ALEC

SEC source: 0001209191-19-009784 · doc4.xml · derivative · entry 8

MCGUIRE TERRANCE · CIK 0001117003 · Director

10b5-1 filing: Not disclosed

Ownership: Indirect · See footnote

Disclosed balance after: 0

Underlying: Common Stock · 5,274,725 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: All of the reported securities are held directly by the Polaris Funds (as defined below). Each of the Series A-1 Preferred Stock, Series A-2 Preferred Stock, Series B Preferred Stock, Series C Preferred Stock, Series D Preferred Stock and Series E Preferred Stock converted into Common Stock on a one-for-one basis upon the closing of the Issuer's initial public offering without payment of further consideration. The shares have no expiration date.

F1 · derivative.exercise_date: All of the reported securities are held directly by the Polaris Funds (as defined below). Each of the Series A-1 Preferred Stock, Series A-2 Preferred Stock, Series B Preferred Stock, Series C Preferred Stock, Series D Preferred Stock and Series E Preferred Stock converted into Common Stock on a one-for-one basis upon the closing of the Issuer's initial public offering without payment of further consideration. The shares have no expiration date.

F1 · derivative.expiration_date: All of the reported securities are held directly by the Polaris Funds (as defined below). Each of the Series A-1 Preferred Stock, Series A-2 Preferred Stock, Series B Preferred Stock, Series C Preferred Stock, Series D Preferred Stock and Series E Preferred Stock converted into Common Stock on a one-for-one basis upon the closing of the Issuer's initial public offering without payment of further consideration. The shares have no expiration date.

F3 · ownership.nature: 291,223 shares are held by PVPFF VI, 4,000,075 shares are held by PVP VI AIV and 983,427 shares are held by PVP VI Feeder. The reporting person disclaims beneficial ownership of the securities held by the Polaris Funds, and this report shall not be deemed an admission that the reporting person is the beneficial owner of such securities, except to the extent of his pecuniary interest therein, if any.

SEC source: 0001209191-19-009784 · doc4.xml · derivative · entry 7

MCGUIRE TERRANCE · CIK 0001117003 · Director

10b5-1 filing: Not disclosed

Ownership: Indirect · See footnote

Disclosed balance after: 0

Underlying: Common Stock · 500,000 shares

Expires not disclosed

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

F1 · derivative.exercise_price: All of the reported securities are held directly by the Polaris Funds (as defined below). Each of the Series A-1 Preferred Stock, Series A-2 Preferred Stock, Series B Preferred Stock, Series C Preferred Stock, Series D Preferred Stock and Series E Preferred Stock converted into Common Stock on a one-for-one basis upon the closing of the Issuer's initial public offering without payment of further consideration. The shares have no expiration date.

F1 · derivative.exercise_date: All of the reported securities are held directly by the Polaris Funds (as defined below). Each of the Series A-1 Preferred Stock, Series A-2 Preferred Stock, Series B Preferred Stock, Series C Preferred Stock, Series D Preferred Stock and Series E Preferred Stock converted into Common Stock on a one-for-one basis upon the closing of the Issuer's initial public offering without payment of further consideration. The shares have no expiration date.

F1 · derivative.expiration_date: All of the reported securities are held directly by the Polaris Funds (as defined below). Each of the Series A-1 Preferred Stock, Series A-2 Preferred Stock, Series B Preferred Stock, Series C Preferred Stock, Series D Preferred Stock and Series E Preferred Stock converted into Common Stock on a one-for-one basis upon the closing of the Issuer's initial public offering without payment of further consideration. The shares have no expiration date.

F2 · ownership.nature: 27,606 shares are held by Polaris Venture Partners Founders' Fund VI, L.P ("PVPFF VI"), 379,174 shares are held by Polaris Venture Partners VI (AIV), L.P. ("PVP VI AIV") and 93,220 shares are held by PVP VI (AIV) Feeder Corp. Holding Partnership, L.P. ("PVP VI Feeder" and, together with PVP VI AIV, PVPFF VI, and Polaris Venture Partners VI, L.P. ("PVP VI"), the "Polaris Funds"). The general partner of each of the Polaris Funds is Polaris Venture Management Co. VI, L.L.C. ("PVM"). PVM may be deemed to have sole power to vote and dispose of the shares held by the Polaris Funds. Amir Nashat, Brian Chee, David Barrett, Bryce Youngren, Jon Flint, and the reporting person are managing members of PVM. The reporting person disclaims beneficial ownership of the securities held by the Polaris Funds, and this report shall not be deemed an admission that the reporting person is the beneficial owner of such securities, except to the extent of his pecuniary interest therein, if any.

SEC source: 0001209191-19-009784 · doc4.xml · nonDerivative · entry 6

MCGUIRE TERRANCE · CIK 0001117003 · Director

10b5-1 filing: Not disclosed

Ownership: Indirect · See footnotes

Disclosed balance after: 12,858,194

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: All of the reported securities are held directly by the Polaris Funds (as defined below). Each of the Series A-1 Preferred Stock, Series A-2 Preferred Stock, Series B Preferred Stock, Series C Preferred Stock, Series D Preferred Stock and Series E Preferred Stock converted into Common Stock on a one-for-one basis upon the closing of the Issuer's initial public offering without payment of further consideration. The shares have no expiration date.

F2 · ownership.nature: 27,606 shares are held by Polaris Venture Partners Founders' Fund VI, L.P ("PVPFF VI"), 379,174 shares are held by Polaris Venture Partners VI (AIV), L.P. ("PVP VI AIV") and 93,220 shares are held by PVP VI (AIV) Feeder Corp. Holding Partnership, L.P. ("PVP VI Feeder" and, together with PVP VI AIV, PVPFF VI, and Polaris Venture Partners VI, L.P. ("PVP VI"), the "Polaris Funds"). The general partner of each of the Polaris Funds is Polaris Venture Management Co. VI, L.L.C. ("PVM"). PVM may be deemed to have sole power to vote and dispose of the shares held by the Polaris Funds. Amir Nashat, Brian Chee, David Barrett, Bryce Youngren, Jon Flint, and the reporting person are managing members of PVM. The reporting person disclaims beneficial ownership of the securities held by the Polaris Funds, and this report shall not be deemed an admission that the reporting person is the beneficial owner of such securities, except to the extent of his pecuniary interest therein, if any.

