Nashat Amir

SEC source: 0000950170-23-065889 · ownership.xml · nonDerivative · entry 1

Nashat Amir · CIK 0001575843 · Director

10b5-1 filing: No plan indicated

Ownership: Indirect · See Footnote

Disclosed balance after: 3,068,136

F1 · kind: Represents a distribution, and not a purchase or sale, without additional consideration by Polaris Venture Partners VI, L.P. ("PVP VI") to its partners.

F2 · ownership.nature: The reportable securities are owned directly by PVP VI. Polaris Venture Management Co. VI, L.L.C. ("PVM VI") is the general partner of PVP VI and PVM VI is managed by its managing members, one of whom is the Reporting Person and a member of the Issuer's Board of Directors (collectively, the "Managing Members"). PVM VI may be deemed to have sole voting and dispositive power with respect to the shares held by PVP VI and each of the Reporting Person and the other Managing Members may be deemed to have shared voting and dispositive power with respect to the shares held by PVP VI. Each of the Reporting Person, PVM VI and the other Managing Members disclaims beneficial ownership of these securities and this report shall not be deemed an admission that the Reporting Person, PVM VI or any of the other Managing Members is a beneficial owner of such securities for purposes of Section 16 or for any other purpose, except to the extent of their respective pecuniary interests therein.

SEC source: 0000899243-23-016770 · doc4.xml · nonDerivative · entry 5

Nashat Amir · CIK 0001575843 · Director

10b5-1 filing: No plan indicated

Ownership: Indirect · By Polaris Entrepreneurs' Fund VII, L.P.

Disclosed balance after: 130,153

F8 · kind: Represents a pro-rata distribution, and not a purchase or sale, without additional consideration by Polaris Entrepreneurs' Fund VII, L.P. ("PEF VII") to its partners.

F9 · ownership.nature: The shares are owned directly by PEF VII. PMC VII is the general partner of PEF VII. Each of the Managing Members, in their respective capacities with respect to PMC VII, may be deemed to have shared voting and dispositive power over the shares held by PEF VII. Each of PMC VII and the Managing Members disclaims beneficial ownership of these securities and this report shall not be deemed an admission that any one of them is the beneficial owner of such securities for purposes of Section 16 or for any other purpose, except to the extent of their respective pecuniary interests therein.

SEC source: 0000899243-23-016770 · doc4.xml · nonDerivative · entry 4

Nashat Amir · CIK 0001575843 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 145

F7 · kind: Represents a change in the form of ownership of the Reporting Person by virtue of the receipt of shares as a result of the pro-rata in-kind distribution of common stock of the Issuer for no consideration by PMC VII.

SEC source: 0000899243-23-016770 · doc4.xml · nonDerivative · entry 3

Nashat Amir · CIK 0001575843 · Director

10b5-1 filing: No plan indicated

Ownership: Indirect · By Polaris Management Co. VII L.L.C.

Disclosed balance after: 0

F6 · kind: Represents a pro-rata distribution, and not a purchase or sale, without additional consideration by PMC VII to its interest holders.

F5 · ownership.nature: The shares are owned by PMC VII. Each of the Managing Members, in their respective capacities with respect to PMC VII, may be deemed to have shared voting and dispositive power over the shares held by PMC VII. The Managing Members disclaim beneficial ownership of these securities and this report shall not be deemed an admission that any one of them is the beneficial owner of such securities for purposes of Section 16 or for any other purpose, except to the extent of their respective pecuniary interests therein.

SEC source: 0000899243-23-016770 · doc4.xml · nonDerivative · entry 2

Nashat Amir · CIK 0001575843 · Director

10b5-1 filing: No plan indicated

Ownership: Indirect · By Polaris Management Co. VII L.L.C.

Disclosed balance after: 935

F4 · kind: Represents a change in the form of ownership of PMC VII by virtue of the receipt of shares in the pro-rata in-kind distribution of common stock of the Issuer for no consideration by PP VII.

F5 · ownership.nature: The shares are owned by PMC VII. Each of the Managing Members, in their respective capacities with respect to PMC VII, may be deemed to have shared voting and dispositive power over the shares held by PMC VII. The Managing Members disclaim beneficial ownership of these securities and this report shall not be deemed an admission that any one of them is the beneficial owner of such securities for purposes of Section 16 or for any other purpose, except to the extent of their respective pecuniary interests therein.

SEC source: 0000899243-23-016770 · doc4.xml · nonDerivative · entry 1

Nashat Amir · CIK 0001575843 · Director

10b5-1 filing: No plan indicated

Ownership: Indirect · By Polaris Partners VII, L.P.

Disclosed balance after: 1,860,498

F1 · kind: Represents a pro-rata distribution, and not a purchase or sale, without additional consideration by Polaris Partners VII, L.P. ("PP VII") to its partners.

F2 · ownership.nature: The shares are owned directly by PP VII. Polaris Management Co. VII, L.L.C. ("PMC VII") is the general partner of PP VII. The Reporting Person, a member of the Issuer's Board of Directors, is a member of PMC VII. Each of the Reporting Person, David Barrett ("Barrett"), Brian Chee ("Chee"), and Bryce Youngren ("Youngren" and, together with the Reporting Person, Barrett, and Chee, the "Managing Members") are the managing members of PMC VII.

F3 · ownership.nature: Each of the Managing Members, in their respective capacities with respect to PMC VII, may be deemed to have shared voting and dispositive power over the shares held by PP VII. Each of PMC VII and the Managing Members disclaims beneficial ownership of these securities and this report shall not be deemed an admission that any one of them is the beneficial owner of such securities for purposes of Section 16 or for any other purpose, except to the extent of their respective pecuniary interests therein.

SEC source: 0001415889-23-010210 · form4-06222023_110642.xml · derivative · entry 1

Nashat Amir · CIK 0001575843 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 36,000

Underlying: Common Stock · 36,000 shares

Expires 2033-06-21

F1 · derivative.exercise_date: This option shall vest and become fully exercisable on the earlier of the first anniversary following the date of grant or on the date of the Issuer's next Annual Meeting subject to continued service to the Issuer through such date.

SEC source: 0001209191-23-034039 · doc4.xml · derivative · entry 1

Nashat Amir · CIK 0001575843 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 12,535

Underlying: Common Stock · 12,535 shares

Expires 2033-05-31

F1 · derivative.exercise_date: The option will vest in full on the earlier of (a) June 1, 2024 and (b) the next annual meeting of the issuer's stockholders, subject to the reporting person's provision of service to the issuer on the vesting date.

