Condensed Consolidated Balance Sheets (Current Period Unaudited) - USD ($)	Jun. 30, 2021	Dec. 31, 2020
Current assets
Cash and cash equivalents	$ 142,432,961	$ 39,553,671
Restricted cash	110,000	110,000
Prepaid expenses	2,391,966	1,813,902
Research and development tax rebate receivable	817,109	634,940
Other current assets	78,882	657,662
Total current assets	145,830,918	42,770,175
Furniture and equipment, net	14,501	20,632
Intangible assets, net	4,458	13,375
Right-of-use asset	4,720	18,053
Other assets	13,408	17,218
Total Assets	145,868,005	42,839,453
Current liabilities
Accounts payable	537,915	1,588,613
Accrued expenses	531,602	93,367
Payroll liabilities	700,588	963,665
Common stock warrant liability	0	13,003,075
Lease liability	4,720	18,053
Other current liabilities	21,278	4,748
Total current liabilities	1,796,103	15,671,521
Commitments and contingencies (Note 13)
Stockholders' equity
Preferred stock - $0.001 par value; 10,000,000 shares authorized; 587 and 621 shares issued and outstanding as of June 30, 2021 and December 31, 2020, respectively	1	1
Common stock - $0.18 par value; 175,000,000 shares authorized; 125,925,096 and 47,548,835 shares issued and outstanding as of June 30, 2021 and December 31, 2020, respectively	22,666,505	8,558,778
Additional paid-in capital	240,023,345	129,887,146
Accumulated deficit	(119,204,948)	(111,898,992)
Total Stockholders' Equity	144,071,902	27,167,932
Total Liabilities and Stockholders' Equity	145,868,005	42,839,453
Series B Preferred Stock [Member]
Stockholders' equity
Additional paid-in capital - Series B convertible preferred stock	$ 586,999	$ 620,999