Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022
Current assets:
Cash and cash equivalents	$ 55,902	$ 45,917
Marketable securities, available for sale	18,027	44,363
Prepaid expenses and other current assets	1,906	2,697
Total current assets	75,835	92,977
Property and equipment, net	88	98
Other non-current assets	975	1,086
Total assets	76,898	94,161
Current liabilities:
Accounts payable	4,043	6,362
Accrued expenses	9,491	9,330
Total current liabilities	13,534	15,692
Non-current liabilities:
Long-term debt, net of discount	29,600	29,435
Restricted stock repurchase liability	0	2
Total liabilities	43,134	45,129
Commitments and contingencies (see note 12)
Stockholders' equity:
Preferred stock, $0.0001 par value; 10,000,000 shares authorized as of March 31, 2023 and December 31, 2022; no shares issued or outstanding as of March 31, 2023 and December 31, 2022, respectively	0	0
Common stock, $0.0001 par value; 500,000,000 shares authorized as of March 31, 2023 and December 31, 2022, respectively; 23,819,751 and 23,345,115 shares issued as of March 31, 2023 and December 31, 2022, respectively; 23,786,337 and 23,312,529 outstanding as of March 31, 2023 and December 31, 2022, respectively	2	2
Additional paid-in capital	201,185	199,492
Accumulated other comprehensive loss	(51)	(161)
Treasury stock; 33,414 and 28,641 shares as of March 31, 2023 and December 31, 2022, respectively; at cost	(47)	(35)
Accumulated deficit	(167,325)	(150,266)
Total stockholders' equity	33,764	49,032
Total liabilities and stockholders' equity	$ 76,898	$ 94,161