Security	Date	Code	Shares	Price	A/D	Owned after	D/I	Nature of ownership
Common Stock^F1,F2	Oct 1, 2018	C	943	—	A	943	I	By International Life Sciences Fund III Co-Investment, L.P.
Common Stock^F3,F2	Oct 1, 2018	C	7,610	—	A	8,553	I	By International Life Sciences Fund III Co-Investment, L.P.
Common Stock^F4,F2	Oct 1, 2018	C	2,399	—	A	10,952	I	By International Life Sciences Fund III Co-Investment, L.P.
Common Stock^F1,F2	Oct 1, 2018	C	79,467	—	A	79,467	I	By International Life Sciences Fund III (LP1), L.P.
Common Stock^F3,F2	Oct 1, 2018	C	641,440	—	A	720,907	I	By International Life Sciences Fund III (LP1), L.P.
Common Stock^F4,F2	Oct 1, 2018	C	202,115	—	A	923,022	I	By International Life Sciences Fund III (LP1), L.P.
Common Stock^F1,F2	Oct 1, 2018	C	758	—	A	758	I	By International Life Sciences Fund III Strategic Partners, L.P.
Common Stock^F3,F2	Oct 1, 2018	C	6,128	—	A	6,886	I	By International Life Sciences Fund III Strategic Partners, L.P.
Common Stock^F4,F2	Oct 1, 2018	C	1,931	—	A	8,817	I	By International Life Sciences Fund III Strategic Partners, L.P.
Common Stock^F4,F5	Oct 1, 2018	C	341,030	—	A	341,030	I	By SV Life Sciences Fund V, L.P.
Common Stock^F6,F5	Oct 1, 2018	C	270,690	—	A	611,720	I	By SV Life Sciences Fund V, L.P.
Common Stock^F7,F5	Oct 1, 2018	C	251,783	—	A	863,503	I	By SV Life Sciences Fund V, L.P.
Common Stock^F4,F8	Oct 1, 2018	C	7,207	—	A	7,207	I	By SV Life Sciences Fund V Strategic Partners, L.P.
Common Stock^F6,F8	Oct 1, 2018	C	5,721	—	A	12,928	I	By SV Life Sciences Fund V Strategic Partners, L.P.
Common Stock^F7,F8	Oct 1, 2018	C	5,320	—	A	18,248	I	By SV Life Sciences Fund V Strategic Partners, L.P.

Table II — derivative securities

Security	Conv. / exercise price	Date	Code	Shares	A/D	Exercisable	Expires	Underlying	Underlying shares	Owned after	D/I
Series C Preferred Stock Warrant (right to buy)^F2,F9	$0.4797	Sep 27, 2018	M	6,183	D	—	—	Series C Preferred Stock	6,183	5,361	I
Series C Preferred Stock^F2,F10	—	Sep 27, 2018	M	6,183	A	—	—	Common Stock	228	64,815	I
Series C Preferred Stock Warrant (right to buy)^F2,F9	$0.4797	Sep 27, 2018	M	521,159	D	—	—	Series C Preferred Stock	521,159	451,869	I
Series C Preferred Stock^F2,F10	—	Sep 27, 2018	M	521,159	A	—	—	Common Stock	19,282	5,462,550	I
Series C Preferred Stock Warrant (right to buy)^F2,F9	$0.4797	Sep 27, 2018	M	4,978	D	—	—	Series C Preferred Stock	4,978	4,315	I
Series C Preferred Stock^F2,F10	—	Sep 27, 2018	M	4,978	A	—	—	Common Stock	184	52,183	I
Series A Preferred Stock^F2,F1	—	Oct 1, 2018	C	21,776	D	—	—	Common Stock	943	0	I
Series B Preferred Stock^F2,F3	—	Oct 1, 2018	C	131,683	D	—	—	Common Stock	7,610	0	I
Series C Preferred Stock^F2,F4	—	Oct 1, 2018	C	64,815	D	—	—	Common Stock	2,399	0	I
Series A Preferred Stock^F2,F1	—	Oct 1, 2018	C	1,835,270	D	—	—	Common Stock	79,467	0	I
Series B Preferred Stock^F2,F3	—	Oct 1, 2018	C	11,097,596	D	—	—	Common Stock	641,440	0	I
Series C Preferred Stock^F2,F4	—	Oct 1, 2018	C	5,462,550	D	—	—	Common Stock	202,115	0	I
Series A Preferred Stock^F2,F1	—	Oct 1, 2018	C	17,533	D	—	—	Common Stock	758	0	I
Series B Preferred Stock^F2,F3	—	Oct 1, 2018	C	106,019	D	—	—	Common Stock	6,128	0	I
Series C Preferred Stock^F2,F4	—	Oct 1, 2018	C	52,183	D	—	—	Common Stock	1,931	0	I
Series C Preferred Stock^F5,F4	—	Oct 1, 2018	C	9,217,015	D	—	—	Common Stock	341,030	0	I
Series D Preferred Stock^F5,F6	—	Oct 1, 2018	C	6,683,697	D	—	—	Common Stock	270,690	0	I
Series E Preferred Stock^F5,F7	—	Oct 1, 2018	C	9,155,794	D	—	—	Common Stock	251,783	0	I
Series C Preferred Stock^F8,F4	—	Oct 1, 2018	C	194,786	D	—	—	Common Stock	7,207	0	I
Series D Preferred Stock^F8,F6	—	Oct 1, 2018	C	141,249	D	—	—	Common Stock	5,721	0	I
Series E Preferred Stock^F8,F7	—	Oct 1, 2018	C	193,492	D	—	—	Common Stock	5,320	0	I