SEC source: 0000899243-22-023965 · doc4.xml · derivative · entry 5

Nashat Amir · CIK 0001575843 · Director

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnote

Disclosed balance after: 16,536

Underlying: Common Stock · 16,536 shares

Expires 2025-12-31

F1 · price: The securities were purchased at a combined public offering price of $4.90 per share of common stock, and such combined offering price included accompanying Common Warrants.

F4 · ownership.nature: The securities are owned directly by Polaris Venture Partners Founders' Fund VI, L.P. ("PVPFF VI"). PVM VI is the general partner of PVPFF VI. PVM VI may be deemed to have sole voting and dispositive power with respect to the shares held by PVPFF VI and each of the Reporting Person and the other Managing Members may be deemed to have shared voting and dispositive power with respect to the shares held by PVPFF VI. Each of the Reporting Person, PVM VI and the other Managing Members disclaims beneficial ownership of these securities and this report shall not be deemed an admission that the Reporting Person, PVM VI or any of the other Managing Members is a beneficial owner of such securities for purposes of Section 16 or for any other purpose, except to the extent of their respective pecuniary interests therein.

SEC source: 0000899243-22-023965 · doc4.xml · derivative · entry 4

Nashat Amir · CIK 0001575843 · Director

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnote

Disclosed balance after: 282,962

Underlying: Common Stock · 282,962 shares

Expires 2025-12-31

F1 · price: The securities were purchased at a combined public offering price of $4.90 per share of common stock, and such combined offering price included accompanying Common Warrants.

F2 · ownership.nature: The securities are owned directly by Polaris Venture Partners VI, L.P. ("PVP VI"). Polaris Venture Management Co. VI, L.L.C. ("PVM VI") is the general partner of PVP VI and PVM VI is managed by its managing members, one of whom is the Reporting Person and a member of the Issuer's Board of Directors (collectively, the "Managing Members"). PVM VI may be deemed to have sole voting and dispositive power with respect to the shares held by PVP VI and each of the Reporting Person and the other Managing Members may be deemed to have shared voting and dispositive power with respect to the shares held by PVP VI.

F3 · ownership.nature: (Continued from Footnote 2) Each of the Reporting Person, PVM VI and the other Managing Members disclaims beneficial ownership of these securities and this report shall not be deemed an admission that the Reporting Person, PVM VI or any of the other Managing Members is a beneficial owner of such securities for purposes of Section 16 or for any other purpose, except to the extent of their respective pecuniary interests therein.

SEC source: 0000899243-22-023965 · doc4.xml · nonDerivative · entry 2

Nashat Amir · CIK 0001575843 · Director

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnote

Disclosed balance after: 206,897

F1 · price: The securities were purchased at a combined public offering price of $4.90 per share of common stock, and such combined offering price included accompanying Common Warrants.

F4 · ownership.nature: The securities are owned directly by Polaris Venture Partners Founders' Fund VI, L.P. ("PVPFF VI"). PVM VI is the general partner of PVPFF VI. PVM VI may be deemed to have sole voting and dispositive power with respect to the shares held by PVPFF VI and each of the Reporting Person and the other Managing Members may be deemed to have shared voting and dispositive power with respect to the shares held by PVPFF VI. Each of the Reporting Person, PVM VI and the other Managing Members disclaims beneficial ownership of these securities and this report shall not be deemed an admission that the Reporting Person, PVM VI or any of the other Managing Members is a beneficial owner of such securities for purposes of Section 16 or for any other purpose, except to the extent of their respective pecuniary interests therein.

SEC source: 0000899243-22-023965 · doc4.xml · nonDerivative · entry 1

Nashat Amir · CIK 0001575843 · Director

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnote

Disclosed balance after: 3,540,530

F1 · price: The securities were purchased at a combined public offering price of $4.90 per share of common stock, and such combined offering price included accompanying Common Warrants.

F2 · ownership.nature: The securities are owned directly by Polaris Venture Partners VI, L.P. ("PVP VI"). Polaris Venture Management Co. VI, L.L.C. ("PVM VI") is the general partner of PVP VI and PVM VI is managed by its managing members, one of whom is the Reporting Person and a member of the Issuer's Board of Directors (collectively, the "Managing Members"). PVM VI may be deemed to have sole voting and dispositive power with respect to the shares held by PVP VI and each of the Reporting Person and the other Managing Members may be deemed to have shared voting and dispositive power with respect to the shares held by PVP VI.

F3 · ownership.nature: (Continued from Footnote 2) Each of the Reporting Person, PVM VI and the other Managing Members disclaims beneficial ownership of these securities and this report shall not be deemed an admission that the Reporting Person, PVM VI or any of the other Managing Members is a beneficial owner of such securities for purposes of Section 16 or for any other purpose, except to the extent of their respective pecuniary interests therein.

SEC source: 0001209191-22-036116 · doc4.xml · derivative · entry 1

Nashat Amir · CIK 0001575843 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 17,550

Underlying: Common Stock · 17,550 shares

Expires 2032-06-07

F1 · derivative.exercise_date: The option will vest in full on the earlier of (a) June 8, 2023 and (b) the next annual meeting of the issuer's stockholders, subject to the reporting person's provision of service to the issuer on the vesting date.

SEC source: 0001209191-22-033710 · doc4.xml · derivative · entry 1

Nashat Amir · CIK 0001575843 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 17,500

Underlying: Common Stock · 17,500 shares

Expires 2032-05-31

F1 · derivative.exercise_date: The option becomes exercisable as to 50% of the shares underlying the award on the six month anniversary of the date of grant, with the remainder vesting in equal monthly installments until the first anniversary of the date of grant, subject to the reporting person's continued service as a director through each applicable vesting date.

SEC source: 0001104659-22-065954 · tm2216969-6_4seq1.xml · derivative · entry 1

Nashat Amir · CIK 0001575843 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 28,000

Underlying: Common Stock · 28,000 shares

Expires 2032-05-26

F1 · derivative.exercise_date: This option shall vest and become fully exercisable on the earlier of the first anniversary following the date of grant or the next scheduled Annual Meeting subject to continued service to the Issuer through such date.

SEC source: 0001209191-22-048888 · doc4.xml · derivative · entry 1

Nashat Amir · CIK 0001575843 · Director · 10% owner

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 16,500

Underlying: Common Stock · 16,500 shares

Expires 2032-05-17

F1 · derivative.exercise_date: The shares subject to the option shall vest on the earlier of (i) the one-year anniversary of the date of grant or (ii) the day immediately prior to the date of the Issuer's 2023 annual meeting of stockholders.

SEC source: 0000899243-21-045401 · doc4.xml · nonDerivative · entry 9

Nashat Amir · CIK 0001575843 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 7,441

F6 · kind: Represents a change in the form of ownership of the Reporting Person by virtue of the receipt of shares as a result of the in-kind distribution of common stock of the Issuer for no consideration by PVM VI.

