Nashat Amir

SEC source: 0001179110-19-008259 · edgar.xml · nonDerivative · entry 3

Nashat Amir · CIK 0001575843 · Director

10b5-1 filing: Not disclosed

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

Disclosed balance after: 2,054,240

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

F5 · price: Each share of the issuer's Series B Preferred Stock automatically converted into one share of the issuer's Common Stock on July 1, 2019 in connection with the closing of the issuer's sale of its Common Stock in its IPO pursuant to the Registration Statement, and had no expiration date.

F2 · 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. 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"), Jonathan A. Flint ("Flint"), Terrance G. McGuire ("McGuire") and Bryce Youngren ("Youngren" and, together with the reporting person, Barrett, Chee, Flint, and McGuire, 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: 0001179110-19-008259 · edgar.xml · nonDerivative · entry 2

Nashat Amir · CIK 0001575843 · Director

10b5-1 filing: Not disclosed

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

Disclosed balance after: 1,709,578

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

F4 · price: Each share of the issuer's Series A Preferred Stock automatically converted into one share of the issuer's Common Stock on July 1, 2019 in connection with the closing of the issuer's sale of its Common Stock in its IPO pursuant to the Registration Statement, and had no expiration date.

F2 · 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. 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"), Jonathan A. Flint ("Flint"), Terrance G. McGuire ("McGuire") and Bryce Youngren ("Youngren" and, together with the reporting person, Barrett, Chee, Flint, and McGuire, 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: 0001179110-19-008259 · edgar.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: 473,276

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

F1 · price: Each share of the issuer's Series Seed Preferred Stock automatically converted into one share of the issuer's Common Stock on July 1, 2019 in connection with the closing of the issuer's sale of its Common Stock in its firm commitment initial public offering (the "IPO") pursuant to a registration statement on Form S-1 (File No. 333-231837) under the Securities Act of 1933, as amended (the "Registration Statement"), and had no expiration date.

F2 · 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. 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"), Jonathan A. Flint ("Flint"), Terrance G. McGuire ("McGuire") and Bryce Youngren ("Youngren" and, together with the reporting person, Barrett, Chee, Flint, and McGuire, 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: 0001453687-19-000072 · wf-form4_156088928720786.xml · derivative · entry 1

Nashat Amir · CIK 0001575843 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 10,000

Underlying: Common Stock · 10,000 shares

Expires 2029-06-13

F1 · derivative.exercise_date: The option vests in full on the earlier of June 14, 2020 or the day immediately prior to the company's 2020 annual meeting of stockholders.

SEC source: 0001209191-19-036361 · doc4.xml · derivative · entry 1

Nashat Amir · CIK 0001575843 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 11,000

Underlying: Common Stock · 11,000 shares

Expires 2029-06-10

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: 0001104659-19-031593 · a4.xml · derivative · entry 1

Nashat Amir · CIK 0001575843 · Director · 10% owner

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 10,158

Underlying: Common Stock · 10,158 shares

Expires 2029-05-21

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 the next scheduled Annual Meeting.

SEC source: 0001209191-19-027951 · doc4.xml · derivative · entry 1

Nashat Amir · CIK 0001575843 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 16,000

Underlying: Common Stock · 16,000 shares

Expires 2029-05-03

F2 · price: Not applicable.

F1 · derivative.exercise_date: The shares subject to this option shall vest and become exercisable on the earlier of (i) May 3, 2020 or (ii) the date of the Issuer's 2020 Annual Meeting of Stockholders, subject to the recipient's continued service on the Issuer's Board of Directors.

SEC source: 0000899243-19-002335 · doc4.xml · nonDerivative · entry 4

Nashat Amir · CIK 0001575843 · Director

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnote

Disclosed balance after: 1,473,186

F1 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $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.

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: 0000899243-19-002335 · doc4.xml · nonDerivative · entry 3

Nashat Amir · CIK 0001575843 · Director

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnote

Disclosed balance after: 1,473,649

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.

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: 0000899243-19-002335 · doc4.xml · nonDerivative · entry 2

Nashat Amir · CIK 0001575843 · Director

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnote

Disclosed balance after: 1,473,989

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.

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: 0000899243-19-002335 · 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: 0000899243-19-002116 · doc4.xml · nonDerivative · entry 4

Nashat Amir · CIK 0001575843 · Director

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnote

Disclosed balance after: 2,676,234

F7 · ownership.nature: The reportable securities are owned directly by Polaris Venture Partners V, L.P. ("PVP V"). PVM V is the general partner of PVP V. PVM V disclaims beneficial ownership of these securities and this report shall not be deemed an admission that PVM V is the beneficial owner of such securities for purposes of Section 16 or for any other purpose, except to the extent of its pecuniary interest therein.

