The Company’s stock option awards generally vest over four years and typically have a contractual life of ten years. At September 30, 2020, there was $3.1 million of unrecognized compensation cost related to stock options, which is expected to be recognized over a weighted-average period of 2.55 years. During the nine months ended September 30, 2020, the Company granted 698,000 stock options with a weighted average exercise price of $4.64 and per share weighted average grant date fair value of 3.69.

Information related to stock options outstanding at September 30, 2020 is as follows:

	Number of Stock Options		Weighted- average Exercise Price		Weighted- average Remaining Contractual Term (Years)		Aggregate Intrinsic Value
Outstanding		1,622,248	$	4.52		5.90	$	15,235,853
Exercisable		458,609	$	5.69		5.74	$	4,537,424
Unvested		1,163,639	$	4.06		5.96	$	10,698,428

Restricted Stock

At September 30, 2020, the Company had unvested restricted stock of 174,908 shares with total unrecognized compensation expense of $0.6 million, which the Company expects to recognize over a weighted average period of approximately 2.17 years. During the nine months ended September 30, 2020, the Company released 60,758 shares of common stock from restriction as a result of the vesting of restricted stock.

During the third quarter of 2020, the Company granted 15,000 shares of restricted stock units which vest over four years. At September 30, 2020, the Company had unvested restricted stock units of 15,000 shares with total unrecognized compensation expense of $0.2 million, which the Company expects to recognize over a weighted average period of approximately 3.99 years.

2019 Employee Stock Purchase Plan

Under the Employee Stock Purchase Plan (“ESPP”), employees purchased 53,852 shares for $0.1 million during the three months ended September 30, 2020. During the three and nine months ended September 30, 2020, the Company recognized compensation expense of $87,092 and $122,177, respectively.

Stock-based Compensation Expense

Stock-based compensation expense is classified in the unaudited consolidated statements of operations and comprehensive loss for the three and nine months ended September 30, 2020 and 2019 as follows:

	For the Three Months Ended September 30,				For the Nine Months Ended September 30,
	2020		2019		2020		2019
Research and development	$	143,844	$	71,662	$	250,783	$	240,345
General and administrative		1,176,245		216,113		1,614,737		744,915
Total	$	1,320,089	$	287,775	$	1,865,520	$	985,260