SEC source: 0000899243-21-045401 · doc4.xml · nonDerivative · entry 8

Nashat Amir · CIK 0001575843 · Director

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnote

Disclosed balance after: 0

F5 · kind: Represents a distribution, and not a purchase or sale, without additional consideration by PVM VI to its members.

F4 · ownership.nature: The reportable securities are owned directly by PVM VI. PVM VI is the general partner of PVP VI and PVM VI is managed by the Managing Members. The Managing Members, one of whom is the Reporting Person who is a member of the Issuer's Board of Directors, may be deemed to have sole voting and dispositive power with respect to the shares held by PVM VI. Each of the Reporting Person and the other Managing Members disclaims beneficial ownership of these securities and this report shall not be deemed an admission that the Reporting Person or any of the other Managing Members is a beneficial owner of such securities for purposes of Section 16 or for any other purpose, except to the extent of their respective pecuniary interests therein.

SEC source: 0000899243-21-045401 · doc4.xml · nonDerivative · entry 7

Nashat Amir · CIK 0001575843 · Director

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnote

Disclosed balance after: 160

F11 · kind: Represents a change in the form of ownership of PVM VI by virtue of the receipt of shares as a result of the in-kind distribution of common stock of the Issuer for no consideration by PVPFF VI.

F4 · ownership.nature: The reportable securities are owned directly by PVM VI. PVM VI is the general partner of PVP VI and PVM VI is managed by the Managing Members. The Managing Members, one of whom is the Reporting Person who is a member of the Issuer's Board of Directors, may be deemed to have sole voting and dispositive power with respect to the shares held by PVM VI. Each of the Reporting Person and the other Managing Members disclaims beneficial ownership of these securities and this report shall not be deemed an admission that the Reporting Person or any of the other Managing Members is a beneficial owner of such securities for purposes of Section 16 or for any other purpose, except to the extent of their respective pecuniary interests therein.

SEC source: 0000899243-21-045401 · doc4.xml · nonDerivative · entry 6

Nashat Amir · CIK 0001575843 · Director

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnote

Disclosed balance after: 182

F9 · kind: Represents a change in the form of ownership of the Reporting Person by virtue of the receipt of shares as a result of the in-kind distribution of common stock of the Issuer for no consideration by PVPFF VI.

F10 · ownership.nature: The reportable securities are owned by North Star Profit Sharing Trust for the benefit of the Reporting Person.

SEC source: 0000899243-21-045401 · doc4.xml · nonDerivative · entry 5

Nashat Amir · CIK 0001575843 · Director

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnote

Disclosed balance after: 140,755

F7 · kind: Represents a distribution, and not a purchase or sale, without additional consideration by Polaris Venture Partners Founders' Fund VI, L.P. ("PVPFF VI") to its partners.

F8 · ownership.nature: The reportable securities are owned directly by PVPFF VI. PVM VI is the general partner of PVPFF VI. PVM VI may be deemed to have sole voting and dispositive power with respect to the shares held by PVPFF VI and each of the Reporting Person and the other Managing Members may be deemed to have shared voting and dispositive power with respect to the shares held by PVPFF VI. Each of the Reporting Person, PVM VI and the other Managing Members disclaims beneficial ownership of these securities and this report shall not be deemed an admission that the Reporting Person, PVM VI or any of the other Managing Members is a beneficial owner of such securities for purposes of Section 16 or for any other purpose, except to the extent of their respective pecuniary interests therein.

SEC source: 0000899243-21-045401 · doc4.xml · nonDerivative · entry 4

Nashat Amir · CIK 0001575843 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 7,420

F6 · kind: Represents a change in the form of ownership of the Reporting Person by virtue of the receipt of shares as a result of the in-kind distribution of common stock of the Issuer for no consideration by PVM VI.

SEC source: 0000899243-21-045401 · doc4.xml · nonDerivative · entry 3

Nashat Amir · CIK 0001575843 · Director

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnote

Disclosed balance after: 0

F5 · kind: Represents a distribution, and not a purchase or sale, without additional consideration by PVM VI to its members.

F4 · ownership.nature: The reportable securities are owned directly by PVM VI. PVM VI is the general partner of PVP VI and PVM VI is managed by the Managing Members. The Managing Members, one of whom is the Reporting Person who is a member of the Issuer's Board of Directors, may be deemed to have sole voting and dispositive power with respect to the shares held by PVM VI. Each of the Reporting Person and the other Managing Members disclaims beneficial ownership of these securities and this report shall not be deemed an admission that the Reporting Person or any of the other Managing Members is a beneficial owner of such securities for purposes of Section 16 or for any other purpose, except to the extent of their respective pecuniary interests therein.

SEC source: 0000899243-21-045401 · doc4.xml · nonDerivative · entry 2

Nashat Amir · CIK 0001575843 · Director

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnote

Disclosed balance after: 55,667

F3 · kind: Represents a change in the form of ownership of PVM VI by virtue of the receipt of shares in the in-kind distribution of common stock of the Issuer for no consideration by PVP VI.

F4 · ownership.nature: The reportable securities are owned directly by PVM VI. PVM VI is the general partner of PVP VI and PVM VI is managed by the Managing Members. The Managing Members, one of whom is the Reporting Person who is a member of the Issuer's Board of Directors, may be deemed to have sole voting and dispositive power with respect to the shares held by PVM VI. Each of the Reporting Person and the other Managing Members disclaims beneficial ownership of these securities and this report shall not be deemed an admission that the Reporting Person or any of the other Managing Members is a beneficial owner of such securities for purposes of Section 16 or for any other purpose, except to the extent of their respective pecuniary interests therein.

SEC source: 0000899243-21-045401 · doc4.xml · nonDerivative · entry 1

Nashat Amir · CIK 0001575843 · Director

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnote

Disclosed balance after: 2,408,680

F1 · kind: Represents a distribution, and not a purchase or sale, without additional consideration by Polaris Venture Partners VI, L.P. ("PVP VI") to its partners.

F2 · ownership.nature: The reportable securities are owned directly by PVP VI. Polaris Venture Management Co. VI, L.L.C. ("PVM VI") is the general partner of PVP VI and PVM VI is managed by its managing members, one of whom is the Reporting Person and a member of the Issuer's Board of Directors (collectively, the "Managing Members"). PVM VI may be deemed to have sole voting and dispositive power with respect to the shares held by PVP VI and each of the Reporting Person and the other Managing Members may be deemed to have shared voting and dispositive power with respect to the shares held by PVP VI. Each of the Reporting Person, PVM VI and the other Managing Members disclaims beneficial ownership of these securities and this report shall not be deemed an admission that the Reporting Person, PVM VI or any of the other Managing Members is a beneficial owner of such securities for purposes of Section 16 or for any other purpose, except to the extent of their respective pecuniary interests therein.

