CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($)	6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015
Cash flows from operating activities:
Net loss	$ (10,510,763)	$ (3,118,345)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation	27,450	4,542
Stock-based compensation	1,576,538
Changes in operating assets and liabilities:
Incentive receivable	(1,335,597)
Prepaid expenses and other assets	(223,077)	(497,148)
Deferred grant revenue	(7,250)	(30,218)
Accounts payable	1,877,165	761,930
Accrued expenses	(755,943)	(608,747)
Net cash used in operating activities	(9,351,477)	(3,487,986)
Cash flows from investing activities:
Purchases of property and equipment	(28,535)	(46,300)
Net cash used in investing activities	(28,535)	(46,300)
Cash flows from financing activities:
Payment of offering costs		(53,631)
Net cash used in financing activities		(53,631)
Net decrease in cash and cash equivalents	(9,380,012)	(3,587,917)
Cash and cash equivalents at beginning of period	41,513,060	9,330,681
Cash and cash equivalents at end of period	$ 32,133,048	5,742,764
Supplemental disclosures of cash flow information:
Deferred offering costs included in accounts payable and accrued expenses		$ 1,897,290