FATE

SEC source: 0000899243-19-002335 · doc4.xml · nonDerivative · entry 1

Nashat Amir · CIK 0001575843 · Director

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnote

Disclosed balance after: 1,474,979

F1 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $13.79 to $14.59, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer or the staff of the United States 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 (1) to this Form 4.

F2 · ownership.nature: The reportable securities are owned directly by Polaris Venture Partners V, L.P. ("PVP V"). Polaris Venture Management Co. V, L.L.C. ("PVM V") is the general partner of PVP V. The Reporting Person, a member of the Issuer's Board of Directors, is a member of PVM V. Each of Jonathan A. Flint ("Flint") and Terrance G. McGuire ("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 PVP 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.

SEC source: 0000899243-19-002256 · doc4.xml · nonDerivative · entry 4

Nashat Amir · CIK 0001575843 · Director

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnote

Disclosed balance after: 1,526,203

F1 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $13.75 to $14.52, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer or the staff of the United States 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 (1) to this Form 4.

F5 · ownership.nature: The reportable securities are owned directly by Polaris Venture Partners Special Founders' Fund V, L.P. ("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.

SEC source: 0000899243-19-002256 · doc4.xml · nonDerivative · entry 3

Nashat Amir · CIK 0001575843 · Director

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnote

Disclosed balance after: 1,527,144

F1 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $13.75 to $14.52, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer or the staff of the United States 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 (1) to this Form 4.

F4 · ownership.nature: The reportable securities are owned directly by Polaris Venture Partners Founders' Fund V, L.P. ("PVPFF V"). PVM V is the general partner of PVPFF 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 PVPFF 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.

SEC source: 0000899243-19-002256 · doc4.xml · nonDerivative · entry 2

Nashat Amir · CIK 0001575843 · Director

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnote

Disclosed balance after: 1,527,788

F1 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $13.75 to $14.52, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer or the staff of the United States 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 (1) to this Form 4.

F3 · ownership.nature: The reportable securities are owned directly by Polaris Venture Partners Entrepreneurs' Fund V, L.P. ("PVPE V"). PVM V is the general partner of PVPE 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 PVPE 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.

SEC source: 0000899243-19-002256 · doc4.xml · nonDerivative · entry 1

Nashat Amir · CIK 0001575843 · Director

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnote

Disclosed balance after: 1,529,622

F1 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $13.75 to $14.52, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer or the staff of the United States 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 (1) to this Form 4.

F2 · ownership.nature: The reportable securities are owned directly by Polaris Venture Partners V, L.P. ("PVP V"). Polaris Venture Management Co. V, L.L.C. ("PVM V") is the general partner of PVP V. The Reporting Person, a member of the Issuer's Board of Directors, is a member of PVM V. Each of Jonathan A. Flint ("Flint") and Terrance G. McGuire ("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 PVP 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.

SEC source: 0000899243-19-002196 · doc4.xml · nonDerivative · entry 4

Nashat Amir · CIK 0001575843 · Director

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnote

Disclosed balance after: 1,623,703

F3 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $13.70 to $14.10, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer or the staff of the United States 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 (3) to this Form 4.

F6 · ownership.nature: The reportable securities are owned directly by Polaris Venture Partners Special Founders' Fund V, L.P. ("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.

SEC source: 0000899243-19-002196 · doc4.xml · nonDerivative · entry 3

Nashat Amir · CIK 0001575843 · Director

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnote

Disclosed balance after: 1,624,378

F3 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $13.70 to $14.10, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer or the staff of the United States 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 (3) to this Form 4.

F5 · ownership.nature: The reportable securities are owned directly by Polaris Venture Partners Founders' Fund V, L.P. ("PVPFF V"). PVM V is the general partner of PVPFF 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 PVPFF 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.

SEC source: 0000899243-19-002196 · doc4.xml · nonDerivative · entry 2

Nashat Amir · CIK 0001575843 · Director

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnote

Disclosed balance after: 1,624,841

F3 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $13.70 to $14.10, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer or the staff of the United States 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 (3) to this Form 4.

