CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Current assets:
Cash and cash equivalents	$ 59,091	$ 62,294
Short-term investments	169,535	230,165
Prepaid expenses and other current assets	9,193	9,945
Total current assets	237,819	302,404
Property and equipment, net	3,331	3,671
Right-of-use asset	1,932	2,045
Restricted cash	403	403
Total assets	243,485	308,523
Current liabilities:
Accounts payable	4,761	10,415
Accrued expenses and other current liabilities	9,640	13,530
Lease liability	503	472
Total current liabilities	14,904	24,417
Long-term liabilities:
Lease liability	2,828	3,086
Total liabilities	17,732	27,503
Commitments and contingencies
Stockholders' equity:
Preferred Stock, $0.001 par value: 10,000,000 shares authorized; no shares issued and outstanding at June 30, 2020 and December 31, 2019
Common stock, $0.001 par value: 120,000,000 shares authorized; 44,115,612 and 43,996,753 shares issued and outstanding at June 30, 2020 and December 31, 2019, respectively	44	44
Additional paid-in capital	615,691	606,307
Accumulated other comprehensive income	630
Accumulated deficit	(390,612)	(325,331)
Total stockholders' equity	225,753	281,020
Total liabilities and stockholders' equity	$ 243,485	$ 308,523