Transaction Details

Footnotes

The shares subject to the option shall vest on the date immediately preceding the date of the Issuer's next annual meeting of stockholders, subject to the Reporting Person's continuous service through the applicable vesting date. | Under the Reporting Person's arrangement with RA Capital Management, L.P. (the "Adviser"), the Reporting Person holds the stock option for the benefit of RA Capital Healthcare Fund, L.P. (the "Fund") and RA Capital Nexus Fund II, L.P. (the "Nexus Fund II"). The Reporting Person is obligated to turn over to the Adviser any net cash or stock received upon exercise of the stock option, which will offset advisory fees owed by the Fund and the Nexus Fund II. The Reporting Person therefore disclaims beneficial ownership of the stock option and underlying Common Stock.