5AM Co-Investors IV, L.P.

SEC source: 0001104659-19-010154 · a4.xml · nonDerivative · entry 2

5AM Ventures IV, L.P. · CIK 0001589315 · 10% owner

5AM Co-Investors IV, L.P. · CIK 0001593361 · 10% owner

5AM Partners IV, LLC · CIK 0001589314 · 10% owner

ROCKLAGE SCOTT M · CIK 0001219014 · 10% owner

DIEKMAN JOHN D · CIK 0001240357 · 10% owner

Schwab Andrew J. · CIK 0001598549 · 10% owner

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

10b5-1 filing: Not disclosed

Ownership: Indirect · See foototes

Disclosed balance after: 110,683

F3 · kind: Represents a pro-rata in-kind distribution of Common Stock of the Issuer by 5AM Co-Investors IV, L.P. ("Co-Investors IV") without consideration to its partners.

F4 · ownership.nature: These securities are held of record by Co-Investors IV.

F8 · ownership.nature: Partners IV is the sole general partner of Ventures IV and Co-Investors IV. Dr. John Diekman, Andrew J. Schwab and Dr. Scott M. Rocklage, are the managing members of Partners IV, and have shared voting and investment power over the shares beneficially owned by Ventures IV and Co-Investors IV. Each of Partners IV, Dr. Diekman, Mr. Schwab, and Dr. Rocklage disclaims beneficial ownership of such shares except to the extent of its or their pecuniary interest therein.

SEC source: 0001104659-19-010154 · a4.xml · nonDerivative · entry 1

5AM Ventures IV, L.P. · CIK 0001589315 · 10% owner

5AM Co-Investors IV, L.P. · CIK 0001593361 · 10% owner

5AM Partners IV, LLC · CIK 0001589314 · 10% owner

ROCKLAGE SCOTT M · CIK 0001219014 · 10% owner

DIEKMAN JOHN D · CIK 0001240357 · 10% owner

Schwab Andrew J. · CIK 0001598549 · 10% owner

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

10b5-1 filing: Not disclosed

Ownership: Indirect · See foototes

Disclosed balance after: 2,656,442

F1 · kind: Represents a pro-rata in-kind distribution of Common Stock of the Issuer by 5AM Ventures IV, L.P. ("Ventures IV") without consideration to its partners.

F2 · ownership.nature: These securities are held of record by Ventures IV.

F8 · ownership.nature: Partners IV is the sole general partner of Ventures IV and Co-Investors IV. Dr. John Diekman, Andrew J. Schwab and Dr. Scott M. Rocklage, are the managing members of Partners IV, and have shared voting and investment power over the shares beneficially owned by Ventures IV and Co-Investors IV. Each of Partners IV, Dr. Diekman, Mr. Schwab, and Dr. Rocklage disclaims beneficial ownership of such shares except to the extent of its or their pecuniary interest therein.

SEC source: 0001104659-19-003219 · a4.xml · nonDerivative · entry 2

5AM Ventures IV, L.P. · CIK 0001589315 · 10% owner

5AM Co-Investors IV, L.P. · CIK 0001593361 · 10% owner

5AM Partners IV, LLC · CIK 0001589314 · 10% owner

ROCKLAGE SCOTT M · CIK 0001219014 · 10% owner

DIEKMAN JOHN D · CIK 0001240357 · 10% owner

Schwab Andrew J. · CIK 0001598549 · 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: 129,483

F2 · ownership.nature: These securities are held of record by 5AM Co-Investors IV, L.P. ("Co-Investors IV"). Following the transactions reported herein, 129,483 shares of Common Stock are held of record by Co-Investors IV.

F3 · ownership.nature: 5AM Partners IV, LLC ("Partners IV") is the sole general partner of Ventures IV and Co-Investors IV. Dr. John Diekman, Andrew J. Schwab and Dr. Scott M. Rocklage, are the managing members of Partners IV, and have shared voting and investment power over the shares beneficially owned by Ventures IV and Co-Investors IV. Each of Partners IV, Dr. Diekman, Mr. Schwab, and Dr. Rocklage disclaims beneficial ownership of such shares except to the extent of its or their pecuniary interest therein.

SEC source: 0001104659-19-003219 · a4.xml · nonDerivative · entry 1

5AM Ventures IV, L.P. · CIK 0001589315 · 10% owner

5AM Co-Investors IV, L.P. · CIK 0001593361 · 10% owner

5AM Partners IV, LLC · CIK 0001589314 · 10% owner

ROCKLAGE SCOTT M · CIK 0001219014 · 10% owner

DIEKMAN JOHN D · CIK 0001240357 · 10% owner

Schwab Andrew J. · CIK 0001598549 · 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: 3,107,642

F1 · ownership.nature: These securities are held of record by 5AM Ventures IV, L.P. ("Ventures IV"). Following the transactions reported herein, 3,107,642 shares of Common Stock are held of record by Ventures IV.

F3 · ownership.nature: 5AM Partners IV, LLC ("Partners IV") is the sole general partner of Ventures IV and Co-Investors IV. Dr. John Diekman, Andrew J. Schwab and Dr. Scott M. Rocklage, are the managing members of Partners IV, and have shared voting and investment power over the shares beneficially owned by Ventures IV and Co-Investors IV. Each of Partners IV, Dr. Diekman, Mr. Schwab, and Dr. Rocklage disclaims beneficial ownership of such shares except to the extent of its or their pecuniary interest therein.

SEC source: 0001104659-18-072619 · a4.xml · nonDerivative · entry 2

5AM Ventures IV, L.P. · CIK 0001589315 · 10% owner

5AM Partners IV, LLC · CIK 0001589314 · 10% owner

ROCKLAGE SCOTT M · CIK 0001219014 · 10% owner

DIEKMAN JOHN D · CIK 0001240357 · 10% owner

Schwab Andrew J. · CIK 0001598549 · 10% owner

5AM Co-Investors IV, L.P. · CIK 0001593361 · 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: 246,035

F2 · ownership.nature: The shares are held by 5AM Co-Investors IV, L.P. ("Co-Investors IV"). Partners IV is the sole general partner of Co-Investors IV. Dr. John Diekman, Andrew J. Schwab and Dr. Scott M. Rocklage, are the managing members of Partners IV, and have shared voting and investment power over the shares beneficially owned by Co-Investors IV. Each of Partners IV, Dr. Diekman, Mr. Schwab, and Dr. Rocklage disclaims beneficial ownership of such shares except to the extent of its or their pecuniary interest therein.

