CONDENSED CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Current assets
Cash and cash equivalents	$ 129,771	$ 94,958
Prepaid expenses and other current assets	8,256	7,688
Total current assets	138,027	102,646
Property and equipment, net	1,921	1,164
Restricted cash	151	151
Other assets	1,628	1,800
Total assets	141,727	105,761
Current liabilities
Accounts payable	3,896	2,312
Accrued expenses	3,537	4,325
Operating lease obligations	254	363
Total current liabilities	7,687	7,000
Non-current liabilities
Operating lease obligations, less current portion	1,180	1,231
Long term debt, net	1,731	1,712
Total non-current liabilities	2,911	2,943
Total liabilities	10,598	9,943
Commitments and contingencies (Note 12)
Stockholders' equity
Common stock; $0.01 par value; 295,000,000 shares authorized, 215,752,926 and 199,502,183 shares issued, and 215,631,426 and 199,380,683 shares outstanding at March 31, 2022 and December 31, 2021, respectively	2,158	1,995
Treasury stock, at cost, 121,500 shares at March 31, 2022 and December 31, 2021	(48)	(48)
Additional paid-in capital	278,704	225,537
Accumulated deficit	(149,686)	(131,667)
Total stockholders' equity	131,129	95,818
Total liabilities and stockholders' equity	141,727	105,761
Series A Preferred Stock
Stockholders' equity
Preferred stock issued	0	0
Series B Preferred Stock
Stockholders' equity
Preferred stock issued	$ 1	$ 1