In January 2020, the number of shares of common stock available for issuance under the 2015 Omnibus Incentive Plan (“2015 Plan”), was increased by 1,085,619 shares due to the automatic annual provision to increase shares available under the 2015 Plan. As of September 30, 2020, the total number of shares of common stock available for issuance under the 2015 Plan was 628,153. The Company recognized stock-based compensation expense related to the issuance of stock option awards to employees and non-employees and related to the 2015 Employee Stock Purchase Plan (“ESPP”) in the condensed consolidated statements of comprehensive loss as follows:

	Three Months Ended September 30,				Nine Months Ended September 30,
	2020		2019		2020		2019
	(In thousands)				(In thousands)
Research and development	$	620	$	510	$	1,713	$	1,581
General and administrative		2,443		1,040		5,309		2,899
Total	$	3,063	$	1,550	$	7,022	$	4,480

Compensation expense by type of award in the three and nine months ended September 30, 2020 and 2019 was as follows:

	Three Months Ended September 30,				Nine Months Ended September 30,
	2020		2019		2020		2019
	(In thousands)				(In thousands)
Stock options	$	3,005	$	1,524	$	6,885	$	4,391
Employee Stock Purchase Plan		58		26		137		89
Total	$	3,063	$	1,550	$	7,022	$	4,480

During the nine months ended September 30, 2020, the Company granted 1,496,125 stock options to certain executives, consultants, and employees having service-based vesting conditions. The grant date fair value of the options granted in the nine months ended September 30, 2020, was $11.7 million, or $7.82 per share on a weighted-average basis and will be recognized as compensation expense over the requisite service period of three to four years.

In July 2020, in connection with the retirement of a certain employee, the Company modified the terms of this individual’s historical stock option awards. As a result of the modifications, the Company recognized approximately $1.0 million of incremental stock compensation expense during the period.

In April 2020, the Company granted 74,000 stock options to certain employees to purchase shares of common stock that contain a performance-based vesting criterion related to filing a New Drug Application with the FDA. In May 2020, these options were cancelled. No expense had been recognized related to this award.

In 2019, the Company granted 583,000 stock options to certain employees to purchase shares of common stock that contain certain performance-based vesting criteria, primarily related to the achievement of certain clinical and regulatory development milestones related to product candidates. Recognition of stock-based compensation expense associated with these performance-based stock options commences when the performance condition is considered probable of achievement, using management’s best estimates, which consider the inherent risk and uncertainty regarding the future outcomes of the milestones. The achievement of one of the performance milestones was considered to be probable and the Company recorded approximately $180,000 of stock compensation expense associated with these awards for the nine months ended September 30, 2020. One performance milestone was not achieved by December 31, 2019, and therefore 194,338 stock options were cancelled on January 1, 2020. For the remaining award containing performance-based vesting criteria, the achievement of the milestone was not met, and therefore 194,331 stock options were cancelled in June 2020. No expense had been recognized related to this award for the nine months ended September 30, 2020.

During the nine months ended September 30, 2020, 311,871 options were exercised for cash proceeds of $3.1 million. During the nine months ended September 30, 2019, 25,857 options were exercised for cash proceeds of $0.2 million.

As of September 30, 2020, there was $15.5 million of unrecognized compensation cost related to employee and non-employee unvested stock options and RSUs granted under the 2015 and 2007 Plans, which is expected to be recognized over a weighted-average remaining service period of 2.7 years. Stock compensation costs have not been capitalized by the Company.

During the nine months ended September 30, 2020, the Company granted 18,500 shares of the Company’s restricted stock units. The shares are scheduled to vest in equal annual tranches over a four-year period on the anniversary date of the related grant. The fair value of these shares totaled $194,000 at the grant date, representing a weighted-average grant date fair value per share of $10.48.