Condensed Consolidated Balance Sheets (Current Period Unaudited) - USD ($) $ in Thousands	Jun. 30, 2022	Dec. 31, 2021
Current assets:
Cash and cash equivalents	$ 91,468	$ 143,745
Short-term investments	38,078	22,742
Accounts receivable	0	71
Prepaid expenses and other current assets	8,264	2,609
Total current assets	137,810	169,167
Long-term investments	1,940	16,210
Property and equipment, net	9,336	6,601
Right-of-use assets, net	12,433	13,168
Intangible assets, net	9,949	10,624
Goodwill	4,508	4,508
Other long-term assets	5,478	890
Total assets	181,454	221,168
Current liabilities:
Accounts payable	5,007	3,872
Current portion of operating lease liability	1,110	1,011
Current portion of liability related to sale of future royalties	1,369	836
Other accrued liabilities	8,440	5,064
Total current liabilities	15,926	10,783
Operating lease liability, net of current portion	11,569	11,997
Liability related to sale of future royalties, net of current portion	10,664	10,686
Other long-term liabilities	201	171
Total liabilities	38,360	33,637
Commitments and contingencies (Note 8)
Stockholders’ equity:
Preferred stock: $0.0001 par value; 5,000,000 shares authorized; none issued and outstanding as of June 30, 2022 and December 31, 2021	0	0
Common stock: $0.0001 par value; 150,000,000 shares authorized; 126,446,036 and 125,594,393 shares issued and outstanding as of June 30, 2022 and December 31, 2021, respectively	13	13
Additional paid-in capital	417,372	406,943
Accumulated deficit	(273,882)	(219,351)
Accumulated other comprehensive loss	(409)	(74)
Total stockholders’ equity	143,094	187,531
Total liabilities and stockholders’ equity	$ 181,454	$ 221,168