Sec Form 4 Filing - ORBIMED ADVISORS LLC @ Repare Therapeutics Inc. - 2020-06-23

FORM 4 Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934, Section 17(a) of the Public Utility Holding Company Act of 1935 or Section 30(h) of the Investment Company Act of 1940

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1. Name and Address of Reporting Person ORBIMED ADVISORS LLC 2. Issuer Name and Ticker or Trading Symbol Repare Therapeutics Inc. [ RPTX] 5. Relationship of Reporting Person(s) to Issuer (Check all applicable) X __ Director _____ 10% Owner _____ Officer (give title below) _____ Other (specify below) (Last) (First) (Middle) 601 LEXINGTON AVENUE, 54TH FLOOR 3. Date of Earliest Transaction (MM/DD/YY) 06/23/2020 (Street) NEW YORK, NY10022 4. If Amendment, Date Original Filed (MM/DD/YY) 6. Individual or Joint/Group Filing (Check Applicable Line) _____ Form filed by One Reporting Person __ X __ Form filed by More than One Reporting Person (City) (State) (Zip)

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned 1.Title of Security (Instr. 3) 2. Transaction Date (MM/DD/YY) 2A. Deemed Execution Date, if any (MM/DD/YY) 3. Transaction Code (Instr. 8) 4. Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5) 5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4) 6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4) 7. Nature of Indirect Beneficial Ownership (Instr. 4) Code V Amount (A) or (D) Price Common Stock 06/23/2020 C( 1 ) 2,601,325 A 2,601,325 I See Footnotes ( 2 ) ( 3 ) Common Stock 06/23/2020 P 675,000 A $ 20 3,276,325 I See Footnotes ( 2 ) ( 3 ) Common Stock 06/23/2020 P 99,200 A $ 20 99,200 I See Footnote ( 3 ) ( 4 )

Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned ( e.g. , puts, calls, warrants, options, convertible securities) 1. Title of Derivative Security (Instr. 3) 2. Conversion or Exercise Price of Derivative Security 3. Transaction Date (MM/DD/YY) 3A. Deemed Execution Date, if any (MM/DD/YY) 4. Transaction Code (Instr. 8) 5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4, and 5) 6. Date Exercisable and Expiration Date (MM/DD/YY) 7. Title and Amount of Underlying Securities (Instr. 3 and 4) 8. Price of Derivative Security (Instr. 5) 9. Number of Derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4) 10. Ownership Form of Derivative Security: Direct (D) or Indirect (I) (Instr. 4) 11. Nature of Indirect Beneficial Ownership (Instr. 4) Code V (A) (D) Date Exercisable Expiration Date Title Amount or Number of Shares Class B Preferred Shares ( 1 ) 06/23/2020 C( 1 ) 2,601,325 ( 1 ) ( 1 ) Common Shares 2,601,325 ( 1 ) 0 I See Footnotes ( 2 ) ( 3 )

Reporting Owners Reporting Owner Name / Address Relationships Director 10% Owner Officer Other ORBIMED ADVISORS LLC 601 LEXINGTON AVENUE 54TH FLOOR NEW YORK, NY10022 X OrbiMed Capital GP VII LLC 601 LEXINGTON AVENUE, 54TH FLOOR NEW YORK, NY10022 X ORBIMED CAPITAL LLC 601 LEXINGTON AVENUE 54TH FLOOR NEW YORK, NY10022 X Signatures /s/ OrbiMed Advisors LLC, By: /s/ Douglas Coon, Chief Compliance Officer 06/25/2020 Signature of Reporting Person Date /s/ OrbiMed Capital GP VII LLC, By: /s/ Douglas Coon, Chief Compliance Officer 06/25/2020 Signature of Reporting Person Date /s/ OrbiMed Capital LLC, By: /s/ Douglas Coon, Chief Compliance Officer 06/25/2020 Signature of Reporting Person Date

Explanation of Responses:

( 1 )Each Series B Preferred Share converted into the same number of Common Shares upon the closing of the Issuer's initial public offering and had no expiration date. ( 2 )These securities are held of record by OrbiMed Private Investments VII, LP ("OPI VII"). OrbiMed Capital GP VII LLC ("OrbiMed GP VII") is the general partner of OPI VII and OrbiMed Advisors LLC ("OrbiMed Advisors") is the managing member of OrbiMed GP VII. By virtue of such relationships, OrbiMed GP VII and OrbiMed Advisors may be deemed to have voting power and investment power over the securities held by OPI VII and as a result, may be deemed to have beneficial ownership over such securities. OrbiMed Capital LLC ("OrbiMed Capital") is a relying advisor of OrbiMed Advisors. OrbiMed Advisors and OrbiMed Capital exercise voting and investment power through a management committee comprised of the Carl L. Gordon, Sven H. Borho, and Jonathan T. Silverstein, each of whom disclaims beneficial ownership of the shares held by OPI VII. ( 3 )This report on Form 4 is jointly filed by OrbiMed Advisors, OrbiMed Capital, and OrbiMed GP VII. Each of the Reporting Persons disclaims beneficial ownership of the securities reported herein for purposes of Rule 16a-1(a) under the Securities Exchange Act of 1934, as amended (the "Exchange Act"), except to the extent of its pecuniary interest therein, if any. The Reporting Persons have designated a representative, David Bonita ("Bonita"), a member of OrbiMed Advisors, to serve on the Issuer's board of directors. This report shall not be deemed an admission that any such entity or person is a beneficial owner of such securities for purpose of Section 16 of the Exchange Act, or for any other purpose. ( 4 )These securities are held of record by OrbiMed Partners Master Fund Limited ("OPM"). OrbiMed Capital is the investment advisor to OPM. OrbiMed Capital is a relying advisor of OrbiMed Advisors. OrbiMed Advisors and OrbiMed Capital exercise voting and investment power through a management committee comprised of the Carl L. Gordon, Sven H. Borho, and Jonathan T. Silverstein, each of whom disclaims beneficial ownership of the shares held by OPM.

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