Flagship V VentureLabs Rx Fund, L.P.

SEC source: 0000899243-20-028807 · doc4.xml · derivative · entry 12

Flagship Ventures Fund V General Partner LLC · CIK 0001724575 · 10% owner

Flagship Ventures Fund V, L.P. · CIK 0001627639 · 10% owner

Flagship V VentureLabs Rx Fund, L.P. · CIK 0001724939 · 10% owner

AFEYAN NOUBAR · CIK 0001222012 · 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 · 338,630 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: Each share of Series B Preferred Stock automatically converted into the Issuer's Common Stock on a 1-for-7.1366 basis upon the closing of the Issuer's initial public offering on October 16, 2020 and had no expiration date. The reporting person previously reported shares of common stock into which the Series B Preferred Stock was convertible based on a 1-for-7.1295 conversion ratio estimated at pricing of the Issuer's initial public offering, which reflected a fixed conversion price plus an estimated adjustment based on the issuance of shares in the Issuer's initial public offering.

F4 · price: Each share of Series B Preferred Stock automatically converted into the Issuer's Common Stock on a 1-for-7.1366 basis upon the closing of the Issuer's initial public offering on October 16, 2020 and had no expiration date. The reporting person previously reported shares of common stock into which the Series B Preferred Stock was convertible based on a 1-for-7.1295 conversion ratio estimated at pricing of the Issuer's initial public offering, which reflected a fixed conversion price plus an estimated adjustment based on the issuance of shares in the Issuer's initial public offering.

F4 · derivative.exercise_date: Each share of Series B Preferred Stock automatically converted into the Issuer's Common Stock on a 1-for-7.1366 basis upon the closing of the Issuer's initial public offering on October 16, 2020 and had no expiration date. The reporting person previously reported shares of common stock into which the Series B Preferred Stock was convertible based on a 1-for-7.1295 conversion ratio estimated at pricing of the Issuer's initial public offering, which reflected a fixed conversion price plus an estimated adjustment based on the issuance of shares in the Issuer's initial public offering.

F4 · derivative.expiration_date: Each share of Series B Preferred Stock automatically converted into the Issuer's Common Stock on a 1-for-7.1366 basis upon the closing of the Issuer's initial public offering on October 16, 2020 and had no expiration date. The reporting person previously reported shares of common stock into which the Series B Preferred Stock was convertible based on a 1-for-7.1295 conversion ratio estimated at pricing of the Issuer's initial public offering, which reflected a fixed conversion price plus an estimated adjustment based on the issuance of shares in the Issuer's initial public offering.

F3 · ownership.nature: Shares held by Flagship V VentureLabs Rx Fund, L.P. ("Flagship Fund V Rx"). Flagship V GP is the general partner of Flagship Fund V Rx. Noubar B. Afeyan, Ph.D. serves as the sole manager of Flagship V GP. Each of the reporting persons except for Flagship Fund V Rx disclaims beneficial ownership of such shares except to the extent of his or its pecuniary interest therein.

SEC source: 0000899243-20-028807 · doc4.xml · derivative · entry 11

Flagship Ventures Fund V General Partner LLC · CIK 0001724575 · 10% owner

Flagship Ventures Fund V, L.P. · CIK 0001627639 · 10% owner

Flagship V VentureLabs Rx Fund, L.P. · CIK 0001724939 · 10% owner

AFEYAN NOUBAR · CIK 0001222012 · 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 · 338,630 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: Each share of Series B Preferred Stock automatically converted into the Issuer's Common Stock on a 1-for-7.1366 basis upon the closing of the Issuer's initial public offering on October 16, 2020 and had no expiration date. The reporting person previously reported shares of common stock into which the Series B Preferred Stock was convertible based on a 1-for-7.1295 conversion ratio estimated at pricing of the Issuer's initial public offering, which reflected a fixed conversion price plus an estimated adjustment based on the issuance of shares in the Issuer's initial public offering.

F4 · price: Each share of Series B Preferred Stock automatically converted into the Issuer's Common Stock on a 1-for-7.1366 basis upon the closing of the Issuer's initial public offering on October 16, 2020 and had no expiration date. The reporting person previously reported shares of common stock into which the Series B Preferred Stock was convertible based on a 1-for-7.1295 conversion ratio estimated at pricing of the Issuer's initial public offering, which reflected a fixed conversion price plus an estimated adjustment based on the issuance of shares in the Issuer's initial public offering.

F4 · derivative.exercise_date: Each share of Series B Preferred Stock automatically converted into the Issuer's Common Stock on a 1-for-7.1366 basis upon the closing of the Issuer's initial public offering on October 16, 2020 and had no expiration date. The reporting person previously reported shares of common stock into which the Series B Preferred Stock was convertible based on a 1-for-7.1295 conversion ratio estimated at pricing of the Issuer's initial public offering, which reflected a fixed conversion price plus an estimated adjustment based on the issuance of shares in the Issuer's initial public offering.

F4 · derivative.expiration_date: Each share of Series B Preferred Stock automatically converted into the Issuer's Common Stock on a 1-for-7.1366 basis upon the closing of the Issuer's initial public offering on October 16, 2020 and had no expiration date. The reporting person previously reported shares of common stock into which the Series B Preferred Stock was convertible based on a 1-for-7.1295 conversion ratio estimated at pricing of the Issuer's initial public offering, which reflected a fixed conversion price plus an estimated adjustment based on the issuance of shares in the Issuer's initial public offering.

F2 · ownership.nature: Shares held by Flagship Ventures Fund V, L.P. ("Flagship Fund V"). Flagship Ventures Fund V General Partner LLC ("Flagship V GP") is the general partner of Flagship Fund V. Noubar B. Afeyan, Ph.D. serves as the sole manager of Flagship V GP. Each of the reporting persons except for Flagship Fund V disclaims beneficial ownership of such shares except to the extent of his or its pecuniary interest therein.

SEC source: 0000899243-20-028807 · doc4.xml · derivative · entry 10

Flagship Ventures Fund V General Partner LLC · CIK 0001724575 · 10% owner

Flagship Ventures Fund V, L.P. · CIK 0001627639 · 10% owner

Flagship V VentureLabs Rx Fund, L.P. · CIK 0001724939 · 10% owner

AFEYAN NOUBAR · CIK 0001222012 · 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 · 543,686 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: Each share of Series A Preferred Stock automatically converted into the Issuer's Common Stock on a 1-for-7.8170 basis upon the closing of the Issuer's initial public offering on October 16, 2020 and had no expiration date.

F1 · price: Each share of Series A Preferred Stock automatically converted into the Issuer's Common Stock on a 1-for-7.8170 basis upon the closing of the Issuer's initial public offering on October 16, 2020 and had no expiration date.

F1 · derivative.exercise_date: Each share of Series A Preferred Stock automatically converted into the Issuer's Common Stock on a 1-for-7.8170 basis upon the closing of the Issuer's initial public offering on October 16, 2020 and had no expiration date.

F1 · derivative.expiration_date: Each share of Series A Preferred Stock automatically converted into the Issuer's Common Stock on a 1-for-7.8170 basis upon the closing of the Issuer's initial public offering on October 16, 2020 and had no expiration date.

F3 · ownership.nature: Shares held by Flagship V VentureLabs Rx Fund, L.P. ("Flagship Fund V Rx"). Flagship V GP is the general partner of Flagship Fund V Rx. Noubar B. Afeyan, Ph.D. serves as the sole manager of Flagship V GP. Each of the reporting persons except for Flagship Fund V Rx disclaims beneficial ownership of such shares except to the extent of his or its pecuniary interest therein.

SEC source: 0000899243-20-028807 · doc4.xml · derivative · entry 9

Flagship Ventures Fund V General Partner LLC · CIK 0001724575 · 10% owner

Flagship Ventures Fund V, L.P. · CIK 0001627639 · 10% owner

Flagship V VentureLabs Rx Fund, L.P. · CIK 0001724939 · 10% owner

AFEYAN NOUBAR · CIK 0001222012 · 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 · 543,686 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: Each share of Series A Preferred Stock automatically converted into the Issuer's Common Stock on a 1-for-7.8170 basis upon the closing of the Issuer's initial public offering on October 16, 2020 and had no expiration date.

F1 · price: Each share of Series A Preferred Stock automatically converted into the Issuer's Common Stock on a 1-for-7.8170 basis upon the closing of the Issuer's initial public offering on October 16, 2020 and had no expiration date.

F1 · derivative.exercise_date: Each share of Series A Preferred Stock automatically converted into the Issuer's Common Stock on a 1-for-7.8170 basis upon the closing of the Issuer's initial public offering on October 16, 2020 and had no expiration date.

F1 · derivative.expiration_date: Each share of Series A Preferred Stock automatically converted into the Issuer's Common Stock on a 1-for-7.8170 basis upon the closing of the Issuer's initial public offering on October 16, 2020 and had no expiration date.

F2 · ownership.nature: Shares held by Flagship Ventures Fund V, L.P. ("Flagship Fund V"). Flagship Ventures Fund V General Partner LLC ("Flagship V GP") is the general partner of Flagship Fund V. Noubar B. Afeyan, Ph.D. serves as the sole manager of Flagship V GP. Each of the reporting persons except for Flagship Fund V disclaims beneficial ownership of such shares except to the extent of his or its pecuniary interest therein.

SEC source: 0000899243-20-028807 · doc4.xml · nonDerivative · entry 7

Flagship Ventures Fund V General Partner LLC · CIK 0001724575 · 10% owner

Flagship Ventures Fund V, L.P. · CIK 0001627639 · 10% owner

Flagship V VentureLabs Rx Fund, L.P. · CIK 0001724939 · 10% owner

AFEYAN NOUBAR · CIK 0001222012 · 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: 1,143,177

F2 · ownership.nature: Shares held by Flagship Ventures Fund V, L.P. ("Flagship Fund V"). Flagship Ventures Fund V General Partner LLC ("Flagship V GP") is the general partner of Flagship Fund V. Noubar B. Afeyan, Ph.D. serves as the sole manager of Flagship V GP. Each of the reporting persons except for Flagship Fund V disclaims beneficial ownership of such shares except to the extent of his or its pecuniary interest therein.

SEC source: 0000899243-20-028807 · doc4.xml · nonDerivative · entry 6

Flagship Ventures Fund V General Partner LLC · CIK 0001724575 · 10% owner

Flagship Ventures Fund V, L.P. · CIK 0001627639 · 10% owner

Flagship V VentureLabs Rx Fund, L.P. · CIK 0001724939 · 10% owner

AFEYAN NOUBAR · CIK 0001222012 · 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: 978,177

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: Each share of Series C Preferred Stock automatically converted into the Issuer's Common Stock on a 1-for-6.8855 basis upon the closing of the Issuer's initial public offering on October 16, 2020 and had no expiration date. The reporting person previously reported shares of common stock into which the Series C Preferred Stock was convertible based on a 1-for-6.8758 conversion ratio estimated at pricing of the Issuer's initial public offering, which reflected a fixed conversion price plus an estimated adjustment based on the issuance of shares in the Issuer's initial public offering.

F3 · ownership.nature: Shares held by Flagship V VentureLabs Rx Fund, L.P. ("Flagship Fund V Rx"). Flagship V GP is the general partner of Flagship Fund V Rx. Noubar B. Afeyan, Ph.D. serves as the sole manager of Flagship V GP. Each of the reporting persons except for Flagship Fund V Rx disclaims beneficial ownership of such shares except to the extent of his or its pecuniary interest therein.

