CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Current assets:
Cash and cash equivalents	$ 38,976	$ 39,196
Marketable securities	66,831	75,401
Prepaid and other current assets	1,197	992
Total current assets	107,004	115,589
Property and equipment, net	2,010	2,180
Operating lease right-of-use asset	2,781
Other assets	514	463
Total assets	112,309	118,232
Current liabilities:
Accounts payable	2,264	1,998
Operating lease liability current	792
Accrued and other liabilities	5,579	5,029
Total current liabilities	8,635	7,027
Operating lease liability noncurrent	2,977
Other liabilities		869
Total liabilities	11,612	7,896
Commitments and contingencies (Note 11)
Stockholders' equity:
Preferred stock: $0.0001 par value; 10,000,000 shares authorized at March 31, 2019 and December 31, 2018; 0 shares issued and outstanding at March 31, 2019 and December 31, 2018
Common stock: $0.0001 par value; 290,000,000 shares authorized at March 31, 2019 and December 31, 2018; 29,326,900 and 29,323,930 shares issued and outstanding at March 31, 2019 and December 31, 2018, respectively	3	3
Additional paid-in capital	282,799	280,840
Accumulated other comprehensive income (loss)	11	(34)
Accumulated deficit	(182,116)	(170,473)
Total stockholders' equity	100,697	110,336
Total liabilities and stockholders' equity	$ 112,309	$ 118,232