Consolidated Balance Sheets-Unaudited - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022
Current assets:
Cash and cash equivalents	$ 26,001	$ 46,345
Short-term investments	79,936	92,012
Accounts receivable, net	261	28
Prepaid expenses and other current assets	3,348	2,481
Total current assets	109,546	140,866
Property and equipment, net of accumulated depreciation and amortization of $4,096 and $3,984, respectively	2,207	2,071
Goodwill	44,543	44,543
Other assets	6,420	6,819
Total assets	162,716	194,299
Current liabilities:
Accounts payable	10,311	10,395
Accrued liabilities	10,060	12,777
Total current liabilities	20,371	23,172
Other long-term liabilities	5,454	5,424
Total liabilities	74,670	77,175
Commitments and contingencies
Equity:
Preferred stock, $0.01 par value; 5,000 shares authorized; no shares issued and outstanding	0	0
Common stock, $0.001 par value; 300,000 shares authorized; 190,430 and 189,214 shares issued, respectively	190	189
Additional paid-in capital	1,712,558	1,709,144
Accumulated deficit	(1,621,654)	(1,589,720)
Accumulated other comprehensive loss	(163)	(428)
Treasury stock, at cost, 868 and 488 shares, respectively	(2,885)	(2,061)
Total stockholder's equity (deficit)	88,046	117,124
Total liabilities and equity	162,716	194,299
Long-term debt, net of deferred issuance costs	$ 48,845	$ 48,579