XFOR

SEC source: 0000899243-17-027009 · doc4.xml · derivative · entry 25

SVLSF V, LLC · CIK 0001644160 · 10% owner

SV Life Sciences Fund VI Strategic Partners, L.P. · CIK 0001667605 · 10% owner

SV Life Sciences Fund VI, L.P. · CIK 0001642251 · 10% owner

SV Life Sciences Fund V Strategic Partners, L.P. · CIK 0001482194 · 10% owner

SV LIFE SCIENCES FUND V LP · CIK 0001460732 · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 0

Underlying: Common Stock · 431,980 shares

Expires not disclosed

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F5 · derivative.exercise_price: The Series D Convertible Preferred Stock converted into Common Stock on a 0.29300-for-one basis upon the closing of the Issuer's initial public offering without payment of consideration. The Series D Convertible Preferred Stock was convertible at any time at the holder's election and automatically upon the closing at the Issuer's initial public offering. The shares had no expiration date.

F5 · derivative.exercise_date: The Series D Convertible Preferred Stock converted into Common Stock on a 0.29300-for-one basis upon the closing of the Issuer's initial public offering without payment of consideration. The Series D Convertible Preferred Stock was convertible at any time at the holder's election and automatically upon the closing at the Issuer's initial public offering. The shares had no expiration date.

F5 · derivative.expiration_date: The Series D Convertible Preferred Stock converted into Common Stock on a 0.29300-for-one basis upon the closing of the Issuer's initial public offering without payment of consideration. The Series D Convertible Preferred Stock was convertible at any time at the holder's election and automatically upon the closing at the Issuer's initial public offering. The shares had no expiration date.

F8 · ownership.direct: These shares are owned directly by SV Life Sciences Fund VI, L.P. ("SVLS VI LP"). SV Life Sciences Fund VI (GP), LP ("SVLS VI GP") is the general partner of SVLS VI LP. The general partner of SVLS VI GP is SVLSF VI, LLC. Kate Bingham, James Garvey, Eugene D. Hill, III, Paul LaViolette, Thomas Flynn and Michael Ross are members of the investment committee of SVLSF VI, LLC. SVLS VI GP, SVLSF VI, LLC and each of the individuals comprising the SVLSF VI, LLC investment committee may be deemed to share voting, dispositive and investment power over the shares held of record by SVLS VI LP. Each of SVLS VI GP, SVLSF VI, LLC and the individual members of the SVLSF VI, 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.

SEC source: 0000899243-17-027009 · doc4.xml · derivative · entry 24

SVLSF V, LLC · CIK 0001644160 · 10% owner

SV Life Sciences Fund VI Strategic Partners, L.P. · CIK 0001667605 · 10% owner

SV Life Sciences Fund VI, L.P. · CIK 0001642251 · 10% owner

SV Life Sciences Fund V Strategic Partners, L.P. · CIK 0001482194 · 10% owner

SV LIFE SCIENCES FUND V LP · CIK 0001460732 · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 0

Underlying: Common Stock · 4,288 shares

Expires not disclosed

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F5 · derivative.exercise_price: The Series D Convertible Preferred Stock converted into Common Stock on a 0.29300-for-one basis upon the closing of the Issuer's initial public offering without payment of consideration. The Series D Convertible Preferred Stock was convertible at any time at the holder's election and automatically upon the closing at the Issuer's initial public offering. The shares had no expiration date.

F5 · derivative.exercise_date: The Series D Convertible Preferred Stock converted into Common Stock on a 0.29300-for-one basis upon the closing of the Issuer's initial public offering without payment of consideration. The Series D Convertible Preferred Stock was convertible at any time at the holder's election and automatically upon the closing at the Issuer's initial public offering. The shares had no expiration date.

F5 · derivative.expiration_date: The Series D Convertible Preferred Stock converted into Common Stock on a 0.29300-for-one basis upon the closing of the Issuer's initial public offering without payment of consideration. The Series D Convertible Preferred Stock was convertible at any time at the holder's election and automatically upon the closing at the Issuer's initial public offering. The shares had no expiration date.

F7 · ownership.direct: These 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 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.

SEC source: 0000899243-17-027009 · doc4.xml · derivative · entry 23

SVLSF V, LLC · CIK 0001644160 · 10% owner

SV Life Sciences Fund VI Strategic Partners, L.P. · CIK 0001667605 · 10% owner

SV Life Sciences Fund VI, L.P. · CIK 0001642251 · 10% owner

SV Life Sciences Fund V Strategic Partners, L.P. · CIK 0001482194 · 10% owner

SV LIFE SCIENCES FUND V LP · CIK 0001460732 · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 0

Underlying: Common Stock · 202,915 shares

Expires not disclosed

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F5 · derivative.exercise_price: The Series D Convertible Preferred Stock converted into Common Stock on a 0.29300-for-one basis upon the closing of the Issuer's initial public offering without payment of consideration. The Series D Convertible Preferred Stock was convertible at any time at the holder's election and automatically upon the closing at the Issuer's initial public offering. The shares had no expiration date.

F5 · derivative.exercise_date: The Series D Convertible Preferred Stock converted into Common Stock on a 0.29300-for-one basis upon the closing of the Issuer's initial public offering without payment of consideration. The Series D Convertible Preferred Stock was convertible at any time at the holder's election and automatically upon the closing at the Issuer's initial public offering. The shares had no expiration date.

F5 · derivative.expiration_date: The Series D Convertible Preferred Stock converted into Common Stock on a 0.29300-for-one basis upon the closing of the Issuer's initial public offering without payment of consideration. The Series D Convertible Preferred Stock was convertible at any time at the holder's election and automatically upon the closing at the Issuer's initial public offering. The shares had no expiration date.

F6 · ownership.direct: These 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 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.

SEC source: 0000899243-17-027009 · doc4.xml · derivative · entry 22

SVLSF V, LLC · CIK 0001644160 · 10% owner

SV Life Sciences Fund VI Strategic Partners, L.P. · CIK 0001667605 · 10% owner

SV Life Sciences Fund VI, L.P. · CIK 0001642251 · 10% owner

SV Life Sciences Fund V Strategic Partners, L.P. · CIK 0001482194 · 10% owner

SV LIFE SCIENCES FUND V LP · CIK 0001460732 · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 0

Underlying: Common Stock · 2,365 shares

Expires not disclosed

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F4 · derivative.exercise_price: The Series C Convertible Preferred Stock converted into Common Stock on a 0.49832-for-one basis upon the closing of the Issuer's initial public offering without payment of consideration. The Series C Convertible Preferred Stock was convertible at any time at the holder's election and automatically upon the closing at the Issuer's initial public offering. The shares had no expiration date.

F4 · derivative.exercise_date: The Series C Convertible Preferred Stock converted into Common Stock on a 0.49832-for-one basis upon the closing of the Issuer's initial public offering without payment of consideration. The Series C Convertible Preferred Stock was convertible at any time at the holder's election and automatically upon the closing at the Issuer's initial public offering. The shares had no expiration date.

F4 · derivative.expiration_date: The Series C Convertible Preferred Stock converted into Common Stock on a 0.49832-for-one basis upon the closing of the Issuer's initial public offering without payment of consideration. The Series C Convertible Preferred Stock was convertible at any time at the holder's election and automatically upon the closing at the Issuer's initial public offering. The shares had no expiration date.

F7 · ownership.direct: These 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 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.

SEC source: 0000899243-17-027009 · doc4.xml · derivative · entry 21

SVLSF V, LLC · CIK 0001644160 · 10% owner

SV Life Sciences Fund VI Strategic Partners, L.P. · CIK 0001667605 · 10% owner

SV Life Sciences Fund VI, L.P. · CIK 0001642251 · 10% owner

SV Life Sciences Fund V Strategic Partners, L.P. · CIK 0001482194 · 10% owner

SV LIFE SCIENCES FUND V LP · CIK 0001460732 · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 0

Underlying: Common Stock · 111,955 shares

Expires not disclosed

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F4 · derivative.exercise_price: The Series C Convertible Preferred Stock converted into Common Stock on a 0.49832-for-one basis upon the closing of the Issuer's initial public offering without payment of consideration. The Series C Convertible Preferred Stock was convertible at any time at the holder's election and automatically upon the closing at the Issuer's initial public offering. The shares had no expiration date.

F4 · derivative.exercise_date: The Series C Convertible Preferred Stock converted into Common Stock on a 0.49832-for-one basis upon the closing of the Issuer's initial public offering without payment of consideration. The Series C Convertible Preferred Stock was convertible at any time at the holder's election and automatically upon the closing at the Issuer's initial public offering. The shares had no expiration date.

F4 · derivative.expiration_date: The Series C Convertible Preferred Stock converted into Common Stock on a 0.49832-for-one basis upon the closing of the Issuer's initial public offering without payment of consideration. The Series C Convertible Preferred Stock was convertible at any time at the holder's election and automatically upon the closing at the Issuer's initial public offering. The shares had no expiration date.

F6 · ownership.direct: These 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 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.

SEC source: 0000899243-17-027009 · doc4.xml · derivative · entry 20

SVLSF V, LLC · CIK 0001644160 · 10% owner

SV Life Sciences Fund VI Strategic Partners, L.P. · CIK 0001667605 · 10% owner

SV Life Sciences Fund VI, L.P. · CIK 0001642251 · 10% owner

SV Life Sciences Fund V Strategic Partners, L.P. · CIK 0001482194 · 10% owner

SV LIFE SCIENCES FUND V LP · CIK 0001460732 · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 0

Underlying: Common Stock · 6,806 shares

Expires not disclosed

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F3 · derivative.exercise_price: The Series B Convertible Preferred Stock converted into Common Stock on a 0.44650-for-one basis upon the closing of the Issuer's initial public offering without payment of consideration. The Series B Convertible Preferred Stock was convertible at any time at the holder's election and automatically upon the closing at the Issuer's initial public offering. The shares had no expiration date.

F3 · derivative.exercise_date: The Series B Convertible Preferred Stock converted into Common Stock on a 0.44650-for-one basis upon the closing of the Issuer's initial public offering without payment of consideration. The Series B Convertible Preferred Stock was convertible at any time at the holder's election and automatically upon the closing at the Issuer's initial public offering. The shares had no expiration date.

F3 · derivative.expiration_date: The Series B Convertible Preferred Stock converted into Common Stock on a 0.44650-for-one basis upon the closing of the Issuer's initial public offering without payment of consideration. The Series B Convertible Preferred Stock was convertible at any time at the holder's election and automatically upon the closing at the Issuer's initial public offering. The shares had no expiration date.

F7 · ownership.direct: These 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 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.

SEC source: 0000899243-17-027009 · doc4.xml · derivative · entry 19

SVLSF V, LLC · CIK 0001644160 · 10% owner

SV Life Sciences Fund VI Strategic Partners, L.P. · CIK 0001667605 · 10% owner

SV Life Sciences Fund VI, L.P. · CIK 0001642251 · 10% owner

SV Life Sciences Fund V Strategic Partners, L.P. · CIK 0001482194 · 10% owner

SV LIFE SCIENCES FUND V LP · CIK 0001460732 · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 0

Underlying: Common Stock · 322,102 shares

Expires not disclosed

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F3 · derivative.exercise_price: The Series B Convertible Preferred Stock converted into Common Stock on a 0.44650-for-one basis upon the closing of the Issuer's initial public offering without payment of consideration. The Series B Convertible Preferred Stock was convertible at any time at the holder's election and automatically upon the closing at the Issuer's initial public offering. The shares had no expiration date.