SEC source: 0000899243-20-028807 · doc4.xml · nonDerivative · entry 5

Flagship Ventures Fund V General Partner LLC · CIK 0001724575 · 10% owner

Flagship Ventures Fund V, L.P. · CIK 0001627639 · 10% owner

Flagship V VentureLabs Rx Fund, L.P. · CIK 0001724939 · 10% owner

AFEYAN NOUBAR · CIK 0001222012 · 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: 978,177

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: Each share of Series C Preferred Stock automatically converted into the Issuer's Common Stock on a 1-for-6.8855 basis upon the closing of the Issuer's initial public offering on October 16, 2020 and had no expiration date. The reporting person previously reported shares of common stock into which the Series C Preferred Stock was convertible based on a 1-for-6.8758 conversion ratio estimated at pricing of the Issuer's initial public offering, which reflected a fixed conversion price plus an estimated adjustment based on the issuance of shares in the Issuer's initial public offering.

F2 · ownership.nature: Shares held by Flagship Ventures Fund V, L.P. ("Flagship Fund V"). Flagship Ventures Fund V General Partner LLC ("Flagship V GP") is the general partner of Flagship Fund V. Noubar B. Afeyan, Ph.D. serves as the sole manager of Flagship V GP. Each of the reporting persons except for Flagship Fund V disclaims beneficial ownership of such shares except to the extent of his or its pecuniary interest therein.

SEC source: 0000899243-20-028807 · doc4.xml · nonDerivative · entry 4

Flagship Ventures Fund V General Partner LLC · CIK 0001724575 · 10% owner

Flagship Ventures Fund V, L.P. · CIK 0001627639 · 10% owner

Flagship V VentureLabs Rx Fund, L.P. · CIK 0001724939 · 10% owner

AFEYAN NOUBAR · CIK 0001222012 · 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: 882,316

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: Each share of Series B Preferred Stock automatically converted into the Issuer's Common Stock on a 1-for-7.1366 basis upon the closing of the Issuer's initial public offering on October 16, 2020 and had no expiration date. The reporting person previously reported shares of common stock into which the Series B Preferred Stock was convertible based on a 1-for-7.1295 conversion ratio estimated at pricing of the Issuer's initial public offering, which reflected a fixed conversion price plus an estimated adjustment based on the issuance of shares in the Issuer's initial public offering.

F3 · ownership.nature: Shares held by Flagship V VentureLabs Rx Fund, L.P. ("Flagship Fund V Rx"). Flagship V GP is the general partner of Flagship Fund V Rx. Noubar B. Afeyan, Ph.D. serves as the sole manager of Flagship V GP. Each of the reporting persons except for Flagship Fund V Rx disclaims beneficial ownership of such shares except to the extent of his or its pecuniary interest therein.

SEC source: 0000899243-20-028807 · doc4.xml · nonDerivative · entry 3

Flagship Ventures Fund V General Partner LLC · CIK 0001724575 · 10% owner

Flagship Ventures Fund V, L.P. · CIK 0001627639 · 10% owner

Flagship V VentureLabs Rx Fund, L.P. · CIK 0001724939 · 10% owner

AFEYAN NOUBAR · CIK 0001222012 · 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: 882,316

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: Each share of Series B Preferred Stock automatically converted into the Issuer's Common Stock on a 1-for-7.1366 basis upon the closing of the Issuer's initial public offering on October 16, 2020 and had no expiration date. The reporting person previously reported shares of common stock into which the Series B Preferred Stock was convertible based on a 1-for-7.1295 conversion ratio estimated at pricing of the Issuer's initial public offering, which reflected a fixed conversion price plus an estimated adjustment based on the issuance of shares in the Issuer's initial public offering.

F2 · ownership.nature: Shares held by Flagship Ventures Fund V, L.P. ("Flagship Fund V"). Flagship Ventures Fund V General Partner LLC ("Flagship V GP") is the general partner of Flagship Fund V. Noubar B. Afeyan, Ph.D. serves as the sole manager of Flagship V GP. Each of the reporting persons except for Flagship Fund V disclaims beneficial ownership of such shares except to the extent of his or its pecuniary interest therein.

SEC source: 0000899243-20-028807 · doc4.xml · nonDerivative · entry 2

Flagship Ventures Fund V General Partner LLC · CIK 0001724575 · 10% owner

Flagship Ventures Fund V, L.P. · CIK 0001627639 · 10% owner

Flagship V VentureLabs Rx Fund, L.P. · CIK 0001724939 · 10% owner

AFEYAN NOUBAR · CIK 0001222012 · 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: 543,686

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: Each share of Series A Preferred Stock automatically converted into the Issuer's Common Stock on a 1-for-7.8170 basis upon the closing of the Issuer's initial public offering on October 16, 2020 and had no expiration date.

F3 · ownership.nature: Shares held by Flagship V VentureLabs Rx Fund, L.P. ("Flagship Fund V Rx"). Flagship V GP is the general partner of Flagship Fund V Rx. Noubar B. Afeyan, Ph.D. serves as the sole manager of Flagship V GP. Each of the reporting persons except for Flagship Fund V Rx disclaims beneficial ownership of such shares except to the extent of his or its pecuniary interest therein.

SEC source: 0000899243-20-028807 · doc4.xml · nonDerivative · entry 1

Flagship Ventures Fund V General Partner LLC · CIK 0001724575 · 10% owner

Flagship Ventures Fund V, L.P. · CIK 0001627639 · 10% owner

Flagship V VentureLabs Rx Fund, L.P. · CIK 0001724939 · 10% owner

AFEYAN NOUBAR · CIK 0001222012 · 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: 543,686

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: Each share of Series A Preferred Stock automatically converted into the Issuer's Common Stock on a 1-for-7.8170 basis upon the closing of the Issuer's initial public offering on October 16, 2020 and had no expiration date.

F2 · ownership.nature: Shares held by Flagship Ventures Fund V, L.P. ("Flagship Fund V"). Flagship Ventures Fund V General Partner LLC ("Flagship V GP") is the general partner of Flagship Fund V. Noubar B. Afeyan, Ph.D. serves as the sole manager of Flagship V GP. Each of the reporting persons except for Flagship Fund V disclaims beneficial ownership of such shares except to the extent of his or its pecuniary interest therein.

SEC source: 0001104659-18-046534 · a4.xml · derivative · entry 21

Flagship Ventures Fund IV General Partner LLC · CIK 0001508051 · Director · 10% owner

Flagship VentureLabs IV, LLC · CIK 0001642578 · 10% owner

Flagship Ventures Fund IV, L.P. · CIK 0001503559 · 10% owner

Flagship Ventures Fund IV-Rx, L.P. · CIK 0001590973 · 10% owner

Flagship Ventures Fund V, L.P. · CIK 0001627639 · 10% owner

Flagship V VentureLabs Rx Fund, L.P. · CIK 0001724939 · 10% owner

Flagship Ventures Opportunities Fund I, L.P. · CIK 0001677345 · 10% owner

AFEYAN NOUBAR · CIK 0001222012 · Director · 10% owner

KANIA EDWIN M JR · CIK 0001255927 · 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 · 781,860 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 preferred stock is convertible into the Issuer's common stock on a one-for-one basis at the holder's election and has no expiration date. The preferred stock automatically convert into common stock upon the closing of the Issuer's initial public offering held on July 20, 2018.

F2 · price: The preferred stock is convertible into the Issuer's common stock on a one-for-one basis at the holder's election and has no expiration date. The preferred stock automatically convert into common stock upon the closing of the Issuer's initial public offering held on July 20, 2018.

F2 · derivative.exercise_date: The preferred stock is convertible into the Issuer's common stock on a one-for-one basis at the holder's election and has no expiration date. The preferred stock automatically convert into common stock upon the closing of the Issuer's initial public offering held on July 20, 2018.

F2 · derivative.expiration_date: The preferred stock is convertible into the Issuer's common stock on a one-for-one basis at the holder's election and has no expiration date. The preferred stock automatically convert into common stock upon the closing of the Issuer's initial public offering held on July 20, 2018.

F7 · ownership.nature: Shares held by Flagship Ventures Opportunities Fund I, L.P. ("Flagship Opportunities Fund I"). Flagship Ventures Opportunities Fund I General Partner LLC ("Flagship Opportunities GP") is the general partner of Flagship Opportunities I. Noubar B. Afeyan, Ph.D. is the sole manager of Flagship Opportunities GP and may be deemed to possess sole voting and investment power with respect to all shares held by Flagship Opportunities I. Each of the filing persons disclaims beneficial ownership of such shares except to the extent of his or its pecuniary interest therein.

SEC source: 0001104659-18-046534 · a4.xml · derivative · entry 20

Flagship Ventures Fund IV General Partner LLC · CIK 0001508051 · Director · 10% owner

Flagship VentureLabs IV, LLC · CIK 0001642578 · 10% owner

Flagship Ventures Fund IV, L.P. · CIK 0001503559 · 10% owner

Flagship Ventures Fund IV-Rx, L.P. · CIK 0001590973 · 10% owner

Flagship Ventures Fund V, L.P. · CIK 0001627639 · 10% owner

Flagship V VentureLabs Rx Fund, L.P. · CIK 0001724939 · 10% owner

Flagship Ventures Opportunities Fund I, L.P. · CIK 0001677345 · 10% owner

AFEYAN NOUBAR · CIK 0001222012 · Director · 10% owner

KANIA EDWIN M JR · CIK 0001255927 · 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 · 195,466 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 preferred stock is convertible into the Issuer's common stock on a one-for-one basis at the holder's election and has no expiration date. The preferred stock automatically convert into common stock upon the closing of the Issuer's initial public offering held on July 20, 2018.

F2 · price: The preferred stock is convertible into the Issuer's common stock on a one-for-one basis at the holder's election and has no expiration date. The preferred stock automatically convert into common stock upon the closing of the Issuer's initial public offering held on July 20, 2018.

F2 · derivative.exercise_date: The preferred stock is convertible into the Issuer's common stock on a one-for-one basis at the holder's election and has no expiration date. The preferred stock automatically convert into common stock upon the closing of the Issuer's initial public offering held on July 20, 2018.

F2 · derivative.expiration_date: The preferred stock is convertible into the Issuer's common stock on a one-for-one basis at the holder's election and has no expiration date. The preferred stock automatically convert into common stock upon the closing of the Issuer's initial public offering held on July 20, 2018.

F6 · ownership.nature: Shares held by Flagship V VentureLabs Rx Fund, L.P. ("VentureLabs Rx V"). Flagship Fund V GP is the general partner of VentureLabs Rx V. Noubar B. Afeyan, Ph.D. is the sole manager of Flagship Fund V GP and may be deemed to possess sole voting and investment power with respect to all shares held by VentureLabs Rx V. Each of the filing persons disclaims beneficial ownership of such shares except to the extent of his or its pecuniary interest therein.

SEC source: 0001104659-18-046534 · a4.xml · derivative · entry 19

Flagship Ventures Fund IV General Partner LLC · CIK 0001508051 · Director · 10% owner

Flagship VentureLabs IV, LLC · CIK 0001642578 · 10% owner

Flagship Ventures Fund IV, L.P. · CIK 0001503559 · 10% owner

Flagship Ventures Fund IV-Rx, L.P. · CIK 0001590973 · 10% owner

Flagship Ventures Fund V, L.P. · CIK 0001627639 · 10% owner

Flagship V VentureLabs Rx Fund, L.P. · CIK 0001724939 · 10% owner

Flagship Ventures Opportunities Fund I, L.P. · CIK 0001677345 · 10% owner

AFEYAN NOUBAR · CIK 0001222012 · Director · 10% owner

KANIA EDWIN M JR · CIK 0001255927 · 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 · 195,466 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 preferred stock is convertible into the Issuer's common stock on a one-for-one basis at the holder's election and has no expiration date. The preferred stock automatically convert into common stock upon the closing of the Issuer's initial public offering held on July 20, 2018.

