Youngren Bryce

SEC source: 0000899243-19-016465 · doc4.xml · nonDerivative · entry 2

Youngren Bryce · CIK 0001489625 · Director · 10% owner

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnote

Disclosed balance after: 42,824

F1 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $25.08 to $25.92, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer or the staff of the Securities Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in this footnote (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: 0000899243-19-016465 · doc4.xml · nonDerivative · entry 1

Youngren Bryce · CIK 0001489625 · Director · 10% owner

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnote

Disclosed balance after: 2,197,475

F1 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $25.08 to $25.92, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer or the staff of the Securities Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in this footnote (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: 0000899243-19-015891 · doc4.xml · nonDerivative · entry 20

Youngren Bryce · CIK 0001489625 · Director · 10% owner

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnote

Disclosed balance after: 22,959

F8 · 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: 0000899243-19-015891 · doc4.xml · nonDerivative · entry 15

Youngren Bryce · CIK 0001489625 · Director · 10% owner

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnote

Disclosed balance after: 15,710

F7 · 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: 0000899243-19-015891 · doc4.xml · nonDerivative · entry 10

Youngren Bryce · CIK 0001489625 · Director · 10% owner

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnote

Disclosed balance after: 44,705

F6 · 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: 0000899243-19-015891 · doc4.xml · nonDerivative · entry 5

Youngren Bryce · CIK 0001489625 · Director · 10% owner

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnote

Disclosed balance after: 2,293,968

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: 0000899243-19-015891 · doc4.xml · nonDerivative · entry 19

Youngren Bryce · CIK 0001489625 · Director · 10% owner

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnote

Disclosed balance after: 22,962

F5 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $25.26 to $25.36, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer or the staff of the Securities Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in this footnote (5) to this Form 4.

F8 · 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: 0000899243-19-015891 · doc4.xml · nonDerivative · entry 18

Youngren Bryce · CIK 0001489625 · Director · 10% owner

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnote

Disclosed balance after: 22,969

F4 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $24.25 to $25.23, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer or the staff of the Securities Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in this footnote (4) to this Form 4.

F8 · 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: 0000899243-19-015891 · doc4.xml · nonDerivative · entry 17

Youngren Bryce · CIK 0001489625 · Director · 10% owner

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnote

Disclosed balance after: 23,276

F3 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $23.25 to $24.19, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer or the staff of the Securities Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in this footnote (3) to this Form 4.

F8 · 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: 0000899243-19-015891 · doc4.xml · nonDerivative · entry 14

Youngren Bryce · CIK 0001489625 · Director · 10% owner

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnote

Disclosed balance after: 15,712

F5 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $25.26 to $25.36, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer or the staff of the Securities Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in this footnote (5) to this Form 4.

F7 · 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: 0000899243-19-015891 · doc4.xml · nonDerivative · entry 13

Youngren Bryce · CIK 0001489625 · Director · 10% owner

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnote

Disclosed balance after: 15,726

F4 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $24.25 to $25.23, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer or the staff of the Securities Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in this footnote (4) to this Form 4.

F7 · ownership.nature: The reportable securities are owned directly by 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: 0000899243-19-015891 · doc4.xml · nonDerivative · entry 12

Youngren Bryce · CIK 0001489625 · Director · 10% owner

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnote

Disclosed balance after: 15,937

F3 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $23.25 to $24.19, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer or the staff of the Securities Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in this footnote (3) to this Form 4.

F7 · 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: 0000899243-19-015891 · doc4.xml · nonDerivative · entry 9

Youngren Bryce · CIK 0001489625 · Director · 10% owner

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnote

Disclosed balance after: 44,711

F5 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $25.26 to $25.36, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer or the staff of the Securities Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in this footnote (5) to this Form 4.

F6 · 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: 0000899243-19-015891 · doc4.xml · nonDerivative · entry 8

Youngren Bryce · CIK 0001489625 · Director · 10% owner

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnote

Disclosed balance after: 44,753

F4 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $24.25 to $25.23, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer or the staff of the Securities Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in this footnote (4) to this Form 4.

