Condensed Consolidated Balance Sheets (Current Period Unaudited) - USD ($) $ in Thousands	Jun. 30, 2021	Dec. 31, 2020
Current assets:
Cash and cash equivalents	$ 165,266	$ 126,870
Short-term investments	19,318	0
Accounts receivable	107	334
Prepaid expenses and other current assets	4,801	1,327
Total current assets	189,492	128,531
Long-term investments	14,339	0
Property and equipment, net	4,339	1,480
Right-of-use assets, net	5,808	6,838
Intangible assets, net	14,495	15,361
Other long-term assets	371	372
Total assets	228,844	152,582
Current liabilities:
Accounts payable	3,702	2,133
Current portion of operating lease liability	1,791	2,052
Liability related to sale of future royalties, current portion	3,150	2,779
Other accrued liabilities	4,137	4,799
Total current liabilities	12,780	11,763
Operating lease liability, net of current portion	4,363	5,156
Liability related to sale of future royalties, net of current portion	11,777	12,150
Other long-term liabilities	142	109
Total liabilities	29,062	29,178
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, 2021 and December 31, 2020	0	0
Common stock: $0.0001 par value; 150,000,000 shares authorized; 122,814,467 and 110,271,093 shares issued and outstanding as of June 30, 2021 and December 31, 2020, respectively	12	11
Additional paid-in capital	380,783	272,274
Accumulated deficit	(181,004)	(148,881)
Accumulated other comprehensive loss	(9)	0
Total stockholders’ equity	199,782	123,404
Total liabilities and stockholders’ equity	$ 228,844	$ 152,582