QTTB

SEC source: 0000899243-19-019172 · doc4.xml · nonDerivative · entry 1

TZIANABOS ARTHUR · CIK 0001586226 · Director · President & CEO

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 165,005

F1 · kind: The sale reported in the Form 4 was effected pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on November 20, 2018.

F2 · price: The price reported is a weighted average price. The shares were sold in multiple transactions at per share prices ranging from $18.53 to $19.44. The Reporting Person undertakes to provide upon request to the SEC staff, the Issuer, or any stockholder of the Issuer, full information regarding the number of shares sold at each separate price within the range set forth in this footnote.

SEC source: 0000899243-19-019182 · doc4.xml · nonDerivative · entry 2

Seymour Albert · CIK 0001735324 · Chief Scientific Officer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 209,650

F1 · kind: The sale reported in the Form 4 was effected pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on November 20, 2018.

SEC source: 0000899243-19-019182 · doc4.xml · nonDerivative · entry 1

Seymour Albert · CIK 0001735324 · Chief Scientific Officer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 209,750

F1 · kind: The sale reported in the Form 4 was effected pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on November 20, 2018.

F2 · price: The price reported is a weighted average price. The shares were sold in multiple transactions at per share prices ranging from $18.52 to $19.28. The Reporting Person undertakes to provide upon request to the SEC staff, the Issuer, or any stockholder of the Issuer, full information regarding the number of shares sold at each separate price within the range set forth in this footnote.

SEC source: 0000899243-19-016224 · doc4.xml · derivative · entry 1

Patterson Matthew R · CIK 0001401018 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 15,580

Underlying: Common Stock · 15,580 shares

Expires 2029-06-06

F1 · derivative.exercise_date: This option shall vest and become exercisable on the earlier of June 6, 2020 or the day immediately prior to the date of the next annual meeting of the Company's stockholders occurring after the date of grant, in either case subject to the Non-Employee Director continuing in service on the Board as a Non-Employee Director through each such vesting date.

SEC source: 0000899243-19-016221 · doc4.xml · derivative · entry 1

GILLIS STEVEN · CIK 0001229592 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 15,580

Underlying: Common Stock · 15,580 shares

Expires 2029-06-06

F1 · derivative.exercise_date: This option shall vest and become exercisable on the earlier of June 6, 2020 or the day immediately prior to the date of the next annual meeting of the Company's stockholders occurring after the date of grant, in either case subject to the Non-Employee Director continuing in service on the Board as a Non-Employee Director through each such vesting date.

SEC source: 0000899243-19-016226 · doc4.xml · derivative · entry 1

Thistle Mary · CIK 0001317917 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 15,580

Underlying: Common Stock · 15,580 shares

Expires 2029-06-06

F1 · derivative.exercise_date: This option shall vest and become exercisable on the earlier of June 6, 2020 or the day immediately prior to the date of the next annual meeting of the Company's stockholders occurring after the date of grant, in either case subject to the Non-Employee Director continuing in service on the Board as a Non-Employee Director through each such vesting date.

SEC source: 0000899243-19-016228 · doc4.xml · derivative · entry 1

Gregory Richard J. · CIK 0001629767 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 15,580

Underlying: Common Stock · 15,580 shares

Expires 2029-06-06

F1 · derivative.exercise_date: This option shall vest and become exercisable on the earlier of June 6, 2020 or the day immediately prior to the date of the next annual meeting of the Company's stockholders occurring after the date of grant, in either case subject to the Non-Employee Director continuing in service on the Board as a Non-Employee Director through each such vesting date.

SEC source: 0000899243-19-016227 · doc4.xml · derivative · entry 1

Wheeler Cameron · CIK 0001735323 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 15,580

Underlying: Common Stock · 15,580 shares

Expires 2029-06-06

F1 · derivative.exercise_date: This option shall vest and become exercisable on the earlier of June 6, 2020 or the day immediately prior to the date of the next annual meeting of the Company's stockholders occurring after the date of grant, in either case subject to the Non-Employee Director continuing in service on the Board as a Non-Employee Director through each such vesting date.

SEC source: 0000899243-19-016223 · doc4.xml · derivative · entry 1

PARMAR KUSH · CIK 0001664281 · Director · 10% owner

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 15,580

Underlying: Common Stock · 15,580 shares

Expires 2029-06-06

F1 · derivative.exercise_date: This option shall vest and become exercisable on the earlier of June 6, 2020 or the day immediately prior to the date of the next annual meeting of the Company's stockholders occurring after the date of grant, in either case subject to the Non-Employee Director continuing in service on the Board as a Non-Employee Director through each such vesting date.

SEC source: 0001193805-19-000567 · e618518_4-homology.xml · derivative · entry 1

Flynn James E · CIK 0001352546 · Director · 10% owner · *Director by Deputization

DEERFIELD MANAGEMENT COMPANY, L.P. (SERIES C) · CIK 0001009258 · Director · 10% owner · *Director by Deputization

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

10b5-1 filing: Not disclosed

Ownership: Indirect · Through Deerfield Management Company, L.P.

Disclosed balance after: 15,580

Underlying: Common Stock · 15,580 shares

Expires 2029-06-06

F1 · shares: Cameron Wheeler, an employee of Deerfield Management Company, L.P. ("Deerfield Management"), serves as a director of the Issuer. The option granted to Cameron Wheeler and reported herein is held for the benefit, and at the direction, of Deerfield Management.

F2 · derivative.exercise_date: The option shall vest and become exercisable on the earlier of June 6, 2020 and the day immediately prior to the date of the next annual meeting of the Issuer's stockholders occurring after the date of grant, in either case subject to Mr. Wheeler continuing in service on the Issuer's board of directors as a non-employee director through each such vesting date.

F1 · derivative.underlying_shares: Cameron Wheeler, an employee of Deerfield Management Company, L.P. ("Deerfield Management"), serves as a director of the Issuer. The option granted to Cameron Wheeler and reported herein is held for the benefit, and at the direction, of Deerfield Management.

F1 · balance_after: Cameron Wheeler, an employee of Deerfield Management Company, L.P. ("Deerfield Management"), serves as a director of the Issuer. The option granted to Cameron Wheeler and reported herein is held for the benefit, and at the direction, of Deerfield Management.

F1 · ownership.nature: Cameron Wheeler, an employee of Deerfield Management Company, L.P. ("Deerfield Management"), serves as a director of the Issuer. The option granted to Cameron Wheeler and reported herein is held for the benefit, and at the direction, of Deerfield Management.