F2 · price: The preferred stock is convertible into the Issuer's common stock on a one-for-one basis at the holder's election and has no expiration date. The preferred stock automatically convert into common stock upon the closing of the Issuer's initial public offering held on July 20, 2018.

F2 · derivative.exercise_date: The preferred stock is convertible into the Issuer's common stock on a one-for-one basis at the holder's election and has no expiration date. The preferred stock automatically convert into common stock upon the closing of the Issuer's initial public offering held on July 20, 2018.

F2 · derivative.expiration_date: The preferred stock is convertible into the Issuer's common stock on a one-for-one basis at the holder's election and has no expiration date. The preferred stock automatically convert into common stock upon the closing of the Issuer's initial public offering held on July 20, 2018.

F5 · ownership.nature: Shares held by Flagship Ventures Fund V, L.P. ("Flagship Fund V"). Flagship Ventures Fund V General Partner LLC ("Flagship Fund V GP") is the general partner of Flagship Fund V. Noubar B. Afeyan, Ph.D. is the sole manager of Flagship Fund V GP and may be deemed to possess sole voting and investment power with respect to all shares held by Flagship Fund V. Each of the filing persons disclaims beneficial ownership of such shares except to the extent of his or its pecuniary interest therein.

SEC source: 0001104659-18-046534 · a4.xml · derivative · entry 18

Flagship Ventures Fund IV General Partner LLC · CIK 0001508051 · Director · 10% owner

Flagship VentureLabs IV, LLC · CIK 0001642578 · 10% owner

Flagship Ventures Fund IV, L.P. · CIK 0001503559 · 10% owner

Flagship Ventures Fund IV-Rx, L.P. · CIK 0001590973 · 10% owner

Flagship Ventures Fund V, L.P. · CIK 0001627639 · 10% owner

Flagship V VentureLabs Rx Fund, L.P. · CIK 0001724939 · 10% owner

Flagship Ventures Opportunities Fund I, L.P. · CIK 0001677345 · 10% owner

AFEYAN NOUBAR · CIK 0001222012 · Director · 10% owner

KANIA EDWIN M JR · CIK 0001255927 · 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 · 1,781,843 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 preferred stock is convertible into the Issuer's common stock on a one-for-one basis at the holder's election and has no expiration date. The preferred stock automatically convert into common stock upon the closing of the Issuer's initial public offering held on July 20, 2018.

F2 · price: The preferred stock is convertible into the Issuer's common stock on a one-for-one basis at the holder's election and has no expiration date. The preferred stock automatically convert into common stock upon the closing of the Issuer's initial public offering held on July 20, 2018.

F2 · derivative.exercise_date: The preferred stock is convertible into the Issuer's common stock on a one-for-one basis at the holder's election and has no expiration date. The preferred stock automatically convert into common stock upon the closing of the Issuer's initial public offering held on July 20, 2018.

F2 · derivative.expiration_date: The preferred stock is convertible into the Issuer's common stock on a one-for-one basis at the holder's election and has no expiration date. The preferred stock automatically convert into common stock upon the closing of the Issuer's initial public offering held on July 20, 2018.

F7 · ownership.nature: Shares held by Flagship Ventures Opportunities Fund I, L.P. ("Flagship Opportunities Fund I"). Flagship Ventures Opportunities Fund I General Partner LLC ("Flagship Opportunities GP") is the general partner of Flagship Opportunities I. Noubar B. Afeyan, Ph.D. is the sole manager of Flagship Opportunities GP and may be deemed to possess sole voting and investment power with respect to all shares held by Flagship Opportunities I. Each of the filing persons disclaims beneficial ownership of such shares except to the extent of his or its pecuniary interest therein.

SEC source: 0001104659-18-046534 · a4.xml · derivative · entry 17

Flagship Ventures Fund IV General Partner LLC · CIK 0001508051 · Director · 10% owner

Flagship VentureLabs IV, LLC · CIK 0001642578 · 10% owner

Flagship Ventures Fund IV, L.P. · CIK 0001503559 · 10% owner

Flagship Ventures Fund IV-Rx, L.P. · CIK 0001590973 · 10% owner

Flagship Ventures Fund V, L.P. · CIK 0001627639 · 10% owner

Flagship V VentureLabs Rx Fund, L.P. · CIK 0001724939 · 10% owner

Flagship Ventures Opportunities Fund I, L.P. · CIK 0001677345 · 10% owner

AFEYAN NOUBAR · CIK 0001222012 · Director · 10% owner

KANIA EDWIN M JR · CIK 0001255927 · 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 · 593,948 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 preferred stock is convertible into the Issuer's common stock on a one-for-one basis at the holder's election and has no expiration date. The preferred stock automatically convert into common stock upon the closing of the Issuer's initial public offering held on July 20, 2018.

F2 · price: The preferred stock is convertible into the Issuer's common stock on a one-for-one basis at the holder's election and has no expiration date. The preferred stock automatically convert into common stock upon the closing of the Issuer's initial public offering held on July 20, 2018.

F2 · derivative.exercise_date: The preferred stock is convertible into the Issuer's common stock on a one-for-one basis at the holder's election and has no expiration date. The preferred stock automatically convert into common stock upon the closing of the Issuer's initial public offering held on July 20, 2018.

F2 · derivative.expiration_date: The preferred stock is convertible into the Issuer's common stock on a one-for-one basis at the holder's election and has no expiration date. The preferred stock automatically convert into common stock upon the closing of the Issuer's initial public offering held on July 20, 2018.

F6 · ownership.nature: Shares held by Flagship V VentureLabs Rx Fund, L.P. ("VentureLabs Rx V"). Flagship Fund V GP is the general partner of VentureLabs Rx V. Noubar B. Afeyan, Ph.D. is the sole manager of Flagship Fund V GP and may be deemed to possess sole voting and investment power with respect to all shares held by VentureLabs Rx V. Each of the filing persons disclaims beneficial ownership of such shares except to the extent of his or its pecuniary interest therein.

SEC source: 0001104659-18-046534 · a4.xml · derivative · entry 16

Flagship Ventures Fund IV General Partner LLC · CIK 0001508051 · Director · 10% owner

Flagship VentureLabs IV, LLC · CIK 0001642578 · 10% owner

Flagship Ventures Fund IV, L.P. · CIK 0001503559 · 10% owner

Flagship Ventures Fund IV-Rx, L.P. · CIK 0001590973 · 10% owner

Flagship Ventures Fund V, L.P. · CIK 0001627639 · 10% owner

Flagship V VentureLabs Rx Fund, L.P. · CIK 0001724939 · 10% owner

Flagship Ventures Opportunities Fund I, L.P. · CIK 0001677345 · 10% owner

AFEYAN NOUBAR · CIK 0001222012 · Director · 10% owner

KANIA EDWIN M JR · CIK 0001255927 · 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 · 593,948 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 preferred stock is convertible into the Issuer's common stock on a one-for-one basis at the holder's election and has no expiration date. The preferred stock automatically convert into common stock upon the closing of the Issuer's initial public offering held on July 20, 2018.

F2 · price: The preferred stock is convertible into the Issuer's common stock on a one-for-one basis at the holder's election and has no expiration date. The preferred stock automatically convert into common stock upon the closing of the Issuer's initial public offering held on July 20, 2018.

F2 · derivative.exercise_date: The preferred stock is convertible into the Issuer's common stock on a one-for-one basis at the holder's election and has no expiration date. The preferred stock automatically convert into common stock upon the closing of the Issuer's initial public offering held on July 20, 2018.

F2 · derivative.expiration_date: The preferred stock is convertible into the Issuer's common stock on a one-for-one basis at the holder's election and has no expiration date. The preferred stock automatically convert into common stock upon the closing of the Issuer's initial public offering held on July 20, 2018.

F5 · ownership.nature: Shares held by Flagship Ventures Fund V, L.P. ("Flagship Fund V"). Flagship Ventures Fund V General Partner LLC ("Flagship Fund V GP") is the general partner of Flagship Fund V. Noubar B. Afeyan, Ph.D. is the sole manager of Flagship Fund V GP and may be deemed to possess sole voting and investment power with respect to all shares held by Flagship Fund V. Each of the filing persons disclaims beneficial ownership of such shares except to the extent of his or its pecuniary interest therein.

SEC source: 0001104659-18-046534 · a4.xml · derivative · entry 15

Flagship Ventures Fund IV General Partner LLC · CIK 0001508051 · Director · 10% owner

Flagship VentureLabs IV, LLC · CIK 0001642578 · 10% owner

Flagship Ventures Fund IV, L.P. · CIK 0001503559 · 10% owner

Flagship Ventures Fund IV-Rx, L.P. · CIK 0001590973 · 10% owner

Flagship Ventures Fund V, L.P. · CIK 0001627639 · 10% owner

Flagship V VentureLabs Rx Fund, L.P. · CIK 0001724939 · 10% owner

Flagship Ventures Opportunities Fund I, L.P. · CIK 0001677345 · 10% owner

AFEYAN NOUBAR · CIK 0001222012 · Director · 10% owner

KANIA EDWIN M JR · CIK 0001255927 · 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 · 5,000,000 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 preferred stock is convertible into the Issuer's common stock on a one-for-one basis at the holder's election and has no expiration date. The preferred stock automatically convert into common stock upon the closing of the Issuer's initial public offering held on July 20, 2018.

F2 · price: The preferred stock is convertible into the Issuer's common stock on a one-for-one basis at the holder's election and has no expiration date. The preferred stock automatically convert into common stock upon the closing of the Issuer's initial public offering held on July 20, 2018.

F2 · derivative.exercise_date: The preferred stock is convertible into the Issuer's common stock on a one-for-one basis at the holder's election and has no expiration date. The preferred stock automatically convert into common stock upon the closing of the Issuer's initial public offering held on July 20, 2018.

F2 · derivative.expiration_date: The preferred stock is convertible into the Issuer's common stock on a one-for-one basis at the holder's election and has no expiration date. The preferred stock automatically convert into common stock upon the closing of the Issuer's initial public offering held on July 20, 2018.

F6 · ownership.nature: Shares held by Flagship V VentureLabs Rx Fund, L.P. ("VentureLabs Rx V"). Flagship Fund V GP is the general partner of VentureLabs Rx V. Noubar B. Afeyan, Ph.D. is the sole manager of Flagship Fund V GP and may be deemed to possess sole voting and investment power with respect to all shares held by VentureLabs Rx V. Each of the filing persons disclaims beneficial ownership of such shares except to the extent of his or its pecuniary interest therein.

