Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Current assets:
Cash and cash equivalents	$ 11,652	$ 15,294
Short-term investments	40,012	22,276
Prepaid expenses and other current assets	985	1,345
Total current assets	52,649	38,915
Property and equipment, net	48	56
Restricted cash	113	113
Right-of-use asset	1,577
Other assets	110	85
Total assets	54,497	39,169
Current liabilities:
Accounts payable	1,588	1,408
Accrued expenses	1,451	2,763
Current portion of operating lease liabilities	1,259
Total current liabilities	4,298	4,171
Long-term portion of operating lease liabilities	330
Other long-term liabilities		56
Total liabilities	4,628	4,227
Commitments (Note 6)
Stockholders' equity:
Preferred stock, $0.001 par value per share, 5,000,000 shares authorized and no shares issued and outstanding
Common stock, $0.001 par value per share, 150,000,000 shares authorized; 11,496,242 and 7,141,996 shares issued and outstanding at March 31, 2019 and December 31, 2018, respectively	11	7
Additional paid-in capital	253,200	232,243
Accumulated other comprehensive loss		(4)
Accumulated deficit	(203,342)	(197,304)
Total stockholders' equity	49,869	34,942
Total liabilities and stockholders' equity	$ 54,497	$ 39,169