EDIT

SEC source: 0001179110-17-011453 · edgar.xml · nonDerivative · entry 2

Bosley Katrine · CIK 0001592469 · Director · President and CEO

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 1,424,429

F1 · kind: The sales reported on this Form 4 were effected pursuant to a Rule 10b5-1 plan adopted by the Reporting Person on March 17, 2017.

F2 · price: This transaction was executed in multiple trades at prices ranging from $20.00 to $20.12. The price reported above reflects the weighted average sale price. The Reporting Person hereby undertakes to provide upon request to the SEC staff, the issuer or a security holder of the issuer full information regarding the number of shares and prices at which the transaction was effected.

SEC source: 0001179110-17-011453 · edgar.xml · nonDerivative · entry 1

Bosley Katrine · CIK 0001592469 · Director · President and CEO

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 1,431,095

F1 · kind: The sales reported on this Form 4 were effected pursuant to a Rule 10b5-1 plan adopted by the Reporting Person on March 17, 2017.

SEC source: 0001179110-17-009264 · edgar.xml · derivative · entry 1

Cole Douglas G. · CIK 0001486373 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 11,538

Underlying: Common Stock · 11,538 shares

Expires 2027-06-14

F1 · derivative.exercise_date: This option was granted on June 15, 2017 and is scheduled to vest in full on June 15, 2018.

SEC source: 0001179110-17-009254 · edgar.xml · derivative · entry 1

Vaishnaw Akshay · CIK 0001458494 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 11,538

Underlying: Common Stock · 11,538 shares

Expires 2027-06-14

F1 · derivative.exercise_date: This option was granted on June 15, 2017 and is scheduled to vest in full on June 15, 2018.

SEC source: 0001179110-17-009260 · edgar.xml · derivative · entry 1

MENDLEIN JOHN · CIK 0001238362 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 11,538

Underlying: Common Stock · 11,538 shares

Expires 2027-06-14

F1 · derivative.exercise_date: This option was granted on June 15, 2017 and is scheduled to vest in full on June 15, 2018.

SEC source: 0001179110-17-009253 · edgar.xml · derivative · entry 1

Borisy Alexis · CIK 0001319446 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 11,538

Underlying: Common Stock · 11,538 shares

Expires 2027-06-14

F1 · derivative.exercise_date: This option granted on June 15, 2017 and is scheduled to vest in full on June 15, 2018.

SEC source: 0001179110-17-009267 · edgar.xml · derivative · entry 1

Bitterman Kevin · CIK 0001591747 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 11,538

Underlying: Common Stock · 11,538 shares

Expires 2027-06-14

F1 · derivative.exercise_date: This option was granted on June 15, 2017 and is scheduled to vest in full on June 15, 2018.

SEC source: 0001179110-17-009257 · edgar.xml · derivative · entry 1

Nikolic Boris · CIK 0001657378 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 11,538

Underlying: Common Stock · 11,538 shares

Expires 2027-06-14

F1 · derivative.exercise_date: This option was granted on June 15, 2017 and is scheduled to vest in full on June 15, 2018.

SEC source: 0001179110-17-008654 · edgar.xml · nonDerivative · entry 1

Cox Gerald Frank · CIK 0001686130 · Chief Medical Officer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 4,000

SEC source: 0001179110-17-008651 · edgar.xml · nonDerivative · entry 1

Nikolic Boris · CIK 0001657378 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 35,000

F1 · price: The price reported in Column 4 is a weighted average price. These shares were purchased in multiple transactions at prices ranging from $13.9 per share to $14.15 per share, inclusive. The Reporting Person undertakes to provide the Issuer, any security holder of the Issuer or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares purchased at each separate price within the ranges set forth in this footnote.

SEC source: 0001179110-17-008256 · edgar.xml · derivative · entry 1

Hirsch Andrew · CIK 0001586707 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 23,076

Underlying: Common Stock · 23,076 shares

Expires 2027-05-29

F1 · derivative.exercise_date: This option was granted on May 30, 2017 and is scheduled to vest over three years in equal yearly installments of one-third of the shares beginning on May 30, 2018 through May 30, 2020.