SEC source: 0001104659-18-072619 · a4.xml · nonDerivative · entry 1

5AM Ventures IV, L.P. · CIK 0001589315 · 10% owner

5AM Partners IV, LLC · CIK 0001589314 · 10% owner

ROCKLAGE SCOTT M · CIK 0001219014 · 10% owner

DIEKMAN JOHN D · CIK 0001240357 · 10% owner

Schwab Andrew J. · CIK 0001598549 · 10% owner

5AM Co-Investors IV, L.P. · CIK 0001593361 · 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: 5,904,884

F1 · ownership.nature: The shares are held by 5AM Ventures IV, L.P. ("Ventures IV"). 5AM Partners IV, LLC ("Partners IV") is the sole general partner of Ventures IV. Dr. John Diekman, Andrew J. Schwab and Dr. Scott M. Rocklage, are the managing members of Partners IV, and have shared voting and investment power over the shares beneficially owned by Ventures IV. Each of Partners IV, Dr. Diekman, Mr. Schwab, and Dr. Rocklage disclaims beneficial ownership of such shares except to the extent of its or their pecuniary interest therein.

SEC source: 0001104659-18-070148 · a4.xml · nonDerivative · entry 2

5AM Ventures IV, L.P. · CIK 0001589315 · 10% owner

5AM Partners IV, LLC · CIK 0001589314 · 10% owner

ROCKLAGE SCOTT M · CIK 0001219014 · 10% owner

DIEKMAN JOHN D · CIK 0001240357 · 10% owner

Schwab Andrew J. · CIK 0001598549 · 10% owner

5AM Co-Investors IV, L.P. · CIK 0001593361 · 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: 246,658

F2 · ownership.nature: The shares are held by 5AM Co-Investors IV, L.P. ("Co-Investors IV"). Partners IV is the sole general partner of Co-Investors IV. Dr. John Diekman, Andrew J. Schwab and Dr. Scott M. Rocklage, are the managing members of Partners IV, and have shared voting and investment power over the shares beneficially owned by Co-Investors IV. Each of Partners IV, Dr. Diekman, Mr. Schwab, and Dr. Rocklage disclaims beneficial ownership of such shares except to the extent of its or their pecuniary interest therein.

SEC source: 0001104659-18-070148 · a4.xml · nonDerivative · entry 1

5AM Ventures IV, L.P. · CIK 0001589315 · 10% owner

5AM Partners IV, LLC · CIK 0001589314 · 10% owner

ROCKLAGE SCOTT M · CIK 0001219014 · 10% owner

DIEKMAN JOHN D · CIK 0001240357 · 10% owner

Schwab Andrew J. · CIK 0001598549 · 10% owner

5AM Co-Investors IV, L.P. · CIK 0001593361 · 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: 5,919,836

F1 · ownership.nature: The shares are held by 5AM Ventures IV, L.P. ("Ventures IV"). 5AM Partners IV, LLC ("Partners IV") is the sole general partner of Ventures IV. Dr. John Diekman, Andrew J. Schwab and Dr. Scott M. Rocklage, are the managing members of Partners IV, and have shared voting and investment power over the shares beneficially owned by Ventures IV. Each of Partners IV, Dr. Diekman, Mr. Schwab, and Dr. Rocklage disclaims beneficial ownership of such shares except to the extent of its or their pecuniary interest therein.

SEC source: 0001104659-18-069431 · a4.xml · nonDerivative · entry 2

5AM Ventures IV, L.P. · CIK 0001589315 · 10% owner

5AM Partners IV, LLC · CIK 0001589314 · 10% owner

ROCKLAGE SCOTT M · CIK 0001219014 · 10% owner

DIEKMAN JOHN D · CIK 0001240357 · 10% owner

Schwab Andrew J. · CIK 0001598549 · 10% owner

5AM Co-Investors IV, L.P. · CIK 0001593361 · 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: 247,845

F2 · ownership.nature: The shares are held by 5AM Co-Investors IV, L.P. ("Co-Investors IV"). Partners IV is the sole general partner of Co-Investors IV. Dr. John Diekman, Andrew J. Schwab and Dr. Scott M. Rocklage, are the managing members of Partners IV, and have shared voting and investment power over the shares beneficially owned by Co-Investors IV. Each of Partners IV, Dr. Diekman, Mr. Schwab, and Dr. Rocklage disclaims beneficial ownership of such shares except to the extent of its or their pecuniary interest therein.

SEC source: 0001104659-18-069431 · a4.xml · nonDerivative · entry 1

5AM Ventures IV, L.P. · CIK 0001589315 · 10% owner

5AM Partners IV, LLC · CIK 0001589314 · 10% owner

ROCKLAGE SCOTT M · CIK 0001219014 · 10% owner

DIEKMAN JOHN D · CIK 0001240357 · 10% owner

Schwab Andrew J. · CIK 0001598549 · 10% owner

5AM Co-Investors IV, L.P. · CIK 0001593361 · 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: 5,948,331

F1 · ownership.nature: The shares are held by 5AM Ventures IV, L.P. ("Ventures IV"). 5AM Partners IV, LLC ("Partners IV") is the sole general partner of Ventures IV. Dr. John Diekman, Andrew J. Schwab and Dr. Scott M. Rocklage, are the managing members of Partners IV, and have shared voting and investment power over the shares beneficially owned by Ventures IV. Each of Partners IV, Dr. Diekman, Mr. Schwab, and Dr. Rocklage disclaims beneficial ownership of such shares except to the extent of its or their pecuniary interest therein.

SEC source: 0001104659-18-046330 · a4.xml · derivative · entry 10

5AM Ventures IV, L.P. · CIK 0001589315 · 10% owner

5AM Co-Investors IV, L.P. · CIK 0001593361 · 10% owner

5AM Partners IV, LLC · CIK 0001589314 · 10% owner

ROCKLAGE SCOTT M · CIK 0001219014 · 10% owner

DIEKMAN JOHN D · CIK 0001240357 · 10% owner

Schwab Andrew J. · CIK 0001598549 · 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: 0

Underlying: Common Stock · 18,802 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.

F4 · derivative.exercise_price: Each share of the Issuer's Series A Preferred Stock and Series B Preferred Stock automatically converted into the Issuer's Common stock on a 3.29-for-1 basis, for no additional consideration, upon the closing of the Issuer's initial public offering. The Series A Preferred Stock and the Series B Preferred Stock had no expiration date.

F4 · price: Each share of the Issuer's Series A Preferred Stock and Series B Preferred Stock automatically converted into the Issuer's Common stock on a 3.29-for-1 basis, for no additional consideration, upon the closing of the Issuer's initial public offering. The Series A Preferred Stock and the Series B Preferred Stock had no expiration date.

F4 · derivative.exercise_date: Each share of the Issuer's Series A Preferred Stock and Series B Preferred Stock automatically converted into the Issuer's Common stock on a 3.29-for-1 basis, for no additional consideration, upon the closing of the Issuer's initial public offering. The Series A Preferred Stock and the Series B Preferred Stock had no expiration date.

F4 · derivative.expiration_date: Each share of the Issuer's Series A Preferred Stock and Series B Preferred Stock automatically converted into the Issuer's Common stock on a 3.29-for-1 basis, for no additional consideration, upon the closing of the Issuer's initial public offering. The Series A Preferred Stock and the Series B Preferred Stock had no expiration date.

