The remainder of this cover page shall be filled out for a reporting person’s initial filing on this form with respect to the subject class of securities, and for any subsequent amendment containing information which would alter disclosures provided in a prior cover page.

NAMES OF REPORTING PERSONS

Omega Fund V, L.P.

CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP (SEE INSTRUCTIONS)

(a)  ☐        (b)  ☒ (1)

SEC USE ONLY

CITIZENSHIP OR PLACE OF ORGANIZATION

Cayman Islands

NUMBER OF SHARES BENEFICIALLY  

OWNED BY EACH REPORTING PERSON

WITH

SOLE VOTING POWER

0

SHARED VOTING POWER

6,119,345

SOLE DISPOSITIVE POWER

0

SHARED DISPOSITIVE POWER

6,119,345

AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

6,119,345

CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES (SEE INSTRUCTIONS)  ☐

PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW 9

9.3% (2)

TYPE OF REPORTING PERSON (SEE INSTRUCTIONS)

PN

This Schedule 13G is filed by Omega Fund V, L.P. (“Omega Fund”), Omega Fund V GP, L.P. (“Omega GP”), Omega Fund V GP Manager, Ltd. (“Omega Ltd”), Claudio Nessi (“Nessi”), Otello Stampacchia (“Stampacchia”), and Anne-Mari Paster (“Paster”) (together, the “Reporting Persons”). Omega Ltd serves as the general partner of Omega GP, which serves as the general partner of Omega Fund; and each of Omega Ltd and Omega GP may be deemed to own beneficially the shares held by Omega Fund. Nessi, Stampacchia, and Paster are the directors of Omega Ltd and may be deemed to beneficially own the shares held by Omega Fund. The Reporting Persons may be deemed a “group” for purposes of Section 13 of the Exchange Act and expressly disclaim status as a “group” for purposes of this Schedule 13G.

The following percentages are based on 66,038,122 share of Common Stock outstanding as of November 6, 2019 as set forth in the Issuer’s most recent Form 10-Q for the period ending September 30, 2019, filed with the Securities and Exchange Commission on November 12, 2019.

NAMES OF REPORTING PERSONS

Omega Fund V GP, L.P.

CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP (SEE INSTRUCTIONS)

(a)  ☐        (b)  ☒ (1)

SEC USE ONLY

CITIZENSHIP OR PLACE OF ORGANIZATION

Cayman Islands

NUMBER OF SHARES BENEFICIALLY  

OWNED BY EACH REPORTING PERSON

WITH

SOLE VOTING POWER

0

SHARED VOTING POWER

6,119,345

SOLE DISPOSITIVE POWER

0

SHARED DISPOSITIVE POWER

6,119,345

AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

6,119,345

CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES (SEE INSTRUCTIONS)  ☐

PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW 9

9.3% (2)

TYPE OF REPORTING PERSON (SEE INSTRUCTIONS)

PN

This Schedule 13G is filed by Omega Fund V, L.P. (“Omega Fund”), Omega Fund V GP, L.P. (“Omega GP”), Omega Fund V GP Manager, Ltd. (“Omega Ltd”), Claudio Nessi (“Nessi”), Otello Stampacchia (“Stampacchia”), and Anne-Mari Paster (“Paster”) (together, the “Reporting Persons”). Omega Ltd serves as the general partner of Omega GP, which serves as the general partner of Omega Fund; and each of Omega Ltd and Omega GP may be deemed to own beneficially the shares held by Omega Fund. Nessi, Stampacchia, and Paster are the directors of Omega Ltd and may be deemed to beneficially own the shares held by Omega Fund. The Reporting Persons may be deemed a “group” for purposes of Section 13 of the Exchange Act and expressly disclaim status as a “group” for purposes of this Schedule 13G.

The following percentages are based on 66,038,122 share of Common Stock outstanding as of November 6, 2019 as set forth in the Issuer’s most recent Form 10-Q for the period ending September 30, 2019, filed with the Securities and Exchange Commission on November 12, 2019.

NAMES OF REPORTING PERSONS

Omega Fund V GP Manager, Ltd.

CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP (SEE INSTRUCTIONS)

(a)  ☐        (b)  ☒ (1)

SEC USE ONLY

CITIZENSHIP OR PLACE OF ORGANIZATION

Cayman Islands

NUMBER OF SHARES BENEFICIALLY  

OWNED BY EACH REPORTING PERSON

WITH

SOLE VOTING POWER

0

SHARED VOTING POWER

6,119,345

SOLE DISPOSITIVE POWER

0

SHARED DISPOSITIVE POWER

6,119,345

AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

6,119,345

CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES (SEE INSTRUCTIONS)  ☐

PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW 9

9.3% (2)

TYPE OF REPORTING PERSON (SEE INSTRUCTIONS)

OO

This Schedule 13G is filed by Omega Fund V, L.P. (“Omega Fund”), Omega Fund V GP, L.P. (“Omega GP”), Omega Fund V GP Manager, Ltd. (“Omega Ltd”), Claudio Nessi (“Nessi”), Otello Stampacchia (“Stampacchia”), and Anne-Mari Paster (“Paster”) (together, the “Reporting Persons”). Omega Ltd serves as the general partner of Omega GP, which serves as the general partner of Omega Fund; and each of Omega Ltd and Omega GP may be deemed to own beneficially the shares held by Omega Fund. Nessi, Stampacchia, and Paster are the directors of Omega Ltd and may be deemed to beneficially own the shares held by Omega Fund. The Reporting Persons may be deemed a “group” for purposes of Section 13 of the Exchange Act and expressly disclaim status as a “group” for purposes of this Schedule 13G.

The following percentages are based on 66,038,122 share of Common Stock outstanding as of November 6, 2019 as set forth in the Issuer’s most recent Form 10-Q for the period ending September 30, 2019, filed with the Securities and Exchange Commission on November 12, 2019.

NAMES OF REPORTING PERSONS

Claudio Nessi

CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP (SEE INSTRUCTIONS)

(a)  ☐        (b)  ☒ (1)

SEC USE ONLY

CITIZENSHIP OR PLACE OF ORGANIZATION

Switzerland

NUMBER OF SHARES BENEFICIALLY  

OWNED BY EACH REPORTING PERSON

WITH

SOLE VOTING POWER

0

SHARED VOTING POWER

6,119,345

SOLE DISPOSITIVE POWER

0

SHARED DISPOSITIVE POWER

6,119,345

AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

6,119,345

CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES (SEE INSTRUCTIONS)  ☐

PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW 9

9.3% (2)

TYPE OF REPORTING PERSON (SEE INSTRUCTIONS)

IN

This Schedule 13G is filed by Omega Fund V, L.P. (“Omega Fund”), Omega Fund V GP, L.P. (“Omega GP”), Omega Fund V GP Manager, Ltd. (“Omega Ltd”), Claudio Nessi (“Nessi”), Otello Stampacchia (“Stampacchia”), and Anne-Mari Paster (“Paster”) (together, the “Reporting Persons”). Omega Ltd serves as the general partner of Omega GP, which serves as the general partner of Omega Fund; and each of Omega Ltd and Omega GP may be deemed to own beneficially the shares held by Omega Fund. Nessi, Stampacchia, and Paster are the directors of Omega Ltd and may be deemed to beneficially own the shares held by Omega Fund. The Reporting Persons may be deemed a “group” for purposes of Section 13 of the Exchange Act and expressly disclaim status as a “group” for purposes of this Schedule 13G.

The following percentages are based on 66,038,122 share of Common Stock outstanding as of November 6, 2019 as set forth in the Issuer’s most recent Form 10-Q for the period ending September 30, 2019, filed with the Securities and Exchange Commission on November 12, 2019.

NAMES OF REPORTING PERSONS

Otello Stampacchia

CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP (SEE INSTRUCTIONS)

(a)  ☐        (b)  ☒ (1)

SEC USE ONLY

CITIZENSHIP OR PLACE OF ORGANIZATION

Italy

NUMBER OF SHARES BENEFICIALLY  

OWNED BY EACH REPORTING PERSON

WITH

SOLE VOTING POWER

0

SHARED VOTING POWER

6,119,345

SOLE DISPOSITIVE POWER

0

SHARED DISPOSITIVE POWER

6,119,345

AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

6,119,345

CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES (SEE INSTRUCTIONS)  ☐

PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW 9

9.3% (2)

TYPE OF REPORTING PERSON (SEE INSTRUCTIONS)

IN

This Schedule 13G is filed by Omega Fund V, L.P. (“Omega Fund”), Omega Fund V GP, L.P. (“Omega GP”), Omega Fund V GP Manager, Ltd. (“Omega Ltd”), Claudio Nessi (“Nessi”), Otello Stampacchia (“Stampacchia”), and Anne-Mari Paster (“Paster”) (together, the “Reporting Persons”). Omega Ltd serves as the general partner of Omega GP, which serves as the general partner of Omega Fund; and each of Omega Ltd and Omega GP may be deemed to own beneficially the shares held by Omega Fund. Nessi, Stampacchia, and Paster are the directors of Omega Ltd and may be deemed to beneficially own the shares held by Omega Fund. The Reporting Persons may be deemed a “group” for purposes of Section 13 of the Exchange Act and expressly disclaim status as a “group” for purposes of this Schedule 13G.

