| Name | Relationship | Address | Signature | Signature date | CIK |
|---|---|---|---|---|---|
| EVNIN LUKE | Director | C/O MPM BIOIMPACT LLC, 399 BOYLSTON STREET, SUITE 1100, BOSTON | /s/ Luke Evnin | 20 Nov 2025 | 0001134657 |
| Type | Sym | Class | Transaction | Value $ | Shares | Change % | * Price $ | Shares After | Date | Ownership | Footnotes |
|---|---|---|---|---|---|---|---|---|---|---|---|
| transaction | HOWL | Common Stock | Sale | $31,412 | -33,776 | -0.96% | $0.9300 | 3,482,104 | 18 Nov 2025 | See Footnotes | F1, F2, F3, F4, F5 |
| transaction | HOWL | Common Stock | Sale | $40,012 | -42,566 | -1.2% | $0.9400 | 3,439,538 | 19 Nov 2025 | See Footnotes | F1, F4, F6, F7, F8 |
| transaction | HOWL | Common Stock | Sale | $23,506 | -26,411 | -0.77% | $0.8900 | 3,413,127 | 20 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: 3,613 by MPM Asset Management LLC ("AM LLC"), 22,827 by MPM BioVentures 2014, L.P. ("BV 2014"), 1,523 by MPM BioVentures 2014(B), L.P. ("BV 2014(B)"), 786 by MPM Asset Management Investors BV2014 LLC ("AM BV2014") and 5,027 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 $0.8902 to $0.9601 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: 372,858 by AM LLC, 2,354,688 by BV 2014, 157,054 by BV 2014(B), 81,046 by AM BV2014 and 516,458 by MPM OIF. |
| F6 | The shares were sold as follows: 4,554 by AM LLC, 28,768 by BV 2014, 1,919 by BV 2014(B), 990 by AM BV2014 and 6,335 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 $0.901 to $0.9806 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: 368,304 by AM LLC, 2,325,920 by BV 2014, 155,135 by BV 2014(B), 80,056 by AM BV2014 and 510,123 by MPM OIF. |
| F9 | The shares were sold as follows: 2,825 by AM LLC, 17,850 by BV 2014, 1,191 by BV 2014(B), 614 by AM BV2014 and 3,931 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 $0.8506 to $0.9556 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: 365,479 by AM LLC, 2,308,070 by BV 2014, 153,944 by BV 2014(B), 79,442 by AM BV2014 and 506,192 by MPM OIF. |