Security	Date	Code	Shares	Price	A/D	Owned after	D/I	Nature of ownership
Common Stock^F1	Jul 2, 2018	C	979,179	—	A	979,179	D
Common Stock^F1,F2	Jul 2, 2018	C	979,179	—	A	979,179	I	By Omega IV
Common Stock^F1	Jul 2, 2018	C	1,458,424	—	A	1,458,424	D
Common Stock^F1,F3	Jul 2, 2018	C	1,458,424	—	A	1,458,424	I	By Omega V

Table II — derivative securities

Security	Conv. / exercise price	Date	Code	Shares	A/D	Exercisable	Expires	Underlying	Underlying shares	D/I
Series A Preferred Stock^F1	—	Jul 2, 2018	C	2,500,000	D	—	—	Common Stock	450,004	D
Series A Preferred Stock^F2,F1	—	Jul 2, 2018	C	2,500,000	D	—	—	Common Stock	450,004	I
Series B Preferred Stock^F1	—	Jul 2, 2018	C	1,676,348	D	—	—	Common Stock	301,745	D
Series B Preferred Stock^F2,F1	—	Jul 2, 2018	C	1,676,348	D	—	—	Common Stock	301,745	I
Series C Preferred Stock^F1	—	Jul 2, 2018	C	1,263,484	D	—	—	Common Stock	227,429	D
Series C Preferred Stock^F2,F1	—	Jul 2, 2018	C	1,263,484	D	—	—	Common Stock	227,429	I
Series A Preferred Stock^F1	—	Jul 2, 2018	C	5,800,000	D	—	—	Common Stock	1,044,010	D
Series A Preferred Stock^F3,F1	—	Jul 2, 2018	C	5,800,000	D	—	—	Common Stock	1,044,010	I
Series B Preferred Stock^F1	—	Jul 2, 2018	C	2,000,103	D	—	—	Common Stock	360,022	D
Series B Preferred Stock^F3,F1	—	Jul 2, 2018	C	2,000,103	D	—	—	Common Stock	360,022	I
Series C Preferred Stock^F1	—	Jul 2, 2018	C	302,173	D	—	—	Common Stock	54,391	D
Series C Preferred Stock^F3,F1	—	Jul 2, 2018	C	302,173	D	—	—	Common Stock	54,391	I

Explanation of responses

F1The Series A, Series B and Series C Preferred Stock converted into Common Stock on a 5.5555-for-one basis upon the closing of the Issuer's initial public offering without payment of consideration. The Series A, Series B and Series C Preferred Stock were convertible at any time at the holder's election and automatically upon the closing of the Issuer's initial pubic offering. The shares had no expiration date.
F2The reported securities are beneficially owned by Omega Fund IV GP, L.P. ("Omega IV GP"), as general partner of Omega Fund IV, L.P. ("Omega IV"). Omega Fund IV G.P. Manager, Ltd. ("Omega IV GP Manager"), is the general partner of Omega IV GP. Otello Stampacchia, Richard Lim and Anne-Mari Paster are all the shareholders and directors of Omega IV GP Manager and have shared voting and investment power over the shares held by Omega IV. Each of the Reporting Persons disclaim beneficial ownership of these securities, except to the extent of his, her or its pecuniary interest therein, if any.
F3The reported securities are beneficially owned by Omega Fund V GP, L.P. ("Omega V GP"), as general partner of Omega Fund V, L.P. ("Omega V"). Omega Fund V GP Manager, Ltd. ("Omega V GP Manager"), is the general partner of Omega V GP. Otello Stampacchia, Richard Lim, Anne-Mari Paster and Claudio Nessi are all the shareholders and directors of Omega V GP Manager and have shared voting and investment power over the shares held by Omega V. Each of the Reporting Persons disclaim beneficial ownership of these securities, except to the extent of his, her or its pecuniary interest therein, if any.