F3 · ownership.nature: This Form 4 is being filed by the undersigned as well as the entity listed on the Joint Filer Information Statement attached as an exhibit hereto (the "Reporting Persons"). James E. Flynn is the sole member of the general partner of Deerfield Management. For purposes of Section 16 of the Securities Exchange Act of 1934, as amended, each Reporting Person disclaims beneficial ownership of any such securities, except to the extent of his/its indirect pecuniary interest therein, if any, and this report shall not be deemed an admission that such Reporting Person is the beneficial owner of such securities for purposes of Section 16 or otherwise.

SEC source: 0000899243-19-016520 · doc4a.xml · derivative · entry 1

Wheeler Cameron · CIK 0001735323 · Director

10b5-1 filing: Not disclosed

Ownership: Indirect · See footnote

Disclosed balance after: 15,580

Underlying: Common Stock · 15,580 shares

Expires 2029-06-06

F1 · derivative.exercise_date: This option shall vest and become exercisable on the earlier of June 6, 2020 or the day immediately prior to the date of the next annual meeting of the Company's stockholders occurring after the date of grant, in either case subject to the Non-Employee Director continuing in service on the Board as a Non-Employee Director through each such vesting date.

F2 · ownership.nature: The Reporting Person, a partner at Deerfield Management Company, L.P., has no pecuniary interest in the securities reported herein and disclaims beneficial ownership of such securities. The Reporting Person holds the option for the benefit, and at the direction, of Deerfield Management Company, L.P.

SEC source: 0000899243-19-015642 · doc4.xml · nonDerivative · entry 1

Rasty Siyamak · CIK 0001735450 · Chief Operating Officer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 230,707

F1 · kind: The sale reported in the Form 4 was effected pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on November 20, 2018.

F2 · price: The price reported is a weighted average price. The shares were sold in multiple transactions at per share prices ranging from $20.00 to $20.42. The Reporting Person undertakes to provide upon request to the SEC staff, the Issuer, or any stockholder of the Issuer, full information regarding the number of shares sold at each separate price within the range set forth in this footnote.

SEC source: 0000899243-19-015653 · doc4.xml · derivative · entry 3

Smith W Bradford · CIK 0001317678 · CFO, Treasurer & Secretary

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 157,404

Underlying: Common Stock · 6,000 shares

Expires 2027-04-05

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_date: The option vested and became exercisable as to 25% of the total grant on the first anniversary of the vesting commencement date and vests in equal monthly installments over a three year period thereafter. The vesting commencement date for this option was April 3, 2017.

SEC source: 0000899243-19-015653 · doc4.xml · nonDerivative · entry 2

Smith W Bradford · CIK 0001317678 · CFO, Treasurer & Secretary

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 0

F1 · kind: The sale reported in the Form 4 was effected pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on November 20, 2018.

F2 · price: The price reported is a weighted average price. The shares were sold in multiple transactions at per share prices ranging from $19.46 to $20.42. The Reporting Person undertakes to provide upon request to the SEC staff, the Issuer, or any stockholder of the Issuer, full information regarding the number of shares sold at each separate price within the range set forth in this footnote.

SEC source: 0000899243-19-015653 · doc4.xml · nonDerivative · entry 1

Smith W Bradford · CIK 0001317678 · CFO, Treasurer & Secretary

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 6,000

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.

SEC source: 0000899243-19-015645 · doc4.xml · nonDerivative · entry 1

TZIANABOS ARTHUR · CIK 0001586226 · Director · President & CEO

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 177,505

F1 · kind: The sale reported in the Form 4 was effected pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on November 20, 2018.

F2 · price: The price reported is a weighted average price. The shares were sold in multiple transactions at per share prices ranging from $19.43 to $20.42. The Reporting Person undertakes to provide upon request to the SEC staff, the Issuer, or any stockholder of the Issuer, full information regarding the number of shares sold at each separate price within the range set forth in this footnote.

SEC source: 0000899243-19-015650 · doc4.xml · nonDerivative · entry 1

Kelly Timothy P · CIK 0001754067 · See Remarks

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 0

F1 · kind: The sale reported in the Form 4 was effected pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on November 20, 2018.

F2 · shares: Consists of 1,288 shares acquired under the Issuer's Employee Stock Purchase Plan.

F3 · price: The price reported is a weighted average price. The shares were sold in multiple transactions at per share prices ranging from $19.48 to $20.33. The Reporting Person undertakes to provide upon request to the SEC staff, the Issuer, or any stockholder of the Issuer, full information regarding the number of shares sold at each separate price within the range set forth in this footnote.

SEC source: 0000899243-19-015647 · doc4.xml · nonDerivative · entry 1

Seymour Albert · CIK 0001735324 · Chief Scientific Officer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 218,950

F1 · kind: The sale reported in the Form 4 was effected pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on November 20, 2018.

F2 · price: The price reported is a weighted average price. The shares were sold in multiple transactions at per share prices ranging from $19.45 to $20.42. The Reporting Person undertakes to provide upon request to the SEC staff, the Issuer, or any stockholder of the Issuer, full information regarding the number of shares sold at each separate price within the range set forth in this footnote.

SEC source: 0001012975-19-000390 · edgar.xml · nonDerivative · entry 1

ARCH Venture Fund VIII, L.P. · CIK 0001605598 · 10% owner

ARCH Venture Fund VIII Overage, L.P. · CIK 0001617237 · 10% owner

ARCH Venture Partners VIII, L.P. · CIK 0001616176 · 10% owner

ARCH Venture Partners VIII, LLC · CIK 0001616165 · 10% owner

BYBEE CLINTON · CIK 0001219043 · 10% owner

CRANDELL KEITH · CIK 0001219039 · 10% owner

NELSEN ROBERT · CIK 0001219042 · 10% owner

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

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 5,768,694

F1 · kind: Distribution of Common Stock held by a limited partnership to its partners for no consideration.

F2 · ownership.direct: Following the transactions reported herein, includes 1,137,663 shares of common stock held of record by ARCH Venture Fund VIII Overage, L.P. ("ARCH Fund Overage") and 4,631,031 shares of common stock held of record by ARCH Venture Fund VIII, L.P. ("ARCH Fund VIII").

