Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Current assets:
Cash and cash equivalents	$ 47,076	$ 25,303
Prepaid expenses and other current assets	3,126	935
Total current assets	50,202	26,238
Property and equipment, net	1,126	3,751
Restricted cash	263	263
Other assets	320	129
Total assets	51,911	30,381
Current liabilities:
Accounts payable	1,061	629
Accrued expenses	1,571	3,122
Current portion of long-term debt	7,467	5,576
Derivative liability related to loan		494
Total current liabilities	10,099	9,821
Long-term debt, net of current portion	1,867	9,293
Total liabilities	11,966	19,114
Commitments and Contingencies (Note 11)
Convertible preferred stock - 207,164 authorized, issued, and outstanding as of December 31, 2019. No shares authorized, issued, and outstanding as of December 31, 2020.		129,870
Stockholders' equity (deficit):
Preferred stock, $0.0001 par value: 10,000 shares authorized; no shares issued and outstanding as of December 31, 2020 and 2019.
Common stock, $0.0001 par value: 300,000 shares authorized; 52,117 and 9,073 shares issued at December 31, 2020 and 2019, respectively; 51,221 and 7,034 shares outstanding at December 31, 2020 and 2019, respectively.	5	1
Additional paid-in-capital	191,348	3,304
Accumulated deficit	(151,408)	(121,908)
Total stockholders' equity (deficit)	39,945	(118,603)
Total liabilities and stockholders' equity (deficit)	$ 51,911	$ 30,381