F3 · ownership.nature: 291,223 shares are held by PVPFF VI, 4,000,075 shares are held by PVP VI AIV and 983,427 shares are held by PVP VI Feeder. The reporting person disclaims beneficial ownership of the securities held by the Polaris Funds, and this report shall not be deemed an admission that the reporting person is the beneficial owner of such securities, except to the extent of his pecuniary interest therein, if any.

F4 · ownership.nature: 138,030 shares are held by PVPFF VI, 1,895,867 shares are held by PVP VI AIV and 466,103 shares are held by PVP VI Feeder. The reporting person disclaims beneficial ownership of the securities held by the Polaris Funds, and this report shall not be deemed an admission that the reporting person is the beneficial owner of such securities, except to the extent of his pecuniary interest therein, if any.

F5 · ownership.nature: 155,087 shares are held by PVPFF VI, 2,130,190 shares are held by PVP VI AIV and 523,712 shares are held by PVP VI Feeder. The reporting person disclaims beneficial ownership of the securities held by the Polaris Funds, and this report shall not be deemed an admission that the reporting person is the beneficial owner of such securities, except to the extent of his pecuniary interest therein, if any.

F6 · ownership.nature: 68,842 shares are held by PVPFF VI, 945,571 shares are held by PVP VI AIV and 232,470 shares are held by PVP VI Feeder. The reporting person disclaims beneficial ownership of the securities held by the Polaris Funds, and this report shall not be deemed an admission that the reporting person is the beneficial owner of such securities, except to the extent of his pecuniary interest therein, if any.

F7 · ownership.nature: 29,129 shares are held by PVPFF VI and 498,468 shares are held by PVP VI. The reporting person disclaims beneficial ownership of the securities held by the Polaris Funds, and this report shall not be deemed an admission that the reporting person is the beneficial owner of such securities, except to the extent of his pecuniary interest therein, if any.

SEC source: 0001209191-19-009784 · doc4.xml · nonDerivative · entry 5

MCGUIRE TERRANCE · CIK 0001117003 · Director

10b5-1 filing: Not disclosed

Ownership: Indirect · See footnotes

Disclosed balance after: 12,330,597

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: All of the reported securities are held directly by the Polaris Funds (as defined below). Each of the Series A-1 Preferred Stock, Series A-2 Preferred Stock, Series B Preferred Stock, Series C Preferred Stock, Series D Preferred Stock and Series E Preferred Stock converted into Common Stock on a one-for-one basis upon the closing of the Issuer's initial public offering without payment of further consideration. The shares have no expiration date.

F2 · ownership.nature: 27,606 shares are held by Polaris Venture Partners Founders' Fund VI, L.P ("PVPFF VI"), 379,174 shares are held by Polaris Venture Partners VI (AIV), L.P. ("PVP VI AIV") and 93,220 shares are held by PVP VI (AIV) Feeder Corp. Holding Partnership, L.P. ("PVP VI Feeder" and, together with PVP VI AIV, PVPFF VI, and Polaris Venture Partners VI, L.P. ("PVP VI"), the "Polaris Funds"). The general partner of each of the Polaris Funds is Polaris Venture Management Co. VI, L.L.C. ("PVM"). PVM may be deemed to have sole power to vote and dispose of the shares held by the Polaris Funds. Amir Nashat, Brian Chee, David Barrett, Bryce Youngren, Jon Flint, and the reporting person are managing members of PVM. The reporting person disclaims beneficial ownership of the securities held by the Polaris Funds, and this report shall not be deemed an admission that the reporting person is the beneficial owner of such securities, except to the extent of his pecuniary interest therein, if any.

F3 · ownership.nature: 291,223 shares are held by PVPFF VI, 4,000,075 shares are held by PVP VI AIV and 983,427 shares are held by PVP VI Feeder. The reporting person disclaims beneficial ownership of the securities held by the Polaris Funds, and this report shall not be deemed an admission that the reporting person is the beneficial owner of such securities, except to the extent of his pecuniary interest therein, if any.

F4 · ownership.nature: 138,030 shares are held by PVPFF VI, 1,895,867 shares are held by PVP VI AIV and 466,103 shares are held by PVP VI Feeder. The reporting person disclaims beneficial ownership of the securities held by the Polaris Funds, and this report shall not be deemed an admission that the reporting person is the beneficial owner of such securities, except to the extent of his pecuniary interest therein, if any.

F5 · ownership.nature: 155,087 shares are held by PVPFF VI, 2,130,190 shares are held by PVP VI AIV and 523,712 shares are held by PVP VI Feeder. The reporting person disclaims beneficial ownership of the securities held by the Polaris Funds, and this report shall not be deemed an admission that the reporting person is the beneficial owner of such securities, except to the extent of his pecuniary interest therein, if any.

F6 · ownership.nature: 68,842 shares are held by PVPFF VI, 945,571 shares are held by PVP VI AIV and 232,470 shares are held by PVP VI Feeder. The reporting person disclaims beneficial ownership of the securities held by the Polaris Funds, and this report shall not be deemed an admission that the reporting person is the beneficial owner of such securities, except to the extent of his pecuniary interest therein, if any.

SEC source: 0001209191-19-009784 · doc4.xml · nonDerivative · entry 4

MCGUIRE TERRANCE · CIK 0001117003 · Director

10b5-1 filing: Not disclosed

Ownership: Indirect · See footnotes

Disclosed balance after: 11,083,714

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: All of the reported securities are held directly by the Polaris Funds (as defined below). Each of the Series A-1 Preferred Stock, Series A-2 Preferred Stock, Series B Preferred Stock, Series C Preferred Stock, Series D Preferred Stock and Series E Preferred Stock converted into Common Stock on a one-for-one basis upon the closing of the Issuer's initial public offering without payment of further consideration. The shares have no expiration date.

