MPM ASSET MANAGEMENT LLC — SEC Form 4 filings
SEC reporting owner CIK 1263048. 11 Form 4 filings on record with FilingPulse; latest filed 2026-01-14.
Transaction summary — filings shown
Covers all 11 filings on record, filed 2025-04-30 to 2026-01-14. Counts and totals are arithmetic on values as filed — descriptive data, not a recommendation.
- Open-market purchases (code P, non-derivative): 1 leg across 1 filing — 1,112,777 shares, $20,029,986 total (shares × price as filed).
- Open-market sales (code S, non-derivative): 29 legs across 10 filings — 1,938,945 shares, $2,227,963 total (shares × price as filed).
- Other reported legs (grants, option exercises, tax withholding, gifts, derivative-security transactions, …): 9.
- Largest priced transaction: purchase of 1,112,777 shares @ $18.00 ($20,029,986) in Aktis Oncology, Inc., filed 2026-01-14.
By issuer — same filings
Open-market purchase/sale legs on non-derivative securities, grouped by issuer. Role is as filed on the newest filing for that issuer. Dollar totals cover priced legs only (shares × price as filed). Ordered by priced transaction value, largest first.
| Issuer | Role (as filed) | Filings | Purchases (P) | Sales (S) | Other legs |
|---|---|---|---|---|---|
| Aktis Oncology, Inc. (AKTS) | 10% owner | 1 | 1 leg · 1,112,777 sh · $20,029,986 | — | 6 |
| Werewolf Therapeutics, Inc. (HOWL) | — | 10 | — | 29 legs · 1,938,945 sh · $2,227,963 | 3 |
Form 4 filings — MPM ASSET MANAGEMENT LLC
| Filed | Form | Issuer | Reported transactions | Source |
|---|---|---|---|---|
| 2026-01-14 | 4 | Aktis Oncology, Inc. (AKTS) jointly with GADICKE ANSBERT, Oncology Impact Private Investment Fund 2, L.P. | Conversion (C): 1,314,262 · Conversion (C): 5,914,197 · Conversion (C): 1,577,119 · Purchase (P): 1,112,777 @ $18 · Conversion (C): 5,000,000 (derivative) @ $0 · Conversion (C): 22,500,000 (derivative) @ $0 · +1 more | EDGAR |
| 2025-12-04 | 4 | Werewolf Therapeutics, Inc. (HOWL) jointly with GADICKE ANSBERT, MPM ONCOLOGY INNOVATIONS FUND LP, UBS Oncology Impact Fund L.P., Oncology Impact Fund (Cayman) Management L.P., MPM BioImpact LLC, MPM Oncology Innovations Fund GP LLC | Sale (S): 59,277 @ $0.89 · Sale (S): 57,225 @ $0.87 · Sale (S): 83,230 @ $0.97 | EDGAR |
| 2025-12-01 | 4 | Werewolf Therapeutics, Inc. (HOWL) jointly with GADICKE ANSBERT, MPM ONCOLOGY INNOVATIONS FUND LP, UBS Oncology Impact Fund L.P., Oncology Impact Fund (Cayman) Management L.P., MPM BioImpact LLC, MPM Oncology Innovations Fund GP LLC | Sale (S): 60,733 @ $0.98 · Sale (S): 20,277 @ $0.99 · Sale (S): 60,917 @ $0.94 | EDGAR |
| 2025-11-25 | 4 | Werewolf Therapeutics, Inc. (HOWL) jointly with GADICKE ANSBERT, MPM ONCOLOGY INNOVATIONS FUND LP, UBS Oncology Impact Fund L.P., Oncology Impact Fund (Cayman) Management L.P., MPM BioImpact LLC, MPM Oncology Innovations Fund GP LLC | Sale (S): 64,331 @ $0.83 · Sale (S): 88,802 @ $0.98 · Sale (S): 42,533 @ $0.92 | EDGAR |