F2 · ownership.nature: These securities are held of record by 5AM Co-Investors IV, L.P. ("Co-Investors IV"). Following the transactions reported herein, 139,969 shares of Common Stock are held of record by Co-Investors IV.

F3 · ownership.nature: 5AM Partners IV, LLC ("Partners IV") is the sole general partner of Ventures IV and Co-Investors IV. Dr. John Diekman, Andrew J. Schwab and Dr. Scott M. Rocklage, are the managing members of Partners IV, and have shared voting and investment power over the shares beneficially owned by Ventures IV and Co-Investors IV. Each of Partners IV, Dr. Diekman, Mr. Schwab, and Dr. Rocklage disclaims beneficial ownership of such shares except to the extent of its or their pecuniary interest therein.

SEC source: 0001104659-18-046330 · a4.xml · derivative · entry 9

5AM Ventures IV, L.P. · CIK 0001589315 · 10% owner

5AM Co-Investors IV, L.P. · CIK 0001593361 · 10% owner

5AM Partners IV, LLC · CIK 0001589314 · 10% owner

ROCKLAGE SCOTT M · CIK 0001219014 · 10% owner

DIEKMAN JOHN D · CIK 0001240357 · 10% owner

Schwab Andrew J. · CIK 0001598549 · 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: 0

Underlying: Common Stock · 116,567 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.

F4 · derivative.exercise_price: Each share of the Issuer's Series A Preferred Stock and Series B Preferred Stock automatically converted into the Issuer's Common stock on a 3.29-for-1 basis, for no additional consideration, upon the closing of the Issuer's initial public offering. The Series A Preferred Stock and the Series B Preferred Stock had no expiration date.

F4 · price: Each share of the Issuer's Series A Preferred Stock and Series B Preferred Stock automatically converted into the Issuer's Common stock on a 3.29-for-1 basis, for no additional consideration, upon the closing of the Issuer's initial public offering. The Series A Preferred Stock and the Series B Preferred Stock had no expiration date.

F4 · derivative.exercise_date: Each share of the Issuer's Series A Preferred Stock and Series B Preferred Stock automatically converted into the Issuer's Common stock on a 3.29-for-1 basis, for no additional consideration, upon the closing of the Issuer's initial public offering. The Series A Preferred Stock and the Series B Preferred Stock had no expiration date.

F4 · derivative.expiration_date: Each share of the Issuer's Series A Preferred Stock and Series B Preferred Stock automatically converted into the Issuer's Common stock on a 3.29-for-1 basis, for no additional consideration, upon the closing of the Issuer's initial public offering. The Series A Preferred Stock and the Series B Preferred Stock had no expiration date.

F2 · ownership.nature: These securities are held of record by 5AM Co-Investors IV, L.P. ("Co-Investors IV"). Following the transactions reported herein, 139,969 shares of Common Stock are held of record by Co-Investors IV.

F3 · ownership.nature: 5AM Partners IV, LLC ("Partners IV") is the sole general partner of Ventures IV and Co-Investors IV. Dr. John Diekman, Andrew J. Schwab and Dr. Scott M. Rocklage, are the managing members of Partners IV, and have shared voting and investment power over the shares beneficially owned by Ventures IV and Co-Investors IV. Each of Partners IV, Dr. Diekman, Mr. Schwab, and Dr. Rocklage disclaims beneficial ownership of such shares except to the extent of its or their pecuniary interest therein.

SEC source: 0001104659-18-046330 · a4.xml · derivative · entry 8

5AM Ventures IV, L.P. · CIK 0001589315 · 10% owner

5AM Co-Investors IV, L.P. · CIK 0001593361 · 10% owner

5AM Partners IV, LLC · CIK 0001589314 · 10% owner

ROCKLAGE SCOTT M · CIK 0001219014 · 10% owner

DIEKMAN JOHN D · CIK 0001240357 · 10% owner

Schwab Andrew J. · CIK 0001598549 · 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: 0

Underlying: Common Stock · 451,274 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.

F4 · derivative.exercise_price: Each share of the Issuer's Series A Preferred Stock and Series B Preferred Stock automatically converted into the Issuer's Common stock on a 3.29-for-1 basis, for no additional consideration, upon the closing of the Issuer's initial public offering. The Series A Preferred Stock and the Series B Preferred Stock had no expiration date.

F4 · price: Each share of the Issuer's Series A Preferred Stock and Series B Preferred Stock automatically converted into the Issuer's Common stock on a 3.29-for-1 basis, for no additional consideration, upon the closing of the Issuer's initial public offering. The Series A Preferred Stock and the Series B Preferred Stock had no expiration date.

F4 · derivative.exercise_date: Each share of the Issuer's Series A Preferred Stock and Series B Preferred Stock automatically converted into the Issuer's Common stock on a 3.29-for-1 basis, for no additional consideration, upon the closing of the Issuer's initial public offering. The Series A Preferred Stock and the Series B Preferred Stock had no expiration date.

F4 · derivative.expiration_date: Each share of the Issuer's Series A Preferred Stock and Series B Preferred Stock automatically converted into the Issuer's Common stock on a 3.29-for-1 basis, for no additional consideration, upon the closing of the Issuer's initial public offering. The Series A Preferred Stock and the Series B Preferred Stock had no expiration date.

F1 · ownership.nature: These securities are held of record by 5AM Ventures IV, L.P. ("Ventures IV"). Following the transactions reported herein, 3,359,309 shares of Common Stock are held of record by Ventures IV.

F3 · ownership.nature: 5AM Partners IV, LLC ("Partners IV") is the sole general partner of Ventures IV and Co-Investors IV. Dr. John Diekman, Andrew J. Schwab and Dr. Scott M. Rocklage, are the managing members of Partners IV, and have shared voting and investment power over the shares beneficially owned by Ventures IV and Co-Investors IV. Each of Partners IV, Dr. Diekman, Mr. Schwab, and Dr. Rocklage disclaims beneficial ownership of such shares except to the extent of its or their pecuniary interest therein.

SEC source: 0001104659-18-046330 · a4.xml · derivative · entry 7

5AM Ventures IV, L.P. · CIK 0001589315 · 10% owner

5AM Co-Investors IV, L.P. · CIK 0001593361 · 10% owner

5AM Partners IV, LLC · CIK 0001589314 · 10% owner

ROCKLAGE SCOTT M · CIK 0001219014 · 10% owner

DIEKMAN JOHN D · CIK 0001240357 · 10% owner

Schwab Andrew J. · CIK 0001598549 · 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: 0

Underlying: Common Stock · 2,797,635 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.

F4 · derivative.exercise_price: Each share of the Issuer's Series A Preferred Stock and Series B Preferred Stock automatically converted into the Issuer's Common stock on a 3.29-for-1 basis, for no additional consideration, upon the closing of the Issuer's initial public offering. The Series A Preferred Stock and the Series B Preferred Stock had no expiration date.

