RA CAPITAL MANAGEMENT, L.P. bought BCAX

Footnotes

Represents the grant of a stock option to Jake Simson pursuant to the Issuer's Non-Employee Director Compensation Policy. The shares underlying this option shall vest upon the earlier of (i) June 9, 2027, and (ii) the date of the next Annual Meeting of Stockholders of the Issuer, subject to Dr. Simson's continued service on such vesting date.; RA Capital Management, L.P. (the "Adviser") is the investment manager for RA Capital Healthcare Fund, L.P. (the "Fund") and RA Capital Nexus Fund III, L.P. (the "Nexus Fund III"). 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. Each of the Adviser, the Adviser GP, the Fund, the Nexus Fund III, Dr. Kolchinsky and Mr. Shah disclaims beneficial ownership of any of the reported securities, except to the extent of its or his respective pecuniary interest therein.; Under Dr. Simson's arrangement with the Adviser, Dr. Simson holds the option for the benefit of the Fund and the Nexus Fund III. Dr. Simson 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 and the Nexus Fund III to the Adviser. The Reporting Persons therefore disclaim beneficial ownership of the option and underlying common stock.