F6 · 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: 0000899243-19-015891 · doc4.xml · nonDerivative · entry 7

Youngren Bryce · CIK 0001489625 · Director · 10% owner

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnote

Disclosed balance after: 45,357

F3 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $23.25 to $24.19, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer or the staff of the Securities Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in this footnote (3) to this Form 4.

F6 · 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: 0000899243-19-015891 · doc4.xml · nonDerivative · entry 4

Youngren Bryce · CIK 0001489625 · Director · 10% owner

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnote

Disclosed balance after: 2,294,262

F5 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $25.26 to $25.36, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer or the staff of the Securities Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in this footnote (5) 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: 0000899243-19-015891 · doc4.xml · nonDerivative · entry 3

Youngren Bryce · CIK 0001489625 · Director · 10% owner

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnote

Disclosed balance after: 2,295,298

F4 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $24.25 to $25.23, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer or the staff of the Securities Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in this footnote (4) to this Form 4.

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: 0000899243-19-015891 · doc4.xml · nonDerivative · entry 2

Youngren Bryce · CIK 0001489625 · Director · 10% owner

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnote

Disclosed balance after: 2,327,592

F3 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $23.25 to $24.19, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer or the staff of the Securities Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in this footnote (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: 0000899243-19-015891 · doc4.xml · nonDerivative · entry 16

Youngren Bryce · CIK 0001489625 · Director · 10% owner

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnote

Disclosed balance after: 23,313

F1 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $23.25 to $23.44, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer or the staff of the Securities Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in this footnote (1) to this Form 4.

F8 · 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: 0000899243-19-015891 · doc4.xml · nonDerivative · entry 11

Youngren Bryce · CIK 0001489625 · Director · 10% owner

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnote

Disclosed balance after: 15,967

F1 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $23.25 to $23.44, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer or the staff of the Securities Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in this footnote (1) to this Form 4.

F7 · 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: 0000899243-19-015891 · doc4.xml · nonDerivative · entry 6

Youngren Bryce · CIK 0001489625 · Director · 10% owner

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnote

Disclosed balance after: 45,437

F1 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $23.25 to $23.44, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer or the staff of the Securities Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in this footnote (1) to this Form 4.

F6 · 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: 0000899243-19-015891 · doc4.xml · nonDerivative · entry 1

Youngren Bryce · CIK 0001489625 · Director · 10% owner

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnote

Disclosed balance after: 2,331,531

F1 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $23.25 to $23.44, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer or the staff of the Securities Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in this footnote (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: 0000899243-19-015238 · doc4.xml · nonDerivative · entry 4

Youngren Bryce · CIK 0001489625 · Director · 10% owner

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnote

Disclosed balance after: 23,664

F1 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $22.61 to $23.54, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer or the staff of the Securities Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in this footnote (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: 0000899243-19-015238 · doc4.xml · nonDerivative · entry 3

Youngren Bryce · CIK 0001489625 · Director · 10% owner

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnote

Disclosed balance after: 16,207

F1 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $22.61 to $23.54, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer or the staff of the Securities Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in this footnote (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: 0000899243-19-015238 · doc4.xml · nonDerivative · entry 2

Youngren Bryce · CIK 0001489625 · Director · 10% owner

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnote

Disclosed balance after: 46,121

F1 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $22.61 to $23.54, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer or the staff of the Securities Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in this footnote (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: 0000899243-19-015238 · doc4.xml · nonDerivative · entry 1

Youngren Bryce · CIK 0001489625 · Director · 10% owner

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnote

Disclosed balance after: 2,366,634

F1 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $22.61 to $23.54, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer or the staff of the Securities Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in this footnote (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: 0001209191-19-024766 · doc4.xml · derivative · entry 6

Youngren Bryce · CIK 0001489625 · Director · 10% owner

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 0

Underlying: Common Stock · 8,484 shares

Expires not disclosed

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

F1 · derivative.exercise_price: Each restricted stock unit ("RSU") represents a contingent right to receive one share of common stock of the Issuer, or at the election of the Issuer, its cash equivalent.

F6 · derivative.exercise_date: The RSUs vested in full on the one-year anniversary of the date of grant.