SEC source: 0001104659-18-046534 · a4.xml · derivative · entry 14

Flagship Ventures Fund IV General Partner LLC · CIK 0001508051 · Director · 10% owner

Flagship VentureLabs IV, LLC · CIK 0001642578 · 10% owner

Flagship Ventures Fund IV, L.P. · CIK 0001503559 · 10% owner

Flagship Ventures Fund IV-Rx, L.P. · CIK 0001590973 · 10% owner

Flagship Ventures Fund V, L.P. · CIK 0001627639 · 10% owner

Flagship V VentureLabs Rx Fund, L.P. · CIK 0001724939 · 10% owner

Flagship Ventures Opportunities Fund I, L.P. · CIK 0001677345 · 10% owner

AFEYAN NOUBAR · CIK 0001222012 · Director · 10% owner

KANIA EDWIN M JR · CIK 0001255927 · 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 · 5,000,000 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 preferred stock is convertible into the Issuer's common stock on a one-for-one basis at the holder's election and has no expiration date. The preferred stock automatically convert into common stock upon the closing of the Issuer's initial public offering held on July 20, 2018.

F2 · price: The preferred stock is convertible into the Issuer's common stock on a one-for-one basis at the holder's election and has no expiration date. The preferred stock automatically convert into common stock upon the closing of the Issuer's initial public offering held on July 20, 2018.

F2 · derivative.exercise_date: The preferred stock is convertible into the Issuer's common stock on a one-for-one basis at the holder's election and has no expiration date. The preferred stock automatically convert into common stock upon the closing of the Issuer's initial public offering held on July 20, 2018.

F2 · derivative.expiration_date: The preferred stock is convertible into the Issuer's common stock on a one-for-one basis at the holder's election and has no expiration date. The preferred stock automatically convert into common stock upon the closing of the Issuer's initial public offering held on July 20, 2018.

F5 · ownership.nature: Shares held by Flagship Ventures Fund V, L.P. ("Flagship Fund V"). Flagship Ventures Fund V General Partner LLC ("Flagship Fund V GP") is the general partner of Flagship Fund V. Noubar B. Afeyan, Ph.D. is the sole manager of Flagship Fund V GP and may be deemed to possess sole voting and investment power with respect to all shares held by Flagship Fund V. Each of the filing persons disclaims beneficial ownership of such shares except to the extent of his or its pecuniary interest therein.

SEC source: 0001104659-18-046534 · a4.xml · derivative · entry 13

Flagship Ventures Fund IV General Partner LLC · CIK 0001508051 · Director · 10% owner

Flagship VentureLabs IV, LLC · CIK 0001642578 · 10% owner

Flagship Ventures Fund IV, L.P. · CIK 0001503559 · 10% owner

Flagship Ventures Fund IV-Rx, L.P. · CIK 0001590973 · 10% owner

Flagship Ventures Fund V, L.P. · CIK 0001627639 · 10% owner

Flagship V VentureLabs Rx Fund, L.P. · CIK 0001724939 · 10% owner

Flagship Ventures Opportunities Fund I, L.P. · CIK 0001677345 · 10% owner

AFEYAN NOUBAR · CIK 0001222012 · Director · 10% owner

KANIA EDWIN M JR · CIK 0001255927 · 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 · 3,830,402 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 preferred stock is convertible into the Issuer's common stock on a one-for-one basis at the holder's election and has no expiration date. The preferred stock automatically convert into common stock upon the closing of the Issuer's initial public offering held on July 20, 2018.

F2 · price: The preferred stock is convertible into the Issuer's common stock on a one-for-one basis at the holder's election and has no expiration date. The preferred stock automatically convert into common stock upon the closing of the Issuer's initial public offering held on July 20, 2018.

F2 · derivative.exercise_date: The preferred stock is convertible into the Issuer's common stock on a one-for-one basis at the holder's election and has no expiration date. The preferred stock automatically convert into common stock upon the closing of the Issuer's initial public offering held on July 20, 2018.

F2 · derivative.expiration_date: The preferred stock is convertible into the Issuer's common stock on a one-for-one basis at the holder's election and has no expiration date. The preferred stock automatically convert into common stock upon the closing of the Issuer's initial public offering held on July 20, 2018.

F4 · ownership.nature: Shares held by Flagship Ventures Fund IV-Rx, L.P. ("Flagship Fund IV-Rx"). Flagship Fund IV GP is the general partner of Flagship IV-Rx. Noubar B. Afeyan, Ph.D. and Edwin M. Kania, Jr. are the managers of Flagship Fund IV GP. Flagship Fund IV GP and each of these individuals may be deemed to share voting and investment power with respect to all shares held by Flagship IV-Rx. Each of the filing persons disclaims beneficial ownership of such shares except to the extent of his or its pecuniary interest therein.

SEC source: 0001104659-18-046534 · a4.xml · derivative · entry 12

Flagship Ventures Fund IV General Partner LLC · CIK 0001508051 · Director · 10% owner

Flagship VentureLabs IV, LLC · CIK 0001642578 · 10% owner

Flagship Ventures Fund IV, L.P. · CIK 0001503559 · 10% owner

Flagship Ventures Fund IV-Rx, L.P. · CIK 0001590973 · 10% owner

Flagship Ventures Fund V, L.P. · CIK 0001627639 · 10% owner

Flagship V VentureLabs Rx Fund, L.P. · CIK 0001724939 · 10% owner

Flagship Ventures Opportunities Fund I, L.P. · CIK 0001677345 · 10% owner

AFEYAN NOUBAR · CIK 0001222012 · Director · 10% owner

KANIA EDWIN M JR · CIK 0001255927 · 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 · 15,323,593 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 preferred stock is convertible into the Issuer's common stock on a one-for-one basis at the holder's election and has no expiration date. The preferred stock automatically convert into common stock upon the closing of the Issuer's initial public offering held on July 20, 2018.

F2 · price: The preferred stock is convertible into the Issuer's common stock on a one-for-one basis at the holder's election and has no expiration date. The preferred stock automatically convert into common stock upon the closing of the Issuer's initial public offering held on July 20, 2018.

F2 · derivative.exercise_date: The preferred stock is convertible into the Issuer's common stock on a one-for-one basis at the holder's election and has no expiration date. The preferred stock automatically convert into common stock upon the closing of the Issuer's initial public offering held on July 20, 2018.

F2 · derivative.expiration_date: The preferred stock is convertible into the Issuer's common stock on a one-for-one basis at the holder's election and has no expiration date. The preferred stock automatically convert into common stock upon the closing of the Issuer's initial public offering held on July 20, 2018.

F3 · ownership.nature: Shares held by Flagship Fund IV. Flagship Fund IV GP is the general partner of Flagship Fund IV. Noubar B. Afeyan, Ph.D. and Edwin M. Kania, Jr. are the managers of Flagship Fund IV GP and each of these individuals may be deemed to share voting and investment power with respect to all shares held by Flagship Fund IV. Each of the filing persons disclaims beneficial ownership of such shares except to the extent of his or its pecuniary interest therein.

SEC source: 0001104659-18-046534 · a4.xml · nonDerivative · entry 11

Flagship Ventures Fund IV General Partner LLC · CIK 0001508051 · Director · 10% owner

Flagship VentureLabs IV, LLC · CIK 0001642578 · 10% owner

Flagship Ventures Fund IV, L.P. · CIK 0001503559 · 10% owner

Flagship Ventures Fund IV-Rx, L.P. · CIK 0001590973 · 10% owner

Flagship Ventures Fund V, L.P. · CIK 0001627639 · 10% owner

Flagship V VentureLabs Rx Fund, L.P. · CIK 0001724939 · 10% owner

Flagship Ventures Opportunities Fund I, L.P. · CIK 0001677345 · 10% owner

AFEYAN NOUBAR · CIK 0001222012 · Director · 10% owner

KANIA EDWIN M JR · CIK 0001255927 · 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: 2,563,703

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 preferred stock is convertible into the Issuer's common stock on a one-for-one basis at the holder's election and has no expiration date. The preferred stock automatically convert into common stock upon the closing of the Issuer's initial public offering held on July 20, 2018.

F7 · ownership.nature: Shares held by Flagship Ventures Opportunities Fund I, L.P. ("Flagship Opportunities Fund I"). Flagship Ventures Opportunities Fund I General Partner LLC ("Flagship Opportunities GP") is the general partner of Flagship Opportunities I. Noubar B. Afeyan, Ph.D. is the sole manager of Flagship Opportunities GP and may be deemed to possess sole voting and investment power with respect to all shares held by Flagship Opportunities I. Each of the filing persons disclaims beneficial ownership of such shares except to the extent of his or its pecuniary interest therein.

SEC source: 0001104659-18-046534 · a4.xml · nonDerivative · entry 10

Flagship Ventures Fund IV General Partner LLC · CIK 0001508051 · Director · 10% owner

Flagship VentureLabs IV, LLC · CIK 0001642578 · 10% owner

Flagship Ventures Fund IV, L.P. · CIK 0001503559 · 10% owner

Flagship Ventures Fund IV-Rx, L.P. · CIK 0001590973 · 10% owner

Flagship Ventures Fund V, L.P. · CIK 0001627639 · 10% owner

Flagship V VentureLabs Rx Fund, L.P. · CIK 0001724939 · 10% owner

Flagship Ventures Opportunities Fund I, L.P. · CIK 0001677345 · 10% owner

AFEYAN NOUBAR · CIK 0001222012 · Director · 10% owner

KANIA EDWIN M JR · CIK 0001255927 · 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: 5,789,414

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 preferred stock is convertible into the Issuer's common stock on a one-for-one basis at the holder's election and has no expiration date. The preferred stock automatically convert into common stock upon the closing of the Issuer's initial public offering held on July 20, 2018.

F6 · ownership.nature: Shares held by Flagship V VentureLabs Rx Fund, L.P. ("VentureLabs Rx V"). Flagship Fund V GP is the general partner of VentureLabs Rx V. Noubar B. Afeyan, Ph.D. is the sole manager of Flagship Fund V GP and may be deemed to possess sole voting and investment power with respect to all shares held by VentureLabs Rx V. Each of the filing persons disclaims beneficial ownership of such shares except to the extent of his or its pecuniary interest therein.

SEC source: 0001104659-18-046534 · a4.xml · nonDerivative · entry 9

Flagship Ventures Fund IV General Partner LLC · CIK 0001508051 · Director · 10% owner

Flagship VentureLabs IV, LLC · CIK 0001642578 · 10% owner

Flagship Ventures Fund IV, L.P. · CIK 0001503559 · 10% owner

Flagship Ventures Fund IV-Rx, L.P. · CIK 0001590973 · 10% owner

Flagship Ventures Fund V, L.P. · CIK 0001627639 · 10% owner

Flagship V VentureLabs Rx Fund, L.P. · CIK 0001724939 · 10% owner

Flagship Ventures Opportunities Fund I, L.P. · CIK 0001677345 · 10% owner

AFEYAN NOUBAR · CIK 0001222012 · Director · 10% owner

KANIA EDWIN M JR · CIK 0001255927 · 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: 5,789,414

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 preferred stock is convertible into the Issuer's common stock on a one-for-one basis at the holder's election and has no expiration date. The preferred stock automatically convert into common stock upon the closing of the Issuer's initial public offering held on July 20, 2018.

F5 · ownership.nature: Shares held by Flagship Ventures Fund V, L.P. ("Flagship Fund V"). Flagship Ventures Fund V General Partner LLC ("Flagship Fund V GP") is the general partner of Flagship Fund V. Noubar B. Afeyan, Ph.D. is the sole manager of Flagship Fund V GP and may be deemed to possess sole voting and investment power with respect to all shares held by Flagship Fund V. Each of the filing persons disclaims beneficial ownership of such shares except to the extent of his or its pecuniary interest therein.

