Condensed Consolidated Balance Sheets (Current Period Unaudited) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Current assets:
Cash and cash equivalents	$ 29,859	$ 13,526
Accounts receivable	2,663	3,619
Prepaid expenses and other current assets	1,143	453
Total current assets	33,665	17,598
Property and equipment, net	191	210
Right-of-use assets, net	1,910	1,990
Intangible assets, net	16,660	17,093
Other long-term assets	138	141
Total assets	52,564	37,032
Current liabilities:
Accounts payable	793	852
Current portion of operating lease liability	855	841
Liability related to sale of future royalties, current portion	1,513	2,916
Other accrued liabilities	4,280	4,565
Total current liabilities	7,441	9,174
Operating lease liability, net of current portion	1,271	1,472
Liability related to sale of future royalties, net of current portion	12,541	13,416
Other long-term liabilities	18	18
Total liabilities	21,271	24,080
Commitments and contingencies (Note 9)
Stockholders’ equity:
Preferred stock: $0.10 par value; 5,000,000 shares authorized; none issued and outstanding as of March 31, 2020 and December 31, 2019
Common stock: $0.10 par value; 100,000,000 shares authorized; 72,004,720 and 48,254,994 shares issued and outstanding as of March 31, 2020 and December 31, 2019, respectively	7,200	4,825
Additional paid-in capital	142,051	124,788
Accumulated deficit	(117,958)	(116,661)
Total stockholders’ equity	31,293	12,952
Total liabilities and stockholders’ equity	$ 52,564	$ 37,032