| Name | Relationship | Address | Signature | Signature date | CIK |
|---|---|---|---|---|---|
| EVNIN LUKE | Director | C/O MPM BIOIMPACT LLC, 399 BOYLSTON STREET, SUITE 1100, BOSTON | /s/ Luke Evnin | 12 Nov 2025 | 0001134657 |
| Type | Sym | Class | Transaction | Value $ | Shares | Change % | * Price $ | Shares After | Date | Ownership | Footnotes |
|---|---|---|---|---|---|---|---|---|---|---|---|
| transaction | HOWL | Common Stock | Sale | -$48.8K | -44K | -1.16% | $1.11 | 3.74M | 07 Nov 2025 | See Footnotes | F1, F2, F3, F4, F5 |
| transaction | HOWL | Common Stock | Sale | -$36.8K | -31.2K | -0.83% | $1.18 | 3.71M | 10 Nov 2025 | See Footnotes | F1, F4, F6, F7, F8 |
| transaction | HOWL | Common Stock | Sale | -$40.8K | -35.8K | -0.96% | $1.14 | 3.68M | 11 Nov 2025 | See Footnotes | F1, F4, F9, F10, F11 |
| transaction | HOWL | Common Stock | Sale | -$28.5K | -26.1K | -0.71% | $1.09 | 3.65M | 12 Nov 2025 | See Footnotes | F1, F4, F12, F13, F14 |
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: 4,702 by MPM Asset Management LLC ("AM LLC"), 29,704 by MPM BioVentures 2014, L.P. ("BV 2014"), 1,981 by MPM BioVentures 2014(B), L.P. ("BV 2014(B)"), 1,022 by MPM Asset Management Investors BV2014 LLC ("AM BV2014") and 6,541 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 $1.075 to $1.188 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: 400,824 by AM LLC, 2,531,366 by BV 2014, 168,839 by BV 2014(B), 87,127 by AM BV2014 and 555,368 by MPM OIF. |
| F6 | The shares were sold as follows: 3,335 by AM LLC, 21,067 by BV 2014, 1,405 by BV 2014(B), 725 by AM BV2014 and 4,640 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 $1.145 to $1.21 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: 397,489 by AM LLC, 2,510,299 by BV 2014, 167,434 by BV 2014(B), 86,402 by AM BV2014 and 550,728 by MPM OIF. |
| F9 | The shares were sold as follows: 3,832 by AM LLC, 24,208 by BV 2014, 1,615 by BV 2014(B), 832 by AM BV2014 and 5,331 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 $1.115 to $1.17 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: 393,657 by AM LLC, 2,486,091 by BV 2014, 165,819 by BV 2014(B), 85,570 by AM BV2014 and 545,397 by MPM OIF. |
| F12 | The shares were sold as follows: 2,792 by AM LLC, 17,640 by BV 2014, 1,177 by BV 2014(B), 607 by AM BV2014 and 3,885 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 $1.065 to $1.145 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: 390,865 by AM LLC, 2,468,451 by BV 2014, 164,642 by BV 2014(B), 84,963 by AM BV2014 and 541,512 by MPM OIF. |