CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Current assets:
Cash and cash equivalents	$ 240,551	$ 122,927
Accounts receivable, net	6,348	2,629
Inventory	77
Contract asset, net		557
Prepaid expenses and other current assets	5,402	5,565
Total current assets	252,378	131,678
Property and equipment, net	4,236	2,499
Other assets	2,904	2,663
Total assets	259,518	136,840
Current liabilities:
Accounts payable	4,461	3,126
Refund liability		21,233
Current portion of revenue interest financing payable	1,020
Accrued expenses	19,536	16,207
Total current liabilities	25,017	40,566
Notes payable, net of deferred financing costs	71,018	40,809
Revenue interest financing payable, net of deferred financing costs	29,857
Contract liabilities, net	16,285
Other long-term liabilities	1,341	1,979
Total liabilities	143,518	83,354
Stockholders' equity:
Series A convertible preferred stock, $0.001 par value; 25,000,000 shares authorized, 4,300 shares issued and outstanding at December 31, 2022 and 4,575 shares issued and outstanding at December 31, 2021	4,043	4,302
Common stock, $0.001 par value; 150,000,000 shares authorized, 49,650,074 issued and 49,642,767 outstanding at December 31, 2022 and 36,797,561 issued and 36,790,254 outstanding at December 31, 2021	50	37
Additional paid-in capital	542,428	459,852
Treasury stock at cost, 7,307 shares at December 31, 2022 and December 31, 2021
Accumulated deficit	(430,521)	(410,705)
Total stockholders' equity	116,000	53,486
Total liabilities and stockholders' equity	$ 259,518	$ 136,840