SEC source: 0000899243-17-014250 · doc4.xml · nonDerivative · entry 1

Bitterman Kevin · CIK 0001591747 · Director

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnote

Disclosed balance after: 2,797,144

F1 · shares: Represents 944,789 shares disposed of by Polaris Venture Partners VI, L.P. ("PVP VI") and 55,211 shares disposed of by Polaris Venture Partners Founders' Fund VI, L.P. ("PVPFF VI", together with PVPVI, the "Polaris Funds").

F2 · ownership.nature: 2,642,714 of these shares are owned directly by PVP VI and 154,430 of the shares are owned by PVPFF VI. Polaris Venture Management Co. VI, L.L.C. ("Polaris Management") is the general partner of each of the Polaris Funds. Kevin Bitterman, a member of the Board of Directors of the Issuer, has an assignee interest in Polaris Management. Each of Polaris Management and Mr. Bitterman disclaim beneficial ownership of all the shares owned by the Polaris Funds and this report shall not be deemed an admission that either is the beneficial owner of such shares for purposes of Section 16 or for any other purpose, except to the extent of their pecuniary interests therein.

SEC source: 0001179110-17-004785 · edgar.xml · derivative · entry 3

Glucksmann Alexandra · CIK 0001658390 · Chief Operating Officer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 30,461

Underlying: Common Stock · 1,000 shares

Expires 2025-04-14

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

F1 · kind: The exercise and sale reported on this Form 4 were effected pursuant to a Rule 10b5-1 plan adopted by the Reporting Person on June 13, 2016.

F2 · derivative.exercise_date: This option was granted on April 16, 2015 and is scheduled to vest over four years with 25% of the shares having vested on March 9, 2016, and the remaining 75% of the shares scheduled to vest in equal monthly installments thereafter through March 9, 2019.

SEC source: 0001179110-17-004785 · edgar.xml · nonDerivative · entry 2

Glucksmann Alexandra · CIK 0001658390 · Chief Operating Officer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 117,788

F1 · kind: The exercise and sale reported on this Form 4 were effected pursuant to a Rule 10b5-1 plan adopted by the Reporting Person on June 13, 2016.

SEC source: 0001179110-17-004785 · edgar.xml · nonDerivative · entry 1

Glucksmann Alexandra · CIK 0001658390 · Chief Operating Officer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 118,788

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 exercise and sale reported on this Form 4 were effected pursuant to a Rule 10b5-1 plan adopted by the Reporting Person on June 13, 2016.

SEC source: 0001179110-17-003790 · edgar.xml · derivative · entry 1

Bosley Katrine · CIK 0001592469 · Director · President and CEO

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 312,000

Underlying: Common Stock · 312,000 shares

Expires 2027-02-28

F1 · derivative.exercise_date: This option was granted on March 1, 2017 and is scheduled to vest over four years in equal monthly installments beginning on March 1, 2017 through March 1, 2021.

SEC source: 0001179110-17-003789 · edgar.xml · derivative · entry 1

Hack Andrew A. F. · CIK 0001657434 · Chief Financial Officer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 92,500

Underlying: Common Stock · 92,500 shares

Expires 2027-02-28

F1 · derivative.exercise_date: This option was granted on March 1, 2017 and is scheduled to vest over four years in equal monthly installments beginning on March 1, 2017 through March 1, 2021.

SEC source: 0001179110-17-003788 · edgar.xml · derivative · entry 1

Albright Charles · CIK 0001682323 · Chief Scientific Officer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 45,000

Underlying: Common Stock · 45,000 shares

Expires 2027-02-28

F1 · derivative.exercise_date: This option was granted on March 1, 2017 and is scheduled to vest over four years in equal monthly installments beginning on March 1, 2017 through March 1, 2021.

SEC source: 0001179110-17-002572 · edgar.xml · derivative · entry 4

Glucksmann Alexandra · CIK 0001658390 · Chief Operating Officer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 31,461

Underlying: Common Stock · 6,000 shares

Expires 2025-04-15

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 exercise and sale reported on this Form 4 were effected pursuant to a Rule 10b5-1 plan adopted by the Reporting Person on June 13, 2016.

F2 · derivative.exercise_date: This option was granted on April 16, 2015 and is scheduled to vest over four years with 25% of the shares having vested on March 9, 2016, and the remaining 75% of the shares scheduled to vest in equal monthly installments thereafter through March 9, 2019.