SEC source: 0001104659-18-046534 · a4.xml · nonDerivative · entry 8

Flagship Ventures Fund IV General Partner LLC · CIK 0001508051 · Director · 10% owner

Flagship VentureLabs IV, LLC · CIK 0001642578 · 10% owner

Flagship Ventures Fund IV, L.P. · CIK 0001503559 · 10% owner

Flagship Ventures Fund IV-Rx, L.P. · CIK 0001590973 · 10% owner

Flagship Ventures Fund V, L.P. · CIK 0001627639 · 10% owner

Flagship V VentureLabs Rx Fund, L.P. · CIK 0001724939 · 10% owner

Flagship Ventures Opportunities Fund I, L.P. · CIK 0001677345 · 10% owner

AFEYAN NOUBAR · CIK 0001222012 · Director · 10% owner

KANIA EDWIN M JR · CIK 0001255927 · 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: 1,781,843

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 preferred stock is convertible into the Issuer's common stock on a one-for-one basis at the holder's election and has no expiration date. The preferred stock automatically convert into common stock upon the closing of the Issuer's initial public offering held on July 20, 2018.

F7 · ownership.nature: Shares held by Flagship Ventures Opportunities Fund I, L.P. ("Flagship Opportunities Fund I"). Flagship Ventures Opportunities Fund I General Partner LLC ("Flagship Opportunities GP") is the general partner of Flagship Opportunities I. Noubar B. Afeyan, Ph.D. is the sole manager of Flagship Opportunities GP and may be deemed to possess sole voting and investment power with respect to all shares held by Flagship Opportunities I. Each of the filing persons disclaims beneficial ownership of such shares except to the extent of his or its pecuniary interest therein.

SEC source: 0001104659-18-046534 · a4.xml · nonDerivative · entry 7

Flagship Ventures Fund IV General Partner LLC · CIK 0001508051 · Director · 10% owner

Flagship VentureLabs IV, LLC · CIK 0001642578 · 10% owner

Flagship Ventures Fund IV, L.P. · CIK 0001503559 · 10% owner

Flagship Ventures Fund IV-Rx, L.P. · CIK 0001590973 · 10% owner

Flagship Ventures Fund V, L.P. · CIK 0001627639 · 10% owner

Flagship V VentureLabs Rx Fund, L.P. · CIK 0001724939 · 10% owner

Flagship Ventures Opportunities Fund I, L.P. · CIK 0001677345 · 10% owner

AFEYAN NOUBAR · CIK 0001222012 · Director · 10% owner

KANIA EDWIN M JR · CIK 0001255927 · 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: 5,593,948

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 preferred stock is convertible into the Issuer's common stock on a one-for-one basis at the holder's election and has no expiration date. The preferred stock automatically convert into common stock upon the closing of the Issuer's initial public offering held on July 20, 2018.

F6 · ownership.nature: Shares held by Flagship V VentureLabs Rx Fund, L.P. ("VentureLabs Rx V"). Flagship Fund V GP is the general partner of VentureLabs Rx V. Noubar B. Afeyan, Ph.D. is the sole manager of Flagship Fund V GP and may be deemed to possess sole voting and investment power with respect to all shares held by VentureLabs Rx V. Each of the filing persons disclaims beneficial ownership of such shares except to the extent of his or its pecuniary interest therein.

SEC source: 0001104659-18-046534 · a4.xml · nonDerivative · entry 6

Flagship Ventures Fund IV General Partner LLC · CIK 0001508051 · Director · 10% owner

Flagship VentureLabs IV, LLC · CIK 0001642578 · 10% owner

Flagship Ventures Fund IV, L.P. · CIK 0001503559 · 10% owner

Flagship Ventures Fund IV-Rx, L.P. · CIK 0001590973 · 10% owner

Flagship Ventures Fund V, L.P. · CIK 0001627639 · 10% owner

Flagship V VentureLabs Rx Fund, L.P. · CIK 0001724939 · 10% owner

Flagship Ventures Opportunities Fund I, L.P. · CIK 0001677345 · 10% owner

AFEYAN NOUBAR · CIK 0001222012 · Director · 10% owner

KANIA EDWIN M JR · CIK 0001255927 · 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: 5,593,948

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 preferred stock is convertible into the Issuer's common stock on a one-for-one basis at the holder's election and has no expiration date. The preferred stock automatically convert into common stock upon the closing of the Issuer's initial public offering held on July 20, 2018.

F5 · ownership.nature: Shares held by Flagship Ventures Fund V, L.P. ("Flagship Fund V"). Flagship Ventures Fund V General Partner LLC ("Flagship Fund V GP") is the general partner of Flagship Fund V. Noubar B. Afeyan, Ph.D. is the sole manager of Flagship Fund V GP and may be deemed to possess sole voting and investment power with respect to all shares held by Flagship Fund V. Each of the filing persons disclaims beneficial ownership of such shares except to the extent of his or its pecuniary interest therein.

SEC source: 0001104659-18-046534 · a4.xml · nonDerivative · entry 5

Flagship Ventures Fund IV General Partner LLC · CIK 0001508051 · Director · 10% owner

Flagship VentureLabs IV, LLC · CIK 0001642578 · 10% owner

Flagship Ventures Fund IV, L.P. · CIK 0001503559 · 10% owner

Flagship Ventures Fund IV-Rx, L.P. · CIK 0001590973 · 10% owner

Flagship Ventures Fund V, L.P. · CIK 0001627639 · 10% owner

Flagship V VentureLabs Rx Fund, L.P. · CIK 0001724939 · 10% owner

Flagship Ventures Opportunities Fund I, L.P. · CIK 0001677345 · 10% owner

AFEYAN NOUBAR · CIK 0001222012 · Director · 10% owner

KANIA EDWIN M JR · CIK 0001255927 · 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: 5,000,000

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 preferred stock is convertible into the Issuer's common stock on a one-for-one basis at the holder's election and has no expiration date. The preferred stock automatically convert into common stock upon the closing of the Issuer's initial public offering held on July 20, 2018.

F6 · ownership.nature: Shares held by Flagship V VentureLabs Rx Fund, L.P. ("VentureLabs Rx V"). Flagship Fund V GP is the general partner of VentureLabs Rx V. Noubar B. Afeyan, Ph.D. is the sole manager of Flagship Fund V GP and may be deemed to possess sole voting and investment power with respect to all shares held by VentureLabs Rx V. Each of the filing persons disclaims beneficial ownership of such shares except to the extent of his or its pecuniary interest therein.

SEC source: 0001104659-18-046534 · a4.xml · nonDerivative · entry 4

Flagship Ventures Fund IV General Partner LLC · CIK 0001508051 · Director · 10% owner

Flagship VentureLabs IV, LLC · CIK 0001642578 · 10% owner

Flagship Ventures Fund IV, L.P. · CIK 0001503559 · 10% owner

Flagship Ventures Fund IV-Rx, L.P. · CIK 0001590973 · 10% owner

Flagship Ventures Fund V, L.P. · CIK 0001627639 · 10% owner

Flagship V VentureLabs Rx Fund, L.P. · CIK 0001724939 · 10% owner

Flagship Ventures Opportunities Fund I, L.P. · CIK 0001677345 · 10% owner

AFEYAN NOUBAR · CIK 0001222012 · Director · 10% owner

KANIA EDWIN M JR · CIK 0001255927 · 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: 5,000,000

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 preferred stock is convertible into the Issuer's common stock on a one-for-one basis at the holder's election and has no expiration date. The preferred stock automatically convert into common stock upon the closing of the Issuer's initial public offering held on July 20, 2018.

F5 · ownership.nature: Shares held by Flagship Ventures Fund V, L.P. ("Flagship Fund V"). Flagship Ventures Fund V General Partner LLC ("Flagship Fund V GP") is the general partner of Flagship Fund V. Noubar B. Afeyan, Ph.D. is the sole manager of Flagship Fund V GP and may be deemed to possess sole voting and investment power with respect to all shares held by Flagship Fund V. Each of the filing persons disclaims beneficial ownership of such shares except to the extent of his or its pecuniary interest therein.

SEC source: 0001104659-18-046534 · a4.xml · nonDerivative · entry 3

Flagship Ventures Fund IV General Partner LLC · CIK 0001508051 · Director · 10% owner

Flagship VentureLabs IV, LLC · CIK 0001642578 · 10% owner

Flagship Ventures Fund IV, L.P. · CIK 0001503559 · 10% owner

Flagship Ventures Fund IV-Rx, L.P. · CIK 0001590973 · 10% owner

Flagship Ventures Fund V, L.P. · CIK 0001627639 · 10% owner

Flagship V VentureLabs Rx Fund, L.P. · CIK 0001724939 · 10% owner

Flagship Ventures Opportunities Fund I, L.P. · CIK 0001677345 · 10% owner

AFEYAN NOUBAR · CIK 0001222012 · Director · 10% owner

KANIA EDWIN M JR · CIK 0001255927 · 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: 3,830,402

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 preferred stock is convertible into the Issuer's common stock on a one-for-one basis at the holder's election and has no expiration date. The preferred stock automatically convert into common stock upon the closing of the Issuer's initial public offering held on July 20, 2018.

F4 · ownership.nature: Shares held by Flagship Ventures Fund IV-Rx, L.P. ("Flagship Fund IV-Rx"). Flagship Fund IV GP is the general partner of Flagship IV-Rx. Noubar B. Afeyan, Ph.D. and Edwin M. Kania, Jr. are the managers of Flagship Fund IV GP. Flagship Fund IV GP and each of these individuals may be deemed to share voting and investment power with respect to all shares held by Flagship IV-Rx. Each of the filing persons disclaims beneficial ownership of such shares except to the extent of his or its pecuniary interest therein.

SEC source: 0001104659-18-046534 · a4.xml · nonDerivative · entry 2

Flagship Ventures Fund IV General Partner LLC · CIK 0001508051 · Director · 10% owner

Flagship VentureLabs IV, LLC · CIK 0001642578 · 10% owner

Flagship Ventures Fund IV, L.P. · CIK 0001503559 · 10% owner

Flagship Ventures Fund IV-Rx, L.P. · CIK 0001590973 · 10% owner

Flagship Ventures Fund V, L.P. · CIK 0001627639 · 10% owner

Flagship V VentureLabs Rx Fund, L.P. · CIK 0001724939 · 10% owner

Flagship Ventures Opportunities Fund I, L.P. · CIK 0001677345 · 10% owner

AFEYAN NOUBAR · CIK 0001222012 · Director · 10% owner

KANIA EDWIN M JR · CIK 0001255927 · 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: 15,323,593

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 preferred stock is convertible into the Issuer's common stock on a one-for-one basis at the holder's election and has no expiration date. The preferred stock automatically convert into common stock upon the closing of the Issuer's initial public offering held on July 20, 2018.

F3 · ownership.nature: Shares held by Flagship Fund IV. Flagship Fund IV GP is the general partner of Flagship Fund IV. Noubar B. Afeyan, Ph.D. and Edwin M. Kania, Jr. are the managers of Flagship Fund IV GP and each of these individuals may be deemed to share voting and investment power with respect to all shares held by Flagship Fund IV. Each of the filing persons disclaims beneficial ownership of such shares except to the extent of his or its pecuniary interest therein.

