Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Current assets:
Cash and cash equivalents	$ 86,758	$ 94,809
Prepaid expenses and other current assets	5,753	4,740
Income tax receivable	134	128
Total current assets	92,645	99,677
Non-current assets:
Property and equipment, net	69	79
Right-of-use asset	476	556
Total non-current assets	545	635
Total assets	93,190	100,312
Current liabilities:
Accounts payable	1,799	612
Accrued expenses	3,098	4,166
Current portion of lease liability	345	352
Total current liabilities	5,242	5,130
Long-term liabilities:
Royalty obligation payable to Iowa Economic Development Authority	6,000	6,000
Lease liability	131	205
Total long-term liabilities	6,131	6,205
Total liabilities	11,373	11,335
Commitments and contingencies
Stockholders' equity:
Undesignated preferred stock, $0.01 par value: Authorized shares - 5,000,000 at March 31, 2022 and December 31, 2021; issued and outstanding shares - 0 at March 31, 2022 and December 31, 2021	0	0
Common stock, $0.01 par value: Authorized shares - 75,000,000 at March 31, 2022 and December 31, 2021; issued shares - 8,368,521 and 8,366,819 at March 31, 2022 and December 31, 2021, respectively, and outstanding shares - 8,358,625 and 8,357,391 at March 31, 2022 and December 31, 2021, respectively	83	83
Treasury stock, at cost, 9,896 and 9,428 shares at March 31, 2022 and December 31, 2021, respectively	(119)	(114)
Additional paid-in capital	185,994	185,429
Accumulated deficit	(104,141)	(96,421)
Total stockholders' equity	81,817	88,977
Total liabilities and stockholders' equity	$ 93,190	$ 100,312