SEC source: 0001179110-17-002572 · edgar.xml · nonDerivative · entry 3

Glucksmann Alexandra · CIK 0001658390 · Chief Operating Officer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 117,788

F1 · kind: The exercise and sale reported on this Form 4 were effected pursuant to a Rule 10b5-1 plan adopted by the Reporting Person on June 13, 2016.

SEC source: 0001179110-17-002572 · edgar.xml · nonDerivative · entry 2

Glucksmann Alexandra · CIK 0001658390 · Chief Operating Officer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 118,788

F1 · kind: The exercise and sale reported on this Form 4 were effected pursuant to a Rule 10b5-1 plan adopted by the Reporting Person on June 13, 2016.

SEC source: 0001179110-17-002572 · edgar.xml · nonDerivative · entry 1

Glucksmann Alexandra · CIK 0001658390 · Chief Operating Officer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 123,788

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 exercise and sale reported on this Form 4 were effected pursuant to a Rule 10b5-1 plan adopted by the Reporting Person on June 13, 2016.

SEC source: 0001179110-17-002574 · edgar.xml · derivative · entry 3

Hack Andrew A. F. · CIK 0001657434 · Chief Financial Officer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 155,076

Underlying: Common Stock · 3,000 shares

Expires 2025-07-13

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 exercise and sale reported on this Form 4 were effected pursuant to a Rule 10b5-1 plan adopted by the Reporting Person on June 15, 2016.

F2 · derivative.exercise_date: This option was granted on July 14, 2015 and is scheduled to vest over four years with 25% of the shares having vested on July 1, 2016, and the remaining 75% of the shares scheduled to vest in equal monthly installments thereafter through July 1, 2019.

SEC source: 0001179110-17-002574 · edgar.xml · nonDerivative · entry 2

Hack Andrew A. F. · CIK 0001657434 · Chief Financial Officer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 0

SEC source: 0001179110-17-002574 · edgar.xml · nonDerivative · entry 1

Hack Andrew A. F. · CIK 0001657434 · Chief Financial Officer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 3,000

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 · kind: The exercise and sale reported on this Form 4 were effected pursuant to a Rule 10b5-1 plan adopted by the Reporting Person on June 15, 2016.

SEC source: 0001179110-17-000931 · edgar.xml · derivative · entry 3

Hack Andrew A. F. · CIK 0001657434 · Chief Financial Officer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 158,076

Underlying: Common Stock · 15,000 shares

Expires 2025-07-13

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 exercise and sale reported on this Form 4 were effected pursuant to a Rule 10b5-1 plan adopted by the Reporting Person on June 15, 2016.

F2 · derivative.exercise_date: This option was granted on July 14, 2015 and is scheduled to vest over four years with 25% of the shares having vested on July 1, 2016, and the remaining 75% of the shares scheduled to vest in equal monthly installments thereafter through July 1, 2019.

SEC source: 0001179110-17-000931 · edgar.xml · nonDerivative · entry 2

Hack Andrew A. F. · CIK 0001657434 · Chief Financial Officer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 0

F1 · kind: The exercise and sale reported on this Form 4 were effected pursuant to a Rule 10b5-1 plan adopted by the Reporting Person on June 15, 2016.

SEC source: 0001179110-17-000931 · edgar.xml · nonDerivative · entry 1

Hack Andrew A. F. · CIK 0001657434 · Chief Financial Officer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 15,000

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 · kind: The exercise and sale reported on this Form 4 were effected pursuant to a Rule 10b5-1 plan adopted by the Reporting Person on June 15, 2016.

SEC source: 0000899243-16-035126 · doc4.xml · nonDerivative · entry 1

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

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

Polaris Venture Partners Founders' Fund VI, L.P. · CIK 0001575691 · 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: 3,797,144

F1 · shares: Represents 70,859 shares disposed of by Polaris Venture Partners VI, L.P. ("PVP VI") and 4,141 shares disposed of by Polaris Venture Partners Founders' Fund VI, L.P ("PVPFF VI").

F2 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $15.70 to $15.93, 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 range set forth in this footnote (2) to this Form 4.

F3 · ownership.nature: 3,587,503 of these shares are owned directly by PVP VI and 209,641 of the shares are owned by PVPFF VI (together with PVP VI, the "Polaris Funds"). Polaris Venture Management Co. VI, L.L.C. ("Polaris Management") is the general partner of each of the Polaris Funds. Kevin Bitterman, a member of the Board of Directors of the Issuer, has an assignee interest in Polaris Management. Each of Polaris Management and Mr. Bitterman disclaim beneficial ownership of all the shares owned by the Polaris Funds and this report shall not be deemed an admission that either is the beneficial owner of such shares for purposes of Section 16 or for any other purpose, except to the extent of their pecuniary interests therein.