F3 · derivative.exercise_date: The Series B Convertible Preferred Stock converted into Common Stock on a 0.44650-for-one basis upon the closing of the Issuer's initial public offering without payment of consideration. The Series B Convertible Preferred Stock was convertible at any time at the holder's election and automatically upon the closing at the Issuer's initial public offering. The shares had no expiration date.

F3 · derivative.expiration_date: The Series B Convertible Preferred Stock converted into Common Stock on a 0.44650-for-one basis upon the closing of the Issuer's initial public offering without payment of consideration. The Series B Convertible Preferred Stock was convertible at any time at the holder's election and automatically upon the closing at the Issuer's initial public offering. The shares had no expiration date.

F6 · ownership.direct: These 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 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.

SEC source: 0000899243-17-027009 · doc4.xml · derivative · entry 18

SVLSF V, LLC · CIK 0001644160 · 10% owner

SV Life Sciences Fund VI Strategic Partners, L.P. · CIK 0001667605 · 10% owner

SV Life Sciences Fund VI, L.P. · CIK 0001642251 · 10% owner

SV Life Sciences Fund V Strategic Partners, L.P. · CIK 0001482194 · 10% owner

SV LIFE SCIENCES FUND V LP · CIK 0001460732 · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 0

Underlying: Common Stock · 5,219 shares

Expires not disclosed

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F2 · derivative.exercise_price: The Series A-2 Convertible Preferred Stock converted into Common Stock on a 0.35785-for-one basis upon the closing of the Issuer's initial public offering without payment of consideration. The Series A-2 Convertible Preferred Stock was convertible at any time at the holder's election and automatically upon the closing at the Issuer's initial public offering. The shares had no expiration date.

F2 · derivative.exercise_date: The Series A-2 Convertible Preferred Stock converted into Common Stock on a 0.35785-for-one basis upon the closing of the Issuer's initial public offering without payment of consideration. The Series A-2 Convertible Preferred Stock was convertible at any time at the holder's election and automatically upon the closing at the Issuer's initial public offering. The shares had no expiration date.

F2 · derivative.expiration_date: The Series A-2 Convertible Preferred Stock converted into Common Stock on a 0.35785-for-one basis upon the closing of the Issuer's initial public offering without payment of consideration. The Series A-2 Convertible Preferred Stock was convertible at any time at the holder's election and automatically upon the closing at the Issuer's initial public offering. The shares had no expiration date.

F7 · ownership.direct: These 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 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.

SEC source: 0000899243-17-027009 · doc4.xml · derivative · entry 17

SVLSF V, LLC · CIK 0001644160 · 10% owner

SV Life Sciences Fund VI Strategic Partners, L.P. · CIK 0001667605 · 10% owner

SV Life Sciences Fund VI, L.P. · CIK 0001642251 · 10% owner

SV Life Sciences Fund V Strategic Partners, L.P. · CIK 0001482194 · 10% owner

SV LIFE SCIENCES FUND V LP · CIK 0001460732 · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 0

Underlying: Common Stock · 247,010 shares

Expires not disclosed

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F2 · derivative.exercise_price: The Series A-2 Convertible Preferred Stock converted into Common Stock on a 0.35785-for-one basis upon the closing of the Issuer's initial public offering without payment of consideration. The Series A-2 Convertible Preferred Stock was convertible at any time at the holder's election and automatically upon the closing at the Issuer's initial public offering. The shares had no expiration date.

F2 · derivative.exercise_date: The Series A-2 Convertible Preferred Stock converted into Common Stock on a 0.35785-for-one basis upon the closing of the Issuer's initial public offering without payment of consideration. The Series A-2 Convertible Preferred Stock was convertible at any time at the holder's election and automatically upon the closing at the Issuer's initial public offering. The shares had no expiration date.

F2 · derivative.expiration_date: The Series A-2 Convertible Preferred Stock converted into Common Stock on a 0.35785-for-one basis upon the closing of the Issuer's initial public offering without payment of consideration. The Series A-2 Convertible Preferred Stock was convertible at any time at the holder's election and automatically upon the closing at the Issuer's initial public offering. The shares had no expiration date.

F6 · ownership.direct: These 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 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.

SEC source: 0000899243-17-027009 · doc4.xml · derivative · entry 16

SVLSF V, LLC · CIK 0001644160 · 10% owner

SV Life Sciences Fund VI Strategic Partners, L.P. · CIK 0001667605 · 10% owner

SV Life Sciences Fund VI, L.P. · CIK 0001642251 · 10% owner

SV Life Sciences Fund V Strategic Partners, L.P. · CIK 0001482194 · 10% owner

SV LIFE SCIENCES FUND V LP · CIK 0001460732 · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 0

Underlying: Common Stock · 404 shares

Expires not disclosed

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · derivative.exercise_price: The Series A-1 Convertible Preferred Stock converted into Common Stock on a 0.29300-for-one basis upon the closing of the Issuer's initial public offering without payment of consideration. The Series A-1 Convertible Preferred Stock was convertible at any time at the holder's election and automatically upon the closing at the Issuer's initial public offering. The shares had no expiration date.

F1 · derivative.exercise_date: The Series A-1 Convertible Preferred Stock converted into Common Stock on a 0.29300-for-one basis upon the closing of the Issuer's initial public offering without payment of consideration. The Series A-1 Convertible Preferred Stock was convertible at any time at the holder's election and automatically upon the closing at the Issuer's initial public offering. The shares had no expiration date.

F1 · derivative.expiration_date: The Series A-1 Convertible Preferred Stock converted into Common Stock on a 0.29300-for-one basis upon the closing of the Issuer's initial public offering without payment of consideration. The Series A-1 Convertible Preferred Stock was convertible at any time at the holder's election and automatically upon the closing at the Issuer's initial public offering. The shares had no expiration date.

F7 · ownership.direct: These 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 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.

SEC source: 0000899243-17-027009 · doc4.xml · derivative · entry 15

SVLSF V, LLC · CIK 0001644160 · 10% owner

SV Life Sciences Fund VI Strategic Partners, L.P. · CIK 0001667605 · 10% owner

SV Life Sciences Fund VI, L.P. · CIK 0001642251 · 10% owner

SV Life Sciences Fund V Strategic Partners, L.P. · CIK 0001482194 · 10% owner

SV LIFE SCIENCES FUND V LP · CIK 0001460732 · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 0

Underlying: Common Stock · 19,128 shares

Expires not disclosed

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · derivative.exercise_price: The Series A-1 Convertible Preferred Stock converted into Common Stock on a 0.29300-for-one basis upon the closing of the Issuer's initial public offering without payment of consideration. The Series A-1 Convertible Preferred Stock was convertible at any time at the holder's election and automatically upon the closing at the Issuer's initial public offering. The shares had no expiration date.

F1 · derivative.exercise_date: The Series A-1 Convertible Preferred Stock converted into Common Stock on a 0.29300-for-one basis upon the closing of the Issuer's initial public offering without payment of consideration. The Series A-1 Convertible Preferred Stock was convertible at any time at the holder's election and automatically upon the closing at the Issuer's initial public offering. The shares had no expiration date.

F1 · derivative.expiration_date: The Series A-1 Convertible Preferred Stock converted into Common Stock on a 0.29300-for-one basis upon the closing of the Issuer's initial public offering without payment of consideration. The Series A-1 Convertible Preferred Stock was convertible at any time at the holder's election and automatically upon the closing at the Issuer's initial public offering. The shares had no expiration date.

F6 · ownership.direct: These 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 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.

SEC source: 0000899243-17-027009 · doc4.xml · nonDerivative · entry 14

SVLSF V, LLC · CIK 0001644160 · 10% owner

SV Life Sciences Fund VI Strategic Partners, L.P. · CIK 0001667605 · 10% owner

SV Life Sciences Fund VI, L.P. · CIK 0001642251 · 10% owner

SV Life Sciences Fund V Strategic Partners, L.P. · CIK 0001482194 · 10% owner

SV LIFE SCIENCES FUND V LP · CIK 0001460732 · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 1,868,961

F9 · ownership.direct: These shares are owned directly by SV Life Sciences Fund VI Strategic Partners, L.P. ("SVLS VI SPP"). SVLS VI GP is the general partner of SVLS VI SPP. The general partner of SVLS VI GP is SVLSF VI, LLC. Kate Bingham, James Garvey, Eugene D. Hill, III, Paul LaViolette, Thomas Flynn, and Michael Ross are members of the investment committee of SVLSF VI, LLC. SVLS VI GP, SVLSF VI, LLC and each of the individuals comprising the SVLSF VI, LLC investment committee may be deemed to share voting, dispositive and investment power over the shares held of record by SVLS VI SPP. Each of SVLS VI GP, SVLSF VI, LLC and the individual members of the SVLSF VI, 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.

SEC source: 0000899243-17-027009 · doc4.xml · nonDerivative · entry 13

SVLSF V, LLC · CIK 0001644160 · 10% owner

SV Life Sciences Fund VI Strategic Partners, L.P. · CIK 0001667605 · 10% owner

SV Life Sciences Fund VI, L.P. · CIK 0001642251 · 10% owner

SV Life Sciences Fund V Strategic Partners, L.P. · CIK 0001482194 · 10% owner

SV LIFE SCIENCES FUND V LP · CIK 0001460732 · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 1,852,409

F8 · ownership.direct: These shares are owned directly by SV Life Sciences Fund VI, L.P. ("SVLS VI LP"). SV Life Sciences Fund VI (GP), LP ("SVLS VI GP") is the general partner of SVLS VI LP. The general partner of SVLS VI GP is SVLSF VI, LLC. Kate Bingham, James Garvey, Eugene D. Hill, III, Paul LaViolette, Thomas Flynn and Michael Ross are members of the investment committee of SVLSF VI, LLC. SVLS VI GP, SVLSF VI, LLC and each of the individuals comprising the SVLSF VI, LLC investment committee may be deemed to share voting, dispositive and investment power over the shares held of record by SVLS VI LP. Each of SVLS VI GP, SVLSF VI, LLC and the individual members of the SVLSF VI, 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.

SEC source: 0000899243-17-027009 · doc4.xml · nonDerivative · entry 12

SVLSF V, LLC · CIK 0001644160 · 10% owner

SV Life Sciences Fund VI Strategic Partners, L.P. · CIK 0001667605 · 10% owner

SV Life Sciences Fund VI, L.P. · CIK 0001642251 · 10% owner

SV Life Sciences Fund V Strategic Partners, L.P. · CIK 0001482194 · 10% owner

SV LIFE SCIENCES FUND V LP · CIK 0001460732 · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 1,368,961

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F5 · price: The Series D Convertible Preferred Stock converted into Common Stock on a 0.29300-for-one basis upon the closing of the Issuer's initial public offering without payment of consideration. The Series D Convertible Preferred Stock was convertible at any time at the holder's election and automatically upon the closing at the Issuer's initial public offering. The shares had no expiration date.

F9 · ownership.direct: These shares are owned directly by SV Life Sciences Fund VI Strategic Partners, L.P. ("SVLS VI SPP"). SVLS VI GP is the general partner of SVLS VI SPP. The general partner of SVLS VI GP is SVLSF VI, LLC. Kate Bingham, James Garvey, Eugene D. Hill, III, Paul LaViolette, Thomas Flynn, and Michael Ross are members of the investment committee of SVLSF VI, LLC. SVLS VI GP, SVLSF VI, LLC and each of the individuals comprising the SVLSF VI, LLC investment committee may be deemed to share voting, dispositive and investment power over the shares held of record by SVLS VI SPP. Each of SVLS VI GP, SVLSF VI, LLC and the individual members of the SVLSF VI, 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.

