CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Sep. 30, 2022	Dec. 31, 2021
Current assets:
Cash and cash equivalents	$ 168,249	$ 122,927
Accounts receivable, net	3,398	2,629
Inventory	104	0
Contract asset		557
Prepaid expenses and other current assets	5,255	5,565
Total current assets	177,006	131,678
Property and equipment, net	5,520	2,499
Other assets	2,315	2,663
Total assets	184,841	136,840
Current liabilities:
Accounts payable	1,622	3,126
Refund liability		21,233
Accrued expenses	19,428	16,207
Total current liabilities	21,050	40,566
Notes payable, net of deferred financing costs	70,780	40,809
Contract liability	9,499
Other long-term liabilities	1,508	1,979
Total liabilities	102,837	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 September 30, 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, 37,203,951 issued and 37,196,644 outstanding at September 30, 2022 and 36,797,561 issued and 36,790,254 outstanding at December 31, 2021	37	37
Additional paid-in capital	474,133	459,852
Treasury stock at cost, 7,307 shares at September 30, 2022 and December 31, 2021
Accumulated deficit	(396,209)	(410,705)
Total stockholders' equity	82,004	53,486
Total liabilities and stockholders' equity	$ 184,841	$ 136,840