 11/25/2025 at $0.92.
The sales were executed under a Rule 10b5-1 trading plan dated September 24, 2025, which is designed to pre-arrange trades. After these transactions, the reporting persons collectively report indirect beneficial ownership of 5,125,770 HOWL shares through several affiliated funds.
Werewolf Therapeutics director Luke Evnin reported a series of open-market sales of the company’s common stock under a pre-established Rule 10b5-1 trading plan dated September 24, 2025. On November 18, 2025, affiliated funds sold 33,776 shares at a weighted average price of $0.93, leaving 3,482,104 shares beneficially owned indirectly. On November 19, 2025, they sold 42,566 shares at a weighted average price of $0.94, leaving 3,439,538 shares. On November 20, 2025, they sold 26,411 shares at a weighted average price of $0.89, leaving 3,413,127 shares. The filing explains that the shares are held through various MPM-affiliated entities and that Evnin disclaims beneficial ownership beyond his pecuniary interest.
Werewolf Therapeutics, Inc. (HOWL) reported insider activity by MPM-affiliated entities on a Form 4. Investment vehicles associated with MPM BioImpact and related funds, which are reported as a director and 10% owner group, sold Werewolf Therapeutics common stock on three days under a pre-arranged Rule 10b5-1 trading plan dated September 24, 2025.
The group sold 52,627 shares on November 18, 2025 at a weighted average price of $0.93, 66,324 shares on November 19, 2025 at a weighted average price of $0.94, and 41,152 shares on November 20, 2025 at a weighted average price of $0.89. After these sales, they reported indirect beneficial ownership of 5,321,436 shares held across several MPM-managed entities, including MPM Asset Management LLC, MPM BioVentures 2014 funds, MPM Oncology Innovations Fund and UBS Oncology Impact Fund, with each reporting person disclaiming beneficial ownership beyond its pecuniary interest.
Werewolf Therapeutics, Inc. (HOWL) reported insider transactions by entities affiliated with MPM BioImpact LLC, which is identified as a director and 10% owner. Over three days, from 11/18/2025 to 11/20/2025, these reporting persons sold a total of 160,103 shares of common stock in open-market transactions. The weighted average sale prices were around $0.93 on 11/18, $0.94 on 11/19, and $0.89 on 11/20, with detailed price ranges provided for each day. After these sales, the reporting group continued to beneficially own 5,321,436 shares of Werewolf Therapeutics indirectly through multiple affiliated investment vehicles. The filing notes that the trades were executed under a Rule 10b5-1 trading plan dated September 24, 2025.
Werewolf Therapeutics (HOWL) director Luke Evnin reported a series of planned insider stock sales under a Rule 10b5-1 trading plan. On 11/13/2025, affiliated MPM entities sold 58,372 shares of common stock at a weighted average price of $0.98. On 11/14/2025, they sold 39,560 shares at a weighted average price of $0.93, and on 11/17/2025, they sold 36,621 shares at a weighted average price of $0.95. After these transactions, Evnin reported 3,515,880 shares of HOWL common stock beneficially owned indirectly through various MPM investment vehicles. The filing notes that prices are reported as weighted averages for multiple trades within specified price ranges.