| 2025-11-20 | 4 | Werewolf Therapeutics, Inc. (HOWL) jointly with GADICKE ANSBERT, MPM ONCOLOGY INNOVATIONS FUND LP, UBS Oncology Impact Fund L.P., Oncology Impact Fund (Cayman) Management L.P., MPM BioImpact LLC, MPM Oncology Innovations Fund GP LLC | Sale (S): 52,627 @ $0.93 · Sale (S): 66,324 @ $0.94 · Sale (S): 41,152 @ $0.89 | EDGAR |
| 2025-11-17 | 4 | Werewolf Therapeutics, Inc. (HOWL) jointly with GADICKE ANSBERT, MPM ONCOLOGY INNOVATIONS FUND LP, UBS Oncology Impact Fund L.P., Oncology Impact Fund (Cayman) Management L.P., MPM BioImpact LLC, MPM Oncology Innovations Fund GP LLC | Sale (S): 90,951 @ $0.98 · Sale (S): 61,640 @ $0.93 · Sale (S): 57,061 @ $0.95 | EDGAR |
| 2025-11-12 | 4 | Werewolf Therapeutics, Inc. (HOWL) jointly with GADICKE ANSBERT, MPM ONCOLOGY INNOVATIONS FUND LP, UBS Oncology Impact Fund L.P., Oncology Impact Fund (Cayman) Management L.P., MPM BioImpact LLC, MPM Oncology Innovations Fund GP LLC | Sale (S): 68,480 @ $1.11 · Sale (S): 48,570 @ $1.18 · Sale (S): 55,810 @ $1.14 · Sale (S): 40,669 @ $1.09 | EDGAR |
| 2025-11-06 | 4 | Werewolf Therapeutics, Inc. (HOWL) jointly with GADICKE ANSBERT, MPM ONCOLOGY INNOVATIONS FUND LP, UBS Oncology Impact Fund L.P., Oncology Impact Fund (Cayman) Management L.P., MPM BioImpact LLC, MPM Oncology Innovations Fund GP LLC | Sale (S): 140,488 @ $1.22 · Sale (S): 47,950 @ $1.22 · Sale (S): 54,452 @ $1.21 | EDGAR |
| 2025-11-03 | 4 | Werewolf Therapeutics, Inc. (HOWL) jointly with GADICKE ANSBERT, MPM ONCOLOGY INNOVATIONS FUND LP, UBS Oncology Impact Fund L.P., Oncology Impact Fund (Cayman) Management L.P., MPM BioImpact LLC, MPM Oncology Innovations Fund GP LLC | Sale (S): 86,936 @ $1.43 · Sale (S): 114,044 @ $1.28 · Sale (S): 94,063 @ $1.29 | EDGAR |
| 2025-10-29 | 4 | Werewolf Therapeutics, Inc. (HOWL) jointly with GADICKE ANSBERT, MPM ONCOLOGY INNOVATIONS FUND LP, UBS Oncology Impact Fund L.P., Oncology Impact Fund (Cayman) Management L.P., MPM BioImpact LLC, MPM Oncology Innovations Fund GP LLC | Sale (S): 72,709 @ $1.72 · Sale (S): 69,068 @ $1.64 · Sale (S): 134,240 @ $1.55 | EDGAR |
| 2025-04-30 | 4 | Werewolf Therapeutics, Inc. (HOWL) jointly with GADICKE ANSBERT, MPM ONCOLOGY INNOVATIONS FUND LP, UBS Oncology Impact Fund L.P., Oncology Impact Fund (Cayman) Management L.P., MPM BioImpact LLC, MPM Oncology Innovations Fund GP LLC | Option exercise/expiry (X): 50,873 @ $0.09 · Sale (S): 4,386 @ $1.05 · Option exercise/expiry (X): 8,031 (derivative) @ $0 · Option exercise/expiry (X): 42,842 (derivative) @ $0 | EDGAR |
FilingPulse's Form 4 archive currently extends back to 2024-01-11 and is expanding backward through EDGAR history — earlier filings by this insider may not be indexed yet. Names and roles are shown as filed.
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