Amendment: SEC Form SCHEDULE 13D/A filed by Mineralys Therapeutics Inc.

This Schedule 13D/A is being filed on behalf of RA Capital Management, L.P. ("RA Capital"), Peter Kolchinsky, Rajeev Shah, and RA Capital Healthcare Fund, L.P. (the "Fund"), who are collectively referred to herein as the "Reporting Persons." The agreement among the Reporting Persons to file this Schedule 13D/A jointly in accordance with Rule 13d-1(k) of the Securities Exchange Act of 1934, as amended (the "Act"), is attached hereto as Exhibit 99.1. The Reporting Persons' ownership of the Issuer's securities includes (i) 5,456,521 shares of common stock held directly by the Fund; (ii) 1,867,229 shares of common stock held by RA Capital Nexus Fund III, L.P. (the "Nexus Fund III"); and (iii) a total of 75,116 shares underlying vested stock options (right to buy), and 7,927 shares underlying stock options (right to buy) which shall vest within 60 days of this filing held by Dr. Derek DiRocco for the benefit of RA Capital. The Fund also holds Pre-Funded Warrants (as defined below) through which it has a right to acquire 549,755 shares of common stock. The Pre-Funded Warrants contain a provision (the "Beneficial Ownership Blocker") which precludes exercise of the warrants to the extent that, following exercise, the Fund, together with its affiliates and other attribution parties, would own more than 9.99% of the common stock outstanding. The Reporting Persons are currently prohibited from exercising the Pre-Funded Warrants to the extent that the exercise would result in beneficial ownership of more than 7,796,433 shares of common stock by the Reporting Persons. RA Capital Healthcare Fund GP, LLC is the general partner of the Fund and RA Capital Nexus Fund III GP, LLC is the general partner of the Nexus Fund III. The general partner of RA Capital is RA Capital Management GP, LLC, of which Dr. Kolchinsky and Mr. Shah are the controlling persons. RA Capital serves as investment adviser for the Fund and the Nexus Fund III and may be deemed a beneficial owner, for purposes of Section 13(d) of the Securities Exchange Act of 1934 (the "Act"), of any securities of the Issuer held by the Fund or the Nexus Fund III. The Fund and the Nexus Fund III have delegated to RA Capital the sole power to vote and the sole power to dispose of all securities held in the Fund's and the Nexus Fund III's portfolio, including the shares of the Issuer's common stock reported herein. Because the Fund and the Nexus Fund III have divested themselves of voting and investment power over the reported securities they hold and may not revoke that delegation on less than 61 days' notice, the Fund and the Nexus Fund III disclaim beneficial ownership of the securities they hold for purposes of Section 13(d) of the Act and therefore disclaim any obligation to report ownership of the reported securities under Section 13(d) of the Act. As managers of RA Capital, Dr. Kolchinsky and Mr. Shah may be deemed beneficial owners, for purposes of Section 13(d) of the Act, of any securities of the Issuer beneficially owned by RA Capital. RA Capital, Dr. Kolchinsky, and Mr. Shah disclaim beneficial ownership of the securities reported in this Schedule 13D/A other than for the purpose of determining their obligations under Section 13(d) of the Act, and the filing of this Schedule 13D/A shall not be deemed an admission that either RA Capital, Dr. Kolchinsky, or Mr. Shah is the beneficial owner of such securities for any other purpose.