F3 · ownership.direct: The sole general partner of ARCH Fund VIII is ARCH Venture Partners VIII, L.P. ("ARCH Partners VIII"). The sole general partner of ARCH Partners VIII and ARCH Fund Overage is ARCH Venture Partners VIII, LLC ("ARCH VIII LLC"). ARCH Partners VIII may therefore be deemed to beneficially own the securities held by ARCH Fund VIII and ARCH VIII LLC may be deemed to beneficially own the securities held by ARCH Fund VIII and ARCH Fund Overage. ARCH Partners VIII and ARCH VIII LLC disclaim beneficial ownership of such securities, except to the extent of any pecuniary interest therein. The managing directors of ARCH VIII LLC are Keith L. Crandell, Clinton Bybee and Robert Nelsen, and they may be deemed to beneficially own the shares held by ARCH Fund VIII and ARCH Fund Overage. Messrs. Crandell, Bybee and Nelsen disclaim beneficial ownership of such shares, except to the extent of any pecuniary interest therein.

SEC source: 0001104659-19-030566 · 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: 221,435

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: 0001104659-19-030566 · 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: 5,314,484

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: 0001104659-19-030565 · a4.xml · nonDerivative · entry 2

PARMAR KUSH · CIK 0001664281 · Director · 10% owner

10b5-1 filing: Not disclosed

Ownership: Indirect · See footnote

Disclosed balance after: 221,435

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.

F3 · ownership.nature: The Reporting Person is an affiliate of Partners IV and disclaims beneficial ownership of such shares, except to the extent of his pecuniary interest therein.

SEC source: 0001104659-19-030565 · a4.xml · nonDerivative · entry 1

PARMAR KUSH · CIK 0001664281 · Director · 10% owner

10b5-1 filing: Not disclosed

Ownership: Indirect · See footnote

Disclosed balance after: 5,314,484

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.

F3 · ownership.nature: The Reporting Person is an affiliate of Partners IV and disclaims beneficial ownership of such shares, except to the extent of his pecuniary interest therein.

SEC source: 0001193805-19-000360 · e618366_4-homology.xml · nonDerivative · entry 1

Flynn James E · CIK 0001352546 · Director · 10% owner · *Director by Deputization

DEERFIELD MANAGEMENT COMPANY, L.P. (SERIES C) · CIK 0001009258 · Director · 10% owner · *Director by Deputization

Deerfield Mgmt L.P. · CIK 0001010823 · Director · 10% owner · *Director by Deputization

DEERFIELD PARTNERS, L.P. · CIK 0001301041 · Director · 10% owner · *Director by Deputization

Deerfield Private Design Fund III, L.P. · CIK 0001603333 · Director · 10% owner · *Director by Deputization

Deerfield Mgmt III, L.P. · CIK 0001610540 · Director · 10% owner · *Director by Deputization

Deerfield Healthcare Innovations Fund, L.P. · CIK 0001646981 · Director · 10% owner · *Director by Deputization

Deerfield Mgmt HIF, L.P. · CIK 0001665736 · Director · 10% owner · *Director by Deputization

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

10b5-1 filing: Not disclosed

Ownership: Indirect · Through Deerfield Partners, L.P.

Disclosed balance after: 1,158,333

F1 · ownership.nature: This Form 4 is being filed by the undersigned as well as the entities listed on the Joint Filer Information Statement attached as an exhibit hereto (the "Reporting Persons"). Deerfield Mgmt III, L.P. is the general partner of Deerfield Private Design Fund III, L.P. ("Fund III"). Deerfield Mgmt, L.P. is the general partner of Deerfield Partners, L.P. ("Deerfield Partners"). Deerfield Mgmt HIF, L.P. is the general partner of Deerfield Healthcare Innovations Fund, L.P. (collectively with Fund III and Deerfield Partners, the "Funds"). Deerfield Management Company, L.P. is the investment manager of the Funds. James E. Flynn is the sole member of the general partner of each of Deerfield Mgmt, L.P., Deerfield Mgmt III, L.P., Deerfield Mgmt HIF, L.P. and Deerfield Management Company, L.P.

F2 · ownership.nature: In accordance with Instruction 4 (b)(iv) to Form 4, the entire amount of the Issuer's securities held by the Funds is reported herein. For purposes of Section 16 of the Securities Exchange Act of 1934, as amended, each Reporting Person disclaims beneficial ownership of any such securities, except to the extent of his/its indirect pecuniary interest therein, if any, and this report shall not be deemed an admission that such Reporting Person is the beneficial owner of such securities for purposes of Section 16 or otherwise.

SEC source: 0000899243-18-031340 · doc4.xml · derivative · entry 1

Smith W Bradford · CIK 0001317678 · CFO, Treasurer & Secretary

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 88,000

Underlying: Common Stock · 88,000 shares

Expires 2028-12-14

F1 · derivative.exercise_date: The option vests in 48 equal monthly installments on the first day of each calendar month following January 1, 2019.

SEC source: 0000899243-18-031342 · doc4.xml · derivative · entry 1

TZIANABOS ARTHUR · CIK 0001586226 · Director · President & CEO

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 203,000

Underlying: Common Stock · 203,000 shares

Expires 2028-12-14

F1 · derivative.exercise_date: The option vests in 48 equal monthly installments on the first day of each calendar month following January 1, 2019.

SEC source: 0000899243-18-031346 · doc4.xml · derivative · entry 1

Seymour Albert · CIK 0001735324 · Chief Scientific Officer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 74,000

Underlying: Common Stock · 74,000 shares

Expires 2028-12-14

F1 · derivative.exercise_date: The option vests in 48 equal monthly installments on the first day of each calendar month following January 1, 2019.

SEC source: 0000899243-18-031344 · doc4.xml · derivative · entry 1

Kelly Timothy P · CIK 0001754067 · See Remarks

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 66,000

Underlying: Common Stock · 66,000 shares

Expires 2028-12-14

F1 · derivative.exercise_date: The option vests in 48 equal monthly installments on the first day of each calendar month following January 1, 2019.

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: 0001104659-18-072618 · a4.xml · nonDerivative · entry 2

PARMAR KUSH · CIK 0001664281 · Director · 10% 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.

F3 · ownership.nature: The Reporting Person is an affiliate of Partners IV and disclaims beneficial ownership of such shares, except to the extent of his pecuniary interest therein.

SEC source: 0001104659-18-072618 · a4.xml · nonDerivative · entry 1

PARMAR KUSH · CIK 0001664281 · Director · 10% 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.

F3 · ownership.nature: The Reporting Person is an affiliate of Partners IV and disclaims beneficial ownership of such shares, except to the extent of his 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: 0001104659-18-070149 · a4.xml · nonDerivative · entry 2

PARMAR KUSH · CIK 0001664281 · Director · 10% 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.

F3 · ownership.nature: The Reporting Person is an affiliate of Partners IV and disclaims beneficial ownership of such shares, except to the extent of his pecuniary interst therein.