F4 · price: Each share of the Issuer's Series A Preferred Stock and Series B Preferred Stock automatically converted into the Issuer's Common stock on a 3.29-for-1 basis, for no additional consideration, upon the closing of the Issuer's initial public offering. The Series A Preferred Stock and the Series B Preferred Stock had no expiration date.

F4 · derivative.exercise_date: Each share of the Issuer's Series A Preferred Stock and Series B Preferred Stock automatically converted into the Issuer's Common stock on a 3.29-for-1 basis, for no additional consideration, upon the closing of the Issuer's initial public offering. The Series A Preferred Stock and the Series B Preferred Stock had no expiration date.

F4 · derivative.expiration_date: Each share of the Issuer's Series A Preferred Stock and Series B Preferred Stock automatically converted into the Issuer's Common stock on a 3.29-for-1 basis, for no additional consideration, upon the closing of the Issuer's initial public offering. The Series A Preferred Stock and the Series B Preferred Stock had no expiration date.

F1 · ownership.nature: These securities are held of record by 5AM Ventures IV, L.P. ("Ventures IV"). Following the transactions reported herein, 3,359,309 shares of Common Stock are held of record by Ventures IV.

F3 · ownership.nature: 5AM Partners IV, LLC ("Partners IV") is the sole general partner of Ventures IV and Co-Investors IV. Dr. John Diekman, Andrew J. Schwab and Dr. Scott M. Rocklage, are the managing members of Partners IV, and have shared voting and investment power over the shares beneficially owned by Ventures IV and Co-Investors IV. Each of Partners IV, Dr. Diekman, Mr. Schwab, and Dr. Rocklage disclaims beneficial ownership of such shares except to the extent of its or their pecuniary interest therein.

SEC source: 0001104659-18-046330 · a4.xml · nonDerivative · entry 6

5AM Ventures IV, L.P. · CIK 0001589315 · 10% owner

5AM Co-Investors IV, L.P. · CIK 0001593361 · 10% owner

5AM Partners IV, LLC · CIK 0001589314 · 10% owner

ROCKLAGE SCOTT M · CIK 0001219014 · 10% owner

DIEKMAN JOHN D · CIK 0001240357 · 10% owner

Schwab Andrew J. · CIK 0001598549 · 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: 139,969

F2 · ownership.nature: These securities are held of record by 5AM Co-Investors IV, L.P. ("Co-Investors IV"). Following the transactions reported herein, 139,969 shares of Common Stock are held of record by Co-Investors IV.

F3 · ownership.nature: 5AM Partners IV, LLC ("Partners IV") is the sole general partner of Ventures IV and Co-Investors IV. Dr. John Diekman, Andrew J. Schwab and Dr. Scott M. Rocklage, are the managing members of Partners IV, and have shared voting and investment power over the shares beneficially owned by Ventures IV and Co-Investors IV. Each of Partners IV, Dr. Diekman, Mr. Schwab, and Dr. Rocklage disclaims beneficial ownership of such shares except to the extent of its or their pecuniary interest therein.

SEC source: 0001104659-18-046330 · a4.xml · nonDerivative · entry 5

5AM Ventures IV, L.P. · CIK 0001589315 · 10% owner

5AM Co-Investors IV, L.P. · CIK 0001593361 · 10% owner

5AM Partners IV, LLC · CIK 0001589314 · 10% owner

ROCKLAGE SCOTT M · CIK 0001219014 · 10% owner

DIEKMAN JOHN D · CIK 0001240357 · 10% owner

Schwab Andrew J. · CIK 0001598549 · 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: 3,359,309

F1 · ownership.nature: These securities are held of record by 5AM Ventures IV, L.P. ("Ventures IV"). Following the transactions reported herein, 3,359,309 shares of Common Stock are held of record by Ventures IV.

F3 · ownership.nature: 5AM Partners IV, LLC ("Partners IV") is the sole general partner of Ventures IV and Co-Investors IV. Dr. John Diekman, Andrew J. Schwab and Dr. Scott M. Rocklage, are the managing members of Partners IV, and have shared voting and investment power over the shares beneficially owned by Ventures IV and Co-Investors IV. Each of Partners IV, Dr. Diekman, Mr. Schwab, and Dr. Rocklage disclaims beneficial ownership of such shares except to the extent of its or their pecuniary interest therein.

SEC source: 0001104659-18-046330 · a4.xml · nonDerivative · entry 4

5AM Ventures IV, L.P. · CIK 0001589315 · 10% owner

5AM Co-Investors IV, L.P. · CIK 0001593361 · 10% owner

5AM Partners IV, LLC · CIK 0001589314 · 10% owner

ROCKLAGE SCOTT M · CIK 0001219014 · 10% owner

DIEKMAN JOHN D · CIK 0001240357 · 10% owner

Schwab Andrew J. · CIK 0001598549 · 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: 135,369

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

F4 · price: Each share of the Issuer's Series A Preferred Stock and Series B Preferred Stock automatically converted into the Issuer's Common stock on a 3.29-for-1 basis, for no additional consideration, upon the closing of the Issuer's initial public offering. The Series A Preferred Stock and the Series B Preferred Stock had no expiration date.

F2 · ownership.nature: These securities are held of record by 5AM Co-Investors IV, L.P. ("Co-Investors IV"). Following the transactions reported herein, 139,969 shares of Common Stock are held of record by Co-Investors IV.

F3 · ownership.nature: 5AM Partners IV, LLC ("Partners IV") is the sole general partner of Ventures IV and Co-Investors IV. Dr. John Diekman, Andrew J. Schwab and Dr. Scott M. Rocklage, are the managing members of Partners IV, and have shared voting and investment power over the shares beneficially owned by Ventures IV and Co-Investors IV. Each of Partners IV, Dr. Diekman, Mr. Schwab, and Dr. Rocklage disclaims beneficial ownership of such shares except to the extent of its or their pecuniary interest therein.

SEC source: 0001104659-18-046330 · a4.xml · nonDerivative · entry 3

5AM Ventures IV, L.P. · CIK 0001589315 · 10% owner

5AM Co-Investors IV, L.P. · CIK 0001593361 · 10% owner

5AM Partners IV, LLC · CIK 0001589314 · 10% owner

ROCKLAGE SCOTT M · CIK 0001219014 · 10% owner

DIEKMAN JOHN D · CIK 0001240357 · 10% owner

Schwab Andrew J. · CIK 0001598549 · 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: 116,567

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

F4 · price: Each share of the Issuer's Series A Preferred Stock and Series B Preferred Stock automatically converted into the Issuer's Common stock on a 3.29-for-1 basis, for no additional consideration, upon the closing of the Issuer's initial public offering. The Series A Preferred Stock and the Series B Preferred Stock had no expiration date.

