CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022
Current assets:
Cash and cash equivalents	$ 146,904	$ 240,551
Short-term investments	52,297
Accounts receivable, net	11,693	6,348
Inventory	37	77
Prepaid expenses and other current assets	9,064	5,402
Total current assets	219,995	252,378
Property and equipment, net	4,037	4,236
Other assets	2,785	2,904
Total assets	226,817	259,518
Current liabilities:
Accounts payable	4,466	4,461
Current portion of revenue interest financing payable	1,321	1,020
Accrued expenses	15,727	19,536
Total current liabilities	21,514	25,017
Notes payable, net of deferred financing costs	71,498	71,018
Revenue interest financing payable, net of deferred financing costs	30,893	29,857
Contract liabilities, net	16,416	16,285
Other long-term liabilities	1,411	1,341
Total liabilities	141,732	143,518
Stockholders' equity:
Series A convertible preferred stock, $0.001 par value; 25,000,000 shares authorized, 4,300 shares issued and outstanding at March 31, 2023 and December 31, 2022	4,043	4,043
Common stock, $0.001 par value; 150,000,000 shares authorized, 49,672,424 issued and 49,665,117 outstanding at March 31, 2023 and 49,650,074 issued and 49,642,767 outstanding at December 31, 2022	50	50
Additional paid-in capital	546,169	542,428
Treasury stock at cost, 7,307 shares at March 31, 2023 and December 31, 2022
Accumulated other comprehensive income	74
Accumulated deficit	(465,251)	(430,521)
Total stockholders' equity	85,085	116,000
Total liabilities and stockholders' equity	$ 226,817	$ 259,518