SEC source: 0001209191-21-041689 · doc4.xml · derivative · entry 1

Nashat Amir · CIK 0001575843 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 12,000

Underlying: Common Stock · 12,000 shares

Expires 2031-06-16

F1 · derivative.exercise_date: The option will vest in full on the earlier of (a) June 16, 2022 and (b) the next annual meeting of the issuer's stockholders, subject to the reporting person's provision of service to the issuer on the vesting date.

SEC source: 0001209191-22-026240 · doc4a.xml · derivative · entry 1

Nashat Amir · CIK 0001575843 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 9,910

Underlying: Common Stock · 9,910 shares

Expires 2031-06-16

F1 · shares: This Form 4 is being amended to reflect the amount actually granted, as the originally reported share number was in error.

F2 · derivative.exercise_date: The option will vest in full on the earlier of (a) June 16, 2022 and (b) the next annual meeting of the issuer's stockholders, subject to the reporting person's provision of service to the issuer on the vesting date.

SEC source: 0001209191-21-039577 · doc4.xml · derivative · entry 1

Nashat Amir · CIK 0001575843 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 17,500

Underlying: Common Stock · 17,500 shares

Expires 2031-06-07

F1 · derivative.exercise_date: The option becomes exercisable as to 50% of the shares underlying the award on the six month anniversary of the date of grant, with the remainder vesting in equal monthly installments until the first anniversary of the date of grant, subject to the reporting person's continued service as a director through each applicable vesting date.

SEC source: 0001179110-21-006140 · edgar.xml · derivative · entry 1

Nashat Amir · CIK 0001575843 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 7,800

Underlying: Common Stock · 7,800 shares

Expires 2031-05-27

F1 · derivative.exercise_date: This option shall vest and become fully exercisable on the earlier of the first anniversary following the date of grant or the next scheduled Annual Meeting.

SEC source: 0001209191-21-035786 · doc4.xml · derivative · entry 1

Nashat Amir · CIK 0001575843 · Director · 10% owner

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 16,500

Underlying: Common Stock · 16,500 shares

Expires 2031-05-23

F1 · derivative.exercise_date: The shares subject to the option shall vest on the earlier of (i) the one-year anniversary of the date of grant or (ii) the day immediately prior to the date of the Issuer's 2022 annual meeting of stockholders.

SEC source: 0000899243-21-020599 · doc4.xml · nonDerivative · entry 2

Nashat Amir · CIK 0001575843 · Director

10b5-1 filing: Not disclosed

Ownership: Indirect · By Polaris Entrepreneurs' Fund VII, L.P.

Disclosed balance after: 136,691

F3 · ownership.nature: The shares are owned directly by Polaris Entrepreneurs' Fund VII, L.P. ("PEF VII"). PMC VII is the general partner of PEF VII. The Reporting Person, a member of the issuer's Board of Directors, is a member of PMC VII. Each of the Reporting Person, Barrett, Chee, and Youngren are the managing members of PMC VII. Each of the Managing Members, in their respective capacities with respect to PMC VII, may be deemed to have shared voting and dispositive power over the shares held by PEF VII. Each of PMC VII and the Managing Members disclaims beneficial ownership of these securities and this report shall not be deemed an admission that any one of them is the beneficial owner of such securities for purposes of Section 16 or for any other purpose, except to the extent of their respective pecuniary interests therein.

SEC source: 0000899243-21-020599 · doc4.xml · nonDerivative · entry 1

Nashat Amir · CIK 0001575843 · Director

10b5-1 filing: Not disclosed

Ownership: Indirect · By Polaris Partners VII, L.P.

Disclosed balance after: 1,953,960

F1 · ownership.nature: The shares are owned directly by Polaris Partners VII, L.P. ("PP VII"). Polaris Management Co. VII, L.L.C. ("PMC VII") is the general partner of PP VII. The Reporting Person, a member of the issuer's Board of Directors, is a member of PMC VII. Each of the Reporting Person, David Barrett ("Barrett"), Brian Chee ("Chee"), and Bryce Youngren ("Youngren" and, together with the Reporting Person, Barrett, and Chee, the "Managing Members") are the managing members of PMC VII.

F2 · ownership.nature: Each of the Managing Members, in their respective capacities with respect to PMC VII, may be deemed to have shared voting and dispositive power over the shares held by PP VII. Each of PMC VII and the Managing Members disclaims beneficial ownership of these securities and this report shall not be deemed an admission that any one of them is the beneficial owner of such securities for purposes of Section 16 or for any other purpose, except to the extent of their respective pecuniary interests therein.

SEC source: 0001209191-20-051504 · doc4.xml · derivative · entry 14

Nashat Amir · CIK 0001575843 · Director · 10% owner

10b5-1 filing: Not disclosed

Ownership: Indirect · See footnote

Disclosed balance after: 0

Underlying: Common Stock · 15,118 shares

Expires not disclosed

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

F5 · derivative.exercise_price: Every 5.1 shares of Series A Convertible Preferred Stock, Series B Convertible Preferred Stock and Series C Convertible Preferred Stock (the "Preferred Stock") automatically converted into 1 share of Common Stock immediately prior to the closing of the Issuer's initial public offering. Share numbers give effect to such conversion. The Preferred Stock had no expiration date.

F5 · price: Every 5.1 shares of Series A Convertible Preferred Stock, Series B Convertible Preferred Stock and Series C Convertible Preferred Stock (the "Preferred Stock") automatically converted into 1 share of Common Stock immediately prior to the closing of the Issuer's initial public offering. Share numbers give effect to such conversion. The Preferred Stock had no expiration date.

F5 · derivative.exercise_date: Every 5.1 shares of Series A Convertible Preferred Stock, Series B Convertible Preferred Stock and Series C Convertible Preferred Stock (the "Preferred Stock") automatically converted into 1 share of Common Stock immediately prior to the closing of the Issuer's initial public offering. Share numbers give effect to such conversion. The Preferred Stock had no expiration date.

F5 · derivative.expiration_date: Every 5.1 shares of Series A Convertible Preferred Stock, Series B Convertible Preferred Stock and Series C Convertible Preferred Stock (the "Preferred Stock") automatically converted into 1 share of Common Stock immediately prior to the closing of the Issuer's initial public offering. Share numbers give effect to such conversion. The Preferred Stock had no expiration date.