F2 · ownership.nature: These securities are held of record by 5AM Co-Investors IV, L.P. ("Co-Investors IV"). Following the transactions reported herein, 139,969 shares of Common Stock are held of record by Co-Investors IV.

F3 · ownership.nature: 5AM Partners IV, LLC ("Partners IV") is the sole general partner of Ventures IV and Co-Investors IV. Dr. John Diekman, Andrew J. Schwab and Dr. Scott M. Rocklage, are the managing members of Partners IV, and have shared voting and investment power over the shares beneficially owned by Ventures IV and Co-Investors IV. Each of Partners IV, Dr. Diekman, Mr. Schwab, and Dr. Rocklage disclaims beneficial ownership of such shares except to the extent of its or their pecuniary interest therein.

SEC source: 0001104659-18-046330 · a4.xml · nonDerivative · entry 2

5AM Ventures IV, L.P. · CIK 0001589315 · 10% owner

5AM Co-Investors IV, L.P. · CIK 0001593361 · 10% owner

5AM Partners IV, LLC · CIK 0001589314 · 10% owner

ROCKLAGE SCOTT M · CIK 0001219014 · 10% owner

DIEKMAN JOHN D · CIK 0001240357 · 10% owner

Schwab Andrew J. · CIK 0001598549 · 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: 3,248,909

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

F4 · price: Each share of the Issuer's Series A Preferred Stock and Series B Preferred Stock automatically converted into the Issuer's Common stock on a 3.29-for-1 basis, for no additional consideration, upon the closing of the Issuer's initial public offering. The Series A Preferred Stock and the Series B Preferred Stock had no expiration date.

F1 · ownership.nature: These securities are held of record by 5AM Ventures IV, L.P. ("Ventures IV"). Following the transactions reported herein, 3,359,309 shares of Common Stock are held of record by Ventures IV.

F3 · ownership.nature: 5AM Partners IV, LLC ("Partners IV") is the sole general partner of Ventures IV and Co-Investors IV. Dr. John Diekman, Andrew J. Schwab and Dr. Scott M. Rocklage, are the managing members of Partners IV, and have shared voting and investment power over the shares beneficially owned by Ventures IV and Co-Investors IV. Each of Partners IV, Dr. Diekman, Mr. Schwab, and Dr. Rocklage disclaims beneficial ownership of such shares except to the extent of its or their pecuniary interest therein.

SEC source: 0001104659-18-046330 · a4.xml · nonDerivative · entry 1

5AM Ventures IV, L.P. · CIK 0001589315 · 10% owner

5AM Co-Investors IV, L.P. · CIK 0001593361 · 10% owner

5AM Partners IV, LLC · CIK 0001589314 · 10% owner

ROCKLAGE SCOTT M · CIK 0001219014 · 10% owner

DIEKMAN JOHN D · CIK 0001240357 · 10% owner

Schwab Andrew J. · CIK 0001598549 · 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: 2,797,635

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

F4 · price: Each share of the Issuer's Series A Preferred Stock and Series B Preferred Stock automatically converted into the Issuer's Common stock on a 3.29-for-1 basis, for no additional consideration, upon the closing of the Issuer's initial public offering. The Series A Preferred Stock and the Series B Preferred Stock had no expiration date.

F1 · ownership.nature: These securities are held of record by 5AM Ventures IV, L.P. ("Ventures IV"). Following the transactions reported herein, 3,359,309 shares of Common Stock are held of record by Ventures IV.

F3 · ownership.nature: 5AM Partners IV, LLC ("Partners IV") is the sole general partner of Ventures IV and Co-Investors IV. Dr. John Diekman, Andrew J. Schwab and Dr. Scott M. Rocklage, are the managing members of Partners IV, and have shared voting and investment power over the shares beneficially owned by Ventures IV and Co-Investors IV. Each of Partners IV, Dr. Diekman, Mr. Schwab, and Dr. Rocklage disclaims beneficial ownership of such shares except to the extent of its or their pecuniary interest therein.

SEC source: 0001104659-18-022462 · a4.xml · derivative · entry 3

5AM Ventures IV, L.P. · CIK 0001589315 · 10% owner

5AM Partners IV, LLC · CIK 0001589314 · 10% owner

ROCKLAGE SCOTT M · CIK 0001219014 · 10% owner

DIEKMAN JOHN D · CIK 0001240357 · 10% owner

Schwab Andrew J. · CIK 0001598549 · 10% owner

5AM Co-Investors IV, L.P. · CIK 0001593361 · 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 · 1,187,535 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.

F3 · derivative.exercise_price: Upon closing of the Issuer's initial public offering, each share of Series A Preferred Stock and Series B Preferred Stock was automatically converted into one share of the Issuer's common stock.

F3 · derivative.exercise_date: Upon closing of the Issuer's initial public offering, each share of Series A Preferred Stock and Series B Preferred Stock was automatically converted into one share of the Issuer's common stock.

F3 · derivative.expiration_date: Upon closing of the Issuer's initial public offering, each share of Series A Preferred Stock and Series B Preferred Stock was automatically converted into one share of the Issuer's common stock.

F2 · ownership.nature: 5AM Partners IV, LLC ("Partners IV") is the sole general partner of Ventures IV and Co-Investors IV. Dr. John Diekman, Andrew J. Schwab and Dr. Scott M. Rocklage, are the managing members of Partners IV, and have shared voting and investment power over the shares beneficially owned by Ventures IV and Co-Investors IV. Each of Partners IV, Dr. Diekman, Mr. Schwab, and Dr. Rocklage disclaims beneficial ownership of such shares except to the extent of its or their pecuniary interest therein.

SEC source: 0001104659-18-022462 · a4.xml · derivative · entry 2

5AM Ventures IV, L.P. · CIK 0001589315 · 10% owner

5AM Partners IV, LLC · CIK 0001589314 · 10% owner

ROCKLAGE SCOTT M · CIK 0001219014 · 10% owner

DIEKMAN JOHN D · CIK 0001240357 · 10% owner

Schwab Andrew J. · CIK 0001598549 · 10% owner

5AM Co-Investors IV, L.P. · CIK 0001593361 · 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 · 4,204,502 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.

F3 · derivative.exercise_price: Upon closing of the Issuer's initial public offering, each share of Series A Preferred Stock and Series B Preferred Stock was automatically converted into one share of the Issuer's common stock.

F3 · derivative.exercise_date: Upon closing of the Issuer's initial public offering, each share of Series A Preferred Stock and Series B Preferred Stock was automatically converted into one share of the Issuer's common stock.

F3 · derivative.expiration_date: Upon closing of the Issuer's initial public offering, each share of Series A Preferred Stock and Series B Preferred Stock was automatically converted into one share of the Issuer's common stock.