SEC source: 0000899243-17-027009 · doc4.xml · nonDerivative · entry 11

SVLSF V, LLC · CIK 0001644160 · 10% owner

SV Life Sciences Fund VI Strategic Partners, L.P. · CIK 0001667605 · 10% owner

SV Life Sciences Fund VI, L.P. · CIK 0001642251 · 10% owner

SV Life Sciences Fund V Strategic Partners, L.P. · CIK 0001482194 · 10% owner

SV LIFE SCIENCES FUND V LP · CIK 0001460732 · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 1,354,172

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F5 · price: The Series D Convertible Preferred Stock converted into Common Stock on a 0.29300-for-one basis upon the closing of the Issuer's initial public offering without payment of consideration. The Series D Convertible Preferred Stock was convertible at any time at the holder's election and automatically upon the closing at the Issuer's initial public offering. The shares had no expiration date.

F8 · ownership.direct: These shares are owned directly by SV Life Sciences Fund VI, L.P. ("SVLS VI LP"). SV Life Sciences Fund VI (GP), LP ("SVLS VI GP") is the general partner of SVLS VI LP. The general partner of SVLS VI GP is SVLSF VI, LLC. Kate Bingham, James Garvey, Eugene D. Hill, III, Paul LaViolette, Thomas Flynn and Michael Ross are members of the investment committee of SVLSF VI, LLC. SVLS VI GP, SVLSF VI, LLC and each of the individuals comprising the SVLSF VI, LLC investment committee may be deemed to share voting, dispositive and investment power over the shares held of record by SVLS VI LP. Each of SVLS VI GP, SVLSF VI, LLC and the individual members of the SVLSF VI, 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.

SEC source: 0000899243-17-027009 · doc4.xml · nonDerivative · entry 10

SVLSF V, LLC · CIK 0001644160 · 10% owner

SV Life Sciences Fund VI Strategic Partners, L.P. · CIK 0001667605 · 10% owner

SV Life Sciences Fund VI, L.P. · CIK 0001642251 · 10% owner

SV Life Sciences Fund V Strategic Partners, L.P. · CIK 0001482194 · 10% owner

SV LIFE SCIENCES FUND V LP · CIK 0001460732 · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 922,192

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F5 · price: The Series D Convertible Preferred Stock converted into Common Stock on a 0.29300-for-one basis upon the closing of the Issuer's initial public offering without payment of consideration. The Series D Convertible Preferred Stock was convertible at any time at the holder's election and automatically upon the closing at the Issuer's initial public offering. The shares had no expiration date.

F7 · ownership.direct: These 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 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.

SEC source: 0000899243-17-027009 · doc4.xml · nonDerivative · entry 9

SVLSF V, LLC · CIK 0001644160 · 10% owner

SV Life Sciences Fund VI Strategic Partners, L.P. · CIK 0001667605 · 10% owner

SV Life Sciences Fund VI, L.P. · CIK 0001642251 · 10% owner

SV Life Sciences Fund V Strategic Partners, L.P. · CIK 0001482194 · 10% owner

SV LIFE SCIENCES FUND V LP · CIK 0001460732 · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 917,904

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F5 · price: The Series D Convertible Preferred Stock converted into Common Stock on a 0.29300-for-one basis upon the closing of the Issuer's initial public offering without payment of consideration. The Series D Convertible Preferred Stock was convertible at any time at the holder's election and automatically upon the closing at the Issuer's initial public offering. The shares had no expiration date.

F6 · ownership.direct: These 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 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.

SEC source: 0000899243-17-027009 · doc4.xml · nonDerivative · entry 8

SVLSF V, LLC · CIK 0001644160 · 10% owner

SV Life Sciences Fund VI Strategic Partners, L.P. · CIK 0001667605 · 10% owner

SV Life Sciences Fund VI, L.P. · CIK 0001642251 · 10% owner

SV Life Sciences Fund V Strategic Partners, L.P. · CIK 0001482194 · 10% owner

SV LIFE SCIENCES FUND V LP · CIK 0001460732 · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 714,989

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F4 · price: The Series C Convertible Preferred Stock converted into Common Stock on a 0.49832-for-one basis upon the closing of the Issuer's initial public offering without payment of consideration. The Series C Convertible Preferred Stock was convertible at any time at the holder's election and automatically upon the closing at the Issuer's initial public offering. The shares had no expiration date.

F7 · ownership.direct: These 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 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.

SEC source: 0000899243-17-027009 · doc4.xml · nonDerivative · entry 7

SVLSF V, LLC · CIK 0001644160 · 10% owner

SV Life Sciences Fund VI Strategic Partners, L.P. · CIK 0001667605 · 10% owner

SV Life Sciences Fund VI, L.P. · CIK 0001642251 · 10% owner

SV Life Sciences Fund V Strategic Partners, L.P. · CIK 0001482194 · 10% owner

SV LIFE SCIENCES FUND V LP · CIK 0001460732 · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 712,624

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F4 · price: The Series C Convertible Preferred Stock converted into Common Stock on a 0.49832-for-one basis upon the closing of the Issuer's initial public offering without payment of consideration. The Series C Convertible Preferred Stock was convertible at any time at the holder's election and automatically upon the closing at the Issuer's initial public offering. The shares had no expiration date.

F6 · ownership.direct: These 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 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.

SEC source: 0000899243-17-027009 · doc4.xml · nonDerivative · entry 6

SVLSF V, LLC · CIK 0001644160 · 10% owner

SV Life Sciences Fund VI Strategic Partners, L.P. · CIK 0001667605 · 10% owner

SV Life Sciences Fund VI, L.P. · CIK 0001642251 · 10% owner

SV Life Sciences Fund V Strategic Partners, L.P. · CIK 0001482194 · 10% owner

SV LIFE SCIENCES FUND V LP · CIK 0001460732 · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 600,669

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F3 · price: The Series B Convertible Preferred Stock converted into Common Stock on a 0.44650-for-one basis upon the closing of the Issuer's initial public offering without payment of consideration. The Series B Convertible Preferred Stock was convertible at any time at the holder's election and automatically upon the closing at the Issuer's initial public offering. The shares had no expiration date.

F7 · ownership.direct: These 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 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.

SEC source: 0000899243-17-027009 · doc4.xml · nonDerivative · entry 5

SVLSF V, LLC · CIK 0001644160 · 10% owner

SV Life Sciences Fund VI Strategic Partners, L.P. · CIK 0001667605 · 10% owner

SV Life Sciences Fund VI, L.P. · CIK 0001642251 · 10% owner

SV Life Sciences Fund V Strategic Partners, L.P. · CIK 0001482194 · 10% owner

SV LIFE SCIENCES FUND V LP · CIK 0001460732 · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 593,863

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F3 · price: The Series B Convertible Preferred Stock converted into Common Stock on a 0.44650-for-one basis upon the closing of the Issuer's initial public offering without payment of consideration. The Series B Convertible Preferred Stock was convertible at any time at the holder's election and automatically upon the closing at the Issuer's initial public offering. The shares had no expiration date.

F6 · ownership.direct: These 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 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.

SEC source: 0000899243-17-027009 · doc4.xml · nonDerivative · entry 4

SVLSF V, LLC · CIK 0001644160 · 10% owner

SV Life Sciences Fund VI Strategic Partners, L.P. · CIK 0001667605 · 10% owner

SV Life Sciences Fund VI, L.P. · CIK 0001642251 · 10% owner

SV Life Sciences Fund V Strategic Partners, L.P. · CIK 0001482194 · 10% owner

SV LIFE SCIENCES FUND V LP · CIK 0001460732 · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 271,761

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F2 · price: The Series A-2 Convertible Preferred Stock converted into Common Stock on a 0.35785-for-one basis upon the closing of the Issuer's initial public offering without payment of consideration. The Series A-2 Convertible Preferred Stock was convertible at any time at the holder's election and automatically upon the closing at the Issuer's initial public offering. The shares had no expiration date.

F7 · ownership.direct: These 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 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.

SEC source: 0000899243-17-027009 · doc4.xml · nonDerivative · entry 3

SVLSF V, LLC · CIK 0001644160 · 10% owner

SV Life Sciences Fund VI Strategic Partners, L.P. · CIK 0001667605 · 10% owner

SV Life Sciences Fund VI, L.P. · CIK 0001642251 · 10% owner

SV Life Sciences Fund V Strategic Partners, L.P. · CIK 0001482194 · 10% owner

SV LIFE SCIENCES FUND V LP · CIK 0001460732 · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 266,542

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F2 · price: The Series A-2 Convertible Preferred Stock converted into Common Stock on a 0.35785-for-one basis upon the closing of the Issuer's initial public offering without payment of consideration. The Series A-2 Convertible Preferred Stock was convertible at any time at the holder's election and automatically upon the closing at the Issuer's initial public offering. The shares had no expiration date.

F6 · ownership.direct: These 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 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.

SEC source: 0000899243-17-027009 · doc4.xml · nonDerivative · entry 2

SVLSF V, LLC · CIK 0001644160 · 10% owner

SV Life Sciences Fund VI Strategic Partners, L.P. · CIK 0001667605 · 10% owner

SV Life Sciences Fund VI, L.P. · CIK 0001642251 · 10% owner

SV Life Sciences Fund V Strategic Partners, L.P. · CIK 0001482194 · 10% owner

SV LIFE SCIENCES FUND V LP · CIK 0001460732 · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 19,532

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · price: The Series A-1 Convertible Preferred Stock converted into Common Stock on a 0.29300-for-one basis upon the closing of the Issuer's initial public offering without payment of consideration. The Series A-1 Convertible Preferred Stock was convertible at any time at the holder's election and automatically upon the closing at the Issuer's initial public offering. The shares had no expiration date.

F7 · ownership.direct: These 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 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.

SEC source: 0000899243-17-027009 · doc4.xml · nonDerivative · entry 1

SVLSF V, LLC · CIK 0001644160 · 10% owner

SV Life Sciences Fund VI Strategic Partners, L.P. · CIK 0001667605 · 10% owner

SV Life Sciences Fund VI, L.P. · CIK 0001642251 · 10% owner

SV Life Sciences Fund V Strategic Partners, L.P. · CIK 0001482194 · 10% owner

SV LIFE SCIENCES FUND V LP · CIK 0001460732 · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 19,128

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · price: The Series A-1 Convertible Preferred Stock converted into Common Stock on a 0.29300-for-one basis upon the closing of the Issuer's initial public offering without payment of consideration. The Series A-1 Convertible Preferred Stock was convertible at any time at the holder's election and automatically upon the closing at the Issuer's initial public offering. The shares had no expiration date.

F6 · ownership.direct: These 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 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.

SEC source: 0000899243-17-026998 · doc4.xml · derivative · entry 44

Polaris Venture Management Co. V, L.L.C. · CIK 0001439589 · 10% owner

Polaris Venture Partners V, L.P. · CIK 0001439590 · 10% owner

Polaris Venture Partners Entrepreneurs' Fund V, L.P. · CIK 0001439587 · 10% owner

Polaris Venture Partners Founders' Fund V, L.P. · CIK 0001439588 · 10% owner

Polaris Venture Partners Special Founders' Fund V, L.P. · CIK 0001439586 · 10% owner

Flint Jonathan A · CIK 0001295676 · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnote

Disclosed balance after: 0

Underlying: Common Stock · 6,310 shares

Expires not disclosed

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F10 · derivative.exercise_price: The Series D Convertible Preferred Stock converted into Common Stock on a 0.29300-for-one basis upon the closing of the Issuer's initial public offering without payment of consideration. The Series D Convertible Preferred Stock was convertible at any time at the holder's election and automatically upon the closing at the Issuer's initial public offering. The shares had no expiration date.