F4 · ownership.nature: The reportable securities are owned directly by Polaris Venture Partners Entrepreneurs' Fund V, L.P. ("PVPE V"). PVM V is the general partner of PVPE 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 PVPE 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.

SEC source: 0000899243-19-002196 · doc4.xml · nonDerivative · entry 1

Nashat Amir · CIK 0001575843 · Director

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnote

Disclosed balance after: 1,626,157

F1 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $13.70 to $14.12, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer or the staff of the United States 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 (1) to this Form 4.

F2 · ownership.nature: The reportable securities are owned directly by Polaris Venture Partners V, L.P. ("PVP V"). Polaris Venture Management Co. V, L.L.C. ("PVM V") is the general partner of PVP V. The Reporting Person, a member of the Issuer's Board of Directors, is a member of PVM V. Each of Jonathan A. Flint ("Flint") and Terrance G. McGuire ("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 PVP 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.

SEC source: 0000899243-19-002114 · doc4.xml · nonDerivative · entry 4

Nashat Amir · CIK 0001575843 · Director

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnote

Disclosed balance after: 1,693,703

F1 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $13.85 to $14.54, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer or the staff of the United States 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 (1) to this Form 4.

F5 · ownership.nature: The reportable securities are owned directly by Polaris Venture Partners Special Founders' Fund V, L.P. ("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.

SEC source: 0000899243-19-002114 · doc4.xml · nonDerivative · entry 3

Nashat Amir · CIK 0001575843 · Director

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnote

Disclosed balance after: 1,694,571

F1 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $13.85 to $14.54, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer or the staff of the United States 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 (1) to this Form 4.

F4 · ownership.nature: The reportable securities are owned directly by Polaris Venture Partners Founders' Fund V, L.P. ("PVPFF V"). PVM V is the general partner of PVPFF 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 PVPFF 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.

SEC source: 0000899243-19-002114 · doc4.xml · nonDerivative · entry 2

Nashat Amir · CIK 0001575843 · Director

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnote

Disclosed balance after: 1,695,166

F1 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $13.85 to $14.54, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer or the staff of the United States 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 (1) to this Form 4.

F3 · ownership.nature: The reportable securities are owned directly by Polaris Venture Partners Entrepreneurs' Fund V, L.P. ("PVPE V"). PVM V is the general partner of PVPE 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 PVPE 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.

SEC source: 0000899243-19-002114 · doc4.xml · nonDerivative · entry 1

Nashat Amir · CIK 0001575843 · Director

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnote

Disclosed balance after: 1,696,859

F1 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $13.85 to $14.54, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer or the staff of the United States 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 (1) to this Form 4.

F2 · ownership.nature: The reportable securities are owned directly by Polaris Venture Partners V, L.P. ("PVP V"). Polaris Venture Management Co. V, L.L.C. ("PVM V") is the general partner of PVP V. The Reporting Person, a member of the Issuer's Board of Directors, is a member of PVM V. Each of Jonathan A. Flint ("Flint") and Terrance G. McGuire ("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 PVP 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.

SEC source: 0000899243-19-001724 · doc4.xml · nonDerivative · entry 4

Nashat Amir · CIK 0001575843 · Director

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnote

Disclosed balance after: 1,783,703

F4 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $16.10 to $16.63, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer or the staff of the United States 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.

F6 · ownership.nature: The reportable securities are owned directly by Polaris Venture Partners Special Founders' Fund V, L.P. ("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.

SEC source: 0000899243-19-001724 · doc4.xml · nonDerivative · entry 3

Nashat Amir · CIK 0001575843 · Director

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnote

Disclosed balance after: 1,784,084

F4 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $16.10 to $16.63, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer or the staff of the United States 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.

F5 · ownership.nature: The reportable securities are owned directly by Polaris Venture Partners Founders' Fund V, L.P. ("PVPFF V"). PVM V is the general partner of PVPFF 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 PVPFF 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.

SEC source: 0000899243-19-001724 · doc4.xml · nonDerivative · entry 2

Nashat Amir · CIK 0001575843 · Director

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnote

Disclosed balance after: 1,784,345

F1 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $16.10 to $16.63, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer or the staff of the United States 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 (1) to this Form 4.