F2 · ownership.nature: 5AM Partners IV, LLC ("Partners IV") is the sole general partner of Ventures IV and Co-Investors IV. Dr. John Diekman, Andrew J. Schwab and Dr. Scott M. Rocklage, are the managing members of Partners IV, and have shared voting and investment power over the shares beneficially owned by Ventures IV and Co-Investors IV. Each of Partners IV, Dr. Diekman, Mr. Schwab, and Dr. Rocklage disclaims beneficial ownership of such shares except to the extent of its or their pecuniary interest therein.

SEC source: 0001104659-18-022462 · a4.xml · nonDerivative · entry 1

5AM Ventures IV, L.P. · CIK 0001589315 · 10% owner

5AM Partners IV, LLC · CIK 0001589314 · 10% owner

ROCKLAGE SCOTT M · CIK 0001219014 · 10% owner

DIEKMAN JOHN D · CIK 0001240357 · 10% owner

Schwab Andrew J. · CIK 0001598549 · 10% owner

5AM Co-Investors IV, L.P. · CIK 0001593361 · 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: 6,722,076

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

F1 · ownership.nature: Following the transactions reported herein, includes 6,453,195 shares of Common Stock held of record by 5AM Ventures IV, L.P. ("Ventures IV") and 268,881 shares of Common Stock held of record by 5AM Co-Investors IV, L.P. ("Co-Investors IV").

F2 · ownership.nature: 5AM Partners IV, LLC ("Partners IV") is the sole general partner of Ventures IV and Co-Investors IV. Dr. John Diekman, Andrew J. Schwab and Dr. Scott M. Rocklage, are the managing members of Partners IV, and have shared voting and investment power over the shares beneficially owned by Ventures IV and Co-Investors IV. Each of Partners IV, Dr. Diekman, Mr. Schwab, and Dr. Rocklage disclaims beneficial ownership of such shares except to the extent of its or their pecuniary interest therein.

SEC source: 0000899243-17-027189 · doc4.xml · derivative · entry 10

5AM Partners IV, LLC · CIK 0001589314 · 10% owner

5AM Ventures IV, L.P. · CIK 0001589315 · 10% owner

5AM Co-Investors IV, L.P. · CIK 0001593361 · 10% owner

Schwab Andrew J. · CIK 0001598549 · 10% owner

DIEKMAN JOHN D · CIK 0001240357 · 10% owner

ROCKLAGE SCOTT M · CIK 0001219014 · 10% owner

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

10b5-1 filing: Not disclosed

Ownership: Indirect · by 5AM Co-Investors IV, L.P.

Disclosed balance after: 0

Underlying: Common Stock · 42,150 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.

F6 · derivative.exercise_price: All series of Convertible Preferred Stock automatically converted into the Issuer's Common Stock on a 7.180193-for-1 basis on November 21, 2017 and had no expiration date.

F6 · derivative.exercise_date: All series of Convertible Preferred Stock automatically converted into the Issuer's Common Stock on a 7.180193-for-1 basis on November 21, 2017 and had no expiration date.

F6 · derivative.expiration_date: All series of Convertible Preferred Stock automatically converted into the Issuer's Common Stock on a 7.180193-for-1 basis on November 21, 2017 and had no expiration date.

F6 · derivative.underlying_shares: All series of Convertible Preferred Stock automatically converted into the Issuer's Common Stock on a 7.180193-for-1 basis on November 21, 2017 and had no expiration date.

F2 · ownership.nature: 5AM Partners IV, LLC is the general partner of 5AM Ventures IV, L.P. and 5AM Co-Investors IV, L.P. (the "5AM Funds"). Dr. John D. Diekman, Andrew J. Schwab, and Dr. Scott M. Rocklage are managing members of 5AM Partners IV, LLC. 5AM Partners IV, LLC may be deemed to have sole voting and investment power over the shares beneficially owned by the 5AM Funds. Dr. Diekman, Mr. Schwab, and Dr. Rocklage may be deemed to have shared voting and investment power over the shares beneficially by the 5AM Funds. Each of 5AM Partners IV, LLC, Dr. Diekman, Mr. Schwab, and Dr. Rocklage disclaim beneficial ownership of such shares except to the extent of its or their pecuniary interest therein.

SEC source: 0000899243-17-027189 · doc4.xml · derivative · entry 9

5AM Partners IV, LLC · CIK 0001589314 · 10% owner

5AM Ventures IV, L.P. · CIK 0001589315 · 10% owner

5AM Co-Investors IV, L.P. · CIK 0001593361 · 10% owner

Schwab Andrew J. · CIK 0001598549 · 10% owner

DIEKMAN JOHN D · CIK 0001240357 · 10% owner

ROCKLAGE SCOTT M · CIK 0001219014 · 10% owner

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

10b5-1 filing: Not disclosed

Ownership: Indirect · by 5AM Co-Investors IV, L.P.

Disclosed balance after: 0

Underlying: Common Stock · 61,795 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.

F6 · derivative.exercise_price: All series of Convertible Preferred Stock automatically converted into the Issuer's Common Stock on a 7.180193-for-1 basis on November 21, 2017 and had no expiration date.

F6 · derivative.exercise_date: All series of Convertible Preferred Stock automatically converted into the Issuer's Common Stock on a 7.180193-for-1 basis on November 21, 2017 and had no expiration date.

F6 · derivative.expiration_date: All series of Convertible Preferred Stock automatically converted into the Issuer's Common Stock on a 7.180193-for-1 basis on November 21, 2017 and had no expiration date.

F6 · derivative.underlying_shares: All series of Convertible Preferred Stock automatically converted into the Issuer's Common Stock on a 7.180193-for-1 basis on November 21, 2017 and had no expiration date.

F2 · ownership.nature: 5AM Partners IV, LLC is the general partner of 5AM Ventures IV, L.P. and 5AM Co-Investors IV, L.P. (the "5AM Funds"). Dr. John D. Diekman, Andrew J. Schwab, and Dr. Scott M. Rocklage are managing members of 5AM Partners IV, LLC. 5AM Partners IV, LLC may be deemed to have sole voting and investment power over the shares beneficially owned by the 5AM Funds. Dr. Diekman, Mr. Schwab, and Dr. Rocklage may be deemed to have shared voting and investment power over the shares beneficially by the 5AM Funds. Each of 5AM Partners IV, LLC, Dr. Diekman, Mr. Schwab, and Dr. Rocklage disclaim beneficial ownership of such shares except to the extent of its or their pecuniary interest therein.

SEC source: 0000899243-17-027189 · doc4.xml · derivative · entry 8

5AM Partners IV, LLC · CIK 0001589314 · 10% owner

5AM Ventures IV, L.P. · CIK 0001589315 · 10% owner

5AM Co-Investors IV, L.P. · CIK 0001593361 · 10% owner

Schwab Andrew J. · CIK 0001598549 · 10% owner

DIEKMAN JOHN D · CIK 0001240357 · 10% owner

ROCKLAGE SCOTT M · CIK 0001219014 · 10% owner

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

10b5-1 filing: Not disclosed

Ownership: Indirect · by 5AM Ventures IV, L.P.