The following percentages are based on 66,038,122 share of Common Stock outstanding as of November 6, 2019 as set forth in the Issuer’s most recent Form 10-Q for the period ending September 30, 2019, filed with the Securities and Exchange Commission on November 12, 2019.

NAMES OF REPORTING PERSONS

Anne-Mari Paster

CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP (SEE INSTRUCTIONS)

(a)  ☐        (b)  ☒ (1)

SEC USE ONLY

CITIZENSHIP OR PLACE OF ORGANIZATION

United States of America

NUMBER OF SHARES BENEFICIALLY  

OWNED BY EACH REPORTING PERSON

WITH

SOLE VOTING POWER

0

SHARED VOTING POWER

6,119,345

SOLE DISPOSITIVE POWER

0

SHARED DISPOSITIVE POWER

6,119,345

AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

6,119,345

CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES (SEE INSTRUCTIONS)  ☐

PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW 9

9.3% (2)

TYPE OF REPORTING PERSON (SEE INSTRUCTIONS)

IN

This Schedule 13G is filed by Omega Fund V, L.P. (“Omega Fund”), Omega Fund V GP, L.P. (“Omega GP”), Omega Fund V GP Manager, Ltd. (“Omega Ltd”), Claudio Nessi (“Nessi”), Otello Stampacchia (“Stampacchia”), and Anne-Mari Paster (“Paster”) (together, the “Reporting Persons”). Omega Ltd serves as the general partner of Omega GP, which serves as the general partner of Omega Fund; and each of Omega Ltd and Omega GP may be deemed to own beneficially the shares held by Omega Fund. Nessi, Stampacchia, and Paster are the directors of Omega Ltd and may be deemed to beneficially own the shares held by Omega Fund. The Reporting Persons may be deemed a “group” for purposes of Section 13 of the Exchange Act and expressly disclaim status as a “group” for purposes of this Schedule 13G.

The following percentages are based on 66,038,122 share of Common Stock outstanding as of November 6, 2019 as set forth in the Issuer’s most recent Form 10-Q for the period ending September 30, 2019, filed with the Securities and Exchange Commission on November 12, 2019.

Name of Issuer:

Address of Issuer’s principal executive offices:

Name of Reporting Persons filing:

Address or principal business office or, if none, residence:

Citizenship:

Name

Citizenship or Place of Organization

Omega Fund

Omega GP

Omega Ltd.

Nessi

Stampacchia

Paster

Title of class of securities:

CUSIP No.:

If this statement is filed pursuant to §§ 240.13d-1(b), or 240.13d-2(b) or (c), check whether the person filings is a:

Ownership

Reporting Persons

Omega Fund(2)(3)

Omega GP(2)(3)

Omega Ltd(2)(3)

Nessi(2)(3)

Stampacchia(2)(3)

Paster(2)(3)

The following percentages are based on 66,038,122 share of Common Stock outstanding as of November 6, 2019 as set forth in the Issuer’s most recent Form 10-Q for the period ending September 30, 2019, filed with the Securities and Exchange Commission on November 12, 2019.

Omega Fund owns 6,119,345 shares of the Common Stock. Omega Ltd serves as the general partner of Omega GP, which serves as the general partner of Omega Fund, and each of Omega GP and Omega Ltd may be deemed to own beneficially the shares held by Omega Fund. Nessi, Stampacchia, and Paster are the directors of Omega Ltd and may be deemed to beneficially own the shares held by Omega Fund.

The Reporting Persons may be deemed a “group” for purposes of Section 13 of the Exchange Act and expressly disclaim status as a “group” for purposes of this Schedule 13G.

Ownership of Five Percent or Less of a Class

Ownership of More than Five Percent on Behalf of Another Person

Identification and Classification of the Subsidiary Which Acquired the Security Being Reported on by the Parent Holding Company or Control Person

Identification and Classification of Members of the Group

Notice of Dissolution of Group

Certifications

execute for and on behalf of each of such person Forms 3, 4, and 5 and Schedules 13D or 13G, as appropriate, and any required amendments thereto (collectively, the “Reports”), with respect to their current or future beneficial ownership of securities of any public company, in accordance with Section 13(d) and/or Section 16(a) of the Securities Exchange Act of 1934, as amended, and the respective rules (including Rule 13d-1) promulgated thereunder;

do and perform any and all acts for and on behalf of such person which may be necessary or desirable to complete and execute any such Report and timely file such form with the United States Securities and Exchange Commission and any stock exchange or similar authority; and

take any other action of any type whatsoever in connection with the foregoing which, in the opinion of an attorney-in-fact, may be of benefit to, in the best interest of, or legally required by, such person, it being understood that the documents executed by an attorney-in-fact on behalf of such person pursuant to this Power of Attorney shall be in such form and shall contain such terms and conditions as such attorney-in-fact may approve in such attorney-in-fact’s discretion.