SEC source: 0001104659-18-070149 · a4.xml · nonDerivative · entry 1

PARMAR KUSH · CIK 0001664281 · Director · 10% 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.

F3 · ownership.nature: The Reporting Person is an affiliate of Partners IV and disclaims beneficial ownership of such shares, except to the extent of his pecuniary interst 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: 0001104659-18-069432 · a4.xml · nonDerivative · entry 2

PARMAR KUSH · CIK 0001664281 · Director · 10% 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.

F3 · ownership.nature: The Reporting Person is an affiliate of Partners IV and disclaims beneficial ownership of such shares, except to the extent of his pecuniary interst therein.

SEC source: 0001104659-18-069432 · a4.xml · nonDerivative · entry 1

PARMAR KUSH · CIK 0001664281 · Director · 10% 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.

F3 · ownership.nature: The Reporting Person is an affiliate of Partners IV and disclaims beneficial ownership of such shares, except to the extent of his pecuniary interst therein.

SEC source: 0001193805-18-000506 · e617881_4-homology.xml · derivative · entry 10

Flynn James E · CIK 0001352546 · Director · 10% owner · *Director by Deputization

DEERFIELD MANAGEMENT COMPANY, L.P. (SERIES C) · CIK 0001009258 · Director · 10% owner · *Director by Deputization

Deerfield Mgmt L.P. · CIK 0001010823 · Director · 10% owner · *Director by Deputization

DEERFIELD PARTNERS, L.P. · CIK 0001301041 · Director · 10% owner · *Director by Deputization

Deerfield Private Design Fund III, L.P. · CIK 0001603333 · Director · 10% owner · *Director by Deputization

Deerfield Mgmt III, L.P. · CIK 0001610540 · Director · 10% owner · *Director by Deputization

Deerfield Healthcare Innovations Fund, L.P. · CIK 0001646981 · Director · 10% owner · *Director by Deputization

Deerfield Mgmt HIF, L.P. · CIK 0001665736 · Director · 10% owner · *Director by Deputization

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

10b5-1 filing: Not disclosed

Ownership: Indirect · Through Deerfield Private Design Fund III, L.P.

Disclosed balance after: 0

Underlying: Common Stock · 1,319,483 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.

F2 · derivative.exercise_price: Each share of Series B Preferred Stock automatically converted into 0.1900057 shares of the Issuer's common stock upon the closing of the Issuer's initial public offering (on an adjusted basis, after giving effect to the 1-for-5.263 reverse stock split effected by the Issuer in connection with its initial public offering).

F2 · price: Each share of Series B Preferred Stock automatically converted into 0.1900057 shares of the Issuer's common stock upon the closing of the Issuer's initial public offering (on an adjusted basis, after giving effect to the 1-for-5.263 reverse stock split effected by the Issuer in connection with its initial public offering).

F2 · derivative.exercise_date: Each share of Series B Preferred Stock automatically converted into 0.1900057 shares of the Issuer's common stock upon the closing of the Issuer's initial public offering (on an adjusted basis, after giving effect to the 1-for-5.263 reverse stock split effected by the Issuer in connection with its initial public offering).

F2 · derivative.expiration_date: Each share of Series B Preferred Stock automatically converted into 0.1900057 shares of the Issuer's common stock upon the closing of the Issuer's initial public offering (on an adjusted basis, after giving effect to the 1-for-5.263 reverse stock split effected by the Issuer in connection with its initial public offering).

F3 · ownership.nature: This Form 4 is being filed by the undersigned as well as the entities listed on the Joint Filer Information Statement attached as an exhibit hereto (the "Reporting Persons"). Deerfield Mgmt III, L.P. is the general partner of Deerfield Private Design Fund III, L.P. ("Fund III"). Deerfield Mgmt, L.P. is the general partner of Deerfield Partners, L.P. ("Deerfield Partners"). Deerfield Mgmt HIF, L.P. is the general partner of Deerfield Healthcare Innovations Fund, L.P. (collectively with Fund III and Deerfield Partners, the "Funds"). Deerfield Management Company, L.P. is the investment manager of the Funds. James E. Flynn is the sole member of the general partner of each of Deerfield Mgmt, L.P., Deerfield Mgmt III, L.P., Deerfield Mgmt HIF, L.P. and Deerfield Management Company, L.P.

F4 · ownership.nature: In accordance with Instruction 4 (b)(iv) to Form 4, the entire amount of the Issuer's securities held by the Funds is reported herein. For purposes of Section 16 of the Securities Exchange Act of 1934, as amended, each Reporting Person disclaims beneficial ownership of any such securities, except to the extent of his/its indirect pecuniary interest therein, if any, and this report shall not be deemed an admission that such Reporting Person is the beneficial owner of such securities for purposes of Section 16 or otherwise.

SEC source: 0001193805-18-000506 · e617881_4-homology.xml · derivative · entry 9

Flynn James E · CIK 0001352546 · Director · 10% owner · *Director by Deputization

DEERFIELD MANAGEMENT COMPANY, L.P. (SERIES C) · CIK 0001009258 · Director · 10% owner · *Director by Deputization

Deerfield Mgmt L.P. · CIK 0001010823 · Director · 10% owner · *Director by Deputization

DEERFIELD PARTNERS, L.P. · CIK 0001301041 · Director · 10% owner · *Director by Deputization

Deerfield Private Design Fund III, L.P. · CIK 0001603333 · Director · 10% owner · *Director by Deputization

Deerfield Mgmt III, L.P. · CIK 0001610540 · Director · 10% owner · *Director by Deputization

Deerfield Healthcare Innovations Fund, L.P. · CIK 0001646981 · Director · 10% owner · *Director by Deputization

Deerfield Mgmt HIF, L.P. · CIK 0001665736 · Director · 10% owner · *Director by Deputization

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

10b5-1 filing: Not disclosed

Ownership: Indirect · Through Deerfield Healthcare Innovations Fund, L.P.

Disclosed balance after: 0

Underlying: Common Stock · 1,319,484 shares

Expires not disclosed

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

F2 · derivative.exercise_price: Each share of Series B Preferred Stock automatically converted into 0.1900057 shares of the Issuer's common stock upon the closing of the Issuer's initial public offering (on an adjusted basis, after giving effect to the 1-for-5.263 reverse stock split effected by the Issuer in connection with its initial public offering).

F2 · price: Each share of Series B Preferred Stock automatically converted into 0.1900057 shares of the Issuer's common stock upon the closing of the Issuer's initial public offering (on an adjusted basis, after giving effect to the 1-for-5.263 reverse stock split effected by the Issuer in connection with its initial public offering).