SEC source: 0000899243-16-035127 · doc4.xml · nonDerivative · entry 1

Bitterman Kevin · CIK 0001591747 · Director · 10% owner

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnote

Disclosed balance after: 3,797,144

F1 · shares: Represents 70,859 shares disposed of by Polaris Venture Partners VI, L.P. ("PVP VI") and 4,141 shares disposed of by Polaris Venture Partners Founders' Fund VI, L.P ("PVPFF VI").

F2 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $15.70 to $15.93, 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 range set forth in this footnote (2) to this Form 4.

F3 · ownership.nature: 3,587,503 of these shares are owned directly by PVP VI and 209,641 of the shares are owned by PVPFF VI (together with PVP VI, the "Polaris Funds"). Polaris Venture Management Co. VI, L.L.C. ("Polaris Management") is the general partner of each of the Polaris Funds. Kevin Bitterman, a member of the Board of Directors of the Issuer, has an assignee interest in Polaris Management. Each of Polaris Management and Mr. Bitterman disclaim beneficial ownership of all the shares owned by the Polaris Funds and this report shall not be deemed an admission that either is the beneficial owner of such shares for purposes of Section 16 or for any other purpose, except to the extent of their pecuniary interests therein.

SEC source: 0000899243-16-035046 · doc4.xml · nonDerivative · entry 2

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

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

Polaris Venture Partners Founders' Fund VI, L.P. · CIK 0001575691 · 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: 3,872,144

F4 · shares: Represents 47,240 shares disposed of by PVP VI and 2,760 shares disposed of by PVPFF VI.

F5 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $15.80 to $15.94, inclusive.

F6 · ownership.nature: 3,658,362 of these shares are owned directly by PVP VI and 213,782 of the shares are owned by PVPFF VI . Each of Polaris Management and Mr. Bitterman disclaim beneficial ownership of all the shares owned by the Polaris Funds and this report shall not be deemed an admission that either is the beneficial owner of such shares for purposes of Section 16 or for any other purpose, except to the extent of their pecuniary interests therein.

SEC source: 0000899243-16-035044 · doc4.xml · nonDerivative · entry 2

Bitterman Kevin · CIK 0001591747 · Director · 10% owner

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnote

Disclosed balance after: 3,872,144

F4 · shares: Represents 47,240 shares disposed of by PVP VI and 2,760 shares disposed of by PVPFF VI.

F5 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $15.80 to $15.94, inclusive.

F6 · ownership.nature: 3,658,362 of these shares are owned directly by PVP VI and 213,782 of the shares are owned by PVPFF VI . Each of Polaris Management and Mr. Bitterman disclaim beneficial ownership of all the shares owned by the Polaris Funds and this report shall not be deemed an admission that either is the beneficial owner of such shares for purposes of Section 16 or for any other purpose, except to the extent of their pecuniary interests therein.

SEC source: 0000899243-16-035046 · doc4.xml · nonDerivative · entry 1

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

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

Polaris Venture Partners Founders' Fund VI, L.P. · CIK 0001575691 · 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: 3,922,144

F1 · shares: Represents 75,583 shares disposed of by Polaris Venture Partners VI, L.P. ("PVP VI") and 4,417 shares disposed of by Polaris Venture Partners Founders' Fund VI, L.P ("PVPFF VI").

F2 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $15.70 to $15.96, 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 footnotes (2) and (5) to this Form 4.

F3 · ownership.nature: 3,705,602 of these shares are owned directly by PVP VI and 216,542 of the shares are owned by PVPFF VI (together with PVP VI, the "Polaris Funds"). Polaris Venture Management Co. VI, L.L.C. ("Polaris Management") is the general partner of each of the Polaris Funds. Kevin Bitterman, a member of the Board of Directors of the Issuer, has an assignee interest in Polaris Management. Each of Polaris Management and Mr. Bitterman disclaim beneficial ownership of all the shares owned by the Polaris Funds and this report shall not be deemed an admission that either is the beneficial owner of such shares for purposes of Section 16 or for any other purpose, except to the extent of their pecuniary interests therein.

