Population Health Equity Partners III, L.P.

Row 1 · Balance 679,822

F1: This Form 3 is not being filed in connection with the acquisition or disposition of any securities of the Issuer.

F2: 359,662 shares of Common Stock are held directly by Population Health Equity Partners III, L.P. ("PH III") and a further 320,160 shares of Common Stock are held directly by Population Health Equity Partners VII, L.P. ("PH VII"). PH III is controlled by Population Health Equity Partners III GP, LLC ("PH III GP"), its general partner, and PH VII is controlled by Population Health Equity Partners VII GP, LLC ("PH VII GP"), its general partner. Clive Meanwell and Christopher Cox are the sole managing members of both PH III GP and PH VII GP and may be deemed to have shared voting and dispositive power with respect to the shares of Common Stock held directly by PH III and PH VII. Clive Meanwell and Christopher Cox disclaim beneficial ownership of the shares held directly by PH III and PH VII, except to the extent of their pecuniary interests therein, if any. Clive Meanwell has filed a separate Form 3 in respect of the Issuer.

F3: On March 28, 2022, PH III, PH VII and Clive Meanwell ("PH") and (i) Mithril II LP ("Mithril"), (ii) M28 Capital Management LP (together with certain of its affiliates, "M28"), (iii) Polaris Venture Partners V, L.P. and certain affiliates (collectively, "Polaris") and (iv) Adimab, LLC, orally agreed to coordinate and cooperate in certain of their activities with regard to the Issuer, which agreement was subsequently memorialized, also on March 28, 2022, in an email circulated among representatives of such persons. That agreement provides that each such person will vote its shares of Common Stock in favor of the election of certain director nominees at the Issuer's 2022 annual meeting. By virtue of such agreement, the forgoing persons may be deemed to be part of a "group" (within the meaning of Section 13(d)(3) of the Exchange Act) comprised of such persons.

F4: The Reporting Persons expressly disclaim beneficial ownership over any Common Stock that they may be deemed to beneficially own solely by reason of the agreement reached among Population Health, Mithril, M28, Polaris and Adimab, LLC, and beneficial ownership of any securities of the Issuer other than those reported on this Form 3 in which they have a direct pecuniary interest. This filing shall not be deemed an admission that the Reporting Persons are 10% shareholders for purposes of Section 16 of the Exchange Act.