Repare Therapeutics Announces Closing of Upsized Offering of Common Shares and Full Exercise of Underwriters' Option to Purchase Additional Shares

Repare Therapeutics Inc. (Nasdaq: RPTX), a leading precision oncology company enabled by its proprietary synthetic lethality approach to the discovery and development of novel therapeutics, today announced the closing on November 1, 2021 of its upsized underwritten public offering of 4,600,000 common shares at a public offering price of $22.00 per share, which included the exercise in full by the underwriters of their option to purchase up to 600,000 additional shares. All common shares were sold by Repare. The total gross proceeds for the offering were approximately $101.2 million, before deducting underwriting commissions and offering expenses payable by Repare.

Morgan Stanley, Goldman Sachs & Co. LLC, Cowen and Piper Sandler acted as joint book-running managers for the offering.

The securities described above were offered pursuant to an automatically effective shelf registration statement that was previously filed with the U.S. Securities and Exchange Commission (SEC) on July 2, 2021. The offering was made only by means of a prospectus supplement and the accompanying prospectus which forms a part of the effective shelf registration statement.

Copies of the final prospectus supplement related to the offering and the accompanying prospectus may be obtained by visiting the SEC's website located at www.sec.gov or by contacting: Morgan Stanley & Co. LLC, Attention: Prospectus Department, 180 Varick Street, 2nd Floor, New York, New York 10014; Goldman Sachs & Co. LLC, Attention: Prospectus Department, 200 West Street, New York, NY 10282, by telephone: 1-866-471-2526 or by emailing [email protected]; Cowen and Company, LLC c/o Broadridge Financial Solutions, 1155 Long Island Avenue, Edgewood, NY, 11717, Attn: Prospectus Department, by email at [email protected] or by telephone at (833) 297-2926; or Piper Sandler & Co., Attn: Prospectus Department, 800 Nicollet Mall, J12S03, Minneapolis, Minnesota 55402, by telephone at 800-747-3924 or by email at [email protected].

This press release shall not constitute an offer to sell or the solicitation of an offer to buy, nor shall there be any sale of, these securities in any state or jurisdiction in which such offer, solicitation or sale would be unlawful prior to registration or qualification under the securities laws of any such state or jurisdiction.

About Repare Therapeutics, Inc.

Repare Therapeutics is a leading clinical-stage precision oncology company enabled by its proprietary synthetic lethality approach to the discovery and development of novel therapeutics. The Company utilizes its genome-wide, CRISPR-enabled SNIPRx® platform to systematically discover and develop highly targeted cancer therapies focused on genomic instability, including DNA damage repair. The Company's pipeline includes its lead product candidate, RP-3500, a potential leading ATR inhibitor currently in Phase 1/2 clinical development, its second clinical candidate, RP-6306, a PKMYT1 inhibitor currently in Phase 1 clinical development, a Pol? inhibitor program, as well as eight other early-stage, pre-clinical programs.

SNIPRx® is a registered trademark of Repare Therapeutics Inc.