F6 · derivative.expiration_date: The RSUs vested in full on the one-year anniversary of the date of grant.

SEC source: 0001209191-19-024766 · doc4.xml · nonDerivative · entry 1

Youngren Bryce · CIK 0001489625 · Director · 10% owner

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 8,484

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 restricted stock unit ("RSU") represents a contingent right to receive one share of common stock of the Issuer, or at the election of the Issuer, its cash equivalent.

SEC source: 0000899243-18-024553 · doc4.xml · nonDerivative · entry 16

Youngren Bryce · CIK 0001489625 · Director · 10% owner

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnote

Disclosed balance after: 24,629

F4 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $26.19 to $26.57, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer or the staff of the Securities Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in this footnote (4) to this Form 4.

F8 · 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: 0000899243-18-024553 · doc4.xml · nonDerivative · entry 15

Youngren Bryce · CIK 0001489625 · Director · 10% owner

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnote

Disclosed balance after: 24,655

F3 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $25.08 to $26.04, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer or the staff of the Securities Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in this footnote (3) to this Form 4.

F8 · 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: 0000899243-18-024553 · doc4.xml · nonDerivative · entry 12

Youngren Bryce · CIK 0001489625 · Director · 10% owner

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnote

Disclosed balance after: 16,868

F4 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $26.19 to $26.57, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer or the staff of the Securities Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in this footnote (4) to this Form 4.

F7 · ownership.nature: The reportable securities are owned directly by 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: 0000899243-18-024553 · doc4.xml · nonDerivative · entry 11

Youngren Bryce · CIK 0001489625 · Director · 10% owner

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnote

Disclosed balance after: 16,885

F3 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $25.08 to $26.04, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer or the staff of the Securities Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in this footnote (3) to this Form 4.

F7 · 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: 0000899243-18-024553 · doc4.xml · nonDerivative · entry 8

Youngren Bryce · CIK 0001489625 · Director · 10% owner

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnote

Disclosed balance after: 48,002

F4 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $26.19 to $26.57, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer or the staff of the Securities Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in this footnote (4) to this Form 4.

F6 · 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. Youngren, 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 Youngren, 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 Youngren 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: 0000899243-18-024553 · doc4.xml · nonDerivative · entry 7

Youngren Bryce · CIK 0001489625 · Director · 10% owner

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnote

Disclosed balance after: 48,051

F3 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $25.08 to $26.04, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer or the staff of the Securities Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in this footnote (3) to this Form 4.

F6 · 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. Youngren, 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 Youngren, 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 Youngren 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: 0000899243-18-024553 · doc4.xml · nonDerivative · entry 4

Youngren Bryce · CIK 0001489625 · Director · 10% owner

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnote

Disclosed balance after: 2,463,127

F4 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $26.19 to $26.57, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer or the staff of the Securities Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in this footnote (4) to this Form 4.

F5 · 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: 0000899243-18-024553 · doc4.xml · nonDerivative · entry 3

Youngren Bryce · CIK 0001489625 · Director · 10% owner

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnote

Disclosed balance after: 2,465,631

F3 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $25.08 to $26.04, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer or the staff of the Securities Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in this footnote (3) to this Form 4.

F5 · 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: 0000899243-18-024553 · doc4.xml · nonDerivative · entry 14

Youngren Bryce · CIK 0001489625 · Director · 10% owner

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnote

Disclosed balance after: 25,111

F2 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $25.03 to $25.35, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer or the staff of the Securities Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in this footnote (2) to this Form 4.

F8 · 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: 0000899243-18-024553 · doc4.xml · nonDerivative · entry 13

Youngren Bryce · CIK 0001489625 · Director · 10% owner

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnote

Disclosed balance after: 25,316

F1 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $24.02 to $25.02, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer or the staff of the Securities Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in this footnote (1) to this Form 4.

F8 · 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: 0000899243-18-024553 · doc4.xml · nonDerivative · entry 10

Youngren Bryce · CIK 0001489625 · Director · 10% owner

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnote

Disclosed balance after: 17,199

F2 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $25.03 to $25.35, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer or the staff of the Securities Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in this footnote (2) to this Form 4.