F2 · derivative.exercise_date: Each share of Series B Preferred Stock automatically converted into 0.1900057 shares of the Issuer's common stock upon the closing of the Issuer's initial public offering (on an adjusted basis, after giving effect to the 1-for-5.263 reverse stock split effected by the Issuer in connection with its initial public offering).

F2 · derivative.expiration_date: Each share of Series B Preferred Stock automatically converted into 0.1900057 shares of the Issuer's common stock upon the closing of the Issuer's initial public offering (on an adjusted basis, after giving effect to the 1-for-5.263 reverse stock split effected by the Issuer in connection with its initial public offering).

F3 · ownership.nature: This Form 4 is being filed by the undersigned as well as the entities listed on the Joint Filer Information Statement attached as an exhibit hereto (the "Reporting Persons"). Deerfield Mgmt III, L.P. is the general partner of Deerfield Private Design Fund III, L.P. ("Fund III"). Deerfield Mgmt, L.P. is the general partner of Deerfield Partners, L.P. ("Deerfield Partners"). Deerfield Mgmt HIF, L.P. is the general partner of Deerfield Healthcare Innovations Fund, L.P. (collectively with Fund III and Deerfield Partners, the "Funds"). Deerfield Management Company, L.P. is the investment manager of the Funds. James E. Flynn is the sole member of the general partner of each of Deerfield Mgmt, L.P., Deerfield Mgmt III, L.P., Deerfield Mgmt HIF, L.P. and Deerfield Management Company, L.P.

F4 · ownership.nature: In accordance with Instruction 4 (b)(iv) to Form 4, the entire amount of the Issuer's securities held by the Funds is reported herein. For purposes of Section 16 of the Securities Exchange Act of 1934, as amended, each Reporting Person disclaims beneficial ownership of any such securities, except to the extent of his/its indirect pecuniary interest therein, if any, and this report shall not be deemed an admission that such Reporting Person is the beneficial owner of such securities for purposes of Section 16 or otherwise.

SEC source: 0001193805-18-000506 · e617881_4-homology.xml · derivative · entry 8

Flynn James E · CIK 0001352546 · Director · 10% owner · *Director by Deputization

DEERFIELD MANAGEMENT COMPANY, L.P. (SERIES C) · CIK 0001009258 · Director · 10% owner · *Director by Deputization

Deerfield Mgmt L.P. · CIK 0001010823 · Director · 10% owner · *Director by Deputization

DEERFIELD PARTNERS, L.P. · CIK 0001301041 · Director · 10% owner · *Director by Deputization

Deerfield Private Design Fund III, L.P. · CIK 0001603333 · Director · 10% owner · *Director by Deputization

Deerfield Mgmt III, L.P. · CIK 0001610540 · Director · 10% owner · *Director by Deputization

Deerfield Healthcare Innovations Fund, L.P. · CIK 0001646981 · Director · 10% owner · *Director by Deputization

Deerfield Mgmt HIF, L.P. · CIK 0001665736 · Director · 10% owner · *Director by Deputization

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

10b5-1 filing: Not disclosed

Ownership: Indirect · Through Deerfield Private Design Fund III, L.P.

Disclosed balance after: 0

Underlying: Common Stock · 669,034 shares

Expires not disclosed

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

F1 · derivative.exercise_price: Each share of Series A Preferred Stock automatically converted into 0.1900057 shares of the Issuer's common stock upon the closing of the Issuer's initial public offering (on an adjusted basis, after giving effect to the 1-for-5.263 reverse stock split effected by the Issuer in connection with its initial public offering).

F1 · price: Each share of Series A Preferred Stock automatically converted into 0.1900057 shares of the Issuer's common stock upon the closing of the Issuer's initial public offering (on an adjusted basis, after giving effect to the 1-for-5.263 reverse stock split effected by the Issuer in connection with its initial public offering).

F1 · derivative.exercise_date: Each share of Series A Preferred Stock automatically converted into 0.1900057 shares of the Issuer's common stock upon the closing of the Issuer's initial public offering (on an adjusted basis, after giving effect to the 1-for-5.263 reverse stock split effected by the Issuer in connection with its initial public offering).

F1 · derivative.expiration_date: Each share of Series A Preferred Stock automatically converted into 0.1900057 shares of the Issuer's common stock upon the closing of the Issuer's initial public offering (on an adjusted basis, after giving effect to the 1-for-5.263 reverse stock split effected by the Issuer in connection with its initial public offering).

F3 · ownership.nature: This Form 4 is being filed by the undersigned as well as the entities listed on the Joint Filer Information Statement attached as an exhibit hereto (the "Reporting Persons"). Deerfield Mgmt III, L.P. is the general partner of Deerfield Private Design Fund III, L.P. ("Fund III"). Deerfield Mgmt, L.P. is the general partner of Deerfield Partners, L.P. ("Deerfield Partners"). Deerfield Mgmt HIF, L.P. is the general partner of Deerfield Healthcare Innovations Fund, L.P. (collectively with Fund III and Deerfield Partners, the "Funds"). Deerfield Management Company, L.P. is the investment manager of the Funds. James E. Flynn is the sole member of the general partner of each of Deerfield Mgmt, L.P., Deerfield Mgmt III, L.P., Deerfield Mgmt HIF, L.P. and Deerfield Management Company, L.P.

F4 · ownership.nature: In accordance with Instruction 4 (b)(iv) to Form 4, the entire amount of the Issuer's securities held by the Funds is reported herein. For purposes of Section 16 of the Securities Exchange Act of 1934, as amended, each Reporting Person disclaims beneficial ownership of any such securities, except to the extent of his/its indirect pecuniary interest therein, if any, and this report shall not be deemed an admission that such Reporting Person is the beneficial owner of such securities for purposes of Section 16 or otherwise.

SEC source: 0001193805-18-000506 · e617881_4-homology.xml · derivative · entry 7

Flynn James E · CIK 0001352546 · Director · 10% owner · *Director by Deputization

DEERFIELD MANAGEMENT COMPANY, L.P. (SERIES C) · CIK 0001009258 · Director · 10% owner · *Director by Deputization

Deerfield Mgmt L.P. · CIK 0001010823 · Director · 10% owner · *Director by Deputization

DEERFIELD PARTNERS, L.P. · CIK 0001301041 · Director · 10% owner · *Director by Deputization

Deerfield Private Design Fund III, L.P. · CIK 0001603333 · Director · 10% owner · *Director by Deputization

Deerfield Mgmt III, L.P. · CIK 0001610540 · Director · 10% owner · *Director by Deputization

Deerfield Healthcare Innovations Fund, L.P. · CIK 0001646981 · Director · 10% owner · *Director by Deputization

Deerfield Mgmt HIF, L.P. · CIK 0001665736 · Director · 10% owner · *Director by Deputization

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

10b5-1 filing: Not disclosed

Ownership: Indirect · Through Deerfield Healthcare Innovations Fund, L.P.