Disclosed balance after: 0

Underlying: Common Stock · 1,011,623 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.

F6 · derivative.exercise_price: All series of Convertible Preferred Stock automatically converted into the Issuer's Common Stock on a 7.180193-for-1 basis on November 21, 2017 and had no expiration date.

F6 · derivative.exercise_date: All series of Convertible Preferred Stock automatically converted into the Issuer's Common Stock on a 7.180193-for-1 basis on November 21, 2017 and had no expiration date.

F6 · derivative.expiration_date: All series of Convertible Preferred Stock automatically converted into the Issuer's Common Stock on a 7.180193-for-1 basis on November 21, 2017 and had no expiration date.

F6 · derivative.underlying_shares: All series of Convertible Preferred Stock automatically converted into the Issuer's Common Stock on a 7.180193-for-1 basis on November 21, 2017 and had no expiration date.

F2 · ownership.nature: 5AM Partners IV, LLC is the general partner of 5AM Ventures IV, L.P. and 5AM Co-Investors IV, L.P. (the "5AM Funds"). Dr. John D. Diekman, Andrew J. Schwab, and Dr. Scott M. Rocklage are managing members of 5AM Partners IV, LLC. 5AM Partners IV, LLC may be deemed to have sole voting and investment power over the shares beneficially owned by the 5AM Funds. Dr. Diekman, Mr. Schwab, and Dr. Rocklage may be deemed to have shared voting and investment power over the shares beneficially by the 5AM Funds. Each of 5AM Partners IV, LLC, Dr. Diekman, Mr. Schwab, and Dr. Rocklage disclaim beneficial ownership of such shares except to the extent of its or their pecuniary interest therein.

SEC source: 0000899243-17-027189 · doc4.xml · derivative · entry 7

5AM Partners IV, LLC · CIK 0001589314 · 10% owner

5AM Ventures IV, L.P. · CIK 0001589315 · 10% owner

5AM Co-Investors IV, L.P. · CIK 0001593361 · 10% owner

Schwab Andrew J. · CIK 0001598549 · 10% owner

DIEKMAN JOHN D · CIK 0001240357 · 10% owner

ROCKLAGE SCOTT M · CIK 0001219014 · 10% owner

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

10b5-1 filing: Not disclosed

Ownership: Indirect · by 5AM Ventures IV, L.P.

Disclosed balance after: 0

Underlying: Common Stock · 1,483,107 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.

F6 · derivative.exercise_price: All series of Convertible Preferred Stock automatically converted into the Issuer's Common Stock on a 7.180193-for-1 basis on November 21, 2017 and had no expiration date.

F6 · derivative.exercise_date: All series of Convertible Preferred Stock automatically converted into the Issuer's Common Stock on a 7.180193-for-1 basis on November 21, 2017 and had no expiration date.

F6 · derivative.expiration_date: All series of Convertible Preferred Stock automatically converted into the Issuer's Common Stock on a 7.180193-for-1 basis on November 21, 2017 and had no expiration date.

F6 · derivative.underlying_shares: All series of Convertible Preferred Stock automatically converted into the Issuer's Common Stock on a 7.180193-for-1 basis on November 21, 2017 and had no expiration date.

F2 · ownership.nature: 5AM Partners IV, LLC is the general partner of 5AM Ventures IV, L.P. and 5AM Co-Investors IV, L.P. (the "5AM Funds"). Dr. John D. Diekman, Andrew J. Schwab, and Dr. Scott M. Rocklage are managing members of 5AM Partners IV, LLC. 5AM Partners IV, LLC may be deemed to have sole voting and investment power over the shares beneficially owned by the 5AM Funds. Dr. Diekman, Mr. Schwab, and Dr. Rocklage may be deemed to have shared voting and investment power over the shares beneficially by the 5AM Funds. Each of 5AM Partners IV, LLC, Dr. Diekman, Mr. Schwab, and Dr. Rocklage disclaim beneficial ownership of such shares except to the extent of its or their pecuniary interest therein.

SEC source: 0000899243-17-027189 · doc4.xml · nonDerivative · entry 6

5AM Partners IV, LLC · CIK 0001589314 · 10% owner

5AM Ventures IV, L.P. · CIK 0001589315 · 10% owner

5AM Co-Investors IV, L.P. · CIK 0001593361 · 10% owner

Schwab Andrew J. · CIK 0001598549 · 10% owner

DIEKMAN JOHN D · CIK 0001240357 · 10% owner

ROCKLAGE SCOTT M · CIK 0001219014 · 10% owner

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

10b5-1 filing: Not disclosed

Ownership: Indirect · by 5AM Co-Investors IV, L.P.

Disclosed balance after: 130,135

F2 · ownership.nature: 5AM Partners IV, LLC is the general partner of 5AM Ventures IV, L.P. and 5AM Co-Investors IV, L.P. (the "5AM Funds"). Dr. John D. Diekman, Andrew J. Schwab, and Dr. Scott M. Rocklage are managing members of 5AM Partners IV, LLC. 5AM Partners IV, LLC may be deemed to have sole voting and investment power over the shares beneficially owned by the 5AM Funds. Dr. Diekman, Mr. Schwab, and Dr. Rocklage may be deemed to have shared voting and investment power over the shares beneficially by the 5AM Funds. Each of 5AM Partners IV, LLC, Dr. Diekman, Mr. Schwab, and Dr. Rocklage disclaim beneficial ownership of such shares except to the extent of its or their pecuniary interest therein.

SEC source: 0000899243-17-027189 · doc4.xml · nonDerivative · entry 5

5AM Partners IV, LLC · CIK 0001589314 · 10% owner

5AM Ventures IV, L.P. · CIK 0001589315 · 10% owner

5AM Co-Investors IV, L.P. · CIK 0001593361 · 10% owner

Schwab Andrew J. · CIK 0001598549 · 10% owner

DIEKMAN JOHN D · CIK 0001240357 · 10% owner

ROCKLAGE SCOTT M · CIK 0001219014 · 10% owner

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

10b5-1 filing: Not disclosed

Ownership: Indirect · by 5AM Co-Investors IV, L.P.

Disclosed balance after: 103,945

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

F5 · price: Represents the total number of shares of Common Stock received by 5AM Co-Investors IV, L.P., upon conversion of the Issuer's Series B Preferred Stock in connection with the closing of the Issuer's initial public offering.

F2 · ownership.nature: 5AM Partners IV, LLC is the general partner of 5AM Ventures IV, L.P. and 5AM Co-Investors IV, L.P. (the "5AM Funds"). Dr. John D. Diekman, Andrew J. Schwab, and Dr. Scott M. Rocklage are managing members of 5AM Partners IV, LLC. 5AM Partners IV, LLC may be deemed to have sole voting and investment power over the shares beneficially owned by the 5AM Funds. Dr. Diekman, Mr. Schwab, and Dr. Rocklage may be deemed to have shared voting and investment power over the shares beneficially by the 5AM Funds. Each of 5AM Partners IV, LLC, Dr. Diekman, Mr. Schwab, and Dr. Rocklage disclaim beneficial ownership of such shares except to the extent of its or their pecuniary interest therein.