SEC source: 0000899243-18-013013 · doc4.xml · derivative · entry 8

Flagship Ventures Fund V General Partner LLC · CIK 0001724575 · 10% owner

Flagship VentureLabs V LLC · CIK 0001724959 · 10% owner

Flagship Ventures Fund V, L.P. · CIK 0001627639 · 10% owner

Flagship V VentureLabs Rx Fund, L.P. · CIK 0001724939 · 10% owner

Nutritional Health Disruptive Innovation Fund, L.P. · CIK 0001725001 · 10% owner

Nutritional Health Side Fund, L.P. · CIK 0001725000 · 10% owner

Flagship Ventures Opportunities Fund I, L.P. · CIK 0001677345 · 10% owner

Flagship Ventures Opportunities Fund I General Partner LLC · CIK 0001725004 · 10% owner

AFEYAN NOUBAR · CIK 0001222012 · Director · 10% owner

KANIA EDWIN M JR · CIK 0001255927 · 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 · 1,138,505 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: Upon closing of the Issuer's initial public offering, each share of preferred stock was automatically converted into the Issuer's common stock on a 0.2452-for-one basis.

F7 · derivative.exercise_date: Upon closing of the Issuer's initial public offering, each share of preferred stock was automatically converted into the Issuer's common stock on a 0.2452-for-one basis.

F7 · derivative.expiration_date: Upon closing of the Issuer's initial public offering, each share of preferred stock was automatically converted into the Issuer's common stock on a 0.2452-for-one basis.

F1 · ownership.nature: Following the transactions reported herein, Flagship VentureLabs IV LLC ("VentureLabs IV") holds 684,372 shares of common stock, Flagship VentureLabs V LLC ("VentureLabs V") holds 2,645,637 shares of common stock, Flagship Ventures Fund IV L.P. ("Flagship Fund IV") holds 1,836,836 shares of common stock, Flagship Ventures Fund IV-Rx, L.P. ("Flagship Fund IV-Rx" and, together with VentureLabs IV and Flagship Fund IV, the "Flagship Fund IV Funds") holds 448,911 shares of common stock, Flagship Ventures Fund V, L.P. ("Flagship Fund V") holds 4,201,284 shares of common stock, Flagship V VentureLabs Rx Fund, L.P. ("VentureLabs Rx V") holds 1,609,871 shares of common stock, Nutritional Health Side Fund, L.P. ("Nutritional Health Side Fund") holds 795,950 shares of common stock,

F2 · ownership.nature: [Continued] Nutritional Health Disruptive Innovation Fund, L.P. ("Nutritional Innovation Fund" and, together with VentureLabs V, Flagship Fund V, VentureLabs Rx V and Nutritional Health Side Fund, the "Flagship Fund V Funds") holds 3,598,177 shares of common stock, and Flagship Ventures Opportunities Fund I, L.P. ("Flagship Opportunities I" and, together with the Flagship Fund IV Funds and Flagship Fund V Funds, the "Flagship Funds") holds 2,412,365 shares of common stock.

F3 · ownership.nature: Flagship Fund IV is a member of VentureLabs IV and also serves as its manager. Flagship Fund V is a member of VentureLabs V and also serves as its manager.

F4 · ownership.nature: The general partner of each of Flagship Fund IV and Flagship Fund IV-Rx is Flagship Ventures Fund IV General Partner LLC ("Flagship Fund IV GP"). The general partner of Flagship Fund V, VentureLabs Rx-V, Nutritional Innovation Fund and Nutritional Health Side Fund is Flagship Ventures Fund V General Partner LLC ("Flagship Fund V GP"). The general partner of Flagship Opportunities Fund I is Flagship Ventures Opportunities Fund I General Partner LLC ("Flagship Opportunities GP," and together with Flagship Fund IV GP and Flagship Fund V GP, the "Flagship General Partners").

F5 · ownership.nature: Noubar B. Afeyan, Ph.D. and Edwin M. Kania, Jr. are the managers of Flagship Fund IV GP and each of these individuals may be deemed to share voting and investment power with respect to all shares held by Flagship Fund IV Funds. Dr. Afeyan also serves as the managing member of the Flagship Fund V GP and Flagship Opportunities Fund GP and may be deemed to possess sole voting and investment control over the shares held by the Flagship Fund V Funds and Flagship Opportunities Fund I. Each of the Flagship General Partners, Dr. Afeyan and Mr. Kania disclaims beneficial ownership of any shares beneficially owned by the Flagship Funds except to the extent of its or his pecuniary interest therein.

SEC source: 0000899243-18-013013 · doc4.xml · derivative · entry 7

Flagship Ventures Fund V General Partner LLC · CIK 0001724575 · 10% owner

Flagship VentureLabs V LLC · CIK 0001724959 · 10% owner

Flagship Ventures Fund V, L.P. · CIK 0001627639 · 10% owner

Flagship V VentureLabs Rx Fund, L.P. · CIK 0001724939 · 10% owner

Nutritional Health Disruptive Innovation Fund, L.P. · CIK 0001725001 · 10% owner

Nutritional Health Side Fund, L.P. · CIK 0001725000 · 10% owner

Flagship Ventures Opportunities Fund I, L.P. · CIK 0001677345 · 10% owner

Flagship Ventures Opportunities Fund I General Partner LLC · CIK 0001725004 · 10% owner

AFEYAN NOUBAR · CIK 0001222012 · Director · 10% owner

KANIA EDWIN M JR · CIK 0001255927 · 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 · 4,562,664 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: Upon closing of the Issuer's initial public offering, each share of preferred stock was automatically converted into the Issuer's common stock on a 0.2452-for-one basis.

F7 · derivative.exercise_date: Upon closing of the Issuer's initial public offering, each share of preferred stock was automatically converted into the Issuer's common stock on a 0.2452-for-one basis.

F7 · derivative.expiration_date: Upon closing of the Issuer's initial public offering, each share of preferred stock was automatically converted into the Issuer's common stock on a 0.2452-for-one basis.

F1 · ownership.nature: Following the transactions reported herein, Flagship VentureLabs IV LLC ("VentureLabs IV") holds 684,372 shares of common stock, Flagship VentureLabs V LLC ("VentureLabs V") holds 2,645,637 shares of common stock, Flagship Ventures Fund IV L.P. ("Flagship Fund IV") holds 1,836,836 shares of common stock, Flagship Ventures Fund IV-Rx, L.P. ("Flagship Fund IV-Rx" and, together with VentureLabs IV and Flagship Fund IV, the "Flagship Fund IV Funds") holds 448,911 shares of common stock, Flagship Ventures Fund V, L.P. ("Flagship Fund V") holds 4,201,284 shares of common stock, Flagship V VentureLabs Rx Fund, L.P. ("VentureLabs Rx V") holds 1,609,871 shares of common stock, Nutritional Health Side Fund, L.P. ("Nutritional Health Side Fund") holds 795,950 shares of common stock,

F2 · ownership.nature: [Continued] Nutritional Health Disruptive Innovation Fund, L.P. ("Nutritional Innovation Fund" and, together with VentureLabs V, Flagship Fund V, VentureLabs Rx V and Nutritional Health Side Fund, the "Flagship Fund V Funds") holds 3,598,177 shares of common stock, and Flagship Ventures Opportunities Fund I, L.P. ("Flagship Opportunities I" and, together with the Flagship Fund IV Funds and Flagship Fund V Funds, the "Flagship Funds") holds 2,412,365 shares of common stock.

F3 · ownership.nature: Flagship Fund IV is a member of VentureLabs IV and also serves as its manager. Flagship Fund V is a member of VentureLabs V and also serves as its manager.

F4 · ownership.nature: The general partner of each of Flagship Fund IV and Flagship Fund IV-Rx is Flagship Ventures Fund IV General Partner LLC ("Flagship Fund IV GP"). The general partner of Flagship Fund V, VentureLabs Rx-V, Nutritional Innovation Fund and Nutritional Health Side Fund is Flagship Ventures Fund V General Partner LLC ("Flagship Fund V GP"). The general partner of Flagship Opportunities Fund I is Flagship Ventures Opportunities Fund I General Partner LLC ("Flagship Opportunities GP," and together with Flagship Fund IV GP and Flagship Fund V GP, the "Flagship General Partners").

F5 · ownership.nature: Noubar B. Afeyan, Ph.D. and Edwin M. Kania, Jr. are the managers of Flagship Fund IV GP and each of these individuals may be deemed to share voting and investment power with respect to all shares held by Flagship Fund IV Funds. Dr. Afeyan also serves as the managing member of the Flagship Fund V GP and Flagship Opportunities Fund GP and may be deemed to possess sole voting and investment control over the shares held by the Flagship Fund V Funds and Flagship Opportunities Fund I. Each of the Flagship General Partners, Dr. Afeyan and Mr. Kania disclaims beneficial ownership of any shares beneficially owned by the Flagship Funds except to the extent of its or his pecuniary interest therein.

SEC source: 0000899243-18-013013 · doc4.xml · derivative · entry 6

Flagship Ventures Fund V General Partner LLC · CIK 0001724575 · 10% owner

Flagship VentureLabs V LLC · CIK 0001724959 · 10% owner

Flagship Ventures Fund V, L.P. · CIK 0001627639 · 10% owner

Flagship V VentureLabs Rx Fund, L.P. · CIK 0001724939 · 10% owner

Nutritional Health Disruptive Innovation Fund, L.P. · CIK 0001725001 · 10% owner

Nutritional Health Side Fund, L.P. · CIK 0001725000 · 10% owner

Flagship Ventures Opportunities Fund I, L.P. · CIK 0001677345 · 10% owner

Flagship Ventures Opportunities Fund I General Partner LLC · CIK 0001725004 · 10% owner

AFEYAN NOUBAR · CIK 0001222012 · Director · 10% owner

KANIA EDWIN M JR · CIK 0001255927 · 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 · 2,042,902 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: Upon closing of the Issuer's initial public offering, each share of preferred stock was automatically converted into the Issuer's common stock on a 0.2452-for-one basis.

F7 · derivative.exercise_date: Upon closing of the Issuer's initial public offering, each share of preferred stock was automatically converted into the Issuer's common stock on a 0.2452-for-one basis.

F7 · derivative.expiration_date: Upon closing of the Issuer's initial public offering, each share of preferred stock was automatically converted into the Issuer's common stock on a 0.2452-for-one basis.

F1 · ownership.nature: Following the transactions reported herein, Flagship VentureLabs IV LLC ("VentureLabs IV") holds 684,372 shares of common stock, Flagship VentureLabs V LLC ("VentureLabs V") holds 2,645,637 shares of common stock, Flagship Ventures Fund IV L.P. ("Flagship Fund IV") holds 1,836,836 shares of common stock, Flagship Ventures Fund IV-Rx, L.P. ("Flagship Fund IV-Rx" and, together with VentureLabs IV and Flagship Fund IV, the "Flagship Fund IV Funds") holds 448,911 shares of common stock, Flagship Ventures Fund V, L.P. ("Flagship Fund V") holds 4,201,284 shares of common stock, Flagship V VentureLabs Rx Fund, L.P. ("VentureLabs Rx V") holds 1,609,871 shares of common stock, Nutritional Health Side Fund, L.P. ("Nutritional Health Side Fund") holds 795,950 shares of common stock,

F2 · ownership.nature: [Continued] Nutritional Health Disruptive Innovation Fund, L.P. ("Nutritional Innovation Fund" and, together with VentureLabs V, Flagship Fund V, VentureLabs Rx V and Nutritional Health Side Fund, the "Flagship Fund V Funds") holds 3,598,177 shares of common stock, and Flagship Ventures Opportunities Fund I, L.P. ("Flagship Opportunities I" and, together with the Flagship Fund IV Funds and Flagship Fund V Funds, the "Flagship Funds") holds 2,412,365 shares of common stock.