Disclosed balance after: 0

Underlying: Common Stock · 669,034 shares

Expires not disclosed

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

F1 · derivative.exercise_price: Each share of Series A Preferred Stock automatically converted into 0.1900057 shares of the Issuer's common stock upon the closing of the Issuer's initial public offering (on an adjusted basis, after giving effect to the 1-for-5.263 reverse stock split effected by the Issuer in connection with its initial public offering).

F1 · price: Each share of Series A Preferred Stock automatically converted into 0.1900057 shares of the Issuer's common stock upon the closing of the Issuer's initial public offering (on an adjusted basis, after giving effect to the 1-for-5.263 reverse stock split effected by the Issuer in connection with its initial public offering).

F1 · derivative.exercise_date: Each share of Series A Preferred Stock automatically converted into 0.1900057 shares of the Issuer's common stock upon the closing of the Issuer's initial public offering (on an adjusted basis, after giving effect to the 1-for-5.263 reverse stock split effected by the Issuer in connection with its initial public offering).

F1 · derivative.expiration_date: Each share of Series A Preferred Stock automatically converted into 0.1900057 shares of the Issuer's common stock upon the closing of the Issuer's initial public offering (on an adjusted basis, after giving effect to the 1-for-5.263 reverse stock split effected by the Issuer in connection with its initial public offering).

F3 · ownership.nature: This Form 4 is being filed by the undersigned as well as the entities listed on the Joint Filer Information Statement attached as an exhibit hereto (the "Reporting Persons"). Deerfield Mgmt III, L.P. is the general partner of Deerfield Private Design Fund III, L.P. ("Fund III"). Deerfield Mgmt, L.P. is the general partner of Deerfield Partners, L.P. ("Deerfield Partners"). Deerfield Mgmt HIF, L.P. is the general partner of Deerfield Healthcare Innovations Fund, L.P. (collectively with Fund III and Deerfield Partners, the "Funds"). Deerfield Management Company, L.P. is the investment manager of the Funds. James E. Flynn is the sole member of the general partner of each of Deerfield Mgmt, L.P., Deerfield Mgmt III, L.P., Deerfield Mgmt HIF, L.P. and Deerfield Management Company, L.P.

F4 · ownership.nature: In accordance with Instruction 4 (b)(iv) to Form 4, the entire amount of the Issuer's securities held by the Funds is reported herein. For purposes of Section 16 of the Securities Exchange Act of 1934, as amended, each Reporting Person disclaims beneficial ownership of any such securities, except to the extent of his/its indirect pecuniary interest therein, if any, and this report shall not be deemed an admission that such Reporting Person is the beneficial owner of such securities for purposes of Section 16 or otherwise.

SEC source: 0001193805-18-000506 · e617881_4-homology.xml · nonDerivative · entry 6

Flynn James E · CIK 0001352546 · Director · 10% owner · *Director by Deputization

DEERFIELD MANAGEMENT COMPANY, L.P. (SERIES C) · CIK 0001009258 · Director · 10% owner · *Director by Deputization

Deerfield Mgmt L.P. · CIK 0001010823 · Director · 10% owner · *Director by Deputization

DEERFIELD PARTNERS, L.P. · CIK 0001301041 · Director · 10% owner · *Director by Deputization

Deerfield Private Design Fund III, L.P. · CIK 0001603333 · Director · 10% owner · *Director by Deputization

Deerfield Mgmt III, L.P. · CIK 0001610540 · Director · 10% owner · *Director by Deputization

Deerfield Healthcare Innovations Fund, L.P. · CIK 0001646981 · Director · 10% owner · *Director by Deputization

Deerfield Mgmt HIF, L.P. · CIK 0001665736 · Director · 10% owner · *Director by Deputization

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

10b5-1 filing: Not disclosed

Ownership: Indirect · Through Deerfield Partners, L.P.

Disclosed balance after: 625,000

F3 · ownership.nature: This Form 4 is being filed by the undersigned as well as the entities listed on the Joint Filer Information Statement attached as an exhibit hereto (the "Reporting Persons"). Deerfield Mgmt III, L.P. is the general partner of Deerfield Private Design Fund III, L.P. ("Fund III"). Deerfield Mgmt, L.P. is the general partner of Deerfield Partners, L.P. ("Deerfield Partners"). Deerfield Mgmt HIF, L.P. is the general partner of Deerfield Healthcare Innovations Fund, L.P. (collectively with Fund III and Deerfield Partners, the "Funds"). Deerfield Management Company, L.P. is the investment manager of the Funds. James E. Flynn is the sole member of the general partner of each of Deerfield Mgmt, L.P., Deerfield Mgmt III, L.P., Deerfield Mgmt HIF, L.P. and Deerfield Management Company, L.P.

F4 · ownership.nature: In accordance with Instruction 4 (b)(iv) to Form 4, the entire amount of the Issuer's securities held by the Funds is reported herein. For purposes of Section 16 of the Securities Exchange Act of 1934, as amended, each Reporting Person disclaims beneficial ownership of any such securities, except to the extent of his/its indirect pecuniary interest therein, if any, and this report shall not be deemed an admission that such Reporting Person is the beneficial owner of such securities for purposes of Section 16 or otherwise.

SEC source: 0001193805-18-000506 · e617881_4-homology.xml · nonDerivative · entry 5

Flynn James E · CIK 0001352546 · Director · 10% owner · *Director by Deputization

DEERFIELD MANAGEMENT COMPANY, L.P. (SERIES C) · CIK 0001009258 · Director · 10% owner · *Director by Deputization

Deerfield Mgmt L.P. · CIK 0001010823 · Director · 10% owner · *Director by Deputization

DEERFIELD PARTNERS, L.P. · CIK 0001301041 · Director · 10% owner · *Director by Deputization

Deerfield Private Design Fund III, L.P. · CIK 0001603333 · Director · 10% owner · *Director by Deputization

Deerfield Mgmt III, L.P. · CIK 0001610540 · Director · 10% owner · *Director by Deputization

Deerfield Healthcare Innovations Fund, L.P. · CIK 0001646981 · Director · 10% owner · *Director by Deputization

Deerfield Mgmt HIF, L.P. · CIK 0001665736 · Director · 10% owner · *Director by Deputization

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

10b5-1 filing: Not disclosed

Ownership: Indirect · Through Deerfield Private Design Fund III, L.P.

