Security	Date	Code	Shares	Price	A/D	Owned after	D/I	Nature of ownership
Common Stock^F2,F3	Aug 12, 2026	S	147,059	$50.27	A	6,068,532	D
Common Stock^F4,F3	Aug 12, 2026	S	141	$51.08	A	6,068,391	D
Common Stock^F5	holding	—	—		—	4,211,659	I	By Third Rock Ventures VI, L.P.

Table II — derivative securities

No Table II lines on this filing.

Explanation of responses

F1The reported transactions were effected pursuant to a Rule 10b5-1 trading plan dated March 26, 2026, previously adopted by the Reporting Person.
F2The price reported is a weighted average price. These shares were sold in multiple transactions at prices ranging from $50.05 to $50.81, 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 ranges set forth in this footnote (2).
F3These shares are directly held 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 the 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.
F4The price reported is a weighted average price. These shares were sold in multiple transactions at prices ranging from $51.00 to $51.10, 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 ranges set forth in this footnote (4).
F5The shares are held directly by Third Rock Ventures VI, L.P. ("TRV VI"). The general partner of TRV VI is Third Rock Ventures GP VI, L.P. ("TRV GP VI"). The general partner of TRV GP VI is TRV GP VI, LLC ("TRV GP VI LLC"). Each of TRV GP VI, and TRV GP VI 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 any TRV V related parties and any TRV VI 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.