F10 · derivative.exercise_date: The Series D Convertible Preferred Stock converted into Common Stock on a 0.29300-for-one basis upon the closing of the Issuer's initial public offering without payment of consideration. The Series D Convertible Preferred Stock was convertible at any time at the holder's election and automatically upon the closing at the Issuer's initial public offering. The shares had no expiration date.

F10 · derivative.expiration_date: The Series D Convertible Preferred Stock converted into Common Stock on a 0.29300-for-one basis upon the closing of the Issuer's initial public offering without payment of consideration. The Series D Convertible Preferred Stock was convertible at any time at the holder's election and automatically upon the closing at the Issuer's initial public offering. The shares had no expiration date.

F6 · ownership.nature: These shares are owned directly by Polaris Special Founders' V, whose general partner is Polaris Management. Each of Flint and McGuire are the managing members of Polaris Management and, may each be deemed to share voting and dispositive power over the shares held by each of the Polaris V Funds. Polaris Management may be deemed to have sole power to vote and dispose of the shares held by the Polaris V Funds. Each of Flint, McGuire and Polaris Management disclaims beneficial ownership of these securities and this report shall not be deemed to be an admission that any of them is the beneficial owner of such securities for purposes of Section 16 or any other purpose, except to the extent of their respective pecuniary interests therein.

SEC source: 0000899243-17-026998 · doc4.xml · derivative · entry 43

Polaris Venture Management Co. V, L.L.C. · CIK 0001439589 · 10% owner

Polaris Venture Partners V, L.P. · CIK 0001439590 · 10% owner

Polaris Venture Partners Entrepreneurs' Fund V, L.P. · CIK 0001439587 · 10% owner

Polaris Venture Partners Founders' Fund V, L.P. · CIK 0001439588 · 10% owner

Polaris Venture Partners Special Founders' Fund V, L.P. · CIK 0001439586 · 10% owner

Flint Jonathan A · CIK 0001295676 · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnote

Disclosed balance after: 0

Underlying: Common Stock · 4,322 shares

Expires not disclosed

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F10 · derivative.exercise_price: The Series D Convertible Preferred Stock converted into Common Stock on a 0.29300-for-one basis upon the closing of the Issuer's initial public offering without payment of consideration. The Series D Convertible Preferred Stock was convertible at any time at the holder's election and automatically upon the closing at the Issuer's initial public offering. The shares had no expiration date.

F10 · derivative.exercise_date: The Series D Convertible Preferred Stock converted into Common Stock on a 0.29300-for-one basis upon the closing of the Issuer's initial public offering without payment of consideration. The Series D Convertible Preferred Stock was convertible at any time at the holder's election and automatically upon the closing at the Issuer's initial public offering. The shares had no expiration date.

F10 · derivative.expiration_date: The Series D Convertible Preferred Stock converted into Common Stock on a 0.29300-for-one basis upon the closing of the Issuer's initial public offering without payment of consideration. The Series D Convertible Preferred Stock was convertible at any time at the holder's election and automatically upon the closing at the Issuer's initial public offering. The shares had no expiration date.

F5 · ownership.nature: These shares are owned directly by Polaris Founders' V, whose general partner is Polaris Management. Each of Flint and McGuire are the managing members of Polaris Management and may each be deemed to share voting and dispositive power over the shares held by each of the Polaris V Funds. Polaris Management may be deemed to have sole power to vote and dispose of the shares held by the Polaris V Funds. Each of Flint, McGuire and Polaris Management disclaims beneficial ownership of these securities and this report shall not be deemed to be an admission that any of them is the beneficial owner of such securities for purposes of Section 16 or any other purpose, except to the extent of their respective pecuniary interests therein.

SEC source: 0000899243-17-026998 · doc4.xml · derivative · entry 42

Polaris Venture Management Co. V, L.L.C. · CIK 0001439589 · 10% owner

Polaris Venture Partners V, L.P. · CIK 0001439590 · 10% owner

Polaris Venture Partners Entrepreneurs' Fund V, L.P. · CIK 0001439587 · 10% owner

Polaris Venture Partners Founders' Fund V, L.P. · CIK 0001439588 · 10% owner

Polaris Venture Partners Special Founders' Fund V, L.P. · CIK 0001439586 · 10% owner

Flint Jonathan A · CIK 0001295676 · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnote

Disclosed balance after: 0

Underlying: Common Stock · 12,298 shares

Expires not disclosed

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F10 · derivative.exercise_price: The Series D Convertible Preferred Stock converted into Common Stock on a 0.29300-for-one basis upon the closing of the Issuer's initial public offering without payment of consideration. The Series D Convertible Preferred Stock was convertible at any time at the holder's election and automatically upon the closing at the Issuer's initial public offering. The shares had no expiration date.

F10 · derivative.exercise_date: The Series D Convertible Preferred Stock converted into Common Stock on a 0.29300-for-one basis upon the closing of the Issuer's initial public offering without payment of consideration. The Series D Convertible Preferred Stock was convertible at any time at the holder's election and automatically upon the closing at the Issuer's initial public offering. The shares had no expiration date.

F10 · derivative.expiration_date: The Series D Convertible Preferred Stock converted into Common Stock on a 0.29300-for-one basis upon the closing of the Issuer's initial public offering without payment of consideration. The Series D Convertible Preferred Stock was convertible at any time at the holder's election and automatically upon the closing at the Issuer's initial public offering. The shares had no expiration date.

F4 · ownership.nature: These shares are owned directly by Polaris Entrepreneurs' V, whose general partner is Polaris Management. Each of Flint and McGuire are the managing members of Polaris Management and may each be deemed to share voting and dispositive power over the shares held by each of the Polaris V Funds. Polaris Management may be deemed to have sole power to vote and dispose of the shares held by the Polaris V Funds. Each of Flint, McGuire and Polaris Management disclaims beneficial ownership of these securities and this report shall not be deemed to be an admission that any of them is the beneficial owner of such securities for purposes of Section 16 or any other purpose, except to the extent of their respective pecuniary interests therein.

SEC source: 0000899243-17-026998 · doc4.xml · derivative · entry 41

Polaris Venture Management Co. V, L.L.C. · CIK 0001439589 · 10% owner

Polaris Venture Partners V, L.P. · CIK 0001439590 · 10% owner

Polaris Venture Partners Entrepreneurs' Fund V, L.P. · CIK 0001439587 · 10% owner

Polaris Venture Partners Founders' Fund V, L.P. · CIK 0001439588 · 10% owner

Polaris Venture Partners Special Founders' Fund V, L.P. · CIK 0001439586 · 10% owner

Flint Jonathan A · CIK 0001295676 · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnotes

Disclosed balance after: 0

Underlying: Common Stock · 631,041 shares

Expires not disclosed

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F10 · derivative.exercise_price: The Series D Convertible Preferred Stock converted into Common Stock on a 0.29300-for-one basis upon the closing of the Issuer's initial public offering without payment of consideration. The Series D Convertible Preferred Stock was convertible at any time at the holder's election and automatically upon the closing at the Issuer's initial public offering. The shares had no expiration date.

F10 · derivative.exercise_date: The Series D Convertible Preferred Stock converted into Common Stock on a 0.29300-for-one basis upon the closing of the Issuer's initial public offering without payment of consideration. The Series D Convertible Preferred Stock was convertible at any time at the holder's election and automatically upon the closing at the Issuer's initial public offering. The shares had no expiration date.

F10 · derivative.expiration_date: The Series D Convertible Preferred Stock converted into Common Stock on a 0.29300-for-one basis upon the closing of the Issuer's initial public offering without payment of consideration. The Series D Convertible Preferred Stock was convertible at any time at the holder's election and automatically upon the closing at the Issuer's initial public offering. The shares had no expiration date.

F2 · ownership.nature: These shares are owned directly by Polaris Venture Partners V, L.P. ("Polaris V"), whose general partner is Polaris Venture Management Co. V, L.L.C. ("Polaris Management"). Each of Jonathan A. Flint ("Flint") and Terrance G. McGuire ("McGuire"), who is a member of the Issuer's Board of Directors and whose beneficial ownership is reported on a separate Form 4, are the managing members of Polaris Management and may each be deemed to share voting and dispositive power with respect to the shares held by each of Polaris V, Polaris Venture Partners Entrepreneurs' Fund V, L.P. ("Polaris Entrepreneurs' V"), Polaris Venture Partners Founders' Fund V, L.P. ("Polaris Founders' V") and Polaris Venture Partners Special Founders' Fund V, L.P. ("Polaris Special Founders' V", and together with Polaris V, Polaris Entrepreneurs' V and Polaris Founders' V, the "Polaris V Funds").

F3 · ownership.nature: (Continued from footnote 2) Polaris Management may be deemed to have sole power to vote and dispose of the shares held by the Polaris V Funds. Each of Flint, McGuire and Polaris Management disclaims beneficial ownership of these securities and this report shall not be deemed to be an admission that any of them is the beneficial owner of such securities for purposes of Section 16 or any other purpose, except to the extent of their respective pecuniary interests therein.

SEC source: 0000899243-17-026998 · doc4.xml · derivative · entry 40

Polaris Venture Management Co. V, L.L.C. · CIK 0001439589 · 10% owner

Polaris Venture Partners V, L.P. · CIK 0001439590 · 10% owner

Polaris Venture Partners Entrepreneurs' Fund V, L.P. · CIK 0001439587 · 10% owner

Polaris Venture Partners Founders' Fund V, L.P. · CIK 0001439588 · 10% owner

Polaris Venture Partners Special Founders' Fund V, L.P. · CIK 0001439586 · 10% owner

Flint Jonathan A · CIK 0001295676 · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnote

Disclosed balance after: 0

Underlying: Common Stock · 1,102 shares

Expires not disclosed

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F9 · derivative.exercise_price: The Series C Convertible Preferred Stock converted into Common Stock on a 0.49832-for-one basis upon the closing of the Issuer's initial public offering without payment of consideration. The Series C Convertible Preferred Stock was convertible at any time at the holder's election and automatically upon the closing at the Issuer's initial public offering. The shares had no expiration date.

F9 · derivative.exercise_date: The Series C Convertible Preferred Stock converted into Common Stock on a 0.49832-for-one basis upon the closing of the Issuer's initial public offering without payment of consideration. The Series C Convertible Preferred Stock was convertible at any time at the holder's election and automatically upon the closing at the Issuer's initial public offering. The shares had no expiration date.

F9 · derivative.expiration_date: The Series C Convertible Preferred Stock converted into Common Stock on a 0.49832-for-one basis upon the closing of the Issuer's initial public offering without payment of consideration. The Series C Convertible Preferred Stock was convertible at any time at the holder's election and automatically upon the closing at the Issuer's initial public offering. The shares had no expiration date.

