CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Current assets:
Cash and cash equivalents	$ 37,159	$ 67,727
Short-term investments	2,730	4,998
Prepaid expenses and other current assets	1,252	1,215
Total current assets	41,141	73,940
Property and equipment, net	2,337	1,294
Other assets	2,322
Total assets	45,800	75,234
Current liabilities:
Accounts payable	3,561	2,472
Accrued expenses	5,010	4,437
Total current liabilities	8,571	6,909
Other long-term liabilities	3,158
Total liabilities	11,729	6,909
Stockholders' equity:
Preferred stock, $0.001 par value; 25,000,000 shares authorized, no shares issued and outstanding
Common stock, $0.001 par value; 100,000,000 shares authorized, 52,608,064 issued and 52,578,833 outstanding at September 30, 2019 and 52,548,244 issued and 52,519,013 outstanding at December 31, 2018	53	53
Additional paid-in capital	254,182	249,727
Treasury stock at cost, 29,231 shares at September 30, 2019 and December 31, 2018
Accumulated other comprehensive income (loss)	1	(2)
Accumulated deficit	(220,165)	(181,453)
Total stockholders’ equity	34,071	68,325
Total liabilities and stockholders’ equity	$ 45,800	$ 75,234