CONDENSED BALANCE SHEETS - USD ($)	Sep. 30, 2017	Dec. 31, 2016
Current assets:
Cash and cash equivalents at carrying value	$ 47,178,505	$ 31,228,192
Short-term investments	55,901,729	106,979,224
Receivables	27,746	55,074
Prepaid expenses	1,159,139	1,737,308
Other assets	125,435	255,912
Total current assets	104,392,554	140,255,710
Property and equipment, net	2,445,550	3,205,077
Other noncurrent assets	7,067	33,567
Total assets	106,845,171	143,494,354
Current liabilities:
Accounts payable	395,046	1,381,545
Accrued wages and benefits	1,542,864	2,705,475
Accrued clinical trial expenses	1,360,587	861,293
Accrued expenses and other liabilities	1,048,764	613,861
Total current liabilities	4,347,261	5,562,174
Other liabilities, net of current portion		2,873
Deferred revenue, net of current portion	744,444	781,944
Total liabilities	5,091,705	6,346,991
Stockholders’ equity:
Common stock: $0.001 par value, 100,000,000 shares authorized; 42,377,522 and 42,859,381 shares issued and outstanding at December 31, 2016 and September 30, 2017	47,860	42,378
Additional paid-in capital	402,100,682	390,768,742
Accumulated other comprehensive (loss) income	(4,560)	(41,196)
Retained deficit	(300,390,516)	(253,622,561)
Total stockholders’ equity	101,753,466	137,147,363
Total liabilities and stockholders’ equity	$ 106,845,171	$ 143,494,354