Organization and Nature of Business	6 Months Ended
Jun. 30, 2020
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Organization and Nature of Business	1. Organization and Nature of Business Repare Therapeutics Inc. (“Repare” or the “Company”) is a precision medicine oncology company focused on the development of synthetic lethality-based therapies to patients with cancer. The Company was incorporated under the Canada Business Corporations Act on September 6, 2016. On June 23, 2020, immediately following the completion of its initial public offering (the “IPO”), the Company was continued as a corporation under the Business Corporations Act (Québec). On June 12, 2020, the Company effected a 1-for-6.062 reverse stock split of the Company’s share capital. Accordingly, all common shares, Series A and B preferred shares, stock options and per share amounts in these unaudited condensed consolidated financial statements have been retroactively adjusted to reflect the reverse stock split on a retroactive basis for all periods presented. On June 23, 2020, the Company completed its IPO of 12,650,000 of its common shares, including the exercise in full by the underwriters of their option to purchase up to 1,650,000 additional common shares, for aggregate gross proceeds of $253,000. The Company’s shares began trading on the Nasdaq Global Select Market under the ticker symbol “RPTX” on June 19, 2020. The Company received $232,043 in net proceeds after deducting underwriting discounts and commissions and other offering expenses payable by the Company. Upon closing of the IPO, all outstanding convertible preferred shares converted into 21,558,393 common shares and the outstanding warrant was automatically exercised into 750,000 common shares.

Organization and Nature of Business

6 Months Ended

Jun. 30, 2020

Organization Consolidation And Presentation Of Financial Statements [Abstract]

1. Organization and Nature of Business

Repare Therapeutics Inc. (“Repare” or the “Company”) is a precision medicine oncology company focused on the development of synthetic lethality-based therapies to patients with cancer. The Company was incorporated under the Canada Business Corporations Act on September 6, 2016. On June 23, 2020, immediately following the completion of its initial public offering (the “IPO”), the Company was continued as a corporation under the Business Corporations Act (Québec).

On June 12, 2020, the Company effected a 1-for-6.062 reverse stock split of the Company’s share capital. Accordingly, all common shares, Series A and B preferred shares, stock options and per share amounts in these unaudited condensed consolidated financial statements have been retroactively adjusted to reflect the reverse stock split on a retroactive basis for all periods presented.

On June 23, 2020, the Company completed its IPO of 12,650,000 of its common shares, including the exercise in full by the underwriters of their option to purchase up to 1,650,000 additional common shares, for aggregate gross proceeds of $253,000. The Company’s shares began trading on the Nasdaq Global Select Market under the ticker symbol “RPTX” on June 19, 2020. The Company received $232,043 in net proceeds after deducting underwriting discounts and commissions and other offering expenses payable by the Company. Upon closing of the IPO, all outstanding convertible preferred shares converted into 21,558,393 common shares and the outstanding warrant was automatically exercised into 750,000 common shares.