F2 · ownership.nature: 27,606 shares are held by Polaris Venture Partners Founders' Fund VI, L.P ("PVPFF VI"), 379,174 shares are held by Polaris Venture Partners VI (AIV), L.P. ("PVP VI AIV") and 93,220 shares are held by PVP VI (AIV) Feeder Corp. Holding Partnership, L.P. ("PVP VI Feeder" and, together with PVP VI AIV, PVPFF VI, and Polaris Venture Partners VI, L.P. ("PVP VI"), the "Polaris Funds"). The general partner of each of the Polaris Funds is Polaris Venture Management Co. VI, L.L.C. ("PVM"). PVM may be deemed to have sole power to vote and dispose of the shares held by the Polaris Funds. Amir Nashat, Brian Chee, David Barrett, Bryce Youngren, Jon Flint, and the reporting person are managing members of PVM. The reporting person disclaims beneficial ownership of the securities held by the Polaris Funds, and this report shall not be deemed an admission that the reporting person is the beneficial owner of such securities, except to the extent of his pecuniary interest therein, if any.

F3 · ownership.nature: 291,223 shares are held by PVPFF VI, 4,000,075 shares are held by PVP VI AIV and 983,427 shares are held by PVP VI Feeder. The reporting person disclaims beneficial ownership of the securities held by the Polaris Funds, and this report shall not be deemed an admission that the reporting person is the beneficial owner of such securities, except to the extent of his pecuniary interest therein, if any.

F4 · ownership.nature: 138,030 shares are held by PVPFF VI, 1,895,867 shares are held by PVP VI AIV and 466,103 shares are held by PVP VI Feeder. The reporting person disclaims beneficial ownership of the securities held by the Polaris Funds, and this report shall not be deemed an admission that the reporting person is the beneficial owner of such securities, except to the extent of his pecuniary interest therein, if any.

F5 · ownership.nature: 155,087 shares are held by PVPFF VI, 2,130,190 shares are held by PVP VI AIV and 523,712 shares are held by PVP VI Feeder. The reporting person disclaims beneficial ownership of the securities held by the Polaris Funds, and this report shall not be deemed an admission that the reporting person is the beneficial owner of such securities, except to the extent of his pecuniary interest therein, if any.

SEC source: 0001209191-19-009784 · doc4.xml · nonDerivative · entry 3

MCGUIRE TERRANCE · CIK 0001117003 · Director

10b5-1 filing: Not disclosed

Ownership: Indirect · See footnotes

Disclosed balance after: 8,274,725

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: All of the reported securities are held directly by the Polaris Funds (as defined below). Each of the Series A-1 Preferred Stock, Series A-2 Preferred Stock, Series B Preferred Stock, Series C Preferred Stock, Series D Preferred Stock and Series E Preferred Stock converted into Common Stock on a one-for-one basis upon the closing of the Issuer's initial public offering without payment of further consideration. The shares have no expiration date.

F2 · ownership.nature: 27,606 shares are held by Polaris Venture Partners Founders' Fund VI, L.P ("PVPFF VI"), 379,174 shares are held by Polaris Venture Partners VI (AIV), L.P. ("PVP VI AIV") and 93,220 shares are held by PVP VI (AIV) Feeder Corp. Holding Partnership, L.P. ("PVP VI Feeder" and, together with PVP VI AIV, PVPFF VI, and Polaris Venture Partners VI, L.P. ("PVP VI"), the "Polaris Funds"). The general partner of each of the Polaris Funds is Polaris Venture Management Co. VI, L.L.C. ("PVM"). PVM may be deemed to have sole power to vote and dispose of the shares held by the Polaris Funds. Amir Nashat, Brian Chee, David Barrett, Bryce Youngren, Jon Flint, and the reporting person are managing members of PVM. The reporting person disclaims beneficial ownership of the securities held by the Polaris Funds, and this report shall not be deemed an admission that the reporting person is the beneficial owner of such securities, except to the extent of his pecuniary interest therein, if any.

F3 · ownership.nature: 291,223 shares are held by PVPFF VI, 4,000,075 shares are held by PVP VI AIV and 983,427 shares are held by PVP VI Feeder. The reporting person disclaims beneficial ownership of the securities held by the Polaris Funds, and this report shall not be deemed an admission that the reporting person is the beneficial owner of such securities, except to the extent of his pecuniary interest therein, if any.

F4 · ownership.nature: 138,030 shares are held by PVPFF VI, 1,895,867 shares are held by PVP VI AIV and 466,103 shares are held by PVP VI Feeder. The reporting person disclaims beneficial ownership of the securities held by the Polaris Funds, and this report shall not be deemed an admission that the reporting person is the beneficial owner of such securities, except to the extent of his pecuniary interest therein, if any.

SEC source: 0001209191-19-009784 · doc4.xml · nonDerivative · entry 2

MCGUIRE TERRANCE · CIK 0001117003 · Director

10b5-1 filing: Not disclosed

Ownership: Indirect · See footnotes

Disclosed balance after: 5,774,725

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: All of the reported securities are held directly by the Polaris Funds (as defined below). Each of the Series A-1 Preferred Stock, Series A-2 Preferred Stock, Series B Preferred Stock, Series C Preferred Stock, Series D Preferred Stock and Series E Preferred Stock converted into Common Stock on a one-for-one basis upon the closing of the Issuer's initial public offering without payment of further consideration. The shares have no expiration date.

F2 · ownership.nature: 27,606 shares are held by Polaris Venture Partners Founders' Fund VI, L.P ("PVPFF VI"), 379,174 shares are held by Polaris Venture Partners VI (AIV), L.P. ("PVP VI AIV") and 93,220 shares are held by PVP VI (AIV) Feeder Corp. Holding Partnership, L.P. ("PVP VI Feeder" and, together with PVP VI AIV, PVPFF VI, and Polaris Venture Partners VI, L.P. ("PVP VI"), the "Polaris Funds"). The general partner of each of the Polaris Funds is Polaris Venture Management Co. VI, L.L.C. ("PVM"). PVM may be deemed to have sole power to vote and dispose of the shares held by the Polaris Funds. Amir Nashat, Brian Chee, David Barrett, Bryce Youngren, Jon Flint, and the reporting person are managing members of PVM. The reporting person disclaims beneficial ownership of the securities held by the Polaris Funds, and this report shall not be deemed an admission that the reporting person is the beneficial owner of such securities, except to the extent of his pecuniary interest therein, if any.

F3 · ownership.nature: 291,223 shares are held by PVPFF VI, 4,000,075 shares are held by PVP VI AIV and 983,427 shares are held by PVP VI Feeder. The reporting person disclaims beneficial ownership of the securities held by the Polaris Funds, and this report shall not be deemed an admission that the reporting person is the beneficial owner of such securities, except to the extent of his pecuniary interest therein, if any.

