CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Current assets:
Cash and cash equivalents	$ 20,705	$ 5,154
Marketable securities	38,553	72,828
Prepaid and other current assets	1,303	1,362
Total current assets	60,561	79,344
Property and equipment, net	1,119	1,462
Operating lease right-of-use asset	1,996	2,327
Other assets	501	513
Total assets	64,177	83,646
Current liabilities:
Accounts payable	2,779	2,448
Operating lease liability	976	878
Accrued and other liabilities	7,798	6,899
Total current liabilities	11,553	10,225
Operating lease liability	1,784	2,310
Total liabilities	13,337	12,535
Commitments and contingencies (Note 12)
Stockholders' equity:
Preferred stock: $0.0001 par value; 10,000,000 shares authorized at June 30, 2020 and December 31, 2019; 0 shares issued and outstanding at June 30, 2020 and December 31, 2019
Common stock: $0.0001 par value; 290,000,000 shares authorized at June 30, 2020 and December 31, 2019; 28,034,733 and 27,953,233 shares issued and outstanding at June 30, 2020 and December 31, 2019, respectively	3	3
Additional paid-in capital	291,475	288,224
Accumulated other comprehensive income	53	29
Accumulated deficit	(240,691)	(217,145)
Total stockholders' equity	50,840	71,111
Total liabilities and stockholders' equity	$ 64,177	$ 83,646