F6 · ownership.nature: These shares are owned directly by Polaris Special Founders' V, whose general partner is Polaris Management. Each of Flint and McGuire are the managing members of Polaris Management and, may each be deemed to share voting and dispositive power over the shares held by each of the Polaris V Funds. Polaris Management may be deemed to have sole power to vote and dispose of the shares held by the Polaris V Funds. Each of Flint, McGuire and Polaris Management disclaims beneficial ownership of these securities and this report shall not be deemed to be an admission that any of them is the beneficial owner of such securities for purposes of Section 16 or any other purpose, except to the extent of their respective pecuniary interests therein.

SEC source: 0000899243-17-026998 · doc4.xml · derivative · entry 39

Polaris Venture Management Co. V, L.L.C. · CIK 0001439589 · 10% owner

Polaris Venture Partners V, L.P. · CIK 0001439590 · 10% owner

Polaris Venture Partners Entrepreneurs' Fund V, L.P. · CIK 0001439587 · 10% owner

Polaris Venture Partners Founders' Fund V, L.P. · CIK 0001439588 · 10% owner

Polaris Venture Partners Special Founders' Fund V, L.P. · CIK 0001439586 · 10% owner

Flint Jonathan A · CIK 0001295676 · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnote

Disclosed balance after: 0

Underlying: Common Stock · 755 shares

Expires not disclosed

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F9 · derivative.exercise_price: The Series C Convertible Preferred Stock converted into Common Stock on a 0.49832-for-one basis upon the closing of the Issuer's initial public offering without payment of consideration. The Series C Convertible Preferred Stock was convertible at any time at the holder's election and automatically upon the closing at the Issuer's initial public offering. The shares had no expiration date.

F9 · derivative.exercise_date: The Series C Convertible Preferred Stock converted into Common Stock on a 0.49832-for-one basis upon the closing of the Issuer's initial public offering without payment of consideration. The Series C Convertible Preferred Stock was convertible at any time at the holder's election and automatically upon the closing at the Issuer's initial public offering. The shares had no expiration date.

F9 · derivative.expiration_date: The Series C Convertible Preferred Stock converted into Common Stock on a 0.49832-for-one basis upon the closing of the Issuer's initial public offering without payment of consideration. The Series C Convertible Preferred Stock was convertible at any time at the holder's election and automatically upon the closing at the Issuer's initial public offering. The shares had no expiration date.

F5 · ownership.nature: These shares are owned directly by Polaris Founders' V, whose general partner is Polaris Management. Each of Flint and McGuire are the managing members of Polaris Management and may each be deemed to share voting and dispositive power over the shares held by each of the Polaris V Funds. Polaris Management may be deemed to have sole power to vote and dispose of the shares held by the Polaris V Funds. Each of Flint, McGuire and Polaris Management disclaims beneficial ownership of these securities and this report shall not be deemed to be an admission that any of them is the beneficial owner of such securities for purposes of Section 16 or any other purpose, except to the extent of their respective pecuniary interests therein.

SEC source: 0000899243-17-026998 · doc4.xml · derivative · entry 38

Polaris Venture Management Co. V, L.L.C. · CIK 0001439589 · 10% owner

Polaris Venture Partners V, L.P. · CIK 0001439590 · 10% owner

Polaris Venture Partners Entrepreneurs' Fund V, L.P. · CIK 0001439587 · 10% owner

Polaris Venture Partners Founders' Fund V, L.P. · CIK 0001439588 · 10% owner

Polaris Venture Partners Special Founders' Fund V, L.P. · CIK 0001439586 · 10% owner

Flint Jonathan A · CIK 0001295676 · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnote

Disclosed balance after: 0

Underlying: Common Stock · 2,150 shares

Expires not disclosed

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F9 · derivative.exercise_price: The Series C Convertible Preferred Stock converted into Common Stock on a 0.49832-for-one basis upon the closing of the Issuer's initial public offering without payment of consideration. The Series C Convertible Preferred Stock was convertible at any time at the holder's election and automatically upon the closing at the Issuer's initial public offering. The shares had no expiration date.

F9 · derivative.exercise_date: The Series C Convertible Preferred Stock converted into Common Stock on a 0.49832-for-one basis upon the closing of the Issuer's initial public offering without payment of consideration. The Series C Convertible Preferred Stock was convertible at any time at the holder's election and automatically upon the closing at the Issuer's initial public offering. The shares had no expiration date.

F9 · derivative.expiration_date: The Series C Convertible Preferred Stock converted into Common Stock on a 0.49832-for-one basis upon the closing of the Issuer's initial public offering without payment of consideration. The Series C Convertible Preferred Stock was convertible at any time at the holder's election and automatically upon the closing at the Issuer's initial public offering. The shares had no expiration date.

F4 · ownership.nature: These shares are owned directly by Polaris Entrepreneurs' V, whose general partner is Polaris Management. Each of Flint and McGuire are the managing members of Polaris Management and may each be deemed to share voting and dispositive power over the shares held by each of the Polaris V Funds. Polaris Management may be deemed to have sole power to vote and dispose of the shares held by the Polaris V Funds. Each of Flint, McGuire and Polaris Management disclaims beneficial ownership of these securities and this report shall not be deemed to be an admission that any of them is the beneficial owner of such securities for purposes of Section 16 or any other purpose, except to the extent of their respective pecuniary interests therein.

SEC source: 0000899243-17-026998 · doc4.xml · derivative · entry 37

Polaris Venture Management Co. V, L.L.C. · CIK 0001439589 · 10% owner

Polaris Venture Partners V, L.P. · CIK 0001439590 · 10% owner

Polaris Venture Partners Entrepreneurs' Fund V, L.P. · CIK 0001439587 · 10% owner

Polaris Venture Partners Founders' Fund V, L.P. · CIK 0001439588 · 10% owner

Polaris Venture Partners Special Founders' Fund V, L.P. · CIK 0001439586 · 10% owner

Flint Jonathan A · CIK 0001295676 · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnotes

Disclosed balance after: 0

Underlying: Common Stock · 110,312 shares

Expires not disclosed

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F9 · derivative.exercise_price: The Series C Convertible Preferred Stock converted into Common Stock on a 0.49832-for-one basis upon the closing of the Issuer's initial public offering without payment of consideration. The Series C Convertible Preferred Stock was convertible at any time at the holder's election and automatically upon the closing at the Issuer's initial public offering. The shares had no expiration date.

F9 · derivative.exercise_date: The Series C Convertible Preferred Stock converted into Common Stock on a 0.49832-for-one basis upon the closing of the Issuer's initial public offering without payment of consideration. The Series C Convertible Preferred Stock was convertible at any time at the holder's election and automatically upon the closing at the Issuer's initial public offering. The shares had no expiration date.

F9 · derivative.expiration_date: The Series C Convertible Preferred Stock converted into Common Stock on a 0.49832-for-one basis upon the closing of the Issuer's initial public offering without payment of consideration. The Series C Convertible Preferred Stock was convertible at any time at the holder's election and automatically upon the closing at the Issuer's initial public offering. The shares had no expiration date.

F2 · ownership.nature: These shares are owned directly by Polaris Venture Partners V, L.P. ("Polaris V"), whose general partner is Polaris Venture Management Co. V, L.L.C. ("Polaris Management"). Each of Jonathan A. Flint ("Flint") and Terrance G. McGuire ("McGuire"), who is a member of the Issuer's Board of Directors and whose beneficial ownership is reported on a separate Form 4, are the managing members of Polaris Management and may each be deemed to share voting and dispositive power with respect to the shares held by each of Polaris V, Polaris Venture Partners Entrepreneurs' Fund V, L.P. ("Polaris Entrepreneurs' V"), Polaris Venture Partners Founders' Fund V, L.P. ("Polaris Founders' V") and Polaris Venture Partners Special Founders' Fund V, L.P. ("Polaris Special Founders' V", and together with Polaris V, Polaris Entrepreneurs' V and Polaris Founders' V, the "Polaris V Funds").

F3 · ownership.nature: (Continued from footnote 2) Polaris Management may be deemed to have sole power to vote and dispose of the shares held by the Polaris V Funds. Each of Flint, McGuire and Polaris Management disclaims beneficial ownership of these securities and this report shall not be deemed to be an admission that any of them is the beneficial owner of such securities for purposes of Section 16 or any other purpose, except to the extent of their respective pecuniary interests therein.

SEC source: 0000899243-17-026998 · doc4.xml · derivative · entry 36

Polaris Venture Management Co. V, L.L.C. · CIK 0001439589 · 10% owner

Polaris Venture Partners V, L.P. · CIK 0001439590 · 10% owner

Polaris Venture Partners Entrepreneurs' Fund V, L.P. · CIK 0001439587 · 10% owner

Polaris Venture Partners Founders' Fund V, L.P. · CIK 0001439588 · 10% owner

Polaris Venture Partners Special Founders' Fund V, L.P. · CIK 0001439586 · 10% owner

Flint Jonathan A · CIK 0001295676 · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnote

Disclosed balance after: 0

Underlying: Common Stock · 3,173 shares

Expires not disclosed

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F8 · derivative.exercise_price: The Series B Convertible Preferred Stock converted into Common Stock on a 0.44650-for-one basis upon the closing of the Issuer's initial public offering without payment of consideration. The Series B Convertible Preferred Stock was convertible at any time at the holder's election and automatically upon the closing at the Issuer's initial public offering. The shares had no expiration date.

F8 · derivative.exercise_date: The Series B Convertible Preferred Stock converted into Common Stock on a 0.44650-for-one basis upon the closing of the Issuer's initial public offering without payment of consideration. The Series B Convertible Preferred Stock was convertible at any time at the holder's election and automatically upon the closing at the Issuer's initial public offering. The shares had no expiration date.

F8 · derivative.expiration_date: The Series B Convertible Preferred Stock converted into Common Stock on a 0.44650-for-one basis upon the closing of the Issuer's initial public offering without payment of consideration. The Series B Convertible Preferred Stock was convertible at any time at the holder's election and automatically upon the closing at the Issuer's initial public offering. The shares had no expiration date.

F6 · ownership.nature: These shares are owned directly by Polaris Special Founders' V, whose general partner is Polaris Management. Each of Flint and McGuire are the managing members of Polaris Management and, may each be deemed to share voting and dispositive power over the shares held by each of the Polaris V Funds. Polaris Management may be deemed to have sole power to vote and dispose of the shares held by the Polaris V Funds. Each of Flint, McGuire and Polaris Management disclaims beneficial ownership of these securities and this report shall not be deemed to be an admission that any of them is the beneficial owner of such securities for purposes of Section 16 or any other purpose, except to the extent of their respective pecuniary interests therein.

SEC source: 0000899243-17-026998 · doc4.xml · derivative · entry 35

Polaris Venture Management Co. V, L.L.C. · CIK 0001439589 · 10% owner

Polaris Venture Partners V, L.P. · CIK 0001439590 · 10% owner

Polaris Venture Partners Entrepreneurs' Fund V, L.P. · CIK 0001439587 · 10% owner

Polaris Venture Partners Founders' Fund V, L.P. · CIK 0001439588 · 10% owner

Polaris Venture Partners Special Founders' Fund V, L.P. · CIK 0001439586 · 10% owner

Flint Jonathan A · CIK 0001295676 · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnote

Disclosed balance after: 0

Underlying: Common Stock · 2,173 shares

Expires not disclosed

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F8 · derivative.exercise_price: The Series B Convertible Preferred Stock converted into Common Stock on a 0.44650-for-one basis upon the closing of the Issuer's initial public offering without payment of consideration. The Series B Convertible Preferred Stock was convertible at any time at the holder's election and automatically upon the closing at the Issuer's initial public offering. The shares had no expiration date.