SEC source: 0001209191-19-009784 · doc4.xml · nonDerivative · entry 1

MCGUIRE TERRANCE · CIK 0001117003 · Director

10b5-1 filing: Not disclosed

Ownership: Indirect · See footnote

Disclosed balance after: 500,000

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

F1 · price: All of the reported securities are held directly by the Polaris Funds (as defined below). Each of the Series A-1 Preferred Stock, Series A-2 Preferred Stock, Series B Preferred Stock, Series C Preferred Stock, Series D Preferred Stock and Series E Preferred Stock converted into Common Stock on a one-for-one basis upon the closing of the Issuer's initial public offering without payment of further consideration. The shares have no expiration date.

F2 · ownership.nature: 27,606 shares are held by Polaris Venture Partners Founders' Fund VI, L.P ("PVPFF VI"), 379,174 shares are held by Polaris Venture Partners VI (AIV), L.P. ("PVP VI AIV") and 93,220 shares are held by PVP VI (AIV) Feeder Corp. Holding Partnership, L.P. ("PVP VI Feeder" and, together with PVP VI AIV, PVPFF VI, and Polaris Venture Partners VI, L.P. ("PVP VI"), the "Polaris Funds"). The general partner of each of the Polaris Funds is Polaris Venture Management Co. VI, L.L.C. ("PVM"). PVM may be deemed to have sole power to vote and dispose of the shares held by the Polaris Funds. Amir Nashat, Brian Chee, David Barrett, Bryce Youngren, Jon Flint, and the reporting person are managing members of PVM. The reporting person disclaims beneficial ownership of the securities held by the Polaris Funds, and this report shall not be deemed an admission that the reporting person is the beneficial owner of such securities, except to the extent of his pecuniary interest therein, if any.

SEC source: 0001209191-19-009780 · doc4.xml · derivative · entry 12

Polaris Venture Management Co. VI, L.L.C. · CIK 0001665594 · 10% owner

Polaris Venture Partners VI (AIV), L.P. · CIK 0001767127 · 10% owner

Polaris Venture Partners Founders' Fund VI, L.P. · CIK 0001575691 · 10% owner

Polaris Venture Partners VI, L.P. · CIK 0001493463 · 10% owner

PVP VI (AIV) Feeder Corp. Holding Partnership, L.P. · CIK 0001767130 · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: Not disclosed

Ownership: Indirect · See footnote

Disclosed balance after: 0

Underlying: Common Stock · 527,597 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 of the Series A-1 Preferred Stock, Series A-2 Preferred Stock, Series B Preferred Stock, Series C Preferred Stock, Series D Preferred Stock and Series E Preferred Stock converted into Common Stock on a one-for-one basis upon the closing of the Issuer's initial public offering without payment of further consideration. The shares have no expiration date.

F1 · derivative.exercise_date: Each of the Series A-1 Preferred Stock, Series A-2 Preferred Stock, Series B Preferred Stock, Series C Preferred Stock, Series D Preferred Stock and Series E Preferred Stock converted into Common Stock on a one-for-one basis upon the closing of the Issuer's initial public offering without payment of further consideration. The shares have no expiration date.

F1 · derivative.expiration_date: Each of the Series A-1 Preferred Stock, Series A-2 Preferred Stock, Series B Preferred Stock, Series C Preferred Stock, Series D Preferred Stock and Series E Preferred Stock converted into Common Stock on a one-for-one basis upon the closing of the Issuer's initial public offering without payment of further consideration. The shares have no expiration date.

F7 · ownership.nature: 29,129 shares are held by PVPFF VI and 498,468 shares are held by PVP VI. PVM disclaims beneficial ownership of the securities held by the Polaris Funds, and this report shall not be deemed an admission that PVM is the beneficial owner of such securities, except to the extent of its pecuniary interest therein, if any.

SEC source: 0001209191-19-009780 · doc4.xml · derivative · entry 11

Polaris Venture Management Co. VI, L.L.C. · CIK 0001665594 · 10% owner

Polaris Venture Partners VI (AIV), L.P. · CIK 0001767127 · 10% owner

Polaris Venture Partners Founders' Fund VI, L.P. · CIK 0001575691 · 10% owner

Polaris Venture Partners VI, L.P. · CIK 0001493463 · 10% owner

PVP VI (AIV) Feeder Corp. Holding Partnership, L.P. · CIK 0001767130 · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: Not disclosed

Ownership: Indirect · See footnote

Disclosed balance after: 0

Underlying: Common Stock · 1,246,883 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 of the Series A-1 Preferred Stock, Series A-2 Preferred Stock, Series B Preferred Stock, Series C Preferred Stock, Series D Preferred Stock and Series E Preferred Stock converted into Common Stock on a one-for-one basis upon the closing of the Issuer's initial public offering without payment of further consideration. The shares have no expiration date.

F1 · derivative.exercise_date: Each of the Series A-1 Preferred Stock, Series A-2 Preferred Stock, Series B Preferred Stock, Series C Preferred Stock, Series D Preferred Stock and Series E Preferred Stock converted into Common Stock on a one-for-one basis upon the closing of the Issuer's initial public offering without payment of further consideration. The shares have no expiration date.

F1 · derivative.expiration_date: Each of the Series A-1 Preferred Stock, Series A-2 Preferred Stock, Series B Preferred Stock, Series C Preferred Stock, Series D Preferred Stock and Series E Preferred Stock converted into Common Stock on a one-for-one basis upon the closing of the Issuer's initial public offering without payment of further consideration. The shares have no expiration date.

F6 · ownership.nature: 68,842 shares are held by PVPFF VI, 945,571 shares are held by PVP VI AIV and 232,470 shares are held by PVP VI Feeder. PVM disclaims beneficial ownership of the securities held by the Polaris Funds, and this report shall not be deemed an admission that PVM is the beneficial owner of such securities, except to the extent of its pecuniary interest therein, if any.