Disclosed balance after: 2,613,517

F3 · ownership.nature: This Form 4 is being filed by the undersigned as well as the entities listed on the Joint Filer Information Statement attached as an exhibit hereto (the "Reporting Persons"). Deerfield Mgmt III, L.P. is the general partner of Deerfield Private Design Fund III, L.P. ("Fund III"). Deerfield Mgmt, L.P. is the general partner of Deerfield Partners, L.P. ("Deerfield Partners"). Deerfield Mgmt HIF, L.P. is the general partner of Deerfield Healthcare Innovations Fund, L.P. (collectively with Fund III and Deerfield Partners, the "Funds"). Deerfield Management Company, L.P. is the investment manager of the Funds. James E. Flynn is the sole member of the general partner of each of Deerfield Mgmt, L.P., Deerfield Mgmt III, L.P., Deerfield Mgmt HIF, L.P. and Deerfield Management Company, L.P.

F4 · ownership.nature: In accordance with Instruction 4 (b)(iv) to Form 4, the entire amount of the Issuer's securities held by the Funds is reported herein. For purposes of Section 16 of the Securities Exchange Act of 1934, as amended, each Reporting Person disclaims beneficial ownership of any such securities, except to the extent of his/its indirect pecuniary interest therein, if any, and this report shall not be deemed an admission that such Reporting Person is the beneficial owner of such securities for purposes of Section 16 or otherwise.

SEC source: 0001193805-18-000506 · e617881_4-homology.xml · nonDerivative · entry 4

Flynn James E · CIK 0001352546 · Director · 10% owner · *Director by Deputization

DEERFIELD MANAGEMENT COMPANY, L.P. (SERIES C) · CIK 0001009258 · Director · 10% owner · *Director by Deputization

Deerfield Mgmt L.P. · CIK 0001010823 · Director · 10% owner · *Director by Deputization

DEERFIELD PARTNERS, L.P. · CIK 0001301041 · Director · 10% owner · *Director by Deputization

Deerfield Private Design Fund III, L.P. · CIK 0001603333 · Director · 10% owner · *Director by Deputization

Deerfield Mgmt III, L.P. · CIK 0001610540 · Director · 10% owner · *Director by Deputization

Deerfield Healthcare Innovations Fund, L.P. · CIK 0001646981 · Director · 10% owner · *Director by Deputization

Deerfield Mgmt HIF, L.P. · CIK 0001665736 · Director · 10% owner · *Director by Deputization

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

10b5-1 filing: Not disclosed

Ownership: Indirect · Through Deerfield Private Design Fund III, L.P.

Disclosed balance after: 1,988,517

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.

F2 · price: Each share of Series B Preferred Stock automatically converted into 0.1900057 shares of the Issuer's common stock upon the closing of the Issuer's initial public offering (on an adjusted basis, after giving effect to the 1-for-5.263 reverse stock split effected by the Issuer in connection with its initial public offering).

F3 · ownership.nature: This Form 4 is being filed by the undersigned as well as the entities listed on the Joint Filer Information Statement attached as an exhibit hereto (the "Reporting Persons"). Deerfield Mgmt III, L.P. is the general partner of Deerfield Private Design Fund III, L.P. ("Fund III"). Deerfield Mgmt, L.P. is the general partner of Deerfield Partners, L.P. ("Deerfield Partners"). Deerfield Mgmt HIF, L.P. is the general partner of Deerfield Healthcare Innovations Fund, L.P. (collectively with Fund III and Deerfield Partners, the "Funds"). Deerfield Management Company, L.P. is the investment manager of the Funds. James E. Flynn is the sole member of the general partner of each of Deerfield Mgmt, L.P., Deerfield Mgmt III, L.P., Deerfield Mgmt HIF, L.P. and Deerfield Management Company, L.P.

F4 · ownership.nature: In accordance with Instruction 4 (b)(iv) to Form 4, the entire amount of the Issuer's securities held by the Funds is reported herein. For purposes of Section 16 of the Securities Exchange Act of 1934, as amended, each Reporting Person disclaims beneficial ownership of any such securities, except to the extent of his/its indirect pecuniary interest therein, if any, and this report shall not be deemed an admission that such Reporting Person is the beneficial owner of such securities for purposes of Section 16 or otherwise.

SEC source: 0001193805-18-000506 · e617881_4-homology.xml · nonDerivative · entry 3

Flynn James E · CIK 0001352546 · Director · 10% owner · *Director by Deputization

DEERFIELD MANAGEMENT COMPANY, L.P. (SERIES C) · CIK 0001009258 · Director · 10% owner · *Director by Deputization

Deerfield Mgmt L.P. · CIK 0001010823 · Director · 10% owner · *Director by Deputization

DEERFIELD PARTNERS, L.P. · CIK 0001301041 · Director · 10% owner · *Director by Deputization

Deerfield Private Design Fund III, L.P. · CIK 0001603333 · Director · 10% owner · *Director by Deputization

Deerfield Mgmt III, L.P. · CIK 0001610540 · Director · 10% owner · *Director by Deputization

Deerfield Healthcare Innovations Fund, L.P. · CIK 0001646981 · Director · 10% owner · *Director by Deputization

Deerfield Mgmt HIF, L.P. · CIK 0001665736 · Director · 10% owner · *Director by Deputization

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

10b5-1 filing: Not disclosed

Ownership: Indirect · Through Deerfield Healthcare Innovations Fund, L.P.

Disclosed balance after: 1,988,518

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.

F2 · price: Each share of Series B Preferred Stock automatically converted into 0.1900057 shares of the Issuer's common stock upon the closing of the Issuer's initial public offering (on an adjusted basis, after giving effect to the 1-for-5.263 reverse stock split effected by the Issuer in connection with its initial public offering).

F3 · ownership.nature: This Form 4 is being filed by the undersigned as well as the entities listed on the Joint Filer Information Statement attached as an exhibit hereto (the "Reporting Persons"). Deerfield Mgmt III, L.P. is the general partner of Deerfield Private Design Fund III, L.P. ("Fund III"). Deerfield Mgmt, L.P. is the general partner of Deerfield Partners, L.P. ("Deerfield Partners"). Deerfield Mgmt HIF, L.P. is the general partner of Deerfield Healthcare Innovations Fund, L.P. (collectively with Fund III and Deerfield Partners, the "Funds"). Deerfield Management Company, L.P. is the investment manager of the Funds. James E. Flynn is the sole member of the general partner of each of Deerfield Mgmt, L.P., Deerfield Mgmt III, L.P., Deerfield Mgmt HIF, L.P. and Deerfield Management Company, L.P.

