Security	Date	Code	Shares	Price	A/D	Owned after	D/I	Nature of ownership
Common Stock^{F1,F2,F3,F4,F5}	Jul 23, 2018	C	11,269,200	—	A	11,269,200	I	See footnote
Common Stock^F4,F5,F6	Jul 23, 2018	P	250,000	$18.00	A	11,519,200	I	See footnote

Table II — derivative securities

Security	Conv. / exercise price	Date	Code	Shares	A/D	Exercisable	Expires	Underlying	Underlying shares	Owned after	D/I
Series A Preferred Stock^F4,F5,F7,F1	—	Jul 23, 2018	C	10,030,193	D	—	—	Common Stock	10,030,193	0	I
Series B Preferred Stock^F4,F5,F8,F2	—	Jul 23, 2018	C	1,239,007	D	—	—	Common Stock	1,239,007	0	I

Explanation of responses

F1The Series A Preferred Stock automatically converted into Common Stock on a one-for-one basis immediately prior to the closing of the Issuer's initial public offering and had no expiration date.
F2The Series B Preferred Stock automatically converted into Common Stock on a one-for-one basis immediately prior to the closing of the Issuer's initial public offering and had no expiration date.
F3Consists of 3,446,265 shares held of record by Alta Partners NextGen Fund I, L.P. ("APNG I") and 7,822,935 shares held of record by Alta Partners VIII, L.P. ("Alta VIII").
F4The shares directly held by 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.
F5The shares directly held by APNG I are indirectly held by Alta Partners NextGen Fund I Management, LLC ("APNG I Management"), which is the general partner of APNG I. The individual managing directors of APNG I Management are Robert More, Peter Hudson and Daniel Janney. The managing directors of APNG I Management exercise sole voting and investment control with respect to the shares held by APNG I. The individual managing directors of APNG I Management disclaim beneficial ownership of all shares held by APNG I, except to the extent of their pecuniary interests therein.
F6Consists of 3,557,377 shares held of record by APNG I and 7,961,823 shares held of record by Alta VIII.
F7APNG I owns 2,941,718 shares of Series A Preferred Stock. Alta VIII owns 7,088,475 shares of Series A Preferred Stock.
F8APNG I owns 504,547 shares of Series B Preferred Stock. Alta VIII owns 734,460 shares of Series B Preferred Stock.