Consolidated Balance Sheets - USD ($)	Dec. 31, 2020	Dec. 31, 2019
Current assets:
Cash and cash equivalents	$ 52,858,311	$ 16,425,830
Cash equivalent - reverse repurchase agreements	25,000,000	28,000,000
Marketable securities		28,938,545
Prepaid expenses and other current assets	5,200,957	1,804,450
Total current assets	83,059,268	75,168,825
Fixed assets, net	59,925	148,449
Right-of-use assets	233,310	201,007
Total assets	83,352,503	75,518,281
Current liabilities:
Accounts payable	381,638	808,302
Accrued expenses	8,134,765	11,873,122
Current portion of credit facility	3,659,776
Current portion of operating lease liabilities	233,310	226,328
Total current liabilities	12,409,489	12,907,752
Long-term debt, net of current portion	11,434,456	14,528,212
Total liabilities	23,843,945	27,435,964
Commitments and contingencies (Note 14)
Stockholders' equity:
Preferred stock, $0.001 par value, 15,000,000 shares authorized, none issued and outstanding
Common stock, voting, $0.001 par value; 150,000,000 authorized and 38,667,491 and 28,656,832 shares issued and outstanding, respectively	38,667	28,657
Additional paid-in capital	296,385,619	247,409,793
Accumulated other comprehensive income		5,866
Accumulated deficit	(236,915,728)	(199,361,999)
Total stockholders’ equity	59,508,558	48,082,317
Total liabilities and stockholders’ equity	$ 83,352,503	$ 75,518,281