F3 · ownership.nature: Flagship Fund IV is a member of VentureLabs IV and also serves as its manager. Flagship Fund V is a member of VentureLabs V and also serves as its manager.

F4 · ownership.nature: The general partner of each of Flagship Fund IV and Flagship Fund IV-Rx is Flagship Ventures Fund IV General Partner LLC ("Flagship Fund IV GP"). The general partner of Flagship Fund V, VentureLabs Rx-V, Nutritional Innovation Fund and Nutritional Health Side Fund is Flagship Ventures Fund V General Partner LLC ("Flagship Fund V GP"). The general partner of Flagship Opportunities Fund I is Flagship Ventures Opportunities Fund I General Partner LLC ("Flagship Opportunities GP," and together with Flagship Fund IV GP and Flagship Fund V GP, the "Flagship General Partners").

F5 · ownership.nature: Noubar B. Afeyan, Ph.D. and Edwin M. Kania, Jr. are the managers of Flagship Fund IV GP and each of these individuals may be deemed to share voting and investment power with respect to all shares held by Flagship Fund IV Funds. Dr. Afeyan also serves as the managing member of the Flagship Fund V GP and Flagship Opportunities Fund GP and may be deemed to possess sole voting and investment control over the shares held by the Flagship Fund V Funds and Flagship Opportunities Fund I. Each of the Flagship General Partners, Dr. Afeyan and Mr. Kania disclaims beneficial ownership of any shares beneficially owned by the Flagship Funds except to the extent of its or his pecuniary interest therein.

SEC source: 0000899243-18-013013 · doc4.xml · derivative · entry 5

Flagship Ventures Fund V General Partner LLC · CIK 0001724575 · 10% owner

Flagship VentureLabs V LLC · CIK 0001724959 · 10% owner

Flagship Ventures Fund V, L.P. · CIK 0001627639 · 10% owner

Flagship V VentureLabs Rx Fund, L.P. · CIK 0001724939 · 10% owner

Nutritional Health Disruptive Innovation Fund, L.P. · CIK 0001725001 · 10% owner

Nutritional Health Side Fund, L.P. · CIK 0001725000 · 10% owner

Flagship Ventures Opportunities Fund I, L.P. · CIK 0001677345 · 10% owner

Flagship Ventures Opportunities Fund I General Partner LLC · CIK 0001725004 · 10% owner

AFEYAN NOUBAR · CIK 0001222012 · Director · 10% owner

KANIA EDWIN M JR · CIK 0001255927 · 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 · 1,327,939 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: Upon closing of the Issuer's initial public offering, each share of preferred stock was automatically converted into the Issuer's common stock on a 0.2452-for-one basis.

F7 · derivative.exercise_date: Upon closing of the Issuer's initial public offering, each share of preferred stock was automatically converted into the Issuer's common stock on a 0.2452-for-one basis.

F7 · derivative.expiration_date: Upon closing of the Issuer's initial public offering, each share of preferred stock was automatically converted into the Issuer's common stock on a 0.2452-for-one basis.

F1 · ownership.nature: Following the transactions reported herein, Flagship VentureLabs IV LLC ("VentureLabs IV") holds 684,372 shares of common stock, Flagship VentureLabs V LLC ("VentureLabs V") holds 2,645,637 shares of common stock, Flagship Ventures Fund IV L.P. ("Flagship Fund IV") holds 1,836,836 shares of common stock, Flagship Ventures Fund IV-Rx, L.P. ("Flagship Fund IV-Rx" and, together with VentureLabs IV and Flagship Fund IV, the "Flagship Fund IV Funds") holds 448,911 shares of common stock, Flagship Ventures Fund V, L.P. ("Flagship Fund V") holds 4,201,284 shares of common stock, Flagship V VentureLabs Rx Fund, L.P. ("VentureLabs Rx V") holds 1,609,871 shares of common stock, Nutritional Health Side Fund, L.P. ("Nutritional Health Side Fund") holds 795,950 shares of common stock,

F2 · ownership.nature: [Continued] Nutritional Health Disruptive Innovation Fund, L.P. ("Nutritional Innovation Fund" and, together with VentureLabs V, Flagship Fund V, VentureLabs Rx V and Nutritional Health Side Fund, the "Flagship Fund V Funds") holds 3,598,177 shares of common stock, and Flagship Ventures Opportunities Fund I, L.P. ("Flagship Opportunities I" and, together with the Flagship Fund IV Funds and Flagship Fund V Funds, the "Flagship Funds") holds 2,412,365 shares of common stock.

F3 · ownership.nature: Flagship Fund IV is a member of VentureLabs IV and also serves as its manager. Flagship Fund V is a member of VentureLabs V and also serves as its manager.

F4 · ownership.nature: The general partner of each of Flagship Fund IV and Flagship Fund IV-Rx is Flagship Ventures Fund IV General Partner LLC ("Flagship Fund IV GP"). The general partner of Flagship Fund V, VentureLabs Rx-V, Nutritional Innovation Fund and Nutritional Health Side Fund is Flagship Ventures Fund V General Partner LLC ("Flagship Fund V GP"). The general partner of Flagship Opportunities Fund I is Flagship Ventures Opportunities Fund I General Partner LLC ("Flagship Opportunities GP," and together with Flagship Fund IV GP and Flagship Fund V GP, the "Flagship General Partners").

F5 · ownership.nature: Noubar B. Afeyan, Ph.D. and Edwin M. Kania, Jr. are the managers of Flagship Fund IV GP and each of these individuals may be deemed to share voting and investment power with respect to all shares held by Flagship Fund IV Funds. Dr. Afeyan also serves as the managing member of the Flagship Fund V GP and Flagship Opportunities Fund GP and may be deemed to possess sole voting and investment control over the shares held by the Flagship Fund V Funds and Flagship Opportunities Fund I. Each of the Flagship General Partners, Dr. Afeyan and Mr. Kania disclaims beneficial ownership of any shares beneficially owned by the Flagship Funds except to the extent of its or his pecuniary interest therein.

SEC source: 0000899243-18-013013 · doc4.xml · derivative · entry 4

Flagship Ventures Fund V General Partner LLC · CIK 0001724575 · 10% owner

Flagship VentureLabs V LLC · CIK 0001724959 · 10% owner

Flagship Ventures Fund V, L.P. · CIK 0001627639 · 10% owner

Flagship V VentureLabs Rx Fund, L.P. · CIK 0001724939 · 10% owner

Nutritional Health Disruptive Innovation Fund, L.P. · CIK 0001725001 · 10% owner

Nutritional Health Side Fund, L.P. · CIK 0001725000 · 10% owner

Flagship Ventures Opportunities Fund I, L.P. · CIK 0001677345 · 10% owner

Flagship Ventures Opportunities Fund I General Partner LLC · CIK 0001725004 · 10% owner

AFEYAN NOUBAR · CIK 0001222012 · Director · 10% owner

KANIA EDWIN M JR · CIK 0001255927 · 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 · 2,476,600 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: Upon closing of the Issuer's initial public offering, each share of preferred stock was automatically converted into the Issuer's common stock on a 0.2452-for-one basis.

F7 · derivative.exercise_date: Upon closing of the Issuer's initial public offering, each share of preferred stock was automatically converted into the Issuer's common stock on a 0.2452-for-one basis.

F7 · derivative.expiration_date: Upon closing of the Issuer's initial public offering, each share of preferred stock was automatically converted into the Issuer's common stock on a 0.2452-for-one basis.

F1 · ownership.nature: Following the transactions reported herein, Flagship VentureLabs IV LLC ("VentureLabs IV") holds 684,372 shares of common stock, Flagship VentureLabs V LLC ("VentureLabs V") holds 2,645,637 shares of common stock, Flagship Ventures Fund IV L.P. ("Flagship Fund IV") holds 1,836,836 shares of common stock, Flagship Ventures Fund IV-Rx, L.P. ("Flagship Fund IV-Rx" and, together with VentureLabs IV and Flagship Fund IV, the "Flagship Fund IV Funds") holds 448,911 shares of common stock, Flagship Ventures Fund V, L.P. ("Flagship Fund V") holds 4,201,284 shares of common stock, Flagship V VentureLabs Rx Fund, L.P. ("VentureLabs Rx V") holds 1,609,871 shares of common stock, Nutritional Health Side Fund, L.P. ("Nutritional Health Side Fund") holds 795,950 shares of common stock,

F2 · ownership.nature: [Continued] Nutritional Health Disruptive Innovation Fund, L.P. ("Nutritional Innovation Fund" and, together with VentureLabs V, Flagship Fund V, VentureLabs Rx V and Nutritional Health Side Fund, the "Flagship Fund V Funds") holds 3,598,177 shares of common stock, and Flagship Ventures Opportunities Fund I, L.P. ("Flagship Opportunities I" and, together with the Flagship Fund IV Funds and Flagship Fund V Funds, the "Flagship Funds") holds 2,412,365 shares of common stock.

F3 · ownership.nature: Flagship Fund IV is a member of VentureLabs IV and also serves as its manager. Flagship Fund V is a member of VentureLabs V and also serves as its manager.

F4 · ownership.nature: The general partner of each of Flagship Fund IV and Flagship Fund IV-Rx is Flagship Ventures Fund IV General Partner LLC ("Flagship Fund IV GP"). The general partner of Flagship Fund V, VentureLabs Rx-V, Nutritional Innovation Fund and Nutritional Health Side Fund is Flagship Ventures Fund V General Partner LLC ("Flagship Fund V GP"). The general partner of Flagship Opportunities Fund I is Flagship Ventures Opportunities Fund I General Partner LLC ("Flagship Opportunities GP," and together with Flagship Fund IV GP and Flagship Fund V GP, the "Flagship General Partners").

F5 · ownership.nature: Noubar B. Afeyan, Ph.D. and Edwin M. Kania, Jr. are the managers of Flagship Fund IV GP and each of these individuals may be deemed to share voting and investment power with respect to all shares held by Flagship Fund IV Funds. Dr. Afeyan also serves as the managing member of the Flagship Fund V GP and Flagship Opportunities Fund GP and may be deemed to possess sole voting and investment control over the shares held by the Flagship Fund V Funds and Flagship Opportunities Fund I. Each of the Flagship General Partners, Dr. Afeyan and Mr. Kania disclaims beneficial ownership of any shares beneficially owned by the Flagship Funds except to the extent of its or his pecuniary interest therein.

SEC source: 0000899243-18-013013 · doc4.xml · derivative · entry 3

Flagship Ventures Fund V General Partner LLC · CIK 0001724575 · 10% owner

Flagship VentureLabs V LLC · CIK 0001724959 · 10% owner

Flagship Ventures Fund V, L.P. · CIK 0001627639 · 10% owner

Flagship V VentureLabs Rx Fund, L.P. · CIK 0001724939 · 10% owner

Nutritional Health Disruptive Innovation Fund, L.P. · CIK 0001725001 · 10% owner

Nutritional Health Side Fund, L.P. · CIK 0001725000 · 10% owner

Flagship Ventures Opportunities Fund I, L.P. · CIK 0001677345 · 10% owner

Flagship Ventures Opportunities Fund I General Partner LLC · CIK 0001725004 · 10% owner

AFEYAN NOUBAR · CIK 0001222012 · Director · 10% owner

KANIA EDWIN M JR · CIK 0001255927 · 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 · 3,073,533 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: Upon closing of the Issuer's initial public offering, each share of preferred stock was automatically converted into the Issuer's common stock on a 0.2452-for-one basis.