SEC source: 0001209191-19-009780 · doc4.xml · derivative · entry 10

Polaris Venture Management Co. VI, L.L.C. · CIK 0001665594 · 10% owner

Polaris Venture Partners VI (AIV), L.P. · CIK 0001767127 · 10% owner

Polaris Venture Partners Founders' Fund VI, L.P. · CIK 0001575691 · 10% owner

Polaris Venture Partners VI, L.P. · CIK 0001493463 · 10% owner

PVP VI (AIV) Feeder Corp. Holding Partnership, L.P. · CIK 0001767130 · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: Not disclosed

Ownership: Indirect · See footnote

Disclosed balance after: 0

Underlying: Common Stock · 2,808,989 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 of the Series A-1 Preferred Stock, Series A-2 Preferred Stock, Series B Preferred Stock, Series C Preferred Stock, Series D Preferred Stock and Series E Preferred Stock converted into Common Stock on a one-for-one basis upon the closing of the Issuer's initial public offering without payment of further consideration. The shares have no expiration date.

F1 · derivative.exercise_date: Each of the Series A-1 Preferred Stock, Series A-2 Preferred Stock, Series B Preferred Stock, Series C Preferred Stock, Series D Preferred Stock and Series E Preferred Stock converted into Common Stock on a one-for-one basis upon the closing of the Issuer's initial public offering without payment of further consideration. The shares have no expiration date.

F1 · derivative.expiration_date: Each of the Series A-1 Preferred Stock, Series A-2 Preferred Stock, Series B Preferred Stock, Series C Preferred Stock, Series D Preferred Stock and Series E Preferred Stock converted into Common Stock on a one-for-one basis upon the closing of the Issuer's initial public offering without payment of further consideration. The shares have no expiration date.

F5 · ownership.nature: 155,087 shares are held by PVPFF VI, 2,130,190 shares are held by PVP VI AIV and 523,712 shares are held by PVP VI Feeder. PVM disclaims beneficial ownership of the securities held by the Polaris Funds, and this report shall not be deemed an admission that PVM is the beneficial owner of such securities, except to the extent of its pecuniary interest therein, if any.

SEC source: 0001209191-19-009780 · doc4.xml · derivative · entry 9

Polaris Venture Management Co. VI, L.L.C. · CIK 0001665594 · 10% owner

Polaris Venture Partners VI (AIV), L.P. · CIK 0001767127 · 10% owner

Polaris Venture Partners Founders' Fund VI, L.P. · CIK 0001575691 · 10% owner

Polaris Venture Partners VI, L.P. · CIK 0001493463 · 10% owner

PVP VI (AIV) Feeder Corp. Holding Partnership, L.P. · CIK 0001767130 · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: Not disclosed

Ownership: Indirect · See footnote

Disclosed balance after: 0

Underlying: Common Stock · 2,500,000 shares

Expires not disclosed

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

F1 · derivative.exercise_price: Each of the Series A-1 Preferred Stock, Series A-2 Preferred Stock, Series B Preferred Stock, Series C Preferred Stock, Series D Preferred Stock and Series E Preferred Stock converted into Common Stock on a one-for-one basis upon the closing of the Issuer's initial public offering without payment of further consideration. The shares have no expiration date.

F1 · derivative.exercise_date: Each of the Series A-1 Preferred Stock, Series A-2 Preferred Stock, Series B Preferred Stock, Series C Preferred Stock, Series D Preferred Stock and Series E Preferred Stock converted into Common Stock on a one-for-one basis upon the closing of the Issuer's initial public offering without payment of further consideration. The shares have no expiration date.

F1 · derivative.expiration_date: Each of the Series A-1 Preferred Stock, Series A-2 Preferred Stock, Series B Preferred Stock, Series C Preferred Stock, Series D Preferred Stock and Series E Preferred Stock converted into Common Stock on a one-for-one basis upon the closing of the Issuer's initial public offering without payment of further consideration. The shares have no expiration date.

F4 · ownership.nature: 138,030 shares are held by PVPFF VI, 1,895,867 shares are held by PVP VI AIV and 466,103 shares are held by PVP VI Feeder. PVM disclaims beneficial ownership of the securities held by the Polaris Funds, and this report shall not be deemed an admission that PVM is the beneficial owner of such securities, except to the extent of its pecuniary interest therein, if any.

SEC source: 0001209191-19-009780 · doc4.xml · derivative · entry 8

Polaris Venture Management Co. VI, L.L.C. · CIK 0001665594 · 10% owner

Polaris Venture Partners VI (AIV), L.P. · CIK 0001767127 · 10% owner

Polaris Venture Partners Founders' Fund VI, L.P. · CIK 0001575691 · 10% owner

Polaris Venture Partners VI, L.P. · CIK 0001493463 · 10% owner

PVP VI (AIV) Feeder Corp. Holding Partnership, L.P. · CIK 0001767130 · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: Not disclosed

Ownership: Indirect · See footnote

Disclosed balance after: 0

Underlying: Common Stock · 5,274,725 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 of the Series A-1 Preferred Stock, Series A-2 Preferred Stock, Series B Preferred Stock, Series C Preferred Stock, Series D Preferred Stock and Series E Preferred Stock converted into Common Stock on a one-for-one basis upon the closing of the Issuer's initial public offering without payment of further consideration. The shares have no expiration date.

F1 · derivative.exercise_date: Each of the Series A-1 Preferred Stock, Series A-2 Preferred Stock, Series B Preferred Stock, Series C Preferred Stock, Series D Preferred Stock and Series E Preferred Stock converted into Common Stock on a one-for-one basis upon the closing of the Issuer's initial public offering without payment of further consideration. The shares have no expiration date.

F1 · derivative.expiration_date: Each of the Series A-1 Preferred Stock, Series A-2 Preferred Stock, Series B Preferred Stock, Series C Preferred Stock, Series D Preferred Stock and Series E Preferred Stock converted into Common Stock on a one-for-one basis upon the closing of the Issuer's initial public offering without payment of further consideration. The shares have no expiration date.

F3 · ownership.nature: 291,223 shares are held by PVPFF VI, 4,000,075 shares are held by PVP VI AIV and 983,427 shares are held by PVP VI Feeder. PVM disclaims beneficial ownership of the securities held by the Polaris Funds, and this report shall not be deemed an admission that PVM is the beneficial owner of such securities, except to the extent of its pecuniary interest therein, if any.

