Security	Date	Code	Shares	Price	A/D	Owned after	D/I	Nature of ownership
Common Stock^F1,F2,F3	Feb 12, 2019	C	1,564,272	—	A	1,564,272	I	See footnote
Common Stock^F1,F2,F3	Feb 12, 2019	C	464,281	—	A	2,028,553	I	See footnote
Common Stock^F1,F4,F5	Feb 12, 2019	C	464,281	—	A	464,281	I	See footnote
Common Stock^F2,F3	Feb 12, 2019	P	214,286	$14.00	A	2,242,839	I	See footnote
Common Stock^F4,F5	Feb 12, 2019	P	214,285	$14.00	A	678,566	I	See footnote

Table II — derivative securities

Security	Conv. / exercise price	Date	Code	Shares	A/D	Exercisable	Expires	Underlying	Underlying shares	D/I
Series B Convertible Preferred Stock^F1,F2,F3	—	Feb 12, 2019	C	1,564,272	D	—	—	Common Stock	1,564,272	I
Series C Convertible Preferred Stock^F1,F2,F3	—	Feb 12, 2019	C	464,281	D	—	—	Common Stock	464,281	I
Series C Convertible Preferred Stock^F1,F4,F5	—	Feb 12, 2019	C	464,281	D	—	—	Common Stock	464,281	I

Explanation of responses

F1All series of convertible preferred stock automatically converted into shares of the Issuer's common stock on a 1-for-1 basis, for no additional consideration, upon the closing of the Issuer's initial public offering.
F2These shares are held directly by New Leaf Ventures III, L.P. ("NLV-III"). The general partner of NLV-III is New Leaf Venture Associates III, L.P. ("NLVA-III"). The general partner of NLVA-III is New Leaf Venture Management III, L.L.C. ("Management-III"). Each of NLVA-III and Management-III disclaim beneficial ownership of these securities and this report shall not be deemed an admission that NLVA-III or Management-III are beneficial owners of such securities for purposes of Section 16 or any other purpose, except to the extent of their respective pecuniary interests therein.
F3Each of Ronald M. Hunt, a member of the Issuer's board of directors, Vijay K. Lathi, and Liam T. Ratcliffe, the managers of Management-III (the "NLV-III Managers"), may each be deemed to have shared voting and investment power with respect to these securities. Each of the NLV-III Managers disclaims beneficial ownership of these securities and this report shall not be deemed an admission that any of them is the beneficial owner of such securities for purposes of Section 16 or for any other purpose, except to the extent of their respective pecuniary interests therein.
F4These shares are held directly by New Leaf Ventures Biopharma Opportunities II, L.P. ("BPO-II"). The general partner of BPO-II is New Leaf BPO Associates II, L.P. ("NLBA-II"). The general partner of NLBA-II is New Leaf BPO Management II, L.L.C. ("BPO Management-II"). Each of NLBA-II and BPO Management-II disclaim beneficial ownership of these securities and this report shall not be deemed an admission that NLBA-II or BPO Management-II are beneficial owners of such securities for purposes of Section 16 or any other purpose, except to the extent of their respective pecuniary interests therein.
F5Each of Ronald M. Hunt, Vijay K. Lathi, Liam T. Ratcliffe and Isaac A. Manke, the managers of BPO Management-II (the "BPO-II Managers"), may each be deemed to have shared voting and investment power with respect to these securities. Each of the BPO-II Managers disclaims beneficial ownership of these securities and this report shall not be deemed an admission that any of them is the beneficial owner of such securities for purposes of Section 16 or for any other purpose, except to the extent of their respective pecuniary interests therein.