F3 · ownership.nature: The reportable securities are owned directly by Polaris Entrepreneurs' Fund VII, L.P. ("PEF VII"). PMC VII is the general partner of PEF VII. Each of the Managing Members, in their respective capacities with respect to PMC VII, may be deemed to have shared voting and dispositive power over the shares held by PEF VII.

F4 · ownership.nature: (continued from Footnote 3) Each of PMC VII and the Managing Members disclaims beneficial ownership of these securities and this report shall not be deemed an admission that any one of them is the beneficial owner of such securities for purposes of Section 16 or for any other purpose, except to the extent of their respective pecuniary interests therein.

SEC source: 0001209191-20-051504 · doc4.xml · derivative · entry 13

Nashat Amir · CIK 0001575843 · Director · 10% owner

10b5-1 filing: Not disclosed

Ownership: Indirect · See footnote

Disclosed balance after: 0

Underlying: Common Stock · 216,106 shares

Expires not disclosed

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

F5 · derivative.exercise_price: Every 5.1 shares of Series A Convertible Preferred Stock, Series B Convertible Preferred Stock and Series C Convertible Preferred Stock (the "Preferred Stock") automatically converted into 1 share of Common Stock immediately prior to the closing of the Issuer's initial public offering. Share numbers give effect to such conversion. The Preferred Stock had no expiration date.

F5 · price: Every 5.1 shares of Series A Convertible Preferred Stock, Series B Convertible Preferred Stock and Series C Convertible Preferred Stock (the "Preferred Stock") automatically converted into 1 share of Common Stock immediately prior to the closing of the Issuer's initial public offering. Share numbers give effect to such conversion. The Preferred Stock had no expiration date.

F5 · derivative.exercise_date: Every 5.1 shares of Series A Convertible Preferred Stock, Series B Convertible Preferred Stock and Series C Convertible Preferred Stock (the "Preferred Stock") automatically converted into 1 share of Common Stock immediately prior to the closing of the Issuer's initial public offering. Share numbers give effect to such conversion. The Preferred Stock had no expiration date.

F5 · derivative.expiration_date: Every 5.1 shares of Series A Convertible Preferred Stock, Series B Convertible Preferred Stock and Series C Convertible Preferred Stock (the "Preferred Stock") automatically converted into 1 share of Common Stock immediately prior to the closing of the Issuer's initial public offering. Share numbers give effect to such conversion. The Preferred Stock had no expiration date.

F1 · ownership.nature: The reportable securities are owned directly by Polaris Partners VII, L.P. ("PP VII"). Polaris Management Co. VII, L.L.C. ("PMC VII") is the general partner of PP VII. Each of the Reporting Person, a member of the Issuer's Board of Directors, David Barrett ("Barrett"), Brian Chee ("Chee") and Bryce Youngren ("Youngren" and, together with the Reporting Person, Barrett and Chee, the "Managing Members") are the managing members of PMC VII.

F2 · ownership.nature: (continued from Footnote 2) Each of the Managing Members, in their respective capacities with respect to PMC VII, may be deemed to have shared voting and dispositive power over the shares held by PP VII. Each of PMC VII and the Managing Members disclaims beneficial ownership of these securities and this report shall not be deemed an admission that any one of them is the beneficial owner of such securities for purposes of Section 16 or for any other purpose, except to the extent of their respective pecuniary interests therein.

SEC source: 0001209191-20-051504 · doc4.xml · derivative · entry 12

Nashat Amir · CIK 0001575843 · Director · 10% owner

10b5-1 filing: Not disclosed

Ownership: Indirect · See footnote

Disclosed balance after: 0

Underlying: Common Stock · 20,585 shares

Expires not disclosed

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

F5 · derivative.exercise_price: Every 5.1 shares of Series A Convertible Preferred Stock, Series B Convertible Preferred Stock and Series C Convertible Preferred Stock (the "Preferred Stock") automatically converted into 1 share of Common Stock immediately prior to the closing of the Issuer's initial public offering. Share numbers give effect to such conversion. The Preferred Stock had no expiration date.

F5 · price: Every 5.1 shares of Series A Convertible Preferred Stock, Series B Convertible Preferred Stock and Series C Convertible Preferred Stock (the "Preferred Stock") automatically converted into 1 share of Common Stock immediately prior to the closing of the Issuer's initial public offering. Share numbers give effect to such conversion. The Preferred Stock had no expiration date.

F5 · derivative.exercise_date: Every 5.1 shares of Series A Convertible Preferred Stock, Series B Convertible Preferred Stock and Series C Convertible Preferred Stock (the "Preferred Stock") automatically converted into 1 share of Common Stock immediately prior to the closing of the Issuer's initial public offering. Share numbers give effect to such conversion. The Preferred Stock had no expiration date.

F5 · derivative.expiration_date: Every 5.1 shares of Series A Convertible Preferred Stock, Series B Convertible Preferred Stock and Series C Convertible Preferred Stock (the "Preferred Stock") automatically converted into 1 share of Common Stock immediately prior to the closing of the Issuer's initial public offering. Share numbers give effect to such conversion. The Preferred Stock had no expiration date.

F3 · ownership.nature: The reportable securities are owned directly by Polaris Entrepreneurs' Fund VII, L.P. ("PEF VII"). PMC VII is the general partner of PEF VII. Each of the Managing Members, in their respective capacities with respect to PMC VII, may be deemed to have shared voting and dispositive power over the shares held by PEF VII.

F4 · ownership.nature: (continued from Footnote 3) Each of PMC VII and the Managing Members disclaims beneficial ownership of these securities and this report shall not be deemed an admission that any one of them is the beneficial owner of such securities for purposes of Section 16 or for any other purpose, except to the extent of their respective pecuniary interests therein.

SEC source: 0001209191-20-051504 · doc4.xml · derivative · entry 11

Nashat Amir · CIK 0001575843 · Director · 10% owner

10b5-1 filing: Not disclosed

Ownership: Indirect · See footnote

Disclosed balance after: 0

Underlying: Common Stock · 451,666 shares

Expires not disclosed

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

F5 · derivative.exercise_price: Every 5.1 shares of Series A Convertible Preferred Stock, Series B Convertible Preferred Stock and Series C Convertible Preferred Stock (the "Preferred Stock") automatically converted into 1 share of Common Stock immediately prior to the closing of the Issuer's initial public offering. Share numbers give effect to such conversion. The Preferred Stock had no expiration date.

F5 · price: Every 5.1 shares of Series A Convertible Preferred Stock, Series B Convertible Preferred Stock and Series C Convertible Preferred Stock (the "Preferred Stock") automatically converted into 1 share of Common Stock immediately prior to the closing of the Issuer's initial public offering. Share numbers give effect to such conversion. The Preferred Stock had no expiration date.

