Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Current assets:
Cash and cash equivalents	$ 48,910	$ 24,393
Short-term investments	27,517	71,783
Prepaid expenses and other current assets	2,313	5,847
Total current assets	78,740	102,023
Property and equipment, net	347	634
Operating lease right-of-use asset	902	1,579
Total assets	79,989	104,236
Current liabilities:
Accounts payable	368	334
Accrued liabilities	6,567	2,951
Current portion of operating lease liability	825	741
Total current liabilities	7,760	4,026
Operating lease liability, net of current portion	181	1,007
Long-term debt, net of debt discount	13,303	9,372
Other long-term liabilities	1,390	552
Commitments and contingencies (Note 3)
Stockholders’ equity:
Preferred stock, $0.0001 par value; authorized shares - 10,000,000 at December 31, 2021 and 2020, respectively; issued and outstanding shares - none at December 31, 2021 and 2020, respectively.
Common stock, $0.0001 par value; authorized shares – 200,000,000 at December 31, 2021 and 2020, respectively; issued shares – 42,110,560 and 26,005,934 at December 31, 2021 and 2020, respectively; outstanding shares – 42,108,428 and 25,969,442 at December 31, 2021 and 2020, respectively.	4	3
Additional paid-in-capital	240,309	210,021
Accumulated other comprehensive income (loss)	(5)	1
Accumulated deficit	(182,953)	(120,746)
Total stockholders’ equity	57,355	89,279
Total liabilities and stockholders’ equity	$ 79,989	$ 104,236