F8 · ownership.nature: Each of Flint and McGuire are the managing members of PVM V. The Reporting Person, who is a member of the Issuer's Board of Directors, is a member of PVM V. Each of Flint, McGuire and the Reporting Person, in their respective capacities with regard to PVM V, may be deemed to have shared voting and dispositive power of the shares held by PVP V. Each of Flint, McGuire and the Reporting Person disclaims beneficial ownership of these securities and this report shall not be deemed an admission that any of them is the beneficial owner of such securities for purposes of Section 16 or for any other purpose, except to the extent of their respective pecuniary interests therein.

SEC source: 0000899243-19-002116 · doc4.xml · nonDerivative · entry 3

Nashat Amir · CIK 0001575843 · Director

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnote

Disclosed balance after: 26,760

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. PVM V disclaims beneficial ownership of these securities and this report shall not be deemed an admission that PVM V is the beneficial owner of such securities for purposes of Section 16 or for any other purpose, except to the extent of its pecuniary interest therein.

F6 · ownership.nature: Each of Flint and McGuire are the managing members of PVM V. The Reporting Person, who is a member of the Issuer's Board of Directors, is a member of PVM V. Each of Flint, McGuire and the Reporting Person, in their respective capacities with regard to PVM V, may be deemed to have shared voting and dispositive power of the shares held by PVPSFF V. Each of Flint, McGuire and the Reporting Person disclaims beneficial ownership of these securities and this report shall not be deemed an admission that any of them is the beneficial owner of such securities for purposes of Section 16 or for any other purpose, except to the extent of their respective pecuniary interests therein.

SEC source: 0000899243-19-002116 · doc4.xml · nonDerivative · entry 2

Nashat Amir · CIK 0001575843 · Director

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnote

Disclosed balance after: 18,329

F3 · 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. PVM V disclaims beneficial ownership of these securities and this report shall not be deemed an admission that PVM V is the beneficial owner of such securities for purposes of Section 16 or for any other purpose, except to the extent of its pecuniary interest therein.

F4 · ownership.nature: Each of Flint and McGuire are the managing members of PVM V. The Reporting Person, who is a member of the Issuer's Board of Directors, is a member of PVM V. Each of Flint, McGuire and the Reporting Person, in their respective capacities with regard to PVM V, may be deemed to have shared voting and dispositive power of the shares held by PVPFF V. Each of Flint, McGuire and the Reporting Person disclaims beneficial ownership of these securities and this report shall not be deemed an admission that any of them is the beneficial owner of such securities for purposes of Section 16 or for any other purpose, except to the extent of their respective pecuniary interests therein.

SEC source: 0000899243-19-002116 · doc4.xml · nonDerivative · entry 1

Nashat Amir · CIK 0001575843 · Director

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnote

Disclosed balance after: 52,156

F1 · ownership.nature: The reportable securities are owned directly by Polaris Venture Partners Entrepreneurs' Fund V, L.P. ("PVPE V"). Polaris Venture Management Co. V, L.L.C. ("PVM V") is the general partner of PVPE V. PVM V disclaims beneficial ownership of these securities and this report shall not be deemed an admission that PVM V is the beneficial owner of such securities for purposes of Section 16 or for any other purpose, except to the extent of its pecuniary interest therein.

F2 · ownership.nature: Each of Jonathan A. Flint ("Flint") and Terrance G. McGuire ("McGuire") are the managing members of PVM V. The Reporting Person, who is a member of the Issuer's Board of Directors, is a member of PVM V. Each of Flint, McGuire and the Reporting Person, in their respective capacities with regard to PVM V, may be deemed to have shared voting and dispositive power of the shares held by PVPE V. Each of Flint, McGuire and the Reporting Person disclaims beneficial ownership of these securities and this report shall not be deemed an admission that any of them is the beneficial owner of such securities for purposes of Section 16 or for any other purpose, except to the extent of their respective pecuniary interests therein.

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: 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.

SEC source: 0000899243-18-031090 · doc4.xml · nonDerivative · entry 4

Nashat Amir · CIK 0001575843 · Director

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnote

Disclosed balance after: 1,965,658

F1 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $16.50 to $17.31, 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 (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: 0000899243-18-031090 · doc4.xml · nonDerivative · entry 3

Nashat Amir · CIK 0001575843 · Director

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnote

Disclosed balance after: 1,969,759

F1 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $16.50 to $17.31, 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 (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: 0000899243-18-031090 · doc4.xml · nonDerivative · entry 2

Nashat Amir · CIK 0001575843 · Director

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnote

Disclosed balance after: 1,972,568

F1 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $16.50 to $17.31, 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 (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.