CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Current assets:
Cash and cash equivalents	$ 15,301	$ 49,360
Short-term investments	33,509	35,732
Accounts receivable	7,000
Grants receivable	1,320	1,706
Prepaid expenses and other current assets	3,992	1,994
Total current assets	61,122	88,792
Property and equipment, net	370	419
Operating lease right-of-use assets	1,732
Other assets	63	63
Total assets	63,287	89,274
Current liabilities:
Accounts payable	948	1,370
Accrued expenses and other current liabilities	5,985	4,846
Total current liabilities	6,933	6,216
Operating lease liabilities, net of current portion	1,460
Deferred rent		175
Total liabilities	8,393	6,391
Commitments (Notes 5 and 11)
Stockholders' equity
Common stock, par value $0.001; 125,000,000 shares authorized and 13,134,538 and 13,124,842 shares issued and outstanding as of September 30, 2019 and December 31, 2018, respectively	13	13
Additional paid-in capital	174,776	172,988
Accumulated other comprehensive income (loss)	22	(9)
Accumulated deficit	(119,917)	(90,109)
Total stockholders' equity	54,894	82,883
Total liabilities and stockholders' equity	$ 63,287	$ 89,274