F3 · ownership.nature: The reportable securities are owned directly by Polaris Venture Partners Entrepreneurs' Fund V, L.P. ("PVPE V"). PVM V is the general partner of PVPE 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 PVPE 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.

SEC source: 0000899243-19-001724 · doc4.xml · nonDerivative · entry 1

Nashat Amir · CIK 0001575843 · Director

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnote

Disclosed balance after: 1,785,088

F1 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $16.10 to $16.63, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer or the staff of the United States 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 (1) to this Form 4.

F2 · ownership.nature: The reportable securities are owned directly by Polaris Venture Partners V, L.P. ("PVP V"). Polaris Venture Management Co. V, L.L.C. ("PVM V") is the general partner of PVP V. The Reporting Person, a member of the Issuer's Board of Directors, is a member of PVM V. Each of Jonathan A. Flint ("Flint") and Terrance G. McGuire ("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 PVP 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.

SEC source: 0001209191-19-003023 · doc4.xml · derivative · entry 2

Wolchko J Scott · CIK 0001586893 · Director · President and CEO

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 500,000

Underlying: Common Stock · 500,000 shares

Expires 2029-01-06

F3 · price: Not applicable.

F2 · derivative.exercise_date: The shares subject to this option shall vest and become exercisable in 48 equal monthly installments beginning on February 1, 2019 such that this option is fully exercisable on January 1, 2023.

SEC source: 0001209191-19-003023 · doc4.xml · nonDerivative · entry 1

Wolchko J Scott · CIK 0001586893 · Director · President and CEO

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 374,881

F1 · security: Award of Restricted Stock Units that vests with respect to 1/2 of the underlying shares on January 7, 2021, and with respect to 1/4 of the underlying shares on each of January 7, 2022 and January 7, 2023. This grant is subject to an accelerated vesting upon a change of control of the Issuer and in the event of termination of employment under certain circumstances following a change of control of the Issuer.

SEC source: 0001209191-19-003022 · doc4.xml · derivative · entry 2

Valamehr Bahram · CIK 0001748177 · Chief Development Officer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 135,000

Underlying: Common Stock · 135,000 shares

Expires 2029-01-06

F3 · price: Not applicable.

F2 · derivative.exercise_date: The shares subject to this option shall vest and become exercisable in 48 equal monthly installments beginning on February 1, 2019 such that this option is fully exercisable on January 1, 2023.

SEC source: 0001209191-19-003022 · doc4.xml · nonDerivative · entry 1

Valamehr Bahram · CIK 0001748177 · Chief Development Officer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 72,958

F1 · security: Award of Restricted Stock Units that vests with respect to 1/3 of the underlying shares on each of January 7, 2020, January 7, 2021, and January 7, 2022. This grant is subject to an accelerated vesting upon a change of control of the Issuer and in the event of termination of employment under certain circumstances following a change of control of the Issuer.

SEC source: 0001209191-19-003020 · doc4.xml · derivative · entry 11

TAHL CINDY · CIK 0001655472 · General Counsel and Secretary

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 135,000

Underlying: Common Stock · 135,000 shares

Expires 2029-01-06

F4 · price: Not applicable.

F6 · derivative.exercise_date: The shares subject to this option shall vest and become exercisable in 48 equal monthly installments beginning on February 1, 2019 such that this option is fully exercisable on January 1, 2023.

SEC source: 0001209191-19-003020 · doc4.xml · derivative · entry 10

TAHL CINDY · CIK 0001655472 · General Counsel and Secretary

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 123,149

Underlying: Common Stock · 12,451 shares

Expires 2026-01-07

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 · kind: This transaction was effected pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on September 20, 2018.

F4 · price: Not applicable.

F5 · derivative.exercise_date: The shares subject to this option shall vest and become exercisable in 48 equal monthly installments beginning on February 8, 2016 such that this option is fully exercisable on January 8, 2020.

