Stock based compensation

6 Months Ended

Jun. 30, 2020

Share-based Payment Arrangement [Abstract]

Stock based compensation

8 – STOCK-BASED COMPENSATION

Stock Options

In August 2015, the Company’s board of directors approved the Checkmate Pharmaceuticals, Inc. 2015 Stock Option and

Grant Plan, or 2015 Plan,

to encourage and enable the officers, employees, directors, consultants

and other key persons to acquire a proprietary interest in the Company. The

2015

Plan provide

for the granting of incentive stock options,

non-statutory

stock options and restricted stock awards as determined by the

board of directors

. Such awards generally vest over a four-year period. The maximum number of

shares of

common stock reserved for issuance under the

2015

Plan

was

2,025,764 shares. As of June 30, 2020, a total of 729,575 shares of common stock

were

available for future grant.

The Company estimates the fair value of stock option awards on the grant date using the Black-Scholes option valuation model with the following weighted-average assumptions:


	Three and Six Months Ended June 30,
	2020		2019
Risk-free interest rate		N/A		1.30	%
Expected term (in years)		N/A		5.75
Expected volatility		N/A		70.0	%
Dividend yield		N/A		—

There were no stock options granted during the three and six months ended June 30, 2020. The per share weighted average grant date fair value of stock options granted during the three and six months ended June 30, 2019 was $1.61. As of June 30, 2020, total unrecognized compensation expense related to stock options totaled $0.95 million, which is expected to be recognized over a weighted average period of 2.6 years.

The following table summarizes the activity under the Company’s stock option plan during the six months ended June 30, 2020:


	Number of Options		Weighted- Average Exercise Price		Weighted- Average Remaining Contractual Term (in years)		Aggregate Intrinsic Value (in thousands)
Outstanding at December 31, 2019		1,073,044	$	2.45		8.7	$	906
Granted		—	$	—
Forfeited		—	$	—
Exercised		—	$	—

Outstanding at June 30, 2020		1,073,044	$	2.45		8.2	$	906

Vested and expected to vest at June 30, 2020		1,073,044	$	2.45		8.2	$	906
Exercisable at June 30, 2020		426,980	$	2.23		7.6	$	468

The aggregate intrinsic value of options is calculated as the difference between the exercise price of the options and the fair value of the Company’s common stock for those options that had exercise prices lower than the fair value of the Company’s common stock. There were no options exercised during the six months ended June 30, 2020.

Restricted Stock

The Company did not grant restricted stock during the six months ended June 30, 2020. All previously granted restricted stock was fully vested as of December 31, 2019.

Stock-based Compensation Expense

Total stock-based compensation expense was classified in the accompanying condensed

statements

operations and comprehensive loss as follows:


	Three Months Ended June 30,				Six Months Ended June 30,
	2020		2019		2020		2019
	( in thousands)				(in thousands)
Research and development	$	39	$	25	$	78	$	49
General and administrative		61		53		123		108

Total stock-based compensation expense	$	100	$	78	$	201	$	157