F5 · derivative.exercise_date: Every 5.1 shares of Series A Convertible Preferred Stock, Series B Convertible Preferred Stock and Series C Convertible Preferred Stock (the "Preferred Stock") automatically converted into 1 share of Common Stock immediately prior to the closing of the Issuer's initial public offering. Share numbers give effect to such conversion. The Preferred Stock had no expiration date.

F5 · derivative.expiration_date: Every 5.1 shares of Series A Convertible Preferred Stock, Series B Convertible Preferred Stock and Series C Convertible Preferred Stock (the "Preferred Stock") automatically converted into 1 share of Common Stock immediately prior to the closing of the Issuer's initial public offering. Share numbers give effect to such conversion. The Preferred Stock had no expiration date.

F1 · ownership.nature: The reportable securities are owned directly by Polaris Partners VII, L.P. ("PP VII"). Polaris Management Co. VII, L.L.C. ("PMC VII") is the general partner of PP VII. Each of the Reporting Person, a member of the Issuer's Board of Directors, David Barrett ("Barrett"), Brian Chee ("Chee") and Bryce Youngren ("Youngren" and, together with the Reporting Person, Barrett and Chee, the "Managing Members") are the managing members of PMC VII.

F2 · ownership.nature: (continued from Footnote 2) Each of the Managing Members, in their respective capacities with respect to PMC VII, may be deemed to have shared voting and dispositive power over the shares held by PP VII. Each of PMC VII and the Managing Members disclaims beneficial ownership of these securities and this report shall not be deemed an admission that any one of them is the beneficial owner of such securities for purposes of Section 16 or for any other purpose, except to the extent of their respective pecuniary interests therein.

SEC source: 0001209191-20-051504 · doc4.xml · derivative · entry 10

Nashat Amir · CIK 0001575843 · Director · 10% owner

10b5-1 filing: Not disclosed

Ownership: Indirect · See footnote

Disclosed balance after: 0

Underlying: Common Stock · 128,201 shares

Expires not disclosed

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

F5 · derivative.exercise_price: Every 5.1 shares of Series A Convertible Preferred Stock, Series B Convertible Preferred Stock and Series C Convertible Preferred Stock (the "Preferred Stock") automatically converted into 1 share of Common Stock immediately prior to the closing of the Issuer's initial public offering. Share numbers give effect to such conversion. The Preferred Stock had no expiration date.

F5 · price: Every 5.1 shares of Series A Convertible Preferred Stock, Series B Convertible Preferred Stock and Series C Convertible Preferred Stock (the "Preferred Stock") automatically converted into 1 share of Common Stock immediately prior to the closing of the Issuer's initial public offering. Share numbers give effect to such conversion. The Preferred Stock had no expiration date.

F5 · derivative.exercise_date: Every 5.1 shares of Series A Convertible Preferred Stock, Series B Convertible Preferred Stock and Series C Convertible Preferred Stock (the "Preferred Stock") automatically converted into 1 share of Common Stock immediately prior to the closing of the Issuer's initial public offering. Share numbers give effect to such conversion. The Preferred Stock had no expiration date.

F5 · derivative.expiration_date: Every 5.1 shares of Series A Convertible Preferred Stock, Series B Convertible Preferred Stock and Series C Convertible Preferred Stock (the "Preferred Stock") automatically converted into 1 share of Common Stock immediately prior to the closing of the Issuer's initial public offering. Share numbers give effect to such conversion. The Preferred Stock had no expiration date.

F3 · ownership.nature: The reportable securities are owned directly by Polaris Entrepreneurs' Fund VII, L.P. ("PEF VII"). PMC VII is the general partner of PEF VII. Each of the Managing Members, in their respective capacities with respect to PMC VII, may be deemed to have shared voting and dispositive power over the shares held by PEF VII.

F4 · ownership.nature: (continued from Footnote 3) Each of PMC VII and the Managing Members disclaims beneficial ownership of these securities and this report shall not be deemed an admission that any one of them is the beneficial owner of such securities for purposes of Section 16 or for any other purpose, except to the extent of their respective pecuniary interests therein.

SEC source: 0001209191-20-051504 · doc4.xml · derivative · entry 9

Nashat Amir · CIK 0001575843 · Director · 10% owner

10b5-1 filing: Not disclosed

Ownership: Indirect · See footnote

Disclosed balance after: 0

Underlying: Common Stock · 1,832,582 shares

Expires not disclosed

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

F5 · derivative.exercise_price: Every 5.1 shares of Series A Convertible Preferred Stock, Series B Convertible Preferred Stock and Series C Convertible Preferred Stock (the "Preferred Stock") automatically converted into 1 share of Common Stock immediately prior to the closing of the Issuer's initial public offering. Share numbers give effect to such conversion. The Preferred Stock had no expiration date.

F5 · price: Every 5.1 shares of Series A Convertible Preferred Stock, Series B Convertible Preferred Stock and Series C Convertible Preferred Stock (the "Preferred Stock") automatically converted into 1 share of Common Stock immediately prior to the closing of the Issuer's initial public offering. Share numbers give effect to such conversion. The Preferred Stock had no expiration date.

F5 · derivative.exercise_date: Every 5.1 shares of Series A Convertible Preferred Stock, Series B Convertible Preferred Stock and Series C Convertible Preferred Stock (the "Preferred Stock") automatically converted into 1 share of Common Stock immediately prior to the closing of the Issuer's initial public offering. Share numbers give effect to such conversion. The Preferred Stock had no expiration date.

F5 · derivative.expiration_date: Every 5.1 shares of Series A Convertible Preferred Stock, Series B Convertible Preferred Stock and Series C Convertible Preferred Stock (the "Preferred Stock") automatically converted into 1 share of Common Stock immediately prior to the closing of the Issuer's initial public offering. Share numbers give effect to such conversion. The Preferred Stock had no expiration date.

F1 · ownership.nature: The reportable securities are owned directly by Polaris Partners VII, L.P. ("PP VII"). Polaris Management Co. VII, L.L.C. ("PMC VII") is the general partner of PP VII. Each of the Reporting Person, a member of the Issuer's Board of Directors, David Barrett ("Barrett"), Brian Chee ("Chee") and Bryce Youngren ("Youngren" and, together with the Reporting Person, Barrett and Chee, the "Managing Members") are the managing members of PMC VII.

F2 · ownership.nature: (continued from Footnote 2) Each of the Managing Members, in their respective capacities with respect to PMC VII, may be deemed to have shared voting and dispositive power over the shares held by PP VII. Each of PMC VII and the Managing Members disclaims beneficial ownership of these securities and this report shall not be deemed an admission that any one of them is the beneficial owner of such securities for purposes of Section 16 or for any other purpose, except to the extent of their respective pecuniary interests therein.

