CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Current assets:
Cash and cash equivalents	$ 34,814	$ 29,429
Marketable securities	388,784	275,523
Accounts and other receivables	2,628	347
Prepaid and other current assets	5,467	12,394
Total current assets	431,693	317,693
Property and equipment, net	4,060	3,747
Operating lease right-of-use assets, net	2,577	4,001
Intangible assets	27,190	27,190
Other assets	107	104
Total assets	465,627	352,735
Current liabilities:
Accounts payable	3,494	3,340
Accrued expenses	22,029	12,835
Current portion of operating lease liabilities	1,614	1,445
Current portion of long-term liabilities	3,988	990
Total current liabilities	31,125	18,610
Long-term portion of operating lease liabilities	928	2,588
Other long-term liabilities	4,403	5,333
Total liabilities	36,456	26,531
Commitments and contingent liabilities (Note 14)
Stockholders' equity:
Convertible preferred stock, $.01 par value; 3,000,000 shares authorized; no shares issued and outstanding at December 31, 2023 and 2022
Common stock, $.001 par value; 297,000,000 shares authorized; 55,883,377 and 47,200,695 shares issued and outstanding at December 31, 2023 and 2022, respectively	56	47
Additional paid-in capital	1,823,168	1,580,829
Accumulated other comprehensive income	3,308	1,260
Accumulated deficit	(1,397,361)	(1,255,932)
Total stockholders' equity	429,171	326,204
Total liabilities and stockholders' equity	$ 465,627	$ 352,735