Consolidated Balance Sheets - USD ($)	Mar. 31, 2021	Dec. 31, 2020
Current assets:
Cash and cash equivalents	$ 164,660,132	$ 183,876,453
Prepaid and other current assets	375,306	148,373
Total current assets	165,035,438	184,024,826
Equipment, net	74,316	52,647
Right-of-use asset - operating lease	1,476,711	1,739,475
Other assets	317,375	317,375
Total assets	166,903,840	186,134,323
Current liabilities:
Accounts payable	14,621,717	13,504,022
Accrued expenses and other current liabilities	5,864,526	8,713,249
Operating lease liability, current portion	1,196,539	1,220,587
Total current liabilities	21,682,782	23,437,858
Loan payable, long-term	48,597,943	48,321,848
Operating lease liability, long-term	329,916	581,708
Total liabilities	70,610,641	72,341,414
Stockholders’ equity:
Preferred stock, $0.0001 par value per share (10,000,000 shares authorized, none issued and outstanding at March 31, 2021 and December 31, 2020, respectively)
Common stock, $0.0001 par value per share (150,000,000 shares authorized, 37,563,882 and 37,374,088 shares issued and outstanding at March 31, 2021 and December 31, 2020, respectively)	3,756	3,737
Additional paid-in capital	404,345,506	392,585,265
Accumulated deficit	(308,056,063)	(278,796,093)
Total stockholders’ equity	96,293,199	113,792,909
Total liabilities and stockholders’ equity	$ 166,903,840	$ 186,134,323