SEC source: 0001209191-19-009780 · doc4.xml · derivative · entry 7

Polaris Venture Management Co. VI, L.L.C. · CIK 0001665594 · 10% owner

Polaris Venture Partners VI (AIV), L.P. · CIK 0001767127 · 10% owner

Polaris Venture Partners Founders' Fund VI, L.P. · CIK 0001575691 · 10% owner

Polaris Venture Partners VI, L.P. · CIK 0001493463 · 10% owner

PVP VI (AIV) Feeder Corp. Holding Partnership, L.P. · CIK 0001767130 · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: Not disclosed

Ownership: Indirect · See footnote

Disclosed balance after: 0

Underlying: Common Stock · 500,000 shares

Expires not disclosed

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

F1 · derivative.exercise_price: Each of the Series A-1 Preferred Stock, Series A-2 Preferred Stock, Series B Preferred Stock, Series C Preferred Stock, Series D Preferred Stock and Series E Preferred Stock converted into Common Stock on a one-for-one basis upon the closing of the Issuer's initial public offering without payment of further consideration. The shares have no expiration date.

F1 · derivative.exercise_date: Each of the Series A-1 Preferred Stock, Series A-2 Preferred Stock, Series B Preferred Stock, Series C Preferred Stock, Series D Preferred Stock and Series E Preferred Stock converted into Common Stock on a one-for-one basis upon the closing of the Issuer's initial public offering without payment of further consideration. The shares have no expiration date.

F1 · derivative.expiration_date: Each of the Series A-1 Preferred Stock, Series A-2 Preferred Stock, Series B Preferred Stock, Series C Preferred Stock, Series D Preferred Stock and Series E Preferred Stock converted into Common Stock on a one-for-one basis upon the closing of the Issuer's initial public offering without payment of further consideration. The shares have no expiration date.

F2 · ownership.nature: 27,606 shares are held by Polaris Venture Partners Founders' Fund VI, L.P ("PVPFF VI"), 379,174 shares are held by Polaris Venture Partners VI (AIV), L.P. ("PVP VI AIV") and 93,220 shares are held by PVP VI (AIV) Feeder Corp. Holding Partnership, L.P. ("PVP VI Feeder" and, together with PVP VI AIV, PVPFF VI, and Polaris Venture Partners VI, L.P. ("PVP VI"), the "Polaris Funds"). The general partner of each of the Polaris Funds is Polaris Venture Management Co. VI, L.L.C. ("PVM"). PVM disclaims beneficial ownership of the securities held by the Polaris Funds, and this report shall not be deemed an admission that PVM is the beneficial owner of such securities, except to the extent of its pecuniary interest therein, if any.

SEC source: 0001209191-19-009780 · doc4.xml · nonDerivative · entry 6

Polaris Venture Management Co. VI, L.L.C. · CIK 0001665594 · 10% owner

Polaris Venture Partners VI (AIV), L.P. · CIK 0001767127 · 10% owner

Polaris Venture Partners Founders' Fund VI, L.P. · CIK 0001575691 · 10% owner

Polaris Venture Partners VI, L.P. · CIK 0001493463 · 10% owner

PVP VI (AIV) Feeder Corp. Holding Partnership, L.P. · CIK 0001767130 · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: Not disclosed

Ownership: Indirect · See footnotes

Disclosed balance after: 12,858,194

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 of the Series A-1 Preferred Stock, Series A-2 Preferred Stock, Series B Preferred Stock, Series C Preferred Stock, Series D Preferred Stock and Series E Preferred Stock converted into Common Stock on a one-for-one basis upon the closing of the Issuer's initial public offering without payment of further consideration. The shares have no expiration date.

F2 · ownership.nature: 27,606 shares are held by Polaris Venture Partners Founders' Fund VI, L.P ("PVPFF VI"), 379,174 shares are held by Polaris Venture Partners VI (AIV), L.P. ("PVP VI AIV") and 93,220 shares are held by PVP VI (AIV) Feeder Corp. Holding Partnership, L.P. ("PVP VI Feeder" and, together with PVP VI AIV, PVPFF VI, and Polaris Venture Partners VI, L.P. ("PVP VI"), the "Polaris Funds"). The general partner of each of the Polaris Funds is Polaris Venture Management Co. VI, L.L.C. ("PVM"). PVM disclaims beneficial ownership of the securities held by the Polaris Funds, and this report shall not be deemed an admission that PVM is the beneficial owner of such securities, except to the extent of its pecuniary interest therein, if any.

F3 · ownership.nature: 291,223 shares are held by PVPFF VI, 4,000,075 shares are held by PVP VI AIV and 983,427 shares are held by PVP VI Feeder. PVM disclaims beneficial ownership of the securities held by the Polaris Funds, and this report shall not be deemed an admission that PVM is the beneficial owner of such securities, except to the extent of its pecuniary interest therein, if any.

F4 · ownership.nature: 138,030 shares are held by PVPFF VI, 1,895,867 shares are held by PVP VI AIV and 466,103 shares are held by PVP VI Feeder. PVM disclaims beneficial ownership of the securities held by the Polaris Funds, and this report shall not be deemed an admission that PVM is the beneficial owner of such securities, except to the extent of its pecuniary interest therein, if any.

F5 · ownership.nature: 155,087 shares are held by PVPFF VI, 2,130,190 shares are held by PVP VI AIV and 523,712 shares are held by PVP VI Feeder. PVM disclaims beneficial ownership of the securities held by the Polaris Funds, and this report shall not be deemed an admission that PVM is the beneficial owner of such securities, except to the extent of its pecuniary interest therein, if any.

F6 · ownership.nature: 68,842 shares are held by PVPFF VI, 945,571 shares are held by PVP VI AIV and 232,470 shares are held by PVP VI Feeder. PVM disclaims beneficial ownership of the securities held by the Polaris Funds, and this report shall not be deemed an admission that PVM is the beneficial owner of such securities, except to the extent of its pecuniary interest therein, if any.

F7 · ownership.nature: 29,129 shares are held by PVPFF VI and 498,468 shares are held by PVP VI. PVM disclaims beneficial ownership of the securities held by the Polaris Funds, and this report shall not be deemed an admission that PVM is the beneficial owner of such securities, except to the extent of its pecuniary interest therein, if any.