SEC source: 0000899243-16-035044 · doc4.xml · nonDerivative · entry 1

Bitterman Kevin · CIK 0001591747 · Director · 10% owner

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnote

Disclosed balance after: 3,922,144

F1 · shares: Represents 75,583 shares disposed of by Polaris Venture Partners VI, L.P. ("PVP VI") and 4,417 shares disposed of by Polaris Venture Partners Founders' Fund VI, L.P ("PVPFF VI").

F2 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $15.70 to $15.96, 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 footnotes (2) and (5) to this Form 4.

F3 · ownership.nature: 3,705,602 of these shares are owned directly by PVP VI and 216,542 of the shares are owned by PVPFF VI (together with PVP VI, the "Polaris Funds"). Polaris Venture Management Co. VI, L.L.C. ("Polaris Management") is the general partner of each of the Polaris Funds. Kevin Bitterman, a member of the Board of Directors of the Issuer, has an assignee interest in Polaris Management. Each of Polaris Management and Mr. Bitterman disclaim beneficial ownership of all the shares owned by the Polaris Funds and this report shall not be deemed an admission that either is the beneficial owner of such shares for purposes of Section 16 or for any other purpose, except to the extent of their pecuniary interests therein.

SEC source: 0000899243-16-034435 · doc4.xml · nonDerivative · entry 1

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

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

Polaris Venture Partners Founders' Fund VI, L.P. · CIK 0001575691 · 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: 4,002,144

F1 · shares: Represents 20,294 shares disposed of by Polaris Venture Partners VI, L.P. ("PVP VI") and 1,186 shares disposed of by Polaris Venture Partners Founders' Fund VI, L.P ("PVPFF VI").

F2 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $15.70 to $15.84, 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 range set forth in this footnote (2) to this Form 4.

F3 · ownership.nature: 3,781,185 of these shares are owned directly by PVP VI and 220,959 of the shares are owned by PVPFF VI (together with PVP VI, the "Polaris Funds"). Polaris Venture Management Co. VI, L.L.C. ("Polaris Management") is the general partner of each of the Polaris Funds. Kevin Bitterman, a member of the Board of Directors of the Issuer, has an assignee interest in Polaris Management. Each of Polaris Management and Mr. Bitterman disclaim beneficial ownership of all the shares owned by the Polaris Funds and this report shall not be deemed an admission that either is the beneficial owner of such shares for purposes of Section 16 or for any other purpose, except to the extent of their pecuniary interests therein.

SEC source: 0000899243-16-034434 · doc4.xml · nonDerivative · entry 1

Bitterman Kevin · CIK 0001591747 · Director · 10% owner

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnote

Disclosed balance after: 4,002,144

F1 · shares: Represents 20,294 shares disposed of by Polaris Venture Partners VI, L.P. ("PVP VI") and 1,186 shares disposed of by Polaris Venture Partners Founders' Fund VI, L.P ("PVPFF VI").

F2 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $15.70 to $15.84, 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 range set forth in this footnote (2) to this Form 4.

F3 · ownership.nature: 3,781,185 of these shares are owned directly by PVP VI and 220,959 of the shares are owned by PVPFF VI (together with PVP VI, the "Polaris Funds"). Polaris Venture Management Co. VI, L.L.C. ("Polaris Management") is the general partner of each of the Polaris Funds. Kevin Bitterman, a member of the Board of Directors of the Issuer, has an assignee interest in Polaris Management. Each of Polaris Management and Mr. Bitterman disclaim beneficial ownership of all the shares owned by the Polaris Funds and this report shall not be deemed an admission that either is the beneficial owner of such shares for purposes of Section 16 or for any other purpose, except to the extent of their pecuniary interests therein.

SEC source: 0000899243-16-034344 · doc4.xml · nonDerivative · entry 1

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

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

Polaris Venture Partners Founders' Fund VI, L.P. · CIK 0001575691 · 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: 4,023,624

F1 · shares: Represents 12,111 shares disposed of by Polaris Venture Partners VI, L.P. ("PVP VI") and 708 shares disposed of by Polaris Venture Partners Founders' Fund VI, L.P ("PVPFF VI").

F2 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $15.75 to $15.86, 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 range set forth in this footnote (2) to this Form 4.

