Transaction Details

Footnotes

On November 4, 2025, Third Rock Ventures IV, L.P. ("TRV IV ") distributed, for no consideration, 1,600,000 shares of Common Stock of the Issuer (the "Shares") to its limited partners and to Third Rock Ventures GP IV, L.P. ("TRV GP IV "), the general partner of TRV IV, representing each such partner's pro rata interest in such Shares. On the same date, TRV GP IV distributed, for no consideration, the Shares it received in the distribution by TRV IV to its partners, representing each such partner's pro rata interest in such Shares. All of the aforementioned distributions were made in accordance with the exemptions afforded by Rules 16a-13 and 16a-9 of the Securities Exchange Act of 1934, as amended. | The shares are held directly by TRV IV. The general partner of TRV IV is TRV GP IV. The general partner of TRV GP IV is TRV GP IV LLC. Each of TRV GP IV, and TRV GP IV LLC, disclaims beneficial ownership of these shares except to the extent of its pecuniary interest therein, if any, and this report shall not be deemed an admission that it is the beneficial owner of such shares. | The shares are held directly by Third Rock Ventures V, L.P. ("TRV V"). The general partner of TRV V is Third Rock Ventures GP V, L.P. ("TRV GP V"). The general partner of TRV GP V is TRV GP V, LLC ("TRV GP V LLC"). Each of TRV GP V, and TRV GP V LLC, disclaims beneficial ownership of these shares except to the extent of its pecuniary interest therein, if any, and this report shall not be deemed an admission that it is the beneficial owner of such shares. | Each of Reporting Persons disclaims the existence of a Section 13(d) "group" as between the TRV IV related parties and the TRV V related parties and this report shall not be deemed an admission that any of such parties is or may be part of such a group with any of the other parties.