CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Current assets:
Cash and cash equivalents	$ 13,535	$ 49,360
Short-term investments	61,020	35,732
Grants receivable	1,728	1,706
Prepaid expenses and other current assets	2,593	1,994
Total current assets	78,876	88,792
Property and equipment, net	379	419
Operating lease right-of-use assets	1,949
Other assets	63	63
Total assets	81,267	89,274
Current liabilities:
Accounts payable	4,080	1,370
Accrued expenses and other current liabilities	4,896	4,846
Total current liabilities	8,976	6,216
Operating lease liabilities, net of current portion	1,717
Deferred rent		175
Total liabilities	10,693	6,391
Commitments (Notes 5 and 11)
Shareholders' equity (deficit):
Common stock, par value $0.001; 125,000,000 shares authorized and 13,127,128 and 13,124,842 shares issued and outstanding as of March 31, 2019 and December 31, 2018, respectively	13	13
Additional paid-in capital	173,577	172,988
Accumulated other comprehensive income (loss)	34	(9)
Accumulated deficit	(103,050)	(90,109)
Total stockholders' equity	70,574	82,883
Total liabilities and stockholders' equity	$ 81,267	$ 89,274