CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Current assets:
Cash and cash equivalents	$ 16,034	$ 49,360
Short-term investments	24,962	35,732
Grants receivable	1,232	1,706
Prepaid expenses	4,560	1,354
Other current assets	2,218	640
Total current assets	49,006	88,792
Property and equipment, net	345	419
Operating lease right-of-use assets	1,620
Other assets	63	63
Total assets	51,034	89,274
Current liabilities:
Accounts payable	1,304	1,370
Accrued expenses and other current liabilities	6,252	4,846
Total current liabilities	7,556	6,216
Operating lease liabilities, net of current portion	1,321
Deferred rent		175
Total liabilities	8,877	6,391
Commitments (Notes 6 and 14)
Stockholders' equity
Common stock, par value $0.001; 125,000,000 shares authorized and 13,291,563 and 13,124,842 shares issued and outstanding as of December 31, 2019 and 2018, respectively	13	13
Additional paid-in capital	176,103	172,988
Accumulated other comprehensive loss		(9)
Accumulated deficit	(133,959)	(90,109)
Total stockholders' equity	42,157	82,883
Total liabilities and stockholders' equity	$ 51,034	$ 89,274