F7 · derivative.exercise_date: Upon closing of the Issuer's initial public offering, each share of preferred stock was automatically converted into the Issuer's common stock on a 0.2452-for-one basis.

F7 · derivative.expiration_date: Upon closing of the Issuer's initial public offering, each share of preferred stock was automatically converted into the Issuer's common stock on a 0.2452-for-one basis.

F1 · ownership.nature: Following the transactions reported herein, Flagship VentureLabs IV LLC ("VentureLabs IV") holds 684,372 shares of common stock, Flagship VentureLabs V LLC ("VentureLabs V") holds 2,645,637 shares of common stock, Flagship Ventures Fund IV L.P. ("Flagship Fund IV") holds 1,836,836 shares of common stock, Flagship Ventures Fund IV-Rx, L.P. ("Flagship Fund IV-Rx" and, together with VentureLabs IV and Flagship Fund IV, the "Flagship Fund IV Funds") holds 448,911 shares of common stock, Flagship Ventures Fund V, L.P. ("Flagship Fund V") holds 4,201,284 shares of common stock, Flagship V VentureLabs Rx Fund, L.P. ("VentureLabs Rx V") holds 1,609,871 shares of common stock, Nutritional Health Side Fund, L.P. ("Nutritional Health Side Fund") holds 795,950 shares of common stock,

F2 · ownership.nature: [Continued] Nutritional Health Disruptive Innovation Fund, L.P. ("Nutritional Innovation Fund" and, together with VentureLabs V, Flagship Fund V, VentureLabs Rx V and Nutritional Health Side Fund, the "Flagship Fund V Funds") holds 3,598,177 shares of common stock, and Flagship Ventures Opportunities Fund I, L.P. ("Flagship Opportunities I" and, together with the Flagship Fund IV Funds and Flagship Fund V Funds, the "Flagship Funds") holds 2,412,365 shares of common stock.

F3 · ownership.nature: Flagship Fund IV is a member of VentureLabs IV and also serves as its manager. Flagship Fund V is a member of VentureLabs V and also serves as its manager.

F4 · ownership.nature: The general partner of each of Flagship Fund IV and Flagship Fund IV-Rx is Flagship Ventures Fund IV General Partner LLC ("Flagship Fund IV GP"). The general partner of Flagship Fund V, VentureLabs Rx-V, Nutritional Innovation Fund and Nutritional Health Side Fund is Flagship Ventures Fund V General Partner LLC ("Flagship Fund V GP"). The general partner of Flagship Opportunities Fund I is Flagship Ventures Opportunities Fund I General Partner LLC ("Flagship Opportunities GP," and together with Flagship Fund IV GP and Flagship Fund V GP, the "Flagship General Partners").

F5 · ownership.nature: Noubar B. Afeyan, Ph.D. and Edwin M. Kania, Jr. are the managers of Flagship Fund IV GP and each of these individuals may be deemed to share voting and investment power with respect to all shares held by Flagship Fund IV Funds. Dr. Afeyan also serves as the managing member of the Flagship Fund V GP and Flagship Opportunities Fund GP and may be deemed to possess sole voting and investment control over the shares held by the Flagship Fund V Funds and Flagship Opportunities Fund I. Each of the Flagship General Partners, Dr. Afeyan and Mr. Kania disclaims beneficial ownership of any shares beneficially owned by the Flagship Funds except to the extent of its or his pecuniary interest therein.

SEC source: 0000899243-18-013013 · doc4.xml · nonDerivative · entry 2

Flagship Ventures Fund V General Partner LLC · CIK 0001724575 · 10% owner

Flagship VentureLabs V LLC · CIK 0001724959 · 10% owner

Flagship Ventures Fund V, L.P. · CIK 0001627639 · 10% owner

Flagship V VentureLabs Rx Fund, L.P. · CIK 0001724939 · 10% owner

Nutritional Health Disruptive Innovation Fund, L.P. · CIK 0001725001 · 10% owner

Nutritional Health Side Fund, L.P. · CIK 0001725000 · 10% owner

Flagship Ventures Opportunities Fund I, L.P. · CIK 0001677345 · 10% owner

Flagship Ventures Opportunities Fund I General Partner LLC · CIK 0001725004 · 10% owner

AFEYAN NOUBAR · CIK 0001222012 · Director · 10% owner

KANIA EDWIN M JR · CIK 0001255927 · 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: 18,233,403

F6 · shares: Includes 35,156, 105,469, and 140,625 shares purchased by Nutritional Health Side Fund, Nutritional Innovation Fund, and Flagship Opportunities I, respectively, in connection with the Issuer's initial public offering.

F1 · ownership.nature: Following the transactions reported herein, Flagship VentureLabs IV LLC ("VentureLabs IV") holds 684,372 shares of common stock, Flagship VentureLabs V LLC ("VentureLabs V") holds 2,645,637 shares of common stock, Flagship Ventures Fund IV L.P. ("Flagship Fund IV") holds 1,836,836 shares of common stock, Flagship Ventures Fund IV-Rx, L.P. ("Flagship Fund IV-Rx" and, together with VentureLabs IV and Flagship Fund IV, the "Flagship Fund IV Funds") holds 448,911 shares of common stock, Flagship Ventures Fund V, L.P. ("Flagship Fund V") holds 4,201,284 shares of common stock, Flagship V VentureLabs Rx Fund, L.P. ("VentureLabs Rx V") holds 1,609,871 shares of common stock, Nutritional Health Side Fund, L.P. ("Nutritional Health Side Fund") holds 795,950 shares of common stock,

F2 · ownership.nature: [Continued] Nutritional Health Disruptive Innovation Fund, L.P. ("Nutritional Innovation Fund" and, together with VentureLabs V, Flagship Fund V, VentureLabs Rx V and Nutritional Health Side Fund, the "Flagship Fund V Funds") holds 3,598,177 shares of common stock, and Flagship Ventures Opportunities Fund I, L.P. ("Flagship Opportunities I" and, together with the Flagship Fund IV Funds and Flagship Fund V Funds, the "Flagship Funds") holds 2,412,365 shares of common stock.

F3 · ownership.nature: Flagship Fund IV is a member of VentureLabs IV and also serves as its manager. Flagship Fund V is a member of VentureLabs V and also serves as its manager.

F4 · ownership.nature: The general partner of each of Flagship Fund IV and Flagship Fund IV-Rx is Flagship Ventures Fund IV General Partner LLC ("Flagship Fund IV GP"). The general partner of Flagship Fund V, VentureLabs Rx-V, Nutritional Innovation Fund and Nutritional Health Side Fund is Flagship Ventures Fund V General Partner LLC ("Flagship Fund V GP"). The general partner of Flagship Opportunities Fund I is Flagship Ventures Opportunities Fund I General Partner LLC ("Flagship Opportunities GP," and together with Flagship Fund IV GP and Flagship Fund V GP, the "Flagship General Partners").

F5 · ownership.nature: Noubar B. Afeyan, Ph.D. and Edwin M. Kania, Jr. are the managers of Flagship Fund IV GP and each of these individuals may be deemed to share voting and investment power with respect to all shares held by Flagship Fund IV Funds. Dr. Afeyan also serves as the managing member of the Flagship Fund V GP and Flagship Opportunities Fund GP and may be deemed to possess sole voting and investment control over the shares held by the Flagship Fund V Funds and Flagship Opportunities Fund I. Each of the Flagship General Partners, Dr. Afeyan and Mr. Kania disclaims beneficial ownership of any shares beneficially owned by the Flagship Funds except to the extent of its or his pecuniary interest therein.

SEC source: 0000899243-18-013013 · doc4.xml · nonDerivative · entry 1

Flagship Ventures Fund V General Partner LLC · CIK 0001724575 · 10% owner

Flagship VentureLabs V LLC · CIK 0001724959 · 10% owner

Flagship Ventures Fund V, L.P. · CIK 0001627639 · 10% owner

Flagship V VentureLabs Rx Fund, L.P. · CIK 0001724939 · 10% owner

Nutritional Health Disruptive Innovation Fund, L.P. · CIK 0001725001 · 10% owner

Nutritional Health Side Fund, L.P. · CIK 0001725000 · 10% owner

Flagship Ventures Opportunities Fund I, L.P. · CIK 0001677345 · 10% owner

Flagship Ventures Opportunities Fund I General Partner LLC · CIK 0001725004 · 10% owner

AFEYAN NOUBAR · CIK 0001222012 · Director · 10% owner

KANIA EDWIN M JR · CIK 0001255927 · 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: 17,952,153

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 · ownership.nature: Following the transactions reported herein, Flagship VentureLabs IV LLC ("VentureLabs IV") holds 684,372 shares of common stock, Flagship VentureLabs V LLC ("VentureLabs V") holds 2,645,637 shares of common stock, Flagship Ventures Fund IV L.P. ("Flagship Fund IV") holds 1,836,836 shares of common stock, Flagship Ventures Fund IV-Rx, L.P. ("Flagship Fund IV-Rx" and, together with VentureLabs IV and Flagship Fund IV, the "Flagship Fund IV Funds") holds 448,911 shares of common stock, Flagship Ventures Fund V, L.P. ("Flagship Fund V") holds 4,201,284 shares of common stock, Flagship V VentureLabs Rx Fund, L.P. ("VentureLabs Rx V") holds 1,609,871 shares of common stock, Nutritional Health Side Fund, L.P. ("Nutritional Health Side Fund") holds 795,950 shares of common stock,

F2 · ownership.nature: [Continued] Nutritional Health Disruptive Innovation Fund, L.P. ("Nutritional Innovation Fund" and, together with VentureLabs V, Flagship Fund V, VentureLabs Rx V and Nutritional Health Side Fund, the "Flagship Fund V Funds") holds 3,598,177 shares of common stock, and Flagship Ventures Opportunities Fund I, L.P. ("Flagship Opportunities I" and, together with the Flagship Fund IV Funds and Flagship Fund V Funds, the "Flagship Funds") holds 2,412,365 shares of common stock.

F3 · ownership.nature: Flagship Fund IV is a member of VentureLabs IV and also serves as its manager. Flagship Fund V is a member of VentureLabs V and also serves as its manager.

F4 · ownership.nature: The general partner of each of Flagship Fund IV and Flagship Fund IV-Rx is Flagship Ventures Fund IV General Partner LLC ("Flagship Fund IV GP"). The general partner of Flagship Fund V, VentureLabs Rx-V, Nutritional Innovation Fund and Nutritional Health Side Fund is Flagship Ventures Fund V General Partner LLC ("Flagship Fund V GP"). The general partner of Flagship Opportunities Fund I is Flagship Ventures Opportunities Fund I General Partner LLC ("Flagship Opportunities GP," and together with Flagship Fund IV GP and Flagship Fund V GP, the "Flagship General Partners").

F5 · ownership.nature: Noubar B. Afeyan, Ph.D. and Edwin M. Kania, Jr. are the managers of Flagship Fund IV GP and each of these individuals may be deemed to share voting and investment power with respect to all shares held by Flagship Fund IV Funds. Dr. Afeyan also serves as the managing member of the Flagship Fund V GP and Flagship Opportunities Fund GP and may be deemed to possess sole voting and investment control over the shares held by the Flagship Fund V Funds and Flagship Opportunities Fund I. Each of the Flagship General Partners, Dr. Afeyan and Mr. Kania disclaims beneficial ownership of any shares beneficially owned by the Flagship Funds except to the extent of its or his pecuniary interest therein.