Consolidated Balance Sheets - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Current assets:
Cash and cash equivalents	$ 209,154	$ 171,017
Short-term investments	129,192	203,210
Prepaid expenses and other current assets	7,468	3,506
Total current assets	345,814	377,733
Property and equipment, net	1,585	1,618
Long-term investments	36,177	54,305
Other long-term assets	1,114	1,481
Restricted cash	60	60
Total assets	384,750	435,197
Current liabilities:
Accounts payable	5,484	16,237
Accrued expenses	18,139	11,052
Notes payable, current portion	0	1,375
Other current liabilities	851	871
Total current liabilities	24,474	29,535
Other long-term liabilities	33	654
Stockholders’ equity:
Preferred stock, $0.001 par value, 10,000 shares authorized and no shares, issued or outstanding at September 30, 2020 and December 31, 2019, respectively	0	0
Common stock, $0.001 par value, 500,000 shares authorized, 27,346 shares and 27,255 shares issued and outstanding at September 30, 2020 and December 31, 2019, respectively	27	27
Additional paid-in capital	657,560	648,669
Accumulated other comprehensive income	259	338
Accumulated deficit	(297,603)	(244,026)
Total stockholders’ equity	360,243	405,008
Total liabilities and stockholders’ equity	$ 384,750	$ 435,197