Condensed Balance Sheets - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Current assets:
Cash and cash equivalents	$ 26,509	$ 40,127
Prepaid expenses and other current assets	2,562	1,457
Total current assets	29,071	41,584
Property and equipment, net	2,474	2,617
Right of use assets	11,782	6,306
Restricted cash	631	631
Other non-current assets	1,234	1,473
Total assets	45,192	52,611
Current liabilities:
Accounts payable	860	553
Accrued expenses and other current liabilities	4,077	4,611
Lease liabilities	2,028	1,117
Current portion of long-term debt	7,700
Total current liabilities	14,665	6,281
Non-current liabilities:
Long-term debt, net of current portion	5,815	13,407
Warrant liability	1,705	2,486
Lease liabilities, net of current portion	9,994	5,395
Total liabilities	32,179	27,569
Commitments and contingencies (Note 5)
Stockholders’ equity:
Preferred stock, $0.001 par value; (shares authorized of 25,000,000 at March 31, 2020 and December 31, 2019; 1,635 shares issued and outstanding at March 31, 2020 and December 31, 2019)	701	701
Common stock, $0.001 par value; (shares authorized of 85,000,000 at March 31, 2020 and December 31, 2019, 27,643,773 shares issued and outstanding at March 31, 2020 and 27,452,900 shares issued and outstanding at December 31, 2019)	28	27
Additional paid-in capital	356,091	355,268
Accumulated deficit	(343,807)	(330,954)
Total stockholders’ equity	13,013	25,042
Total liabilities and stockholders’ equity	$ 45,192	$ 52,611