| Name | Relationship | Address | Signature | Signature date | CIK |
|---|---|---|---|---|---|
| EVNIN LUKE | Director | C/O MPM BIOIMPACT LLC, 399 BOYLSTON STREET, SUITE 1100, BOSTON | /s/ Luke Evnin | 29 Dec 2025 | 0001134657 |
| Type | Sym | Class | Transaction | Value $ | Shares | Change % | * Price $ | Shares After | Date | Ownership | Footnotes |
|---|---|---|---|---|---|---|---|---|---|---|---|
| transaction | HOWL | Common Stock | Sale | $40,922 | -59,307 | -2.1% | $0.6900 | 2,782,650 | 22 Dec 2025 | See Footnotes | F1, F2, F3, F4, F5 |
| transaction | HOWL | Common Stock | Sale | $45,000 | -71,428 | -2.6% | $0.6300 | 2,711,222 | 23 Dec 2025 | See Footnotes | F1, F4, F6, F7, F8 |
| transaction | HOWL | Common Stock | Sale | $10,602 | -16,310 | -0.6% | $0.6500 | 2,694,912 | 24 Dec 2025 | See Footnotes | F1, F4, F9, F10, F11 |
| transaction | HOWL | Common Stock | Sale | $22,448 | -35,632 | -1.3% | $0.6300 | 2,659,280 | 26 Dec 2025 | See Footnotes | F1, F4, F12, F13, F14 |
| transaction | HOWL | Common Stock | Sale | $66,250 | -108,606 | -4.1% | $0.6100 | 2,550,674 | 29 Dec 2025 | See Footnotes | F1, F4, F15, F16, F17 |
Buy Plan / Sale Plan: These are also open market purchases/sales of shares, but in this case the transaction is part of a trading plan. Rule 10b5-1 allows insiders to setup a trading plan to buy/sell stocks over a certain period of time. Since the purchases/sales are predetermined, this protects the insiders from violating insider trading law.
Transaction was made pursuant to a contract, instruction or written plan for the purchase or sale of equity securities of the issuer that is intended to satisfy the affirmative defense conditions of Rule 10b5-1(c).
| Id | Content |
|---|---|
| F1 | Transaction effected pursuant to a plan established pursuant to Rule 10b5-1 dated September 24, 2025. |
| F2 | The shares were sold as follows: 6,344 by MPM Asset Management LLC ("AM LLC"), 40,082 by MPM BioVentures 2014, L.P. ("BV 2014"), 2,673 by MPM BioVentures 2014(B), L.P. ("BV 2014(B)"), 1,381 by MPM Asset Management Investors BV2014 LLC ("AM BV2014") and 8,827 by MPM Oncology Innovations Fund, L.P. ("MPM OIF"). |
| F3 | The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $0.6596 to $0.7341 inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote. |
| F4 | MPM BioVentures 2014 GP LLC and MPM BioVentures 2014 LLC ("BV LLC") are the direct and indirect general partners of BV 2014 and BV 2014(B). BV LLC is the manager of AM BV2014. MPM Oncology Innovations Fund GP LLC ("MPM OIF GP") is the general partner of MPM OIF. Luke Evnin is a member of AM LLC, a Managing Director of BV LLC and a manager of MPM OIF GP. The Reporting Person disclaims beneficial ownership of the securities except to the extent of his pecuniary interest therein. |
| F5 | The shares are held as follows: 298,034 by AM LLC, 1,881,964 by BV 2014, 125,523 by BV 2014(B), 64,775 by AM BV2014 and 412,354 by MPM OIF. |
| F6 | The shares were sold as follows: 7,641 by AM LLC, 48,274 by BV 2014, 3,220 by BV 2014(B), 1,662 by AM BV2014 and 10,631 by MPM OIF. |
| F7 | The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $0.61 to $0.6728 inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote. |
| F8 | The shares are held as follows: 290,393 by AM LLC, 1,833,690 by BV 2014, 122,303 by BV 2014(B), 63,113 by AM BV2014 and 401,723 by MPM OIF. |
| F9 | The shares were sold as follows: 1,745 by AM LLC, 11,023 by BV 2014, 735 by BV 2014(B), 379 by AM BV2014 and 2,428 by MPM OIF. |
| F10 | The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $0.6337 to $0.66 inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote. |
| F11 | The shares are held as follows: 288,648 by AM LLC, 1,822,667 by BV 2014, 121,568 by BV 2014(B), 62,734 by AM BV2014 and 399,295 by MPM OIF. |
| F12 | The shares were sold as follows: 3,812 by AM LLC, 24,082 by BV 2014, 1,606 by BV 2014(B), 829 by AM BV2014 and 5,303 by MPM OIF. |
| F13 | The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $0.6165 to $0.66 inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote |
| F14 | The shares are held as follows: 284,836 by AM LLC, 1,798,585 by BV 2014, 119,962 by BV 2014(B), 61,905 by AM BV2014 and 393,992 by MPM OIF. |
| F15 | The shares were sold as follows: 11,618 by AM LLC, 73,401 by BV 2014, 4,896 by BV 2014(B), 2,526 by AM BV2014 and 16,165 by MPM OIF. |
| F16 | The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $0.58955 to $0.65 inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote |
| F17 | The shares are held as follows: 273,218 by AM LLC, 1,725,184 by BV 2014, 115,066 by BV 2014(B), 59,379 by AM BV2014 and 377,827 by MPM OIF. |