F3 · ownership.nature: 3,801,479 of these shares are owned directly by PVP VI and 222,145 of the shares are owned by PVPFF VI (together with PVP VI, the "Polaris Funds"). Polaris Venture Management Co. VI, L.L.C. ("Polaris Management") is the general partner of each of the Polaris Funds. Kevin Bitterman, a member of the Board of Directors of the Issuer, has an assignee interest in Polaris Management. Each of Polaris Management and Mr. Bitterman disclaim beneficial ownership of all the shares owned by the Polaris Funds and this report shall not be deemed an admission that either is the beneficial owner of such shares for purposes of Section 16 or for any other purpose, except to the extent of their pecuniary interests therein.

SEC source: 0000899243-16-034342 · doc4.xml · nonDerivative · entry 1

Bitterman Kevin · CIK 0001591747 · Director · 10% owner

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnote

Disclosed balance after: 4,023,624

F1 · shares: Represents 12,111 shares disposed of by Polaris Venture Partners VI, L.P. ("PVP VI") and 708 shares disposed of by Polaris Venture Partners Founders' Fund VI, L.P ("PVPFF VI").

F2 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $15.75 to $15.86, 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 range set forth in this footnote (2) to this Form 4.

F3 · ownership.nature: 3,801,479 of these shares are owned directly by PVP VI and 222,145 of the shares are owned by PVPFF VI (together with PVP VI, the "Polaris Funds"). Polaris Venture Management Co. VI, L.L.C. ("Polaris Management") is the general partner of each of the Polaris Funds. Kevin Bitterman, a member of the Board of Directors of the Issuer, has an assignee interest in Polaris Management. Each of Polaris Management and Mr. Bitterman disclaim beneficial ownership of all the shares owned by the Polaris Funds and this report shall not be deemed an admission that either is the beneficial owner of such shares for purposes of Section 16 or for any other purpose, except to the extent of their pecuniary interests therein.

SEC source: 0000899243-16-033918 · doc4.xml · nonDerivative · entry 1

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

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

Polaris Venture Partners Founders' Fund VI, L.P. · CIK 0001575691 · 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: 4,036,443

F1 · shares: Represents 29,128 shares disposed of by Polaris Venture Partners VI, L.P. ("PVP VI") and 1,702 shares disposed of by Polaris Venture Partners Founders' Fund VI, L.P ("PVPFF VI").

F2 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $16.25 to $16.5167, 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 range set forth in this footnote (2) to this Form 4.

F3 · ownership.nature: 3,813,590 of these shares are owned directly by PVP VI and 222,853 of the shares are owned by PVPFF VI (together with PVP VI, the "Polaris Funds"). Polaris Venture Management Co. VI, L.L.C. ("Polaris Management") is the general partner of each of the Polaris Funds. Kevin Bitterman, a member of the Board of Directors of the Issuer, has an assignee interest in Polaris Management. Each of Polaris Management and Mr. Bitterman disclaim beneficial ownership of all the shares owned by the Polaris Funds and this report shall not be deemed an admission that either is the beneficial owner of such shares for purposes of Section 16 or for any other purpose, except to the extent of their pecuniary interests therein.

SEC source: 0000899243-16-033916 · doc4.xml · nonDerivative · entry 1

Bitterman Kevin · CIK 0001591747 · Director · 10% owner

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnote

Disclosed balance after: 4,036,443

F1 · shares: Represents 29,128 shares disposed of by Polaris Venture Partners VI, L.P. ("PVP VI") and 1,702 shares disposed of by Polaris Venture Partners Founders' Fund VI, L.P ("PVPFF VI").

F2 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $16.25 to $16.5167, 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 range set forth in this footnote (2) to this Form 4.

F3 · ownership.nature: 3,813,590 of these shares are owned directly by PVP VI and 222,853 of the shares are owned by PVPFF VI (together with PVP VI, the "Polaris Funds"). Polaris Venture Management Co. VI, L.L.C. ("Polaris Management") is the general partner of each of the Polaris Funds. Kevin Bitterman, a member of the Board of Directors of the Issuer, has an assignee interest in Polaris Management. Each of Polaris Management and Mr. Bitterman disclaim beneficial ownership of all the shares owned by the Polaris Funds and this report shall not be deemed an admission that either is the beneficial owner of such shares for purposes of Section 16 or for any other purpose, except to the extent of their pecuniary interests therein.

