BALANCE SHEETS - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Current assets:
Cash and cash equivalents	$ 23,498	$ 5,154
Marketable securities	45,209	72,828
Prepaid and other current assets	1,136	1,362
Total current assets	69,843	79,344
Property and equipment, net	1,278	1,462
Operating lease right-of-use asset	2,163	2,327
Other assets	513	513
Total assets	73,797	83,646
Current liabilities:
Accounts payable	3,356	2,448
Operating lease liability	927	878
Accrued and other liabilities	7,429	6,899
Total current liabilities	11,712	10,225
Operating lease liability	2,050	2,310
Total liabilities	13,762	12,535
Commitments and contingencies (Note 12)
Stockholders' equity:
Preferred stock: $0.0001 par value; 10,000,000 shares authorized at March 31, 2020 and December 31, 2019; 0 shares issued and outstanding at March 31, 2020 and December 31, 2019
Common stock: $0.0001 par value; 290,000,000 shares authorized at March 31, 2020 and December 31, 2019; 27,953,233 and 27,953,233 shares issued and outstanding at March 31, 2020 and December 31, 2019, respectively	3	3
Additional paid-in capital	290,069	288,224
Accumulated other comprehensive income	43	29
Accumulated deficit	(230,080)	(217,145)
Total stockholders' equity	60,035	71,111
Total liabilities and stockholders' equity	$ 73,797	$ 83,646