SEC source: 0001209191-19-003020 · doc4.xml · derivative · entry 9

TAHL CINDY · CIK 0001655472 · General Counsel and Secretary

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 0

Underlying: Common Stock · 8,461 shares

Expires 2021-03-11

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 · kind: This transaction was effected pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on September 20, 2018.

F4 · price: Not applicable.

F3 · derivative.exercise_date: This option is fully vested.

SEC source: 0001209191-19-003020 · doc4.xml · derivative · entry 8

TAHL CINDY · CIK 0001655472 · General Counsel and Secretary

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 0

Underlying: Common Stock · 2,080 shares

Expires 2020-02-10

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 · kind: This transaction was effected pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on September 20, 2018.

F4 · price: Not applicable.

F3 · derivative.exercise_date: This option is fully vested.

SEC source: 0001209191-19-003020 · doc4.xml · derivative · entry 7

TAHL CINDY · CIK 0001655472 · General Counsel and Secretary

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 0

Underlying: Common Stock · 2,008 shares

Expires 2023-01-14

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 · kind: This transaction was effected pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on September 20, 2018.

F4 · price: Not applicable.

F3 · derivative.exercise_date: This option is fully vested.

SEC source: 0001209191-19-003020 · doc4.xml · nonDerivative · entry 6

TAHL CINDY · CIK 0001655472 · General Counsel and Secretary

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 90,418

F2 · security: Award of Restricted Stock Units that vests with respect to 1/3 of the underlying shares on each of January 7, 2020, January 7, 2021, and January 7, 2022. This grant is subject to an accelerated vesting upon a change of control of the Issuer and in the event of termination of employment under certain circumstances following a change of control of the Issuer.

SEC source: 0001209191-19-003020 · doc4.xml · nonDerivative · entry 5

TAHL CINDY · CIK 0001655472 · General Counsel and Secretary

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 45,418

F1 · kind: This transaction was effected pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on September 20, 2018.

SEC source: 0001209191-19-003020 · doc4.xml · nonDerivative · entry 4

TAHL CINDY · CIK 0001655472 · General Counsel and Secretary

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 70,418

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 · kind: This transaction was effected pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on September 20, 2018.

SEC source: 0001209191-19-003020 · doc4.xml · nonDerivative · entry 3

TAHL CINDY · CIK 0001655472 · General Counsel and Secretary

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 57,967

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 · kind: This transaction was effected pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on September 20, 2018.

SEC source: 0001209191-19-003020 · doc4.xml · nonDerivative · entry 2

TAHL CINDY · CIK 0001655472 · General Counsel and Secretary

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 49,506

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 · kind: This transaction was effected pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on September 20, 2018.

SEC source: 0001209191-19-003020 · doc4.xml · nonDerivative · entry 1

TAHL CINDY · CIK 0001655472 · General Counsel and Secretary

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 47,426

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 · kind: This transaction was effected pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on September 20, 2018.

SEC source: 0001209191-19-003019 · doc4.xml · derivative · entry 2

Shoemaker Daniel D · CIK 0001586892 · Chief Scientific Officer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 135,000

Underlying: Common Stock · 135,000 shares

Expires 2029-01-06

F3 · price: Not applicable.

F2 · derivative.exercise_date: The shares subject to this option shall vest and become exercisable in 48 equal monthly installments beginning on February 1, 2019 such that this option is fully exercisable on January 1, 2023.

SEC source: 0001209191-19-003019 · doc4.xml · nonDerivative · entry 1

Shoemaker Daniel D · CIK 0001586892 · Chief Scientific Officer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 135,591

F1 · security: Award of Restricted Stock Units that vests with respect to 1/3 of the underlying shares on each of January 7, 2020, January 7, 2021, and January 7, 2022. This grant is subject to an accelerated vesting upon a change of control of the Issuer and in the event of termination of employment under certain circumstances following a change of control of the Issuer.

SEC source: 0000899243-18-031703 · doc4.xml · nonDerivative · entry 4

Nashat Amir · CIK 0001575843 · Director

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnote

Disclosed balance after: 1,823,186

F1 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $12.100 to $12.645, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer or the staff of the United States 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 (1) to this Form 4.

