| Name | Relationship | Address | Signature | Signature date | CIK |
|---|---|---|---|---|---|
| EVNIN LUKE | Director | C/O MPM BIOIMPACT LLC, 399 BOYLSTON STREET, SUITE 1100, BOSTON | /s/ Luke Evnin | 09 Dec 2025 | 0001134657 |
| Type | Sym | Class | Transaction | Value $ | Shares | Change % | * Price $ | Shares After | Date | Ownership | Footnotes |
|---|---|---|---|---|---|---|---|---|---|---|---|
| transaction | HOWL | Common Stock | Sale | $16,071 | -16,568 | -0.54% | $0.9700 | 3,051,710 | 05 Dec 2025 | See Footnotes | F1, F2, F3, F4, F5 |
| transaction | HOWL | Common Stock | Sale | $33,701 | -34,041 | -1.1% | $0.9900 | 3,017,669 | 08 Dec 2025 | See Footnotes | F1, F4, F6, F7, F8 |
| transaction | HOWL | Common Stock | Sale | $45,016 | -44,570 | -1.5% | $1.01 | 2,973,099 | 09 Dec 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: 1,772 by MPM Asset Management LLC ("AM LLC"), 11,197 by MPM BioVentures 2014, L.P. ("BV 2014"), 747 by MPM BioVentures 2014(B), L.P. ("BV 2014(B)"), 386 by MPM Asset Management Investors BV2014 LLC ("AM BV2014") and 2,466 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 $0.9434 to $0.9863 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: 326,816 by AM LLC, 2,063,807 by BV 2014, 137,652 by BV 2014(B), 71,035 by AM BV2014 and 452,400 by MPM OIF. |
| F6 | The shares were sold as follows: 3,642 by AM LLC, 23,006 by BV 2014, 1,534 by BV 2014(B), 792 by AM BV2014 and 5,067 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 $0.9582 to $1.01 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: 323,174 by AM LLC, 2,040,801 by BV 2014, 136,118 by BV 2014(B), 70,243 by AM BV2014 and 447,333 by MPM OIF. |
| F9 | The shares were sold as follows: 4,768 by AM LLC, 30,123 by BV 2014, 2,009 by BV 2014(B), 1,036 by AM BV2014 and 6,634 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 $0.99 to $1.025 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: 318,406 by AM LLC, 2,010,678 by BV 2014, 134,109 by BV 2014(B), 69,207 by AM BV2014 and 440,699 by MPM OIF. |