Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Current assets:
Cash and cash equivalents	$ 59,716	$ 44,973
Investment securities	85,258	118,902
Prepaid expenses and other current assets	2,784	2,808
Total current assets	147,758	166,683
Property and equipment, net	4,264	4,232
Operating lease right-of-use asset	2,627
Restricted cash	500	500
Total assets	155,149	171,415
Current liabilities:
Accounts payable	2,705	1,456
Accrued expenses and other current liabilities	3,243	4,190
Accrued compensation and benefits	1,802	2,279
Total current liabilities	7,750	7,925
Non-current operating lease liability	5,226
Deferred rent		3,063
Unvested stock liability	72	202
Total liabilities	13,048	11,190
Commitments and contingencies (Note 7)
Stockholders’ equity:
Preferred stock, $0.001 par, 10,000 shares authorized; no shares issued or outstanding at June 30, 2019 or at December 31, 2018
Common stock and paid-in capital, $0.001 par, 200,000 shares authorized; 24,245 and 24,195 shares issued and outstanding at June 30, 2019; 24,188 and 24,061 shares issued and outstanding at December 31, 2018	206,690	203,544
Accumulated other comprehensive income	234	61
Accumulated deficit	(64,823)	(43,380)
Total stockholders’ equity	142,101	160,225
Total liabilities and stockholders’ equity	$ 155,149	$ 171,415