Security	Date	Code	Shares	Price	A/D	Owned after	D/I
Common Stock^F1,F2	Oct 1, 2018	C	589,661	—	A	589,661	D
Common Stock^F3,F2	Oct 1, 2018	C	458,331	—	A	1,047,992	D
Common Stock^F4,F2	Oct 1, 2018	C	382,698	—	A	1,430,690	D
Common Stock^F5,F2	Oct 1, 2018	C	514,211	—	A	1,944,901	D

Table II — derivative securities

Security	Conv. / exercise price	Date	Code	Shares	A/D	Exercisable	Expires	Underlying	Underlying shares	D/I
Series B Preferred Stock^F2,F1	—	Oct 1, 2018	C	10,201,769	D	—	—	Common Stock	589,661	D
Series C Preferred Stock^F2,F3	—	Oct 1, 2018	C	12,387,324	D	—	—	Common Stock	458,331	D
Series D Preferred Stock^F2,F4	—	Oct 1, 2018	C	9,449,318	D	—	—	Common Stock	382,698	D
Series E Preferred Stock^F2,F5	—	Oct 1, 2018	C	18,698,578	D	—	—	Common Stock	514,211	D

Explanation of responses

F1Each share of the issuer's Series B Preferred Stock automatically converted into 0.0578 share of the issuer's Common Stock on October 1, 2018 in connection with the closing of the issuer's sale of its Common Stock in its firm commitment initial public offering (the "IPO") pursuant to a registration statement on Form S-1 (File No. 333-227103) under the Securities Act of 1933, as amended (the "Registration Statement"), and had no expiration date.
F2The shares directly held by Alta Partners VIII, L.P. ("Alta VIII") are indirectly held by Alta Partners Management VIII, LLC ("Alta Management VIII"), which is the general partner of Alta VIII. The individual managing directors of Alta Management VIII are Farah Champsi, Guy Nohra and Daniel Janney. The managing directors of Alta Management VIII exercise sole voting and investment control with respect to the shares held by Alta VIII. The individual managing directors of Alta Management VIII disclaim beneficial ownership of all shares held by Alta VIII, except to the extent of their pecuniary interests therein.
F3Each share of the issuer's Series C Preferred Stock automatically converted into 0.0370 share of the issuer's Common Stock on October 1, 2018 in connection with the closing of the issuer's sale of its Common Stock in its IPO pursuant to the Registration Statement, and had no expiration date.
F4Each share of the issuer's Series D Preferred Stock automatically converted into 0.0405 share of the issuer's Common Stock on October 1, 2018 in connection with the closing of the issuer's sale of its Common Stock in its IPO pursuant to the Registration Statement, and had no expiration date.
F5Each share of the issuer's Series E Preferred Stock automatically converted into 0.0275 share of the issuer's Common Stock on October 1, 2018 in connection with the closing of the issuer's sale of its Common Stock in its IPO pursuant to the Registration Statement, and had no expiration date.