Security	Date	Code	Shares	Price	A/D	Owned after	D/I	Nature of ownership
Common Stock^F1,F2,F3,F4	Apr 3, 2018	P$0	345,551	—	A	1,556,676	I	See Footnotes
Common Stock^F5,F3,F4,F6	Apr 3, 2018	P$0	6,478	—	A	29,178	I	See Footnotes
Common Stock^F7,F8,F9,F10	Apr 3, 2018	P$0	769,989	—	A	3,468,190	I	See Footnotes
Common Stock^{F11,F9,F10,F12}	Apr 3, 2018	P$0	15,007	—	A	67,729	I	See Footnotes
Common Stock^{F13,F9,F10,F14}	Apr 3, 2018	P$0	5,275	—	A	23,875	I	See Footnotes
Common Stock^{F15,F9,F10,F16}	Apr 3, 2018	P$0	7,700	—	A	34,587	I	See Footnotes

Table II — derivative securities

Security	Conv. / exercise price	Date	Code	Shares	A/D	Exercisable	Expires	Underlying	Underlying shares	Owned after	D/I
Series A Warrant (right to buy)^F1,F2,F3,F4	$0.65	Apr 3, 2018	P	345,551	A	Apr 3, 2018	Oct 3, 2018	Common Stock	345,551	345,551	I
Series B Warrant (right to buy)^F1,F2,F3,F4	$0.75	Apr 3, 2018	P	345,551	A	Apr 3, 2018	Apr 3, 2023	Common Stock	345,551	345,551	I
Series A Warrant (right to buy)^F5,F3,F4,F6	$0.65	Apr 3, 2018	P	6,478	A	Apr 3, 2018	Oct 3, 2018	Common Stock	6,478	6,478	I
Series B Warrant (right to buy)^F5,F3,F4,F6	$0.75	Apr 3, 2018	P	6,478	A	Apr 3, 2018	Apr 3, 2023	Common Stock	6,478	6,478	I
Series A Warrant (right to buy)^F7,F8,F9,F10	$0.65	Apr 3, 2018	P	769,989	A	Apr 3, 2018	Oct 3, 2018	Common Stock	769,989	769,989	I
Series B Warrant (right to buy)^F7,F8,F9,F10	$0.75	Apr 3, 2018	P	769,989	A	Apr 3, 2018	Apr 3, 2023	Common Stock	769,989	769,989	I
Series A Warrant (right to buy)^{F11,F9,F10,F12}	$0.65	Apr 3, 2018	P	15,007	A	Apr 3, 2018	Oct 3, 2018	Common Stock	15,007	15,007	I
Series B Warrant (right to buy)^{F11,F9,F10,F12}	$0.75	Apr 3, 2018	P	15,007	A	Apr 3, 2018	Apr 3, 2023	Common Stock	15,007	15,007	I
Series A Warrant (right to buy)^{F13,F9,F10,F14}	$0.65	Apr 3, 2018	P	5,275	A	Apr 3, 2018	Oct 3, 2018	Common Stock	5,275	5,275	I
Series B Warrant (right to buy)^{F13,F9,F10,F14}	$0.75	Apr 3, 2018	P	5,275	A	Apr 3, 2018	Apr 3, 2023	Common Stock	5,275	5,275	I
Series A Warrant (right to buy)^{F15,F9,F10,F16}	$0.65	Apr 3, 2018	P	7,700	A	Apr 3, 2018	Oct 3, 2018	Common Stock	7,700	7,700	I
Series B Warrant (right to buy)^{F15,F9,F10,F16}	$0.75	Apr 3, 2018	P	7,700	A	Apr 3, 2018	Apr 3, 2023	Common Stock	7,700	7,700	I

Explanation of responses

F1The reported securities were included within 345,551 Units purchased by Polaris Venture Partners IV, L.P. ("PVP IV") for $0.65 per Unit (each, a "Unit"). Each Unit consisted of one share of common stock, one Series A Warrant to purchase one share of common stock at an exercise price of $0.65 per share, and one Series B Warrant to purchase one share of common stock at an exercise price of $0.75 per share.
F10Each of Messrs. Flint and McGuire 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.
F11The reported securities were included within 15,007 Units purchased by PVPEF V.
F12Securities held of record by PVPEF V.
F13The reported securities were included within 5,275 Units purchased by PVPFF V.
F14Securities held of record by PVPFF V.
F15The reported securities were included within 7,700 Units purchased by PVPSFF V.
F16Securities held of record by PVPSFF V.
F2Securities held of record by PVP IV.
F3Polaris Venture Management Co. IV, L.L.C. ("PVM IV") is the general partner of PVP IV and Polaris Venture Partners Entrepreneurs' Fund IV, L.P. ("PVPE IV"). Each of Jonathan A. Flint and Terrance G. McGuire are the managing members of PVM IV. PVM IV disclaims beneficial ownership of these securities and this report shall not be deemed an admission that PVM IV is the beneficial owner of such securities for purposes of Section 16 or for any other purpose, except to the extent of its pecuniary interest therein. Each of Jonathan A. Flint and Terrance G. McGuire, in their respective capacities with regard to PVM IV, may be deemed to have shared voting and dispositive power over the shares held by each of PVP IV and PVPE IV.
F4Each of Messrs. Flint and McGuire 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.
F5The reported securities were included within 6,478 Units purchased by PVPE IV.
F6Securities held of record by PVPE IV.
F7The reported securities were included within 769,989 Units purchased by Polaris Venture Partners V, L.P. ("PVP V").
F8Securities held of record by PVP V.
F9Polaris Venture Management Co. V, LLC ("PVM V") is the general partner of PVP V, Polaris Venture Partners Founders' Fund V, L.P. ("PVPFF V"), Polaris Venture Partners Special Founders' Fund V, L.P. ("PVPSFF V") and Polaris Venture Partners Entrepreneurs' Fund V, L.P. ("PVPEF V"). Each of Jonathan A. Flint and Terrance G. McGuire are the managing members of PVM V. PVM V disclaims beneficial ownership of these securities and this report shall not be deemed an admission that PVM V is the beneficial owner of such securities for purposes of Section 16 or for any other purpose, except to the extent of its pecuniary interest therein. Each of Jonathan A. Flint and Terrance G. McGuire, in their respective capacities with regard to PVM V, may be deemed to have shared voting and dispositive power over the shares held by each of PVP V, PVPFF V, PFPSFF V and PVPEF V.

Remarks

Exhibit 24 - Power of Attorney Polaris Venture Partners IV, L.P. Polaris Venture Partners Entrepreneurs' Fund IV, L.P. Polaris Venture Management Co. IV, L.L.C. Jonathan A. Flint Terrance G. McGuire