BALANCE SHEETS - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Current assets:
Cash and cash equivalents	$ 41,800	$ 28,122
Prepaid expenses and other assets	6,984	12,027
Total current assets	48,784	40,149
Property and equipment, net	10,230	8,224
Operating lease right-of-use assets	1,469	1,927
Other assets	57	57
Total assets	60,540	50,357
Current liabilities:
Current portion of long-term debt	5,413	5,355
Current portion of deferred sublicense revenue	1,547	0
Accounts payable	12,570	3,674
Accrued expenses and other current liabilities	8,353	5,931
Total current liabilities	27,883	14,960
Long-term debt, net	1,359	6,773
Operating lease liabilities, net	1,073	1,548
Long-term portion of deferred sublicense revenue	7,622	0
Development derivative liability	114,843	51,719
Other long-term liabilities	794	559
Total liabilities	153,574	75,559
Commitments and contingencies (Notes 9, 10, 13)
Stockholders’ deficit:
Preferred stock, $0.001 par value; 10,000,000 shares authorized; zero shares issued and outstanding at December 31, 2021 and 2020	0	0
Common stock, $0.001 par value; 200,000,000 shares authorized; 48,220,557 shares issued and 48,190,590 shares outstanding at December 31, 2021; 29,471,854 shares issued and 29,441,887 shares outstanding at December 31, 2020	48	29
Treasury stock, at cost, 29,967 shares as of December 31, 2021 and 2020	(24)	(24)
Additional paid-in capital	298,736	235,516
Accumulated deficit	(391,794)	(260,723)
Total stockholders’ deficit	(93,034)	(25,202)
Total liabilities and stockholders' deficit	$ 60,540	$ 50,357