Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Current assets
Cash and cash equivalents	$ 125,699	$ 131,201
Prepaid expenses and other current assets	2,043	2,086
Income tax receivable	882	0
Total current assets	128,624	133,287
Property and equipment, net	173	335
Right-of-use assets, net	496
Income tax receivable, non-current	882	3,529
Other assets	12	14
Total assets	130,187	137,165
Current liabilities
Accrued research and development expenses	6,860	7,337
Accounts payable and accrued expenses	5,629	5,869
Lease liability, current	495
Total current liabilities	12,984	13,206
Total liabilities	12,984	13,206
Stockholders' equity
Preferred stock—$0.001 par value, 5,000,000 shares authorized, no shares issued or outstanding	0	0
Common stock—$0.001 par value, 200,000,000 shares authorized, 49,627,064 and 41,397,197 shares issued and outstanding at December 31, 2019 and December 31, 2018, respectively	50	41
Additional paid-in capital	597,679	545,585
Accumulated deficit	(480,526)	(421,667)
Total stockholders' equity	117,203	123,959
Total liabilities and stockholders' equity	$ 130,187	$ 137,165