RA CAPITAL MANAGEMENT, L.P. bought ARTV

Footnotes

Represents the grant of a stock option to Laura Stoppel pursuant to the Issuer's non-employee director compensation policy. The shares subject to the option will vest on the earlier of September 8, 2027 or the date of the Issuer's 2027 annual stockholder meeting, subject to Dr. Stoppel's continuous service as a director through such vesting date.; RA Capital Management, L.P. (the "Adviser") is the investment manager for RA Capital Healthcare Fund, L.P. (the "Fund"), RA Capital Nexus Fund, L.P. (the "Nexus Fund"), RA Capital Nexus Fund III, L.P. (the "Nexus Fund III"), and a separately managed account (the "Account"). The general partner of the Adviser is RA Capital Management GP, LLC (the "Adviser GP"), of which Dr. Peter Kolchinsky and Mr. Rajeev Shah are the managing members. The Adviser, the Adviser GP, the Fund, the Nexus Fund, the Nexus Fund III, Dr. Kolchinsky and Mr. Shah disclaim beneficial ownership of any of the reported securities, except to the extent of its or his pecuniary interest therein.; Under Dr. Stoppel's arrangement with the Adviser, Dr. Stoppel holds the option for the benefit of the Fund, the Nexus Fund, the Nexus Fund III and the Account. Dr. Stoppel is obligated to turn over to the Adviser any net cash or stock received upon exercise of the option, which will offset advisory fees owed by the Fund, the Nexus Fund, the Nexus Fund III and the Account to the Adviser. The Reporting Persons therefore disclaim beneficial ownership of the option and underlying common stock.