Condensed Balance Sheets - USD ($)	Mar. 31, 2017	Dec. 31, 2016
Current assets:
Cash and cash equivalents	$ 16,475,482	$ 58,083,409
Marketable securities	64,065,876	18,931,715
Other receivables		2,500,000
Prepaid and other current assets	889,862	937,436
Total current assets	81,431,220	80,452,560
Property and equipment, net	237,775	261,446
Other assets	1,884,993	1,609,834
Total assets	83,553,988	82,323,840
Current liabilities:
Accounts payable and accrued expenses	5,697,714	5,311,093
Accrued compensation	938,735	2,351,703
Current portion of deferred revenue	27,449,116	30,897,192
Note payable		1,000,000
Total current liabilities	34,085,565	39,559,988
Deferred revenue, less current portion	17,253,762	20,803,762
Convertible note payable	12,592,466
Deferred rent	161,451	171,544
Stockholders’ equity:
Preferred stock, $0.0001 par value; 10,000,000 shares authorized; no shares issued and outstanding
Common stock, $0.0001 par value; 200,000,000 shares authorized; 26,169,896 shares issued and outstanding at March 31, 2017; 26,118,722 shares issued and outstanding at December 31, 2016	2,617	2,612
Additional paid-in capital	173,710,486	172,424,531
Accumulated other comprehensive loss	(19,162)	(6,145)
Accumulated deficit	(154,233,197)	(150,632,452)
Total stockholders’ equity	19,460,744	21,788,546
Total liabilities and stockholders’ equity	$ 83,553,988	$ 82,323,840