SEC source: 0001209191-20-051504 · doc4.xml · nonDerivative · entry 8

Nashat Amir · CIK 0001575843 · Director · 10% owner

10b5-1 filing: Not disclosed

Ownership: Indirect · See footnote

Disclosed balance after: 178,942

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: Every 5.1 shares of Series A Convertible Preferred Stock, Series B Convertible Preferred Stock and Series C Convertible Preferred Stock (the "Preferred Stock") automatically converted into 1 share of Common Stock immediately prior to the closing of the Issuer's initial public offering. Share numbers give effect to such conversion. The Preferred Stock had no expiration date.

F3 · ownership.nature: The reportable securities are owned directly by Polaris Entrepreneurs' Fund VII, L.P. ("PEF VII"). PMC VII is the general partner of PEF VII. Each of the Managing Members, in their respective capacities with respect to PMC VII, may be deemed to have shared voting and dispositive power over the shares held by PEF VII.

F4 · ownership.nature: (continued from Footnote 3) Each of PMC VII and the Managing Members disclaims beneficial ownership of these securities and this report shall not be deemed an admission that any one of them is the beneficial owner of such securities for purposes of Section 16 or for any other purpose, except to the extent of their respective pecuniary interests therein.

SEC source: 0001209191-20-051504 · doc4.xml · nonDerivative · entry 7

Nashat Amir · CIK 0001575843 · Director · 10% owner

10b5-1 filing: Not disclosed

Ownership: Indirect · See footnote

Disclosed balance after: 2,715,316

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.

F5 · price: Every 5.1 shares of Series A Convertible Preferred Stock, Series B Convertible Preferred Stock and Series C Convertible Preferred Stock (the "Preferred Stock") automatically converted into 1 share of Common Stock immediately prior to the closing of the Issuer's initial public offering. Share numbers give effect to such conversion. The Preferred Stock had no expiration date.

F1 · ownership.nature: The reportable securities are owned directly by Polaris Partners VII, L.P. ("PP VII"). Polaris Management Co. VII, L.L.C. ("PMC VII") is the general partner of PP VII. Each of the Reporting Person, a member of the Issuer's Board of Directors, David Barrett ("Barrett"), Brian Chee ("Chee") and Bryce Youngren ("Youngren" and, together with the Reporting Person, Barrett and Chee, the "Managing Members") are the managing members of PMC VII.

F2 · ownership.nature: (continued from Footnote 2) Each of the Managing Members, in their respective capacities with respect to PMC VII, may be deemed to have shared voting and dispositive power over the shares held by PP VII. Each of PMC VII and the Managing Members disclaims beneficial ownership of these securities and this report shall not be deemed an admission that any one of them is the beneficial owner of such securities for purposes of Section 16 or for any other purpose, except to the extent of their respective pecuniary interests therein.

SEC source: 0001209191-20-051504 · doc4.xml · nonDerivative · entry 6

Nashat Amir · CIK 0001575843 · Director · 10% owner

10b5-1 filing: Not disclosed

Ownership: Indirect · See footnote

Disclosed balance after: 163,824

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: Every 5.1 shares of Series A Convertible Preferred Stock, Series B Convertible Preferred Stock and Series C Convertible Preferred Stock (the "Preferred Stock") automatically converted into 1 share of Common Stock immediately prior to the closing of the Issuer's initial public offering. Share numbers give effect to such conversion. The Preferred Stock had no expiration date.

F3 · ownership.nature: The reportable securities are owned directly by Polaris Entrepreneurs' Fund VII, L.P. ("PEF VII"). PMC VII is the general partner of PEF VII. Each of the Managing Members, in their respective capacities with respect to PMC VII, may be deemed to have shared voting and dispositive power over the shares held by PEF VII.

F4 · ownership.nature: (continued from Footnote 3) Each of PMC VII and the Managing Members disclaims beneficial ownership of these securities and this report shall not be deemed an admission that any one of them is the beneficial owner of such securities for purposes of Section 16 or for any other purpose, except to the extent of their respective pecuniary interests therein.

SEC source: 0001209191-20-051504 · doc4.xml · nonDerivative · entry 5

Nashat Amir · CIK 0001575843 · Director · 10% owner

10b5-1 filing: Not disclosed

Ownership: Indirect · See footnote

Disclosed balance after: 2,499,210

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: Every 5.1 shares of Series A Convertible Preferred Stock, Series B Convertible Preferred Stock and Series C Convertible Preferred Stock (the "Preferred Stock") automatically converted into 1 share of Common Stock immediately prior to the closing of the Issuer's initial public offering. Share numbers give effect to such conversion. The Preferred Stock had no expiration date.

F1 · ownership.nature: The reportable securities are owned directly by Polaris Partners VII, L.P. ("PP VII"). Polaris Management Co. VII, L.L.C. ("PMC VII") is the general partner of PP VII. Each of the Reporting Person, a member of the Issuer's Board of Directors, David Barrett ("Barrett"), Brian Chee ("Chee") and Bryce Youngren ("Youngren" and, together with the Reporting Person, Barrett and Chee, the "Managing Members") are the managing members of PMC VII.

F2 · ownership.nature: (continued from Footnote 2) Each of the Managing Members, in their respective capacities with respect to PMC VII, may be deemed to have shared voting and dispositive power over the shares held by PP VII. Each of PMC VII and the Managing Members disclaims beneficial ownership of these securities and this report shall not be deemed an admission that any one of them is the beneficial owner of such securities for purposes of Section 16 or for any other purpose, except to the extent of their respective pecuniary interests therein.

SEC source: 0001209191-20-051504 · doc4.xml · nonDerivative · entry 4

Nashat Amir · CIK 0001575843 · Director · 10% owner

10b5-1 filing: Not disclosed

Ownership: Indirect · See footnote

Disclosed balance after: 143,239

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: Every 5.1 shares of Series A Convertible Preferred Stock, Series B Convertible Preferred Stock and Series C Convertible Preferred Stock (the "Preferred Stock") automatically converted into 1 share of Common Stock immediately prior to the closing of the Issuer's initial public offering. Share numbers give effect to such conversion. The Preferred Stock had no expiration date.

F3 · ownership.nature: The reportable securities are owned directly by Polaris Entrepreneurs' Fund VII, L.P. ("PEF VII"). PMC VII is the general partner of PEF VII. Each of the Managing Members, in their respective capacities with respect to PMC VII, may be deemed to have shared voting and dispositive power over the shares held by PEF VII.