F5 · ownership.nature: The reportable securities are owned directly by Polaris Venture Partners Special Founders' Fund V, L.P. ("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.

SEC source: 0000899243-18-031703 · doc4.xml · nonDerivative · entry 3

Nashat Amir · CIK 0001575843 · Director

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnote

Disclosed balance after: 1,823,509

F1 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $12.100 to $12.645, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer or the staff of the United States 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 (1) to this Form 4.

F4 · ownership.nature: The reportable securities are owned directly by Polaris Venture Partners Founders' Fund V, L.P. ("PVPFF V"). PVM V is the general partner of PVPFF 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 PVPFF 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.

SEC source: 0000899243-18-031703 · doc4.xml · nonDerivative · entry 2

Nashat Amir · CIK 0001575843 · Director

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnote

Disclosed balance after: 1,823,730

F1 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $12.100 to $12.645, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer or the staff of the United States 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 (1) to this Form 4.

F3 · ownership.nature: The reportable securities are owned directly by Polaris Venture Partners Entrepreneurs' Fund V, L.P. ("PVPE V"). PVM V is the general partner of PVPE 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 PVPE 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.

SEC source: 0000899243-18-031703 · doc4.xml · nonDerivative · entry 1

Nashat Amir · CIK 0001575843 · Director

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnote

Disclosed balance after: 1,824,360

F1 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $12.100 to $12.645, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer or the staff of the United States 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 (1) to this Form 4.

F2 · ownership.nature: The reportable securities are owned directly by Polaris Venture Partners V, L.P. ("PVP V"). Polaris Venture Management Co. V, L.L.C. ("PVM V") is the general partner of PVP V. The Reporting Person, a member of the Issuer's Board of Directors, is a member of PVM V. Each of Jonathan A. Flint ("Flint") and Terrance G. McGuire ("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 PVP 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.

SEC source: 0000899243-18-031588 · doc4.xml · nonDerivative · entry 8

Nashat Amir · CIK 0001575843 · Director

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnote

Disclosed balance after: 1,856,660

F3 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $13.72 to $14.31, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer or the staff of the United States 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 (3) to this Form 4.

F7 · ownership.nature: The reportable securities are owned directly by Polaris Venture Partners Special Founders' Fund V, L.P. ("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.

SEC source: 0000899243-18-031588 · doc4.xml · nonDerivative · entry 7

Nashat Amir · CIK 0001575843 · Director

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnote

Disclosed balance after: 1,856,900

F1 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $12.72 to $13.71, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer or the staff of the United States 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 (1) to this Form 4.

F7 · ownership.nature: The reportable securities are owned directly by Polaris Venture Partners Special Founders' Fund V, L.P. ("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.

SEC source: 0000899243-18-031588 · doc4.xml · nonDerivative · entry 6

Nashat Amir · CIK 0001575843 · Director

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnote

Disclosed balance after: 1,857,540

F3 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $13.72 to $14.31, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer or the staff of the United States 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 (3) to this Form 4.

F6 · ownership.nature: The reportable securities are owned directly by Polaris Venture Partners Founders' Fund V, L.P. ("PVPFF V"). PVM V is the general partner of PVPFF 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 PVPFF 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.

SEC source: 0000899243-18-031588 · doc4.xml · nonDerivative · entry 5

Nashat Amir · CIK 0001575843 · Director

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnote

Disclosed balance after: 1,857,720

F1 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $12.72 to $13.71, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer or the staff of the United States 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 (1) to this Form 4.

F6 · ownership.nature: The reportable securities are owned directly by Polaris Venture Partners Founders' Fund V, L.P. ("PVPFF V"). PVM V is the general partner of PVPFF 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 PVPFF 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.

SEC source: 0000899243-18-031588 · doc4.xml · nonDerivative · entry 4

Nashat Amir · CIK 0001575843 · Director

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnote

Disclosed balance after: 1,858,143

F5 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $13.72 to $14.26, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer or the staff of the United States 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 (5) to this Form 4.

F4 · ownership.nature: The reportable securities are owned directly by Polaris Venture Partners Entrepreneurs' Fund V, L.P. ("PVPE V"). PVM V is the general partner of PVPE 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 PVPE 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.