SEC source: 0000899243-16-033690 · doc4.xml · nonDerivative · entry 3

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

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

Polaris Venture Partners Founders' Fund VI, L.P. · CIK 0001575691 · 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: 4,067,273

F7 · shares: Represents 472 shares disposed of by PVP VI and 26 shares disposed of by PVPFF VI.

F8 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $17.50 to $17.86, inclusive.

F9 · ownership.nature: 3,842,718 of these shares are owned directly by PVP VI and 224,555 of the shares are owned by PVPFF VI. Each of Polaris Management and Mr. Bitterman disclaim beneficial ownership of all the shares owned by the Polaris Funds and this report shall not be deemed an admission that either is the beneficial owner of such shares for purposes of Section 16 or for any other purpose, except to the extent of their pecuniary interests therein.

SEC source: 0000899243-16-033690 · doc4.xml · nonDerivative · entry 2

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

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

Polaris Venture Partners Founders' Fund VI, L.P. · CIK 0001575691 · 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: 4,067,771

F4 · shares: Represents 28,689 shares disposed of by PVP VI and 1,678 shares disposed of by PVPFF VI.

F5 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $16.50 to $17.09, inclusive.

F6 · ownership.nature: 3,843,190 of these shares are owned directly by PVP VI and 224,581 of the shares are owned by PVPFF VI. Each of Polaris Management and Mr. Bitterman disclaim beneficial ownership of all the shares owned by the Polaris Funds and this report shall not be deemed an admission that either is the beneficial owner of such shares for purposes of Section 16 or for any other purpose, except to the extent of their pecuniary interests therein.

SEC source: 0000899243-16-033689 · doc4.xml · nonDerivative · entry 3

Bitterman Kevin · CIK 0001591747 · Director · 10% owner

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnote

Disclosed balance after: 4,067,273

F7 · shares: Represents 472 shares disposed of by PVP VI and 26 shares disposed of by PVPFF VI.

F8 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $17.50 to $17.86, inclusive.

F9 · ownership.nature: 3,842,718 of these shares are owned directly by PVP VI and 224,555 of the shares are owned by PVPFF VI. Each of Polaris Management and Mr. Bitterman disclaim beneficial ownership of all the shares owned by the Polaris Funds and this report shall not be deemed an admission that either is the beneficial owner of such shares for purposes of Section 16 or for any other purpose, except to the extent of their pecuniary interests therein.

SEC source: 0000899243-16-033689 · doc4.xml · nonDerivative · entry 2

Bitterman Kevin · CIK 0001591747 · Director · 10% owner

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnote

Disclosed balance after: 4,067,771

F4 · shares: Represents 28,689 shares disposed of by PVP VI and 1,678 shares disposed of by PVPFF VI.

F5 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $16.50 to $17.09, inclusive.

F6 · ownership.nature: 3,843,190 of these shares are owned directly by PVP VI and 224,581 of the shares are owned by PVPFF VI. Each of Polaris Management and Mr. Bitterman disclaim beneficial ownership of all the shares owned by the Polaris Funds and this report shall not be deemed an admission that either is the beneficial owner of such shares for purposes of Section 16 or for any other purpose, except to the extent of their pecuniary interests therein.

SEC source: 0000899243-16-033690 · doc4.xml · nonDerivative · entry 1

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

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

Polaris Venture Partners Founders' Fund VI, L.P. · CIK 0001575691 · 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: 4,098,138

F1 · shares: Represents 54,831 shares disposed of by Polaris Venture Partners VI, L.P. ("PVP VI") and 3,204 shares disposed of by Polaris Venture Partners Founders' Fund VI, L.P ("PVPFF VI").

F2 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $17.00 to $17.51, 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 footnotes (2),(5), and (8) to this Form 4.

F3 · ownership.nature: 3,871,879 of these shares are owned directly by PVP VI and 226,259 of the shares are owned by PVPFF VI (together with PVP VI, the "Polaris Funds"). Polaris Venture Management Co. VI, L.L.C. ("Polaris Management") is the general partner of each of the Polaris Funds. Kevin Bitterman, a member of the Board of Directors of the Issuer, has an assignee interest in Polaris Management. Each of Polaris Management and Mr. Bitterman disclaim beneficial ownership of all the shares owned by the Polaris Funds and this report shall not be deemed an admission that either is the beneficial owner of such shares for purposes of Section 16 or for any other purpose, except to the extent of their pecuniary interests therein.