F8 · derivative.exercise_date: The Series B Convertible Preferred Stock converted into Common Stock on a 0.44650-for-one basis upon the closing of the Issuer's initial public offering without payment of consideration. The Series B Convertible Preferred Stock was convertible at any time at the holder's election and automatically upon the closing at the Issuer's initial public offering. The shares had no expiration date.

F8 · derivative.expiration_date: The Series B Convertible Preferred Stock converted into Common Stock on a 0.44650-for-one basis upon the closing of the Issuer's initial public offering without payment of consideration. The Series B Convertible Preferred Stock was convertible at any time at the holder's election and automatically upon the closing at the Issuer's initial public offering. The shares had no expiration date.

F5 · ownership.nature: These shares are owned directly by Polaris Founders' V, whose general partner is Polaris Management. Each of Flint and McGuire are the managing members of Polaris Management and may each be deemed to share voting and dispositive power over the shares held by each of the Polaris V Funds. Polaris Management may be deemed to have sole power to vote and dispose of the shares held by the Polaris V Funds. Each of Flint, McGuire and Polaris Management disclaims beneficial ownership of these securities and this report shall not be deemed to be an admission that any of them is the beneficial owner of such securities for purposes of Section 16 or any other purpose, except to the extent of their respective pecuniary interests therein.

SEC source: 0000899243-17-026998 · doc4.xml · derivative · entry 34

Polaris Venture Management Co. V, L.L.C. · CIK 0001439589 · 10% owner

Polaris Venture Partners V, L.P. · CIK 0001439590 · 10% owner

Polaris Venture Partners Entrepreneurs' Fund V, L.P. · CIK 0001439587 · 10% owner

Polaris Venture Partners Founders' Fund V, L.P. · CIK 0001439588 · 10% owner

Polaris Venture Partners Special Founders' Fund V, L.P. · CIK 0001439586 · 10% owner

Flint Jonathan A · CIK 0001295676 · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnote

Disclosed balance after: 0

Underlying: Common Stock · 6,185 shares

Expires not disclosed

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F8 · derivative.exercise_price: The Series B Convertible Preferred Stock converted into Common Stock on a 0.44650-for-one basis upon the closing of the Issuer's initial public offering without payment of consideration. The Series B Convertible Preferred Stock was convertible at any time at the holder's election and automatically upon the closing at the Issuer's initial public offering. The shares had no expiration date.

F8 · derivative.exercise_date: The Series B Convertible Preferred Stock converted into Common Stock on a 0.44650-for-one basis upon the closing of the Issuer's initial public offering without payment of consideration. The Series B Convertible Preferred Stock was convertible at any time at the holder's election and automatically upon the closing at the Issuer's initial public offering. The shares had no expiration date.

F8 · derivative.expiration_date: The Series B Convertible Preferred Stock converted into Common Stock on a 0.44650-for-one basis upon the closing of the Issuer's initial public offering without payment of consideration. The Series B Convertible Preferred Stock was convertible at any time at the holder's election and automatically upon the closing at the Issuer's initial public offering. The shares had no expiration date.

F4 · ownership.nature: These shares are owned directly by Polaris Entrepreneurs' V, whose general partner is Polaris Management. Each of Flint and McGuire are the managing members of Polaris Management and may each be deemed to share voting and dispositive power over the shares held by each of the Polaris V Funds. Polaris Management may be deemed to have sole power to vote and dispose of the shares held by the Polaris V Funds. Each of Flint, McGuire and Polaris Management disclaims beneficial ownership of these securities and this report shall not be deemed to be an admission that any of them is the beneficial owner of such securities for purposes of Section 16 or any other purpose, except to the extent of their respective pecuniary interests therein.

SEC source: 0000899243-17-026998 · doc4.xml · derivative · entry 33

Polaris Venture Management Co. V, L.L.C. · CIK 0001439589 · 10% owner

Polaris Venture Partners V, L.P. · CIK 0001439590 · 10% owner

Polaris Venture Partners Entrepreneurs' Fund V, L.P. · CIK 0001439587 · 10% owner

Polaris Venture Partners Founders' Fund V, L.P. · CIK 0001439588 · 10% owner

Polaris Venture Partners Special Founders' Fund V, L.P. · CIK 0001439586 · 10% owner

Flint Jonathan A · CIK 0001295676 · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnotes

Disclosed balance after: 0

Underlying: Common Stock · 317,376 shares

Expires not disclosed

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F8 · derivative.exercise_price: The Series B Convertible Preferred Stock converted into Common Stock on a 0.44650-for-one basis upon the closing of the Issuer's initial public offering without payment of consideration. The Series B Convertible Preferred Stock was convertible at any time at the holder's election and automatically upon the closing at the Issuer's initial public offering. The shares had no expiration date.

F8 · derivative.exercise_date: The Series B Convertible Preferred Stock converted into Common Stock on a 0.44650-for-one basis upon the closing of the Issuer's initial public offering without payment of consideration. The Series B Convertible Preferred Stock was convertible at any time at the holder's election and automatically upon the closing at the Issuer's initial public offering. The shares had no expiration date.

F8 · derivative.expiration_date: The Series B Convertible Preferred Stock converted into Common Stock on a 0.44650-for-one basis upon the closing of the Issuer's initial public offering without payment of consideration. The Series B Convertible Preferred Stock was convertible at any time at the holder's election and automatically upon the closing at the Issuer's initial public offering. The shares had no expiration date.

F2 · ownership.nature: These shares are owned directly by Polaris Venture Partners V, L.P. ("Polaris V"), whose general partner is Polaris Venture Management Co. V, L.L.C. ("Polaris Management"). Each of Jonathan A. Flint ("Flint") and Terrance G. McGuire ("McGuire"), who is a member of the Issuer's Board of Directors and whose beneficial ownership is reported on a separate Form 4, are the managing members of Polaris Management and may each be deemed to share voting and dispositive power with respect to the shares held by each of Polaris V, Polaris Venture Partners Entrepreneurs' Fund V, L.P. ("Polaris Entrepreneurs' V"), Polaris Venture Partners Founders' Fund V, L.P. ("Polaris Founders' V") and Polaris Venture Partners Special Founders' Fund V, L.P. ("Polaris Special Founders' V", and together with Polaris V, Polaris Entrepreneurs' V and Polaris Founders' V, the "Polaris V Funds").

F3 · ownership.nature: (Continued from footnote 2) Polaris Management may be deemed to have sole power to vote and dispose of the shares held by the Polaris V Funds. Each of Flint, McGuire and Polaris Management disclaims beneficial ownership of these securities and this report shall not be deemed to be an admission that any of them is the beneficial owner of such securities for purposes of Section 16 or any other purpose, except to the extent of their respective pecuniary interests therein.

SEC source: 0000899243-17-026998 · doc4.xml · derivative · entry 32

Polaris Venture Management Co. V, L.L.C. · CIK 0001439589 · 10% owner

Polaris Venture Partners V, L.P. · CIK 0001439590 · 10% owner

Polaris Venture Partners Entrepreneurs' Fund V, L.P. · CIK 0001439587 · 10% owner

Polaris Venture Partners Founders' Fund V, L.P. · CIK 0001439588 · 10% owner

Polaris Venture Partners Special Founders' Fund V, L.P. · CIK 0001439586 · 10% owner

Flint Jonathan A · CIK 0001295676 · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnote

Disclosed balance after: 0

Underlying: Common Stock · 2,433 shares

Expires not disclosed

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F7 · derivative.exercise_price: The Series A-2 Convertible Preferred Stock converted into Common Stock on a 0.35785-for-one basis upon the closing of the Issuer's initial public offering without payment of consideration. The Series A-2 Convertible Preferred Stock was convertible at any time at the holder's election and automatically upon the closing at the Issuer's initial public offering. The shares had no expiration date.

F7 · derivative.exercise_date: The Series A-2 Convertible Preferred Stock converted into Common Stock on a 0.35785-for-one basis upon the closing of the Issuer's initial public offering without payment of consideration. The Series A-2 Convertible Preferred Stock was convertible at any time at the holder's election and automatically upon the closing at the Issuer's initial public offering. The shares had no expiration date.

F7 · derivative.expiration_date: The Series A-2 Convertible Preferred Stock converted into Common Stock on a 0.35785-for-one basis upon the closing of the Issuer's initial public offering without payment of consideration. The Series A-2 Convertible Preferred Stock was convertible at any time at the holder's election and automatically upon the closing at the Issuer's initial public offering. The shares had no expiration date.

F6 · ownership.nature: These shares are owned directly by Polaris Special Founders' V, whose general partner is Polaris Management. Each of Flint and McGuire are the managing members of Polaris Management and, may each be deemed to share voting and dispositive power over the shares held by each of the Polaris V Funds. Polaris Management may be deemed to have sole power to vote and dispose of the shares held by the Polaris V Funds. Each of Flint, McGuire and Polaris Management disclaims beneficial ownership of these securities and this report shall not be deemed to be an admission that any of them is the beneficial owner of such securities for purposes of Section 16 or any other purpose, except to the extent of their respective pecuniary interests therein.

SEC source: 0000899243-17-026998 · doc4.xml · derivative · entry 31

Polaris Venture Management Co. V, L.L.C. · CIK 0001439589 · 10% owner

Polaris Venture Partners V, L.P. · CIK 0001439590 · 10% owner

Polaris Venture Partners Entrepreneurs' Fund V, L.P. · CIK 0001439587 · 10% owner

Polaris Venture Partners Founders' Fund V, L.P. · CIK 0001439588 · 10% owner

Polaris Venture Partners Special Founders' Fund V, L.P. · CIK 0001439586 · 10% owner

Flint Jonathan A · CIK 0001295676 · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnote

Disclosed balance after: 0

Underlying: Common Stock · 1,667 shares

Expires not disclosed

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F7 · derivative.exercise_price: The Series A-2 Convertible Preferred Stock converted into Common Stock on a 0.35785-for-one basis upon the closing of the Issuer's initial public offering without payment of consideration. The Series A-2 Convertible Preferred Stock was convertible at any time at the holder's election and automatically upon the closing at the Issuer's initial public offering. The shares had no expiration date.

F7 · derivative.exercise_date: The Series A-2 Convertible Preferred Stock converted into Common Stock on a 0.35785-for-one basis upon the closing of the Issuer's initial public offering without payment of consideration. The Series A-2 Convertible Preferred Stock was convertible at any time at the holder's election and automatically upon the closing at the Issuer's initial public offering. The shares had no expiration date.

F7 · derivative.expiration_date: The Series A-2 Convertible Preferred Stock converted into Common Stock on a 0.35785-for-one basis upon the closing of the Issuer's initial public offering without payment of consideration. The Series A-2 Convertible Preferred Stock was convertible at any time at the holder's election and automatically upon the closing at the Issuer's initial public offering. The shares had no expiration date.

F5 · ownership.nature: These shares are owned directly by Polaris Founders' V, whose general partner is Polaris Management. Each of Flint and McGuire are the managing members of Polaris Management and may each be deemed to share voting and dispositive power over the shares held by each of the Polaris V Funds. Polaris Management may be deemed to have sole power to vote and dispose of the shares held by the Polaris V Funds. Each of Flint, McGuire and Polaris Management disclaims beneficial ownership of these securities and this report shall not be deemed to be an admission that any of them is the beneficial owner of such securities for purposes of Section 16 or any other purpose, except to the extent of their respective pecuniary interests therein.