SEC source: 0000899243-18-031588 · doc4.xml · nonDerivative · entry 3

Nashat Amir · CIK 0001575843 · Director

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnote

Disclosed balance after: 1,858,597

F1 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $12.72 to $13.71, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer or the staff of the United States 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 (1) to this Form 4.

F4 · ownership.nature: The reportable securities are owned directly by Polaris Venture Partners Entrepreneurs' Fund V, L.P. ("PVPE V"). PVM V is the general partner of PVPE 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 PVPE 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.

SEC source: 0000899243-18-031588 · doc4.xml · nonDerivative · entry 2

Nashat Amir · CIK 0001575843 · Director

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnote

Disclosed balance after: 1,859,858

F3 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $13.72 to $14.31, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer or the staff of the United States 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 (3) to this Form 4.

F2 · ownership.nature: The reportable securities are owned directly by Polaris Venture Partners V, L.P. ("PVP V"). Polaris Venture Management Co. V, L.L.C. ("PVM V") is the general partner of PVP V. The Reporting Person, a member of the Issuer's Board of Directors, is a member of PVM V. Each of Jonathan A. Flint ("Flint") and Terrance G. McGuire ("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 PVP 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.

SEC source: 0000899243-18-031588 · doc4.xml · nonDerivative · entry 1

Nashat Amir · CIK 0001575843 · Director

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnote

Disclosed balance after: 1,882,881

F1 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $12.72 to $13.71, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer or the staff of the United States 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 (1) to this Form 4.

F2 · ownership.nature: The reportable securities are owned directly by Polaris Venture Partners V, L.P. ("PVP V"). Polaris Venture Management Co. V, L.L.C. ("PVM V") is the general partner of PVP V. The Reporting Person, a member of the Issuer's Board of Directors, is a member of PVM V. Each of Jonathan A. Flint ("Flint") and Terrance G. McGuire ("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 PVP 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.

SEC source: 0000899243-18-031217 · doc4.xml · nonDerivative · entry 4

Nashat Amir · CIK 0001575843 · Director

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnote

Disclosed balance after: 1,947,870

F1 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $16.70 to $16.95, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer or the staff of the United States 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 (1) to this Form 4.

F5 · ownership.nature: The reportable securities are owned directly by Polaris Venture Partners Special Founders' Fund V, L.P. ("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.

SEC source: 0000899243-18-031217 · doc4.xml · nonDerivative · entry 3

Nashat Amir · CIK 0001575843 · Director

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnote

Disclosed balance after: 1,948,042

F1 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $16.70 to $16.95, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer or the staff of the United States 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 (1) to this Form 4.

F4 · ownership.nature: The reportable securities are owned directly by Polaris Venture Partners Founders' Fund V, L.P. ("PVPFF V"). PVM V is the general partner of PVPFF 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 PVPFF 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.

SEC source: 0000899243-18-031217 · doc4.xml · nonDerivative · entry 2

Nashat Amir · CIK 0001575843 · Director

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnote

Disclosed balance after: 1,948,160

F1 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $16.70 to $16.95, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer or the staff of the United States 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 (1) to this Form 4.

F3 · ownership.nature: The reportable securities are owned directly by Polaris Venture Partners Entrepreneurs' Fund V, L.P. ("PVPE V"). PVM V is the general partner of PVPE 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 PVPE 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.

SEC source: 0000899243-18-031217 · doc4.xml · nonDerivative · entry 1

Nashat Amir · CIK 0001575843 · Director

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnote

Disclosed balance after: 1,948,494

F1 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $16.70 to $16.95, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer or the staff of the United States 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 (1) to this Form 4.

F2 · ownership.nature: The reportable securities are owned directly by Polaris Venture Partners V, L.P. ("PVP V"). Polaris Venture Management Co. V, L.L.C. ("PVM V") is the general partner of PVP V. The Reporting Person, a member of the Issuer's Board of Directors, is a member of PVM V. Each of Jonathan A. Flint ("Flint") and Terrance G. McGuire ("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 PVP 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.