Repare Therapeutics Reports Second Quarter 2020 Financial Results and Operational Highlights

Repare Therapeutics Inc. ("Repare") (Nasdaq: RPTX), a leading precision oncology company enabled by its proprietary synthetic lethality approach to the discovery and development of novel therapeutics, today reported financial results for the second quarter ended June 30, 2020, as well as recent operational highlights.

"We set out in 2016 to become the leading precision oncology company focused on synthetic lethality in genomic instability and DNA damage repair, and have since built a strong pipeline of product candidates based upon our proprietary genome-wide, CRISPR enabled SNIPRx platform," said Lloyd M. Segal, President and Chief Executive Officer of Repare. "With the successful completion of our initial public offering in June and our entry into a strategic collaboration with Bristol Myers Squibb in May, we have established a strong cash position to advance our pipeline. I am proud of our entire team and the remarkable progress they have made."

Operational Highlights:

• Initiated a phase 1/2 clinical trial evaluating RP-3500 as a monotherapy and in combination with Pfizer's PARPi, talazoparib. In July 2020, the Company received acceptance from the U.S. Food and Drug Administration (FDA) of an investigational new drug (IND) application and commenced dosing for the first patient in the Phase 1/2 clinical trial of RP-3500.

• Completed initial public offering (IPO). In June 2020, Repare closed an upsized IPO of 12,650,000 of its common shares, including the exercise in full of the underwriters' option to purchase up to an additional 1,650,000 common shares, at a public offering price of $20.00 per share. The net proceeds to Repare, after deducting underwriting commissions and offering expenses, were $232 million.

• Bristol Myers Squibb collaboration. In May 2020, Repare entered into an exclusive, worldwide target discovery collaboration with Bristol Myers Squibb. Repare received an upfront payment from Bristol Myers Squibb of $65 million in Q2 2020, which included a $15 million equity investment in Repare in the form of a warrant that automatically exercised into 750,000 common shares at the public offering price of $20.00 per share upon IPO. In addition, Repare will be eligible to receive additional contingent payments of up to approximately $3 billion in the form of license fees, discovery, development, regulatory and sales-based milestones, in addition to royalty payments on net sales of each product commercialized by Bristol Myers Squibb.

• Appointed new director. In June 2020, Repare appointed Ann D. Rhoads to its Board of Directors and as Chairperson of its Audit Committee.

Second Quarter 2020 Financial Results:

• Cash and restricted cash: Cash and restricted cash as of June 30, 2020 were $370.1 million.

• Research and development expenses, net of tax credits (Net R&D): Net R&D expenses were $9.0 million and $17.6 million for the three and six month periods ended June 30, 2020, respectively, as compared to $4.9 million and $8.6 million in the same periods in the prior year, respectively. Increases in R&D for the three and six month periods ended June 30, 2020 were primarily due to increases in development costs related to Repare's RP-3500 and CCNE1-SL programs, as well as increases in personnel related expenses and certain other R&D expenses.

• General and administrative (G&A) expenses: G&A expenses were $3.4 million and $5.4 million for the three and six month periods ended June 30, 2020, respectively, as compared to $1 million and $2.1 million in the same periods in the prior year, respectively. Increases in G&A for the three and six month periods ended June 30, 2020 were due to increases in payroll and personnel costs as well as increases in legal, professional and D&O insurance costs, which in turn increased as a result of our recent IPO.

• Net loss: Net loss was $11.8 million, or $2.45 per share in the second quarter of 2020 and $24.4 million, or $7.56 per share, in the first half of 2020.

About Repare Therapeutics' SNIPRx® Platform

Repare's SNIPRx® platform is a genome-wide CRISPR-based screening approach that utilizes proprietary isogenic cell lines to identify novel and known synthetic lethal gene pairs and the corresponding patients who are most likely to benefit from the Company's therapies based on the genetic profile of their tumors. Repare's platform enables the development of precision therapeutics in patients whose tumors contain one or more genomic alterations identified by SNIPRx® screening, in order to selectively target those patients most likely to achieve clinical benefit from resulting product candidates.

About Repare Therapeutics, Inc.

Repare Therapeutics is a leading 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, as well as CCNE1-SL inhibitor and Pol? inhibitor programs. For more information, please visit reparerx.com.

SNIPRx® is a registered trademark of Repare Therapeutics Inc.

Forward-Looking Statement

This press release contains "forward-looking statements" within the meaning of the Private Securities Litigation Reform Act of 1995. All statements in this press release other than statements of historical facts are "forward-looking statements. These statements may be identified by words such as "aims," "anticipates," "believes," "could," "estimates," "expects," "forecasts," "goal," "intends," "may," "plans," "possible," "potential," "seeks," "will" and variations of these words or similar expressions that are intended to identify forward-looking statements, although not all forward-looking statements contain these words. Forward-looking statements in this press release include, but are not limited to, statements regarding the Company's collaboration with Bristol Myers Squibb; the discovery of potential product candidates using SNIPRx® platform; and the clinical development of the Company's pipeline and its research and development programs. These forward-looking statements are based on the Company's expectations and assumptions as of the date of this press release. Each of these forward-looking statements involves risks and uncertainties that could cause the Company's clinical development programs, future results or performance to differ materially from those expressed or implied by the forward-looking statements. Many factors may cause differences between current expectations and actual results, including the impacts of the COVID-19 pandemic on the Company's business, clinical trials and financial position, unexpected safety or efficacy data observed during preclinical studies or clinical trials, clinical trial site activation or enrollment rates that are lower than expected, changes in expected or existing competition, changes in the regulatory environment, the uncertainties and timing of the regulatory approval process, and unexpected litigation or other disputes. Other factors that may cause the Company's actual results to differ from those expressed or implied in the forward-looking statements in this press release are identified in the section titled "Risk Factors" in the Company's final prospectus dated June 18, 2020 and filed with the Securities and Exchange Commission pursuant to Rule 424(b) promulgated under the U.S. Securities Act of 1933, as amended. The Company expressly disclaims any obligation to update any forward-looking statements contained herein, whether as a result of any new information, future events, changed circumstances or otherwise, except as otherwise required by law.