Stockholders' Equity (Tables)

3 Months Ended

Mar. 31, 2020

Stockholders' Equity

Schedule of common reserved shares of common stock for issuance

	March 31,	December 31,
	2020	2019
	(unaudited)
Options issued and outstanding	4,508,021	3,902,675
Inducement options issued and outstanding	74	74
Options available for grant under stock option plans	160,697	479,829
Restricted stock unit awards issued and outstanding	5,613	5,613
Warrants issued and outstanding	17,622,930	19,421,892
Series A convertible preferred stock	473,565	473,565
Series B convertible preferred stock	4,423,250	985,500
Series B-2 convertible preferred stock	1,431,460	1,931,350
Total	28,625,610	27,200,498