SEC source: 0000899243-17-026998 · doc4.xml · derivative · entry 30

Polaris Venture Management Co. V, L.L.C. · CIK 0001439589 · 10% owner

Polaris Venture Partners V, L.P. · CIK 0001439590 · 10% owner

Polaris Venture Partners Entrepreneurs' Fund V, L.P. · CIK 0001439587 · 10% owner

Polaris Venture Partners Founders' Fund V, L.P. · CIK 0001439588 · 10% owner

Polaris Venture Partners Special Founders' Fund V, L.P. · CIK 0001439586 · 10% owner

Flint Jonathan A · CIK 0001295676 · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnote

Disclosed balance after: 0

Underlying: Common Stock · 4,743 shares

Expires not disclosed

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F7 · derivative.exercise_price: The Series A-2 Convertible Preferred Stock converted into Common Stock on a 0.35785-for-one basis upon the closing of the Issuer's initial public offering without payment of consideration. The Series A-2 Convertible Preferred Stock was convertible at any time at the holder's election and automatically upon the closing at the Issuer's initial public offering. The shares had no expiration date.

F7 · derivative.exercise_date: The Series A-2 Convertible Preferred Stock converted into Common Stock on a 0.35785-for-one basis upon the closing of the Issuer's initial public offering without payment of consideration. The Series A-2 Convertible Preferred Stock was convertible at any time at the holder's election and automatically upon the closing at the Issuer's initial public offering. The shares had no expiration date.

F7 · derivative.expiration_date: The Series A-2 Convertible Preferred Stock converted into Common Stock on a 0.35785-for-one basis upon the closing of the Issuer's initial public offering without payment of consideration. The Series A-2 Convertible Preferred Stock was convertible at any time at the holder's election and automatically upon the closing at the Issuer's initial public offering. The shares had no expiration date.

F4 · ownership.nature: These shares are owned directly by Polaris Entrepreneurs' V, whose general partner is Polaris Management. Each of Flint and McGuire are the managing members of Polaris Management and may each be deemed to share voting and dispositive power over the shares held by each of the Polaris V Funds. Polaris Management may be deemed to have sole power to vote and dispose of the shares held by the Polaris V Funds. Each of Flint, McGuire and Polaris Management disclaims beneficial ownership of these securities and this report shall not be deemed to be an admission that any of them is the beneficial owner of such securities for purposes of Section 16 or any other purpose, except to the extent of their respective pecuniary interests therein.

SEC source: 0000899243-17-026998 · doc4.xml · derivative · entry 29

Polaris Venture Management Co. V, L.L.C. · CIK 0001439589 · 10% owner

Polaris Venture Partners V, L.P. · CIK 0001439590 · 10% owner

Polaris Venture Partners Entrepreneurs' Fund V, L.P. · CIK 0001439587 · 10% owner

Polaris Venture Partners Founders' Fund V, L.P. · CIK 0001439588 · 10% owner

Polaris Venture Partners Special Founders' Fund V, L.P. · CIK 0001439586 · 10% owner

Flint Jonathan A · CIK 0001295676 · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnotes

Disclosed balance after: 0

Underlying: Common Stock · 243,385 shares

Expires not disclosed

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F7 · derivative.exercise_price: The Series A-2 Convertible Preferred Stock converted into Common Stock on a 0.35785-for-one basis upon the closing of the Issuer's initial public offering without payment of consideration. The Series A-2 Convertible Preferred Stock was convertible at any time at the holder's election and automatically upon the closing at the Issuer's initial public offering. The shares had no expiration date.

F7 · derivative.exercise_date: The Series A-2 Convertible Preferred Stock converted into Common Stock on a 0.35785-for-one basis upon the closing of the Issuer's initial public offering without payment of consideration. The Series A-2 Convertible Preferred Stock was convertible at any time at the holder's election and automatically upon the closing at the Issuer's initial public offering. The shares had no expiration date.

F7 · derivative.expiration_date: The Series A-2 Convertible Preferred Stock converted into Common Stock on a 0.35785-for-one basis upon the closing of the Issuer's initial public offering without payment of consideration. The Series A-2 Convertible Preferred Stock was convertible at any time at the holder's election and automatically upon the closing at the Issuer's initial public offering. The shares had no expiration date.

F2 · ownership.nature: These shares are owned directly by Polaris Venture Partners V, L.P. ("Polaris V"), whose general partner is Polaris Venture Management Co. V, L.L.C. ("Polaris Management"). Each of Jonathan A. Flint ("Flint") and Terrance G. McGuire ("McGuire"), who is a member of the Issuer's Board of Directors and whose beneficial ownership is reported on a separate Form 4, are the managing members of Polaris Management and may each be deemed to share voting and dispositive power with respect to the shares held by each of Polaris V, Polaris Venture Partners Entrepreneurs' Fund V, L.P. ("Polaris Entrepreneurs' V"), Polaris Venture Partners Founders' Fund V, L.P. ("Polaris Founders' V") and Polaris Venture Partners Special Founders' Fund V, L.P. ("Polaris Special Founders' V", and together with Polaris V, Polaris Entrepreneurs' V and Polaris Founders' V, the "Polaris V Funds").

F3 · ownership.nature: (Continued from footnote 2) Polaris Management may be deemed to have sole power to vote and dispose of the shares held by the Polaris V Funds. Each of Flint, McGuire and Polaris Management disclaims beneficial ownership of these securities and this report shall not be deemed to be an admission that any of them is the beneficial owner of such securities for purposes of Section 16 or any other purpose, except to the extent of their respective pecuniary interests therein.

SEC source: 0000899243-17-026998 · doc4.xml · derivative · entry 28

Polaris Venture Management Co. V, L.L.C. · CIK 0001439589 · 10% owner

Polaris Venture Partners V, L.P. · CIK 0001439590 · 10% owner

Polaris Venture Partners Entrepreneurs' Fund V, L.P. · CIK 0001439587 · 10% owner

Polaris Venture Partners Founders' Fund V, L.P. · CIK 0001439588 · 10% owner

Polaris Venture Partners Special Founders' Fund V, L.P. · CIK 0001439586 · 10% owner

Flint Jonathan A · CIK 0001295676 · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnote

Disclosed balance after: 0

Underlying: Common Stock · 188 shares

Expires not disclosed

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · derivative.exercise_price: The Series A-1 Convertible Preferred Stock converted into Common Stock on a 0.29300-for-one basis upon the closing of the Issuer's initial public offering without payment of consideration. The Series A-1 Convertible Preferred Stock was convertible at any time at the holder's election and automatically upon the closing at the Issuer's initial public offering. The shares had no expiration date.

F1 · derivative.exercise_date: The Series A-1 Convertible Preferred Stock converted into Common Stock on a 0.29300-for-one basis upon the closing of the Issuer's initial public offering without payment of consideration. The Series A-1 Convertible Preferred Stock was convertible at any time at the holder's election and automatically upon the closing at the Issuer's initial public offering. The shares had no expiration date.

F1 · derivative.expiration_date: The Series A-1 Convertible Preferred Stock converted into Common Stock on a 0.29300-for-one basis upon the closing of the Issuer's initial public offering without payment of consideration. The Series A-1 Convertible Preferred Stock was convertible at any time at the holder's election and automatically upon the closing at the Issuer's initial public offering. The shares had no expiration date.

F6 · ownership.nature: These shares are owned directly by Polaris Special Founders' V, whose general partner is Polaris Management. Each of Flint and McGuire are the managing members of Polaris Management and, may each be deemed to share voting and dispositive power over the shares held by each of the Polaris V Funds. Polaris Management may be deemed to have sole power to vote and dispose of the shares held by the Polaris V Funds. Each of Flint, McGuire and Polaris Management disclaims beneficial ownership of these securities and this report shall not be deemed to be an admission that any of them is the beneficial owner of such securities for purposes of Section 16 or any other purpose, except to the extent of their respective pecuniary interests therein.

SEC source: 0000899243-17-026998 · doc4.xml · derivative · entry 27

Polaris Venture Management Co. V, L.L.C. · CIK 0001439589 · 10% owner

Polaris Venture Partners V, L.P. · CIK 0001439590 · 10% owner

Polaris Venture Partners Entrepreneurs' Fund V, L.P. · CIK 0001439587 · 10% owner

Polaris Venture Partners Founders' Fund V, L.P. · CIK 0001439588 · 10% owner

Polaris Venture Partners Special Founders' Fund V, L.P. · CIK 0001439586 · 10% owner

Flint Jonathan A · CIK 0001295676 · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnote

Disclosed balance after: 0

Underlying: Common Stock · 129 shares

Expires not disclosed

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · derivative.exercise_price: The Series A-1 Convertible Preferred Stock converted into Common Stock on a 0.29300-for-one basis upon the closing of the Issuer's initial public offering without payment of consideration. The Series A-1 Convertible Preferred Stock was convertible at any time at the holder's election and automatically upon the closing at the Issuer's initial public offering. The shares had no expiration date.

F1 · derivative.exercise_date: The Series A-1 Convertible Preferred Stock converted into Common Stock on a 0.29300-for-one basis upon the closing of the Issuer's initial public offering without payment of consideration. The Series A-1 Convertible Preferred Stock was convertible at any time at the holder's election and automatically upon the closing at the Issuer's initial public offering. The shares had no expiration date.

F1 · derivative.expiration_date: The Series A-1 Convertible Preferred Stock converted into Common Stock on a 0.29300-for-one basis upon the closing of the Issuer's initial public offering without payment of consideration. The Series A-1 Convertible Preferred Stock was convertible at any time at the holder's election and automatically upon the closing at the Issuer's initial public offering. The shares had no expiration date.

F5 · ownership.nature: These shares are owned directly by Polaris Founders' V, whose general partner is Polaris Management. Each of Flint and McGuire are the managing members of Polaris Management and may each be deemed to share voting and dispositive power over the shares held by each of the Polaris V Funds. Polaris Management may be deemed to have sole power to vote and dispose of the shares held by the Polaris V Funds. Each of Flint, McGuire and Polaris Management disclaims beneficial ownership of these securities and this report shall not be deemed to be an admission that any of them is the beneficial owner of such securities for purposes of Section 16 or any other purpose, except to the extent of their respective pecuniary interests therein.

SEC source: 0000899243-17-026998 · doc4.xml · derivative · entry 26

Polaris Venture Management Co. V, L.L.C. · CIK 0001439589 · 10% owner

Polaris Venture Partners V, L.P. · CIK 0001439590 · 10% owner

Polaris Venture Partners Entrepreneurs' Fund V, L.P. · CIK 0001439587 · 10% owner

Polaris Venture Partners Founders' Fund V, L.P. · CIK 0001439588 · 10% owner

Polaris Venture Partners Special Founders' Fund V, L.P. · CIK 0001439586 · 10% owner

Flint Jonathan A · CIK 0001295676 · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnote

Disclosed balance after: 0

Underlying: Common Stock · 367 shares

Expires not disclosed

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · derivative.exercise_price: The Series A-1 Convertible Preferred Stock converted into Common Stock on a 0.29300-for-one basis upon the closing of the Issuer's initial public offering without payment of consideration. The Series A-1 Convertible Preferred Stock was convertible at any time at the holder's election and automatically upon the closing at the Issuer's initial public offering. The shares had no expiration date.

F1 · derivative.exercise_date: The Series A-1 Convertible Preferred Stock converted into Common Stock on a 0.29300-for-one basis upon the closing of the Issuer's initial public offering without payment of consideration. The Series A-1 Convertible Preferred Stock was convertible at any time at the holder's election and automatically upon the closing at the Issuer's initial public offering. The shares had no expiration date.