F7 · 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: 0000899243-18-024553 · doc4.xml · nonDerivative · entry 9

Youngren Bryce · CIK 0001489625 · Director · 10% owner

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnote

Disclosed balance after: 17,342

F1 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $24.02 to $25.02, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer or the staff of the Securities Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in this footnote (1) to this Form 4.

F7 · 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: 0000899243-18-024553 · doc4.xml · nonDerivative · entry 6

Youngren Bryce · CIK 0001489625 · Director · 10% owner

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnote

Disclosed balance after: 48,942

F2 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $25.03 to $25.35, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer or the staff of the Securities Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in this footnote (2) to this Form 4.

F6 · 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. Youngren, 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 Youngren, 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 Youngren 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: 0000899243-18-024553 · doc4.xml · nonDerivative · entry 5

Youngren Bryce · CIK 0001489625 · Director · 10% owner

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnote

Disclosed balance after: 49,346

F1 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $24.02 to $25.02, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer or the staff of the Securities Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in this footnote (1) to this Form 4.

F6 · 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. Youngren, 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 Youngren, 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 Youngren 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: 0000899243-18-024553 · doc4.xml · nonDerivative · entry 2

Youngren Bryce · CIK 0001489625 · Director · 10% owner

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnote

Disclosed balance after: 2,511,374

F2 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $25.03 to $25.35, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer or the staff of the Securities Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in this footnote (2) to this Form 4.

F5 · 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: 0000899243-18-024553 · doc4.xml · nonDerivative · entry 1

Youngren Bryce · CIK 0001489625 · Director · 10% owner

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnote

Disclosed balance after: 2,532,062

F1 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $24.02 to $25.02, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer or the staff of the Securities Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in this footnote (1) to this Form 4.

F5 · 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: 0001209191-18-046122 · doc4.xml · derivative · entry 12

Youngren Bryce · CIK 0001489625 · Director · 10% owner

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnote

Disclosed balance after: 0

Underlying: Common Stock · 641 shares

Expires 2023-08-07

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: The shares acquired upon exercise of the warrant were acquired through a net exercise procedure in accordance with the terms of the warrant and did not involve any sale of shares.

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: 0001209191-18-046122 · doc4.xml · derivative · entry 11

Youngren Bryce · CIK 0001489625 · Director · 10% owner

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnote

Disclosed balance after: 0

Underlying: Common Stock · 438 shares

Expires 2023-08-07

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: The shares acquired upon exercise of the warrant were acquired through a net exercise procedure in accordance with the terms of the warrant and did not involve any sale of shares.

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: 0001209191-18-046122 · doc4.xml · derivative · entry 10

Youngren Bryce · CIK 0001489625 · Director · 10% owner

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnote

Disclosed balance after: 0

Underlying: Common Stock · 1,247 shares

Expires 2023-08-07

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: The shares acquired upon exercise of the warrant were acquired through a net exercise procedure in accordance with the terms of the warrant and did not involve any sale of shares.

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: 0001209191-18-046122 · doc4.xml · derivative · entry 9

Youngren Bryce · CIK 0001489625 · Director · 10% owner

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnote

Disclosed balance after: 0

Underlying: Common Stock · 64,038 shares

Expires 2023-08-07

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: The shares acquired upon exercise of the warrant were acquired through a net exercise procedure in accordance with the terms of the warrant and did not involve any sale of shares.

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: 0001209191-18-046122 · doc4.xml · nonDerivative · entry 4

Youngren Bryce · CIK 0001489625 · Director · 10% owner

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnote

Disclosed balance after: 26,076

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: The shares acquired upon exercise of the warrant were acquired through a net exercise procedure in accordance with the terms of the warrant and did not involve any sale of shares.

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: 0001209191-18-046122 · doc4.xml · nonDerivative · entry 3

Youngren Bryce · CIK 0001489625 · Director · 10% owner

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnote

Disclosed balance after: 17,860

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: The shares acquired upon exercise of the warrant were acquired through a net exercise procedure in accordance with the terms of the warrant and did not involve any sale of shares.

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.