| 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 Dec 2025 | 0001134657 |
| Type | Sym | Class | Transaction | Value $ | Shares | Change % | * Price $ | Shares After | Date | Ownership | Footnotes |
|---|---|---|---|---|---|---|---|---|---|---|---|
| transaction | HOWL | Common Stock | Sale | $39,330 | -37,104 | -1.2% | $1.06 | 2,935,995 | 10 Dec 2025 | See Footnotes | F1, F2, F3, F4, F5 |
| transaction | HOWL | Common Stock | Sale | $29,970 | -28,009 | -0.95% | $1.07 | 2,907,986 | 11 Dec 2025 | See Footnotes | F1, F4, F6, F7, F8 |
| transaction | HOWL | Common Stock | Sale | $19,287 | -17,858 | -0.61% | $1.08 | 2,890,128 | 12 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: 3,969 by MPM Asset Management LLC ("AM LLC"), 25,077 by MPM BioVentures 2014, L.P. ("BV 2014"), 1,673 by MPM BioVentures 2014(B), L.P. ("BV 2014(B)"), 863 by MPM Asset Management Investors BV2014 LLC ("AM BV2014") and 5,522 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 $0.9742 to $1.11 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: 314,437 by AM LLC, 1,985,601 by BV 2014, 132,436 by BV 2014(B), 68,344 by AM BV2014 and 435,177 by MPM OIF. |
| F6 | The shares were sold as follows: 2,996 by AM LLC, 18,930 by BV 2014, 1,263 by BV 2014(B), 651 by AM BV2014 and 4,169 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 $1.045 to $1.10 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: 311,441 by AM LLC, 1,966,671 by BV 2014, 131,173 by BV 2014(B), 67,693 by AM BV2014 and 431,008 by MPM OIF. |
| F9 | The shares were sold as follows: 1,910 by AM LLC, 12,069 by BV 2014, 805 by BV 2014(B), 416 by AM BV2014 and 2,658 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 $1.06 to $1.10 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: 309,531 by AM LLC, 1,954,602 by BV 2014, 130,368 by BV 2014(B),67,277 by AM BV2014 and 428,350 by MPM OIF. |