The Company’s Series A and Series B convertible preferred shares were convertible on a one-to-one basis into common shares. Upon completion of the IPO, all issued and outstanding Series A and Series B convertible preferred shares were converted into 21,558,393 common shares and the existing classes of Series A and Series B convertible preferred shares were removed (unlimited preferred shares authorized, 11,090,135 Series A convertible preferred shares and 10,468,258 Series B convertible preferred shares issued and outstanding as of December 31, 2019).

Effective upon the closing of the IPO, the Company authorized for issue an unlimited number of preferred shares, issuable in series. No preferred shares were issued and outstanding as of June 30, 2020.

In conjunction with the collaboration and license agreement with Bristol Myers Squibb, the Company entered into a warrant agreement with an affiliate of Bristol Myers Squibb pursuant to which the Company issued a warrant for total proceeds of $15,000 on May 26, 2020. Upon closing of the IPO, the warrant was automatically exercised at the public offering price of $20.00 per share into 750,000 common shares of the Company.

An unlimited number of common shares, voting and participating, without par value.

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, at the public offering price of $20.00 per share, for aggregate gross proceeds of $253,000. 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 automatically converted into 750,000 common shares.

In June 2020, the Company’s board of directors adopted, and the Company’s shareholders approved the 2020 Employee Share Purchase Plan (the “ESPP”). The maximum number of common shares that may be issued under the ESPP is 327,000. Additionally, the number of shares reserved and available for issuance under the ESPP will automatically increase each January 1, beginning on January 1, 2021 and each January 1 thereafter through January 31, 2030, by the lesser of (1) 1.0% of the total number of common shares outstanding on December 31 of the preceding calendar year, (2) 3,300,000 common shares, or (3) such smaller number of common shares as the Company’s board of directors may designate. The ESPP enables eligible employees to purchase common shares of the Company at the end of each offering period at a price equal to 85% of the fair market value of the shares on the first business day or the last business day of the offering period, whichever is lower. The ESPP will become active upon approval of the plan administrator, which is the Company’s board of directors. As of June 30, 2020, no common shares have been issued under the ESPP.

In December 2016, as further amended in December 2017 and September 2019, the Company adopted the Repare Therapeutics Inc. Option Plan (the “Option Plan”) for the issuance of share options and other share-based awards to directors, officers, employees or consultants. The Option Plan authorized up to 4,074,135 shares of the Company’s common shares to be issued.

In June 2020, the Company’s board of directors adopted, and the Company’s shareholders approved the 2020 Equity Incentive Plan (the “2020 Plan”). The 2020 Plan became effective on the effective date of the IPO, at which time the Company ceased making awards under the Option Plan. The 2020 Plan allows the Company’s compensation committee to make equity-based and cash-based incentive awards to the Company’s officers, employees, directors and consultants. A total of 3,600,000 common shares were initially reserved for issuance under the 2020 Plan, plus the number of shares (not to exceed 3,807,448 shares) (i) 298,605 common shares that were available for the issuance of awards under the Option Plan at the time the 2020 Plan became effective, which ceased to be available for future issuance under the Option Plan at such time and (ii) any shares subject to outstanding options or other share awards that were granted under the Option Plan that terminate or expire prior to exercise or settlement; are forfeited because of the failure to vest; or are reacquired or withheld (or not issued) to satisfy a tax withholding obligation or the purchase or exercise price. In addition, the number of shares reserved and available for issuance under the 2020 Plan will automatically increase each January 1, beginning on January 1, 2021 and each January 1 thereafter through January 31, 2030, by 5% of the outstanding number of common shares on the immediately preceding December 31, or such lesser number of shares as determined by the Company’s board of directors.

The 2020 Plan is administered by the Company’s board of directors. The exercise prices, vesting and other restrictions are determined by the board of directors, except that the exercise price per share may not be less than 100% of the fair value of the common share on the date of grant, determined based on the average of the daily volume-weighted average trading price of shares on each of the five trading days immediately preceding the date of grant. Stock option awards under the 2020 Plan expire 10 years after the grant date and generally have vesting conditions of 25% on the first anniversary date of the grant and 75% on a monthly basis at a rate of 1/36^th unless otherwise decided by the board of directors.

	2020					2019
	Number of shares			Weighted average exercise price		Number of shares		Weighted average exercise price
Outstanding at beginning of period		3,505,119		$	2.07		907,315	$	1.66
Granted		869,075		$	16.35		1,013,635	$	2.06
Exercised		(266,687	)	$	1.83		—		—
Cancelled or forfeited		(7,962	)	$	2.13		—		—
Outstanding at end of period		4,099,545		$	5.11		1,920,950	$	1.87

During the six months ended June 30, 2020, an aggregate of 266,687 options were exercised at a weighted-average exercise price of $1.83 per share, for aggregate proceeds of $488. As a result, an amount of $289 previously included in additional paid-in capital related to the exercised options has been credited to common shares and deducted from additional paid-in capital.

	Three Months Ended June 30,				Six Months Ended June 30,
	2020		2019		2020		2019
Research and development	$	163	$	63	$	296	$	103
General and administrative		226		58		364		83
Total share-based compensation expense	$	389	$	121	$	660	$	186

The assumptions that the Company used in the Black Scholes option-pricing model to determine the grant date fair value of stock options granted to employees and non-employees were as follows, presented on a weighted average basis:

	Three Months Ended June 30,					Six Months Ended June 30,
	2020			2019		2020			2019
Fair value of stock options	$	10.30			—	$	10.30		$	0.97
Exercise price	$	16.35			—	$	16.35		$	2.06
Share price	$	16.35			—	$	16.35		$	2.06
Risk-free interest rate		0.43	%		—		0.43	%		2.27	%
Expected terms (in years)		6.07			—		6.07			6.08
Expected volatility		71.99	%		—		71.99	%		70.79	%
Expected dividend yield		0.00	%		—		0.00	%		0.00	%

As of June 30, 2020, there was $11,837 of unrecognized share-based compensation expense related to unvested stock options to be recognized over a period of 3.0 years.