F4 · ownership.nature: In accordance with Instruction 4 (b)(iv) to Form 4, the entire amount of the Issuer's securities held by the Funds is reported herein. For purposes of Section 16 of the Securities Exchange Act of 1934, as amended, each Reporting Person disclaims beneficial ownership of any such securities, except to the extent of his/its indirect pecuniary interest therein, if any, and this report shall not be deemed an admission that such Reporting Person is the beneficial owner of such securities for purposes of Section 16 or otherwise.

SEC source: 0001193805-18-000506 · e617881_4-homology.xml · nonDerivative · entry 2

Flynn James E · CIK 0001352546 · Director · 10% owner · *Director by Deputization

DEERFIELD MANAGEMENT COMPANY, L.P. (SERIES C) · CIK 0001009258 · Director · 10% owner · *Director by Deputization

Deerfield Mgmt L.P. · CIK 0001010823 · Director · 10% owner · *Director by Deputization

DEERFIELD PARTNERS, L.P. · CIK 0001301041 · Director · 10% owner · *Director by Deputization

Deerfield Private Design Fund III, L.P. · CIK 0001603333 · Director · 10% owner · *Director by Deputization

Deerfield Mgmt III, L.P. · CIK 0001610540 · Director · 10% owner · *Director by Deputization

Deerfield Healthcare Innovations Fund, L.P. · CIK 0001646981 · Director · 10% owner · *Director by Deputization

Deerfield Mgmt HIF, L.P. · CIK 0001665736 · Director · 10% owner · *Director by Deputization

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

10b5-1 filing: Not disclosed

Ownership: Indirect · Through Deerfield Private Design Fund III, L.P.

Disclosed balance after: 669,034

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

F1 · price: Each share of Series A Preferred Stock automatically converted into 0.1900057 shares of the Issuer's common stock upon the closing of the Issuer's initial public offering (on an adjusted basis, after giving effect to the 1-for-5.263 reverse stock split effected by the Issuer in connection with its initial public offering).

F3 · ownership.nature: This Form 4 is being filed by the undersigned as well as the entities listed on the Joint Filer Information Statement attached as an exhibit hereto (the "Reporting Persons"). Deerfield Mgmt III, L.P. is the general partner of Deerfield Private Design Fund III, L.P. ("Fund III"). Deerfield Mgmt, L.P. is the general partner of Deerfield Partners, L.P. ("Deerfield Partners"). Deerfield Mgmt HIF, L.P. is the general partner of Deerfield Healthcare Innovations Fund, L.P. (collectively with Fund III and Deerfield Partners, the "Funds"). Deerfield Management Company, L.P. is the investment manager of the Funds. James E. Flynn is the sole member of the general partner of each of Deerfield Mgmt, L.P., Deerfield Mgmt III, L.P., Deerfield Mgmt HIF, L.P. and Deerfield Management Company, L.P.

F4 · ownership.nature: In accordance with Instruction 4 (b)(iv) to Form 4, the entire amount of the Issuer's securities held by the Funds is reported herein. For purposes of Section 16 of the Securities Exchange Act of 1934, as amended, each Reporting Person disclaims beneficial ownership of any such securities, except to the extent of his/its indirect pecuniary interest therein, if any, and this report shall not be deemed an admission that such Reporting Person is the beneficial owner of such securities for purposes of Section 16 or otherwise.

SEC source: 0001193805-18-000506 · e617881_4-homology.xml · nonDerivative · entry 1

Flynn James E · CIK 0001352546 · Director · 10% owner · *Director by Deputization

DEERFIELD MANAGEMENT COMPANY, L.P. (SERIES C) · CIK 0001009258 · Director · 10% owner · *Director by Deputization

Deerfield Mgmt L.P. · CIK 0001010823 · Director · 10% owner · *Director by Deputization

DEERFIELD PARTNERS, L.P. · CIK 0001301041 · Director · 10% owner · *Director by Deputization

Deerfield Private Design Fund III, L.P. · CIK 0001603333 · Director · 10% owner · *Director by Deputization

Deerfield Mgmt III, L.P. · CIK 0001610540 · Director · 10% owner · *Director by Deputization

Deerfield Healthcare Innovations Fund, L.P. · CIK 0001646981 · Director · 10% owner · *Director by Deputization

Deerfield Mgmt HIF, L.P. · CIK 0001665736 · Director · 10% owner · *Director by Deputization

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

10b5-1 filing: Not disclosed

Ownership: Indirect · Through Deerfield Healthcare Innovations Fund, L.P.

Disclosed balance after: 669,034

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

F1 · price: Each share of Series A Preferred Stock automatically converted into 0.1900057 shares of the Issuer's common stock upon the closing of the Issuer's initial public offering (on an adjusted basis, after giving effect to the 1-for-5.263 reverse stock split effected by the Issuer in connection with its initial public offering).

F3 · ownership.nature: This Form 4 is being filed by the undersigned as well as the entities listed on the Joint Filer Information Statement attached as an exhibit hereto (the "Reporting Persons"). Deerfield Mgmt III, L.P. is the general partner of Deerfield Private Design Fund III, L.P. ("Fund III"). Deerfield Mgmt, L.P. is the general partner of Deerfield Partners, L.P. ("Deerfield Partners"). Deerfield Mgmt HIF, L.P. is the general partner of Deerfield Healthcare Innovations Fund, L.P. (collectively with Fund III and Deerfield Partners, the "Funds"). Deerfield Management Company, L.P. is the investment manager of the Funds. James E. Flynn is the sole member of the general partner of each of Deerfield Mgmt, L.P., Deerfield Mgmt III, L.P., Deerfield Mgmt HIF, L.P. and Deerfield Management Company, L.P.

F4 · ownership.nature: In accordance with Instruction 4 (b)(iv) to Form 4, the entire amount of the Issuer's securities held by the Funds is reported herein. For purposes of Section 16 of the Securities Exchange Act of 1934, as amended, each Reporting Person disclaims beneficial ownership of any such securities, except to the extent of his/its indirect pecuniary interest therein, if any, and this report shall not be deemed an admission that such Reporting Person is the beneficial owner of such securities for purposes of Section 16 or otherwise.