F1 · derivative.expiration_date: The Series A-1 Convertible Preferred Stock converted into Common Stock on a 0.29300-for-one basis upon the closing of the Issuer's initial public offering without payment of consideration. The Series A-1 Convertible Preferred Stock was convertible at any time at the holder's election and automatically upon the closing at the Issuer's initial public offering. The shares had no expiration date.

F4 · ownership.nature: These shares are owned directly by Polaris Entrepreneurs' V, whose general partner is Polaris Management. Each of Flint and McGuire are the managing members of Polaris Management and may each be deemed to share voting and dispositive power over the shares held by each of the Polaris V Funds. Polaris Management may be deemed to have sole power to vote and dispose of the shares held by the Polaris V Funds. Each of Flint, McGuire and Polaris Management disclaims beneficial ownership of these securities and this report shall not be deemed to be an admission that any of them is the beneficial owner of such securities for purposes of Section 16 or any other purpose, except to the extent of their respective pecuniary interests therein.

SEC source: 0000899243-17-026998 · doc4.xml · derivative · entry 25

Polaris Venture Management Co. V, L.L.C. · CIK 0001439589 · 10% owner

Polaris Venture Partners V, L.P. · CIK 0001439590 · 10% owner

Polaris Venture Partners Entrepreneurs' Fund V, L.P. · CIK 0001439587 · 10% owner

Polaris Venture Partners Founders' Fund V, L.P. · CIK 0001439588 · 10% owner

Polaris Venture Partners Special Founders' Fund V, L.P. · CIK 0001439586 · 10% owner

Flint Jonathan A · CIK 0001295676 · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnotes

Disclosed balance after: 0

Underlying: Common Stock · 18,848 shares

Expires not disclosed

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · derivative.exercise_price: The Series A-1 Convertible Preferred Stock converted into Common Stock on a 0.29300-for-one basis upon the closing of the Issuer's initial public offering without payment of consideration. The Series A-1 Convertible Preferred Stock was convertible at any time at the holder's election and automatically upon the closing at the Issuer's initial public offering. The shares had no expiration date.

F1 · derivative.exercise_date: The Series A-1 Convertible Preferred Stock converted into Common Stock on a 0.29300-for-one basis upon the closing of the Issuer's initial public offering without payment of consideration. The Series A-1 Convertible Preferred Stock was convertible at any time at the holder's election and automatically upon the closing at the Issuer's initial public offering. The shares had no expiration date.

F1 · derivative.expiration_date: The Series A-1 Convertible Preferred Stock converted into Common Stock on a 0.29300-for-one basis upon the closing of the Issuer's initial public offering without payment of consideration. The Series A-1 Convertible Preferred Stock was convertible at any time at the holder's election and automatically upon the closing at the Issuer's initial public offering. The shares had no expiration date.

F2 · ownership.nature: These shares are owned directly by Polaris Venture Partners V, L.P. ("Polaris V"), whose general partner is Polaris Venture Management Co. V, L.L.C. ("Polaris Management"). Each of Jonathan A. Flint ("Flint") and Terrance G. McGuire ("McGuire"), who is a member of the Issuer's Board of Directors and whose beneficial ownership is reported on a separate Form 4, are the managing members of Polaris Management and may each be deemed to share voting and dispositive power with respect to the shares held by each of Polaris V, Polaris Venture Partners Entrepreneurs' Fund V, L.P. ("Polaris Entrepreneurs' V"), Polaris Venture Partners Founders' Fund V, L.P. ("Polaris Founders' V") and Polaris Venture Partners Special Founders' Fund V, L.P. ("Polaris Special Founders' V", and together with Polaris V, Polaris Entrepreneurs' V and Polaris Founders' V, the "Polaris V Funds").

F3 · ownership.nature: (Continued from footnote 2) Polaris Management may be deemed to have sole power to vote and dispose of the shares held by the Polaris V Funds. Each of Flint, McGuire and Polaris Management disclaims beneficial ownership of these securities and this report shall not be deemed to be an admission that any of them is the beneficial owner of such securities for purposes of Section 16 or any other purpose, except to the extent of their respective pecuniary interests therein.

SEC source: 0000899243-17-026998 · doc4.xml · nonDerivative · entry 24

Polaris Venture Management Co. V, L.L.C. · CIK 0001439589 · 10% owner

Polaris Venture Partners V, L.P. · CIK 0001439590 · 10% owner

Polaris Venture Partners Entrepreneurs' Fund V, L.P. · CIK 0001439587 · 10% owner

Polaris Venture Partners Founders' Fund V, L.P. · CIK 0001439588 · 10% owner

Polaris Venture Partners Special Founders' Fund V, L.P. · CIK 0001439586 · 10% owner

Flint Jonathan A · CIK 0001295676 · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnote

Disclosed balance after: 18,031

F6 · ownership.nature: These shares are owned directly by Polaris Special Founders' V, whose general partner is Polaris Management. Each of Flint and McGuire are the managing members of Polaris Management and, may each be deemed to share voting and dispositive power over the shares held by each of the Polaris V Funds. Polaris Management may be deemed to have sole power to vote and dispose of the shares held by the Polaris V Funds. Each of Flint, McGuire and Polaris Management disclaims beneficial ownership of these securities and this report shall not be deemed to be an admission that any of them is the beneficial owner of such securities for purposes of Section 16 or any other purpose, except to the extent of their respective pecuniary interests therein.

SEC source: 0000899243-17-026998 · doc4.xml · nonDerivative · entry 23

Polaris Venture Management Co. V, L.L.C. · CIK 0001439589 · 10% owner

Polaris Venture Partners V, L.P. · CIK 0001439590 · 10% owner

Polaris Venture Partners Entrepreneurs' Fund V, L.P. · CIK 0001439587 · 10% owner

Polaris Venture Partners Founders' Fund V, L.P. · CIK 0001439588 · 10% owner

Polaris Venture Partners Special Founders' Fund V, L.P. · CIK 0001439586 · 10% owner

Flint Jonathan A · CIK 0001295676 · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnote

Disclosed balance after: 12,351

F5 · ownership.nature: These shares are owned directly by Polaris Founders' V, whose general partner is Polaris Management. Each of Flint and McGuire are the managing members of Polaris Management and may each be deemed to share voting and dispositive power over the shares held by each of the Polaris V Funds. Polaris Management may be deemed to have sole power to vote and dispose of the shares held by the Polaris V Funds. Each of Flint, McGuire and Polaris Management disclaims beneficial ownership of these securities and this report shall not be deemed to be an admission that any of them is the beneficial owner of such securities for purposes of Section 16 or any other purpose, except to the extent of their respective pecuniary interests therein.

SEC source: 0000899243-17-026998 · doc4.xml · nonDerivative · entry 22

Polaris Venture Management Co. V, L.L.C. · CIK 0001439589 · 10% owner

Polaris Venture Partners V, L.P. · CIK 0001439590 · 10% owner

Polaris Venture Partners Entrepreneurs' Fund V, L.P. · CIK 0001439587 · 10% owner

Polaris Venture Partners Founders' Fund V, L.P. · CIK 0001439588 · 10% owner

Polaris Venture Partners Special Founders' Fund V, L.P. · CIK 0001439586 · 10% owner

Flint Jonathan A · CIK 0001295676 · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnote

Disclosed balance after: 35,146

F4 · ownership.nature: These shares are owned directly by Polaris Entrepreneurs' V, whose general partner is Polaris Management. Each of Flint and McGuire are the managing members of Polaris Management and may each be deemed to share voting and dispositive power over the shares held by each of the Polaris V Funds. Polaris Management may be deemed to have sole power to vote and dispose of the shares held by the Polaris V Funds. Each of Flint, McGuire and Polaris Management disclaims beneficial ownership of these securities and this report shall not be deemed to be an admission that any of them is the beneficial owner of such securities for purposes of Section 16 or any other purpose, except to the extent of their respective pecuniary interests therein.

SEC source: 0000899243-17-026998 · doc4.xml · nonDerivative · entry 21

Polaris Venture Management Co. V, L.L.C. · CIK 0001439589 · 10% owner

Polaris Venture Partners V, L.P. · CIK 0001439590 · 10% owner

Polaris Venture Partners Entrepreneurs' Fund V, L.P. · CIK 0001439587 · 10% owner

Polaris Venture Partners Founders' Fund V, L.P. · CIK 0001439588 · 10% owner

Polaris Venture Partners Special Founders' Fund V, L.P. · CIK 0001439586 · 10% owner

Flint Jonathan A · CIK 0001295676 · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnotes

Disclosed balance after: 1,803,429

F2 · ownership.nature: These shares are owned directly by Polaris Venture Partners V, L.P. ("Polaris V"), whose general partner is Polaris Venture Management Co. V, L.L.C. ("Polaris Management"). Each of Jonathan A. Flint ("Flint") and Terrance G. McGuire ("McGuire"), who is a member of the Issuer's Board of Directors and whose beneficial ownership is reported on a separate Form 4, are the managing members of Polaris Management and may each be deemed to share voting and dispositive power with respect to the shares held by each of Polaris V, Polaris Venture Partners Entrepreneurs' Fund V, L.P. ("Polaris Entrepreneurs' V"), Polaris Venture Partners Founders' Fund V, L.P. ("Polaris Founders' V") and Polaris Venture Partners Special Founders' Fund V, L.P. ("Polaris Special Founders' V", and together with Polaris V, Polaris Entrepreneurs' V and Polaris Founders' V, the "Polaris V Funds").

F3 · ownership.nature: (Continued from footnote 2) Polaris Management may be deemed to have sole power to vote and dispose of the shares held by the Polaris V Funds. Each of Flint, McGuire and Polaris Management disclaims beneficial ownership of these securities and this report shall not be deemed to be an admission that any of them is the beneficial owner of such securities for purposes of Section 16 or any other purpose, except to the extent of their respective pecuniary interests therein.

SEC source: 0000899243-17-026998 · doc4.xml · nonDerivative · entry 20

Polaris Venture Management Co. V, L.L.C. · CIK 0001439589 · 10% owner

Polaris Venture Partners V, L.P. · CIK 0001439590 · 10% owner

Polaris Venture Partners Entrepreneurs' Fund V, L.P. · CIK 0001439587 · 10% owner

Polaris Venture Partners Founders' Fund V, L.P. · CIK 0001439588 · 10% owner

Polaris Venture Partners Special Founders' Fund V, L.P. · CIK 0001439586 · 10% owner

Flint Jonathan A · CIK 0001295676 · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnote

Disclosed balance after: 13,206

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F10 · price: The Series D Convertible Preferred Stock converted into Common Stock on a 0.29300-for-one basis upon the closing of the Issuer's initial public offering without payment of consideration. The Series D Convertible Preferred Stock was convertible at any time at the holder's election and automatically upon the closing at the Issuer's initial public offering. The shares had no expiration date.

F6 · ownership.nature: These shares are owned directly by Polaris Special Founders' V, whose general partner is Polaris Management. Each of Flint and McGuire are the managing members of Polaris Management and, may each be deemed to share voting and dispositive power over the shares held by each of the Polaris V Funds. Polaris Management may be deemed to have sole power to vote and dispose of the shares held by the Polaris V Funds. Each of Flint, McGuire and Polaris Management disclaims beneficial ownership of these securities and this report shall not be deemed to be an admission that any of them is the beneficial owner of such securities for purposes of Section 16 or any other purpose, except to the extent of their respective pecuniary interests therein.