F4 · ownership.nature: (continued from Footnote 3) Each of PMC VII and the Managing Members disclaims beneficial ownership of these securities and this report shall not be deemed an admission that any one of them is the beneficial owner of such securities for purposes of Section 16 or for any other purpose, except to the extent of their respective pecuniary interests therein.

SEC source: 0001209191-20-051504 · doc4.xml · nonDerivative · entry 3

Nashat Amir · CIK 0001575843 · Director · 10% owner

10b5-1 filing: Not disclosed

Ownership: Indirect · See footnote

Disclosed balance after: 2,047,544

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: Every 5.1 shares of Series A Convertible Preferred Stock, Series B Convertible Preferred Stock and Series C Convertible Preferred Stock (the "Preferred Stock") automatically converted into 1 share of Common Stock immediately prior to the closing of the Issuer's initial public offering. Share numbers give effect to such conversion. The Preferred Stock had no expiration date.

F1 · ownership.nature: The reportable securities are owned directly by Polaris Partners VII, L.P. ("PP VII"). Polaris Management Co. VII, L.L.C. ("PMC VII") is the general partner of PP VII. Each of the Reporting Person, a member of the Issuer's Board of Directors, David Barrett ("Barrett"), Brian Chee ("Chee") and Bryce Youngren ("Youngren" and, together with the Reporting Person, Barrett and Chee, the "Managing Members") are the managing members of PMC VII.

F2 · ownership.nature: (continued from Footnote 2) Each of the Managing Members, in their respective capacities with respect to PMC VII, may be deemed to have shared voting and dispositive power over the shares held by PP VII. Each of PMC VII and the Managing Members disclaims beneficial ownership of these securities and this report shall not be deemed an admission that any one of them is the beneficial owner of such securities for purposes of Section 16 or for any other purpose, except to the extent of their respective pecuniary interests therein.

SEC source: 0001209191-20-051504 · doc4.xml · nonDerivative · entry 2

Nashat Amir · CIK 0001575843 · Director · 10% owner

10b5-1 filing: Not disclosed

Ownership: Indirect · See footnote

Disclosed balance after: 15,038

F3 · ownership.nature: The reportable securities are owned directly by Polaris Entrepreneurs' Fund VII, L.P. ("PEF VII"). PMC VII is the general partner of PEF VII. Each of the Managing Members, in their respective capacities with respect to PMC VII, may be deemed to have shared voting and dispositive power over the shares held by PEF VII.

F4 · ownership.nature: (continued from Footnote 3) Each of PMC VII and the Managing Members disclaims beneficial ownership of these securities and this report shall not be deemed an admission that any one of them is the beneficial owner of such securities for purposes of Section 16 or for any other purpose, except to the extent of their respective pecuniary interests therein.

SEC source: 0001209191-20-051504 · doc4.xml · nonDerivative · entry 1

Nashat Amir · CIK 0001575843 · Director · 10% owner

10b5-1 filing: Not disclosed

Ownership: Indirect · See footnote

Disclosed balance after: 214,962

F1 · ownership.nature: The reportable securities are owned directly by Polaris Partners VII, L.P. ("PP VII"). Polaris Management Co. VII, L.L.C. ("PMC VII") is the general partner of PP VII. Each of the Reporting Person, a member of the Issuer's Board of Directors, David Barrett ("Barrett"), Brian Chee ("Chee") and Bryce Youngren ("Youngren" and, together with the Reporting Person, Barrett and Chee, the "Managing Members") are the managing members of PMC VII.

F2 · ownership.nature: (continued from Footnote 2) Each of the Managing Members, in their respective capacities with respect to PMC VII, may be deemed to have shared voting and dispositive power over the shares held by PP VII. Each of PMC VII and the Managing Members disclaims beneficial ownership of these securities and this report shall not be deemed an admission that any one of them is the beneficial owner of such securities for purposes of Section 16 or for any other purpose, except to the extent of their respective pecuniary interests therein.

SEC source: 0001209191-20-038049 · doc4.xml · derivative · entry 1

Nashat Amir · CIK 0001575843 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 12,000

Underlying: Common Stock · 12,000 shares

Expires 2030-06-18

F1 · derivative.exercise_date: The option will vest in full on June 18, 2021, subject to the reporting person's provision of service to the issuer on the vesting date.

SEC source: 0001179110-20-007537 · edgar.xml · derivative · entry 1

Nashat Amir · CIK 0001575843 · Director · 10% owner

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 13,000

Underlying: Common Stock · 13,000 shares

Expires 2030-06-16

F1 · derivative.exercise_date: This option shall vest and become fully exercisable on the earlier of the first anniversary following the date of grant or the next scheduled Annual Meeting.

SEC source: 0001209191-20-035967 · doc4.xml · derivative · entry 1

Nashat Amir · CIK 0001575843 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 17,500

Underlying: Common Stock · 17,500 shares

Expires 2030-06-10

F1 · derivative.exercise_date: The option becomes exercisable as to 50% of the shares underlying the award on the six month anniversary of the date of grant, with the remainder vesting in equal monthly installments until the first anniversary of the date of grant, subject to the reporting person's continued service as a director through each applicable vesting date.

SEC source: 0000899243-19-020915 · doc4.xml · nonDerivative · entry 8

Nashat Amir · CIK 0001575843 · Director

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnote

Disclosed balance after: 11,034

F1 · kind: The sale of these shares were effected pursuant to Rule 10b5-1 trading plans adopted by each of Polaris Venture Partners V, L.P. ("PVP V"), Polaris Venture Partners Entrepreneurs' Fund V, L.P. ("PVPE V"), Polaris Venture Partners Founders' Fund V, L.P. ("PVPFF V") and Polaris Venture Partners Special Founders' Fund V, L.P. ("PVPSFF V", together with PVP V, PVPE V, PVPFF V, the "Polaris Funds") on June 17, 2019.

F4 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $22.50 to $22.62, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer or the staff of the Securities Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in this footnote (4) to this Form 4.

F7 · ownership.nature: The reportable securities are owned directly by PVPSFF V. PVM V is the general partner of PVPSFF V. The Reporting Person, a member of the Issuer's Board of Directors, is a member of PVM V. Each of Flint and McGuire are the managing members of PVM V. Each of Flint, McGuire and the Reporting Person, in their respective capacities with respect to PVM V, may be deemed to have shared voting and dispositive power over the shares held by PVPSFF V. Each of PVM V, Flint, McGuire and the Reporting Person disclaims beneficial ownership of these securities and this report shall not be deemed an admission that any one of them is the beneficial owner of such securities for purposes of Section 16 or for any other purpose, except to the extent of their respective pecuniary interests therein.