SEC source: 0001209191-19-009780 · doc4.xml · nonDerivative · entry 5

Polaris Venture Management Co. VI, L.L.C. · CIK 0001665594 · 10% owner

Polaris Venture Partners VI (AIV), L.P. · CIK 0001767127 · 10% owner

Polaris Venture Partners Founders' Fund VI, L.P. · CIK 0001575691 · 10% owner

Polaris Venture Partners VI, L.P. · CIK 0001493463 · 10% owner

PVP VI (AIV) Feeder Corp. Holding Partnership, L.P. · CIK 0001767130 · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: Not disclosed

Ownership: Indirect · See footnotes

Disclosed balance after: 12,330,597

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 of the Series A-1 Preferred Stock, Series A-2 Preferred Stock, Series B Preferred Stock, Series C Preferred Stock, Series D Preferred Stock and Series E Preferred Stock converted into Common Stock on a one-for-one basis upon the closing of the Issuer's initial public offering without payment of further consideration. The shares have no expiration date.

F2 · ownership.nature: 27,606 shares are held by Polaris Venture Partners Founders' Fund VI, L.P ("PVPFF VI"), 379,174 shares are held by Polaris Venture Partners VI (AIV), L.P. ("PVP VI AIV") and 93,220 shares are held by PVP VI (AIV) Feeder Corp. Holding Partnership, L.P. ("PVP VI Feeder" and, together with PVP VI AIV, PVPFF VI, and Polaris Venture Partners VI, L.P. ("PVP VI"), the "Polaris Funds"). The general partner of each of the Polaris Funds is Polaris Venture Management Co. VI, L.L.C. ("PVM"). PVM disclaims beneficial ownership of the securities held by the Polaris Funds, and this report shall not be deemed an admission that PVM is the beneficial owner of such securities, except to the extent of its pecuniary interest therein, if any.

F3 · ownership.nature: 291,223 shares are held by PVPFF VI, 4,000,075 shares are held by PVP VI AIV and 983,427 shares are held by PVP VI Feeder. PVM disclaims beneficial ownership of the securities held by the Polaris Funds, and this report shall not be deemed an admission that PVM is the beneficial owner of such securities, except to the extent of its pecuniary interest therein, if any.

F4 · ownership.nature: 138,030 shares are held by PVPFF VI, 1,895,867 shares are held by PVP VI AIV and 466,103 shares are held by PVP VI Feeder. PVM disclaims beneficial ownership of the securities held by the Polaris Funds, and this report shall not be deemed an admission that PVM is the beneficial owner of such securities, except to the extent of its pecuniary interest therein, if any.

F5 · ownership.nature: 155,087 shares are held by PVPFF VI, 2,130,190 shares are held by PVP VI AIV and 523,712 shares are held by PVP VI Feeder. PVM disclaims beneficial ownership of the securities held by the Polaris Funds, and this report shall not be deemed an admission that PVM is the beneficial owner of such securities, except to the extent of its pecuniary interest therein, if any.

F6 · ownership.nature: 68,842 shares are held by PVPFF VI, 945,571 shares are held by PVP VI AIV and 232,470 shares are held by PVP VI Feeder. PVM disclaims beneficial ownership of the securities held by the Polaris Funds, and this report shall not be deemed an admission that PVM is the beneficial owner of such securities, except to the extent of its pecuniary interest therein, if any.

SEC source: 0001209191-19-009780 · doc4.xml · nonDerivative · entry 4

Polaris Venture Management Co. VI, L.L.C. · CIK 0001665594 · 10% owner

Polaris Venture Partners VI (AIV), L.P. · CIK 0001767127 · 10% owner

Polaris Venture Partners Founders' Fund VI, L.P. · CIK 0001575691 · 10% owner

Polaris Venture Partners VI, L.P. · CIK 0001493463 · 10% owner

PVP VI (AIV) Feeder Corp. Holding Partnership, L.P. · CIK 0001767130 · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: Not disclosed

Ownership: Indirect · See footnotes

Disclosed balance after: 11,083,714

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 of the Series A-1 Preferred Stock, Series A-2 Preferred Stock, Series B Preferred Stock, Series C Preferred Stock, Series D Preferred Stock and Series E Preferred Stock converted into Common Stock on a one-for-one basis upon the closing of the Issuer's initial public offering without payment of further consideration. The shares have no expiration date.

F2 · ownership.nature: 27,606 shares are held by Polaris Venture Partners Founders' Fund VI, L.P ("PVPFF VI"), 379,174 shares are held by Polaris Venture Partners VI (AIV), L.P. ("PVP VI AIV") and 93,220 shares are held by PVP VI (AIV) Feeder Corp. Holding Partnership, L.P. ("PVP VI Feeder" and, together with PVP VI AIV, PVPFF VI, and Polaris Venture Partners VI, L.P. ("PVP VI"), the "Polaris Funds"). The general partner of each of the Polaris Funds is Polaris Venture Management Co. VI, L.L.C. ("PVM"). PVM disclaims beneficial ownership of the securities held by the Polaris Funds, and this report shall not be deemed an admission that PVM is the beneficial owner of such securities, except to the extent of its pecuniary interest therein, if any.

F3 · ownership.nature: 291,223 shares are held by PVPFF VI, 4,000,075 shares are held by PVP VI AIV and 983,427 shares are held by PVP VI Feeder. PVM disclaims beneficial ownership of the securities held by the Polaris Funds, and this report shall not be deemed an admission that PVM is the beneficial owner of such securities, except to the extent of its pecuniary interest therein, if any.

F4 · ownership.nature: 138,030 shares are held by PVPFF VI, 1,895,867 shares are held by PVP VI AIV and 466,103 shares are held by PVP VI Feeder. PVM disclaims beneficial ownership of the securities held by the Polaris Funds, and this report shall not be deemed an admission that PVM is the beneficial owner of such securities, except to the extent of its pecuniary interest therein, if any.

F5 · ownership.nature: 155,087 shares are held by PVPFF VI, 2,130,190 shares are held by PVP VI AIV and 523,712 shares are held by PVP VI Feeder. PVM disclaims beneficial ownership of the securities held by the Polaris Funds, and this report shall not be deemed an admission that PVM is the beneficial owner of such securities, except to the extent of its pecuniary interest therein, if any.

