CONDENSED BALANCE SHEETS - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Current assets:
Cash and cash equivalents	$ 18,688	$ 41,800
Prepaid expenses and other assets	8,881	6,984
Total current assets	27,569	48,784
Property and equipment, net	9,697	10,230
Operating lease right-of-use assets	1,341	1,469
Other assets	57	57
Total assets	38,664	60,540
Current liabilities:
Current portion of long-term debt	5,425	5,413
Current portion of deferred sublicense revenue	1,594	1,547
Accounts payable	6,778	12,570
Accrued expenses and other current liabilities	7,891	8,353
Total current liabilities	21,688	27,883
Long-term debt, net	0	1,359
Operating lease liabilities, net	969	1,073
Long-term portion of deferred sublicense revenue	7,458	7,622
Development derivative liability	110,944	114,843
Other long-term liabilities	0	794
Total liabilities	141,059	153,574
Commitments and contingencies (Note 8, 10, 13)
Stockholders’ deficit:
Preferred stock, $0.001 par value; 10,000,000 shares authorized; zero shares issued and outstanding at March 31, 2022 and December 31, 2021	0	0
Common stock, $0.001 par value; 200,000,000 shares authorized; 48,720,557 shares issued and 48,690,590 shares outstanding at March 31, 2022; 48,220,557 shares issued and 48,190,590 shares outstanding at December 31, 2021	49	48
Treasury stock, at cost, 29,967 shares as of March 31, 2022 and December 31, 2021	(24)	(24)
Additional paid-in capital	300,515	298,736
Accumulated deficit	(402,935)	(391,794)
Total stockholders’ deficit	(102,395)	(93,034)
Total liabilities and stockholders' deficit	$ 38,664	$ 60,540