SEC source: 0000899243-17-027189 · doc4.xml · nonDerivative · entry 4

5AM Partners IV, LLC · CIK 0001589314 · 10% owner

5AM Ventures IV, L.P. · CIK 0001589315 · 10% owner

5AM Co-Investors IV, L.P. · CIK 0001593361 · 10% owner

Schwab Andrew J. · CIK 0001598549 · 10% owner

DIEKMAN JOHN D · CIK 0001240357 · 10% owner

ROCKLAGE SCOTT M · CIK 0001219014 · 10% owner

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

10b5-1 filing: Not disclosed

Ownership: Indirect · by 5AM Co-Investors IV, L.P.

Disclosed balance after: 61,795

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

F4 · price: Represents the total number of shares of Common Stock received by 5AM Co-Investors IV, L.P., upon conversion of the Issuer's Series A Preferred Stock in connection with the closing of the Issuer's initial public offering.

F2 · ownership.nature: 5AM Partners IV, LLC is the general partner of 5AM Ventures IV, L.P. and 5AM Co-Investors IV, L.P. (the "5AM Funds"). Dr. John D. Diekman, Andrew J. Schwab, and Dr. Scott M. Rocklage are managing members of 5AM Partners IV, LLC. 5AM Partners IV, LLC may be deemed to have sole voting and investment power over the shares beneficially owned by the 5AM Funds. Dr. Diekman, Mr. Schwab, and Dr. Rocklage may be deemed to have shared voting and investment power over the shares beneficially by the 5AM Funds. Each of 5AM Partners IV, LLC, Dr. Diekman, Mr. Schwab, and Dr. Rocklage disclaim beneficial ownership of such shares except to the extent of its or their pecuniary interest therein.

SEC source: 0000899243-17-027189 · doc4.xml · nonDerivative · entry 3

5AM Partners IV, LLC · CIK 0001589314 · 10% owner

5AM Ventures IV, L.P. · CIK 0001589315 · 10% owner

5AM Co-Investors IV, L.P. · CIK 0001593361 · 10% owner

Schwab Andrew J. · CIK 0001598549 · 10% owner

DIEKMAN JOHN D · CIK 0001240357 · 10% owner

ROCKLAGE SCOTT M · CIK 0001219014 · 10% owner

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

10b5-1 filing: Not disclosed

Ownership: Indirect · by 5AM Ventures IV, L.P.

Disclosed balance after: 3,123,302

F2 · ownership.nature: 5AM Partners IV, LLC is the general partner of 5AM Ventures IV, L.P. and 5AM Co-Investors IV, L.P. (the "5AM Funds"). Dr. John D. Diekman, Andrew J. Schwab, and Dr. Scott M. Rocklage are managing members of 5AM Partners IV, LLC. 5AM Partners IV, LLC may be deemed to have sole voting and investment power over the shares beneficially owned by the 5AM Funds. Dr. Diekman, Mr. Schwab, and Dr. Rocklage may be deemed to have shared voting and investment power over the shares beneficially by the 5AM Funds. Each of 5AM Partners IV, LLC, Dr. Diekman, Mr. Schwab, and Dr. Rocklage disclaim beneficial ownership of such shares except to the extent of its or their pecuniary interest therein.

SEC source: 0000899243-17-027189 · doc4.xml · nonDerivative · entry 2

5AM Partners IV, LLC · CIK 0001589314 · 10% owner

5AM Ventures IV, L.P. · CIK 0001589315 · 10% owner

5AM Co-Investors IV, L.P. · CIK 0001593361 · 10% owner

Schwab Andrew J. · CIK 0001598549 · 10% owner

DIEKMAN JOHN D · CIK 0001240357 · 10% owner

ROCKLAGE SCOTT M · CIK 0001219014 · 10% owner

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

10b5-1 filing: Not disclosed

Ownership: Indirect · by 5AM Ventures IV, L.P.

Disclosed balance after: 2,494,730

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.

F3 · price: Represents the total number of shares of Common Stock received by 5AM Ventures IV, L.P., upon conversion of the Issuer's Series B Preferred Stock in connection with the closing of the Issuer's initial public offering.

F2 · ownership.nature: 5AM Partners IV, LLC is the general partner of 5AM Ventures IV, L.P. and 5AM Co-Investors IV, L.P. (the "5AM Funds"). Dr. John D. Diekman, Andrew J. Schwab, and Dr. Scott M. Rocklage are managing members of 5AM Partners IV, LLC. 5AM Partners IV, LLC may be deemed to have sole voting and investment power over the shares beneficially owned by the 5AM Funds. Dr. Diekman, Mr. Schwab, and Dr. Rocklage may be deemed to have shared voting and investment power over the shares beneficially by the 5AM Funds. Each of 5AM Partners IV, LLC, Dr. Diekman, Mr. Schwab, and Dr. Rocklage disclaim beneficial ownership of such shares except to the extent of its or their pecuniary interest therein.

SEC source: 0000899243-17-027189 · doc4.xml · nonDerivative · entry 1

5AM Partners IV, LLC · CIK 0001589314 · 10% owner

5AM Ventures IV, L.P. · CIK 0001589315 · 10% owner

5AM Co-Investors IV, L.P. · CIK 0001593361 · 10% owner

Schwab Andrew J. · CIK 0001598549 · 10% owner

DIEKMAN JOHN D · CIK 0001240357 · 10% owner

ROCKLAGE SCOTT M · CIK 0001219014 · 10% owner

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

10b5-1 filing: Not disclosed

Ownership: Indirect · by 5AM Ventures IV, L.P.

Disclosed balance after: 1,483,107

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: Represents the total number of shares of Common Stock received by 5AM Ventures IV, L.P., upon conversion of the Issuer's Series A Preferred Stock in connection with the closing of the Issuer's initial public offering.

F2 · ownership.nature: 5AM Partners IV, LLC is the general partner of 5AM Ventures IV, L.P. and 5AM Co-Investors IV, L.P. (the "5AM Funds"). Dr. John D. Diekman, Andrew J. Schwab, and Dr. Scott M. Rocklage are managing members of 5AM Partners IV, LLC. 5AM Partners IV, LLC may be deemed to have sole voting and investment power over the shares beneficially owned by the 5AM Funds. Dr. Diekman, Mr. Schwab, and Dr. Rocklage may be deemed to have shared voting and investment power over the shares beneficially by the 5AM Funds. Each of 5AM Partners IV, LLC, Dr. Diekman, Mr. Schwab, and Dr. Rocklage disclaim beneficial ownership of such shares except to the extent of its or their pecuniary interest therein.