SEC source: 0001209191-19-009780 · doc4.xml · nonDerivative · entry 3

Polaris Venture Management Co. VI, L.L.C. · CIK 0001665594 · 10% owner

Polaris Venture Partners VI (AIV), L.P. · CIK 0001767127 · 10% owner

Polaris Venture Partners Founders' Fund VI, L.P. · CIK 0001575691 · 10% owner

Polaris Venture Partners VI, L.P. · CIK 0001493463 · 10% owner

PVP VI (AIV) Feeder Corp. Holding Partnership, L.P. · CIK 0001767130 · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: Not disclosed

Ownership: Indirect · See footnotes

Disclosed balance after: 8,274,725

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 of the Series A-1 Preferred Stock, Series A-2 Preferred Stock, Series B Preferred Stock, Series C Preferred Stock, Series D Preferred Stock and Series E Preferred Stock converted into Common Stock on a one-for-one basis upon the closing of the Issuer's initial public offering without payment of further consideration. The shares have no expiration date.

F2 · ownership.nature: 27,606 shares are held by Polaris Venture Partners Founders' Fund VI, L.P ("PVPFF VI"), 379,174 shares are held by Polaris Venture Partners VI (AIV), L.P. ("PVP VI AIV") and 93,220 shares are held by PVP VI (AIV) Feeder Corp. Holding Partnership, L.P. ("PVP VI Feeder" and, together with PVP VI AIV, PVPFF VI, and Polaris Venture Partners VI, L.P. ("PVP VI"), the "Polaris Funds"). The general partner of each of the Polaris Funds is Polaris Venture Management Co. VI, L.L.C. ("PVM"). PVM disclaims beneficial ownership of the securities held by the Polaris Funds, and this report shall not be deemed an admission that PVM is the beneficial owner of such securities, except to the extent of its pecuniary interest therein, if any.

F3 · ownership.nature: 291,223 shares are held by PVPFF VI, 4,000,075 shares are held by PVP VI AIV and 983,427 shares are held by PVP VI Feeder. PVM disclaims beneficial ownership of the securities held by the Polaris Funds, and this report shall not be deemed an admission that PVM is the beneficial owner of such securities, except to the extent of its pecuniary interest therein, if any.

F4 · ownership.nature: 138,030 shares are held by PVPFF VI, 1,895,867 shares are held by PVP VI AIV and 466,103 shares are held by PVP VI Feeder. PVM disclaims beneficial ownership of the securities held by the Polaris Funds, and this report shall not be deemed an admission that PVM is the beneficial owner of such securities, except to the extent of its pecuniary interest therein, if any.

SEC source: 0001209191-19-009780 · doc4.xml · nonDerivative · entry 2

Polaris Venture Management Co. VI, L.L.C. · CIK 0001665594 · 10% owner

Polaris Venture Partners VI (AIV), L.P. · CIK 0001767127 · 10% owner

Polaris Venture Partners Founders' Fund VI, L.P. · CIK 0001575691 · 10% owner

Polaris Venture Partners VI, L.P. · CIK 0001493463 · 10% owner

PVP VI (AIV) Feeder Corp. Holding Partnership, L.P. · CIK 0001767130 · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: Not disclosed

Ownership: Indirect · See footnotes

Disclosed balance after: 5,774,725

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 of the Series A-1 Preferred Stock, Series A-2 Preferred Stock, Series B Preferred Stock, Series C Preferred Stock, Series D Preferred Stock and Series E Preferred Stock converted into Common Stock on a one-for-one basis upon the closing of the Issuer's initial public offering without payment of further consideration. The shares have no expiration date.

F2 · ownership.nature: 27,606 shares are held by Polaris Venture Partners Founders' Fund VI, L.P ("PVPFF VI"), 379,174 shares are held by Polaris Venture Partners VI (AIV), L.P. ("PVP VI AIV") and 93,220 shares are held by PVP VI (AIV) Feeder Corp. Holding Partnership, L.P. ("PVP VI Feeder" and, together with PVP VI AIV, PVPFF VI, and Polaris Venture Partners VI, L.P. ("PVP VI"), the "Polaris Funds"). The general partner of each of the Polaris Funds is Polaris Venture Management Co. VI, L.L.C. ("PVM"). PVM disclaims beneficial ownership of the securities held by the Polaris Funds, and this report shall not be deemed an admission that PVM is the beneficial owner of such securities, except to the extent of its pecuniary interest therein, if any.

F3 · ownership.nature: 291,223 shares are held by PVPFF VI, 4,000,075 shares are held by PVP VI AIV and 983,427 shares are held by PVP VI Feeder. PVM disclaims beneficial ownership of the securities held by the Polaris Funds, and this report shall not be deemed an admission that PVM is the beneficial owner of such securities, except to the extent of its pecuniary interest therein, if any.

SEC source: 0001209191-19-009780 · doc4.xml · nonDerivative · entry 1

Polaris Venture Management Co. VI, L.L.C. · CIK 0001665594 · 10% owner

Polaris Venture Partners VI (AIV), L.P. · CIK 0001767127 · 10% owner

Polaris Venture Partners Founders' Fund VI, L.P. · CIK 0001575691 · 10% owner

Polaris Venture Partners VI, L.P. · CIK 0001493463 · 10% owner

PVP VI (AIV) Feeder Corp. Holding Partnership, L.P. · CIK 0001767130 · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: Not disclosed

Ownership: Indirect · See footnote

Disclosed balance after: 500,000

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

F1 · price: Each of the Series A-1 Preferred Stock, Series A-2 Preferred Stock, Series B Preferred Stock, Series C Preferred Stock, Series D Preferred Stock and Series E Preferred Stock converted into Common Stock on a one-for-one basis upon the closing of the Issuer's initial public offering without payment of further consideration. The shares have no expiration date.

F2 · ownership.nature: 27,606 shares are held by Polaris Venture Partners Founders' Fund VI, L.P ("PVPFF VI"), 379,174 shares are held by Polaris Venture Partners VI (AIV), L.P. ("PVP VI AIV") and 93,220 shares are held by PVP VI (AIV) Feeder Corp. Holding Partnership, L.P. ("PVP VI Feeder" and, together with PVP VI AIV, PVPFF VI, and Polaris Venture Partners VI, L.P. ("PVP VI"), the "Polaris Funds"). The general partner of each of the Polaris Funds is Polaris Venture Management Co. VI, L.L.C. ("PVM"). PVM disclaims beneficial ownership of the securities held by the Polaris Funds, and this report shall not be deemed an admission that PVM is the beneficial owner of such securities, except to the extent of its pecuniary interest therein, if any.