| Name | Relationship | Address | Signature | Signature date | CIK |
|---|---|---|---|---|---|
| EVNIN LUKE | Director | C/O MPM BIOIMPACT LLC, 399 BOYLSTON STREET, SUITE 1100, BOSTON | /s/ Luke Evnin | 17 Nov 2025 | 0001134657 |
| Type | Sym | Class | Transaction | Value $ | Shares | Change % | * Price $ | Shares After | Date | Ownership | Footnotes |
|---|---|---|---|---|---|---|---|---|---|---|---|
| transaction | HOWL | Common Stock | Sale | $57,205 | -58,372 | -1.6% | $0.9800 | 3,592,061 | 13 Nov 2025 | See Footnotes | F1, F2, F3, F4, F5 |
| transaction | HOWL | Common Stock | Sale | $36,791 | -39,560 | -1.1% | $0.9300 | 3,552,501 | 14 Nov 2025 | See Footnotes | F1, F4, F6, F7, F8 |
| transaction | HOWL | Common Stock | Sale | $34,790 | -36,621 | -1% | $0.9500 | 3,515,880 | 17 Nov 2025 | See Footnotes | F1, F4, F9, F10, F11 |
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: 6,244 by MPM Asset Management LLC ("AM LLC"), 39,450 by MPM BioVentures 2014, L.P. ("BV 2014"), 2,631 by MPM BioVentures 2014(B), L.P. ("BV 2014(B)"), 1,359 by MPM Asset Management Investors BV2014 LLC ("AM BV2014") and 8,688 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 $0.918 to $1.07 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: 384,621 by AM LLC, 2,429,001 by BV 2014, 162,011 by BV 2014(B), 83,604 by AM BV2014 and 532,824 by MPM OIF. |
| F6 | The shares were sold as follows: 4,232 by AM LLC, 26,736 by BV 2014, 1,783 by BV 2014(B), 921 by AM BV2014 and 5,888 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 $0.895 to $0.9551 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: 380,389 by AM LLC, 2,402,265 by BV 2014, 160,228 by BV 2014(B), 82,683 by AM BV2014 and 526,936 by MPM OIF. |
| F9 | The shares were sold as follows: 3,918 by AM LLC, 24,750 by BV 2014, 1,651 by BV 2014(B), 851 by AM BV2014 and 5,451 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 $0.9183 to $0.99 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: 376,471 by AM LLC, 2,377,515 by BV 2014, 158,577 by BV 2014(B), 81,832 by AM BV2014 and 521,485 by MPM OIF. |