Explanation of responses

F1Each share of the issuer's Series A Preferred Stock automatically converted into 0.0433 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.
F10Each share of the issuer's Series C Preferred Stock will automatically convert into 0.0370 share of the issuer's Common Stock immediately upon the closing of the issuer's IPO and has no expiration date.
F2International Life Sciences Fund III (GP), LP. ("Fund III GP") is the general partner of each of: (i) International Life Sciences Fund III (LP1), L.P. ("ILSF LP1"), (ii) International Life Sciences Fund III Co-Investment, L.P. ("ILSF Co-Invest") and (iii) International Life Sciences Fund III Strategic Partners, L.P. ("ILSF Strategic" and collectively, the "Fund III Entities"). ILSF III, LLC (the "ILSF General Partner") is the general partner of Fund III GP and, through an investment committee comprised of James Garvey, Kate Bingham, Eugene D. Hill, III and Michael J. Ross controls voting and investment decisions over the Issuer's shares held by the Fund III Entities by majority vote. Each of Fund III GP, ILSF General Partner, and each member of the investment committee of ILSF General Partner disclaims beneficial ownership over the Shares held by the Fund III Entities except to the extent of any pecuniary interest therein.
F3Each 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 IPO pursuant to the Registration Statement, and had no expiration date.
F4Each 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.
F5These shares are owned directly by SV Life Sciences Fund V, L.P. ("SVLS V LP"). SV Life Sciences Fund V (GP), LP ("SVLS V GP") is the general partner of SVLS V LP. The general partner of SVLS V GP is SVLSF V, LLC. Kate Bingham, James Garvey, Eugene D. Hill, III and Michael J. Ross are members of the investment committee of SVLSF V, LLC. SVLS V GP, SVLSF V, LLC and each of the individuals comprising the SVLSF V, LLC investment committee may be deemed to share voting, dispositive and investment power over the shares held of record by SVLS V LP. Each of SVLS V GP, SVLSF V, LLC and the individual members of the SVLSF V, LLC investment committee disclaims beneficial ownership of these securities and this report shall not be deemed to be an admission that any one of them is the beneficial owner of such securities for purposes of Section 16 or any other purpose, except to the extent of their pecuniary interest therein.
F6Each 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.
F7Each 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.
F8These shares are owned directly by SV Life Sciences Fund V Strategic Partners, L.P. ("SVLS V SPP"). SVLS V GP is the general partner of SVLS V SPP. The general partner of SVLS V GP is SVLSF V, LLC. Kate Bingham, James Garvey, Eugene D. Hill, III and Michael J. Ross are members of the investment committee of SVLSF V, LLC. SVLS V GP, SVLSF V, LLC and each of the individuals comprising the SVLSF V, LLC investment committee may be deemed to share voting, dispositive and investment power over the shares held of record by SVLS V SPP. Each of SVLS V GP, SVLSF V, LLC and the individual members of the SVLSF V, LLC investment committee disclaims beneficial ownership of these securities and this report shall not be deemed to be an admission that any one of them is the beneficial owner of such securities for purposes of Section 16 or any other purpose, except to the extent of their pecuniary interest therein.
F9The warrant is exercisable at any time at the holder's election on a one-for one basis and automatically terminates on the completion of the issuer's initial public offering if not earlier exercised.