Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Current assets:
Cash and cash equivalents	$ 30,772	$ 27,042
Marketable securities	59,487	78,792
Prepaid expenses and other current assets	2,911	3,764
Total current assets	93,170	109,598
Long-term equity investments	22,022	17,626
Restricted cash	1,931	1,931
Right-of-use asset, net	13,628	13,894
Property and equipment, net	686	769
Other noncurrent assets	174	210
Total assets	131,613	144,027
Current liabilities:
Accounts payable	3,596	3,703
Accrued expenses	4,039	6,525
Current portion, lease liability	1,268	1,246
Total current liabilities	8,903	11,474
Long-term liabilities:
Lease liability	14,430	14,756
Royalty monetization liability	30,000	30,000
Total liabilities	53,333	56,230
Stockholders' equity:
Preferred stock, $0.001 par value; 10,000,000 shares authorized; Series A convertible preferred stock, 10,000 shares designated, 1,250 shares issued and outstanding at March 31, 2024 and December 31, 2023	0	0
Common stock, $0.001 par value; 125,000,000 shares authorized; 70,783,961 and 70,691,992 shares issued and outstanding at March 31, 2024 and December 31, 2023, respectively	71	71
Additional paid-in-capital	367,787	365,591
Accumulated other comprehensive (loss) income	(19)	1
Accumulated deficit	(289,560)	(277,866)
Total stockholders' equity	78,279	87,797
Total liabilities and stockholders' equity	$ 131,613	$ 144,027