SEC source: 0000899243-16-033689 · doc4.xml · nonDerivative · entry 1

Bitterman Kevin · CIK 0001591747 · Director · 10% owner

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnote

Disclosed balance after: 4,098,138

F1 · shares: Represents 54,831 shares disposed of by Polaris Venture Partners VI, L.P. ("PVP VI") and 3,204 shares disposed of by Polaris Venture Partners Founders' Fund VI, L.P ("PVPFF VI").

F2 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $17.00 to $17.51, 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 footnotes (2),(5) and (8) to this Form 4.

F3 · ownership.nature: 3,871,879 of these shares are owned directly by PVP VI and 226,259 of the shares are owned by PVPFF VI (together with PVP VI, the "Polaris Funds"). Polaris Venture Management Co. VI, L.L.C. ("Polaris Management") is the general partner of each of the Polaris Funds. Kevin Bitterman, a member of the Board of Directors of the Issuer, has an assignee interest in Polaris Management. Each of Polaris Management and Mr. Bitterman disclaim beneficial ownership of all the shares owned by the Polaris Funds and this report shall not be deemed an admission that either is the beneficial owner of such shares for purposes of Section 16 or for any other purpose, except to the extent of their pecuniary interests therein.

SEC source: 0001179110-16-030578 · edgar.xml · derivative · entry 1

Cox Gerald Frank · CIK 0001686130 · Chief Medical Officer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 225,000

Underlying: Common Stock · 225,000 shares

Expires 2026-10-04

F1 · derivative.exercise_date: This option was granted on October 5, 2016 and is scheduled to vest over four years with 25% of the shares scheduled to vest on October 3, 2017, and the remaining 75% of the shares scheduled to vest in equal monthly installments thereafter through October 3, 2020.

SEC source: 0001179110-16-029608 · edgar.xml · derivative · entry 1

Albright Charles · CIK 0001682323 · Chief Scientific Officer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 225,000

Underlying: Common Stock · 225,000 shares

Expires 2026-09-08

F1 · derivative.exercise_date: This option was granted on September 9, 2016 and is scheduled to vest over four years with 25% of the shares scheduled to vest on August 22, 2017, and the remaining 75% of the shares scheduled to vest in equal monthly installments thereafter through August 22, 2020.

SEC source: 0000899243-16-028807 · doc4.xml · nonDerivative · entry 1

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

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

Polaris Venture Partners Founders' Fund VI, L.P. · CIK 0001575691 · 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: 4,156,173

F1 · ownership.nature: 3,926,710 of these shares are owned directly by Polaris Venture Partners VI, L.P. and 229,463 of the shares are owned by Polaris Venture Partners Founders' Fund VI, L.P. (together with Polaris Venture Partners VI, L.P., the "Polaris Funds"). Polaris Venture Management Co. VI, L.L.C. ("Polaris Management") is the general partner of each of the Polaris Funds. Kevin Bitterman, a member of the Board of Directors of the Issuer, has an assignee interest in Polaris Management. Each of Polaris Management and Mr. Bitterman disclaim beneficial ownership of all the shares owned by the Polaris Funds and this report shall not be deemed an admission that either is the beneficial owner of such shares for purposes of Section 16 or for any other purpose, except to the extent of their pecuniary interests therein.

SEC source: 0000899243-16-028808 · doc4.xml · nonDerivative · entry 1

Bitterman Kevin · CIK 0001591747 · Director · 10% owner

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnote

Disclosed balance after: 4,156,173

F1 · ownership.nature: 3,926,710 of these shares are owned directly by Polaris Venture Partners VI, L.P. and 229,463 of the shares are owned by Polaris Venture Partners Founders' Fund VI, L.P. (together with Polaris Venture Partners VI, L.P., the "Polaris Funds"). Polaris Venture Management Co. VI, L.L.C. ("Polaris Management") is the general partner of each of the Polaris Funds. Kevin Bitterman, a member of the Board of Directors of the Issuer, has an assignee interest in Polaris Management. Each of Polaris Management and Mr. Bitterman disclaim beneficial ownership of all the shares owned by the Polaris Funds and this report shall not be deemed an admission that either is the beneficial owner of such shares for purposes of Section 16 or for any other purpose, except to the extent of their pecuniary interests therein.