Summary of Significant Accounting Policies (Tables)

9 Months Ended

Sep. 30, 2016

Cash, Cash Equivalents and Investments [Table Text Block]

Cash and cash equivalents and short-term investments consist of the following:

	Amortized Cost				Fair Value
	September 30,		Unrealized		September 30,
Description	2016		Gains		2016
Cash and cash equivalents:
Cash and money market funds	$	14,142,002	$	-	$	14,142,002
Government-sponsored enterprise securities (original maturities within three months)		54,964,977		-		54,964,977
Total cash and cash equivalents	$	69,106,979	$	-	$	69,106,979
Short-term investments:
U.S. Treasury securities	$	20,074,630	$	5,020	$	20,079,650
Government-sponsored enterprise securities (original maturities within six months)		46,754,714		7,326		46,762,040
Total short-term investments	$	66,829,344	$	12,346	$	66,841,690
Total cash, cash equivalents and short-term investments	$	135,936,323	$	12,346	$	135,948,669

Schedule of Restructuring Reserve by Type of Cost [Table Text Block]

The remaining accrued liability relating to our restructuring expense as of September 30, 2016 is as follows:

	Balance as of						Balance as of
	December 31,		Paid		Amortized		September 30,
Description	2015		2016		2016		2016

Accrued severance expense	$	131,822	$	131,822	$	-	$	-
Accrued sublease expense		358,769		-		185,468		173,301
Total accrued restructuring expense	$	490,591	$	131,822	$	185,468	$	173,301

Schedule of Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Table Text Block]

Share-based compensation expense for the three and nine months ended September 30, 2016 and 2015 was:

	Three months ended September 30,				Nine months ended September 30,
	2016		2015		2016		2015

Research and development	$	83,900	$	12,034	$	136,374	$	85,259
General and administrative		1,463,922		81,723		1,760,168		395,470
Restructuring benefit		-		-		-		(53,741)
Total share-based compensation expense	$	1,547,822	$	93,757	$	1,896,542	$	426,988

Schedule of Earnings Per Share, Basic and Diluted [Table Text Block]

A reconciliation of the numerators and denominators of the basic and diluted per share computations for the three and nine months ended September 30, 2016 is as follows (a reconciliation is not required for the three and nine months ended September 30, 2015 since the Company recorded a net loss for those periods):

	Three months ended		Nine months ended
	September 30, 2016		September 30, 2016

Numerator

Net income	$	109,235,013	$	116,052,581
Net income allocated to participating securities		-		-
Numerator for basic income per share		109,235,013		116,052,581
Incremental allocation of net income to participating securities		-		-
Change in fair value of dilutive warrants		352,057		642,643
Numerator for diluted income per share	$	109,587,070	$	116,695,224

Denominator

Weighted average outstanding common shares for basic income per share	65,001,584	64,715,647
Dilutive effect of stock options	454,803	382,373
Dilutive effect of warrants	358,379	224,137
Denominator for diluted income per share	65,814,766	65,322,157