The Company’s stock option awards generally vest over four years and typically have a contractual life of ten years. At June 30, 2020, there was $1.9 million of unrecognized compensation cost related to stock options, which is expected to be recognized over a weighted-average period of 3.06 years. During the six months ended June 30, 2020, the Company granted 520,500 stock options with a weighted average exercise price of $2.31 and per share weighted average grant date fair value of $1.83.

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

	Number of Stock Options		Weighted- average Exercise Price		Weighted- average Remaining Contractual Term (Years)		Aggregate Intrinsic Value
Outstanding		1,477,153	$	3.65		5.96	$	12,804,940
Exercisable		416,022	$	5.97		5.69	$	3,097,502
Unvested		1,061,131	$	2.74		6.07	$	9,707,438

At June 30, 2020, the Company had unvested restricted stock of 195,161 shares with total unrecognized compensation expense of $0.7 million, which the Company expects to recognize over a weighted average period of approximately 2.42 years. During the six months ended June 30, 2020, the Company released 40,505 shares of common stock from restriction as a result of the vesting of restricted stock.

During the three months ended June 30, 2020, the Company granted 109,525 shares of restricted stock units which vest during the third quarter of 2020. At June 30, 2020, the Company had unvested restricted stock units of 109,525 shares with total unrecognized compensation expense of $0.9 million, which the Company expects to recognize over a weighted average period of approximately 0.25 years.

Under the Employee Stock Purchase Plan (“ESPP”), employees purchased 38,809 shares for $56,739 during the six months ended June 30, 2020. During the three and six months ended June 30, 2020, the Company recognized compensation expense of $20,372 and $35,084, respectively.

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

	For the Three Months Ended June 30,				For the Six Months Ended June 30,
	2020		2019		2020		2019
Research and development	$	77,939	$	92,060	$	106,939	$	168,684
General and administrative		252,571		197,712		438,492		528,802
Total	$	330,510	$	289,772	$	545,431	$	697,486