Share-Based Compensation (Tables)

6 Months Ended

Jun. 30, 2013

Disclosure of Compensation Related Costs, Share-based Payments [Abstract]

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

The compensation expense related to the Company’s share-based compensation arrangements is recorded as components of general and administrative expense and research and development expense, as follows:

	SIX MONTH PERIOD
	ENDED
	JUNE 30,
	2013		2012
Research and development	$	465,353	$	92,126
General and administrative		699,225		376,227
Share-based compensation expense	$	1,164,578	$	468,353
Net share-based compensation expense, per common share:
Basic and diluted	$	0.05	$	0.03

Schedule of Share-based Payment Award, Stock Options, Valuation Assumptions [Table Text Block]

Following are the weighted-average assumptions used in valuing the stock options granted during the six-month periods ended June 30, 2013 and 2012:

	SIX MONTH PERIOD ENDED JUNE 30,
	2013		2012
Expected volatility	105.37	%	102.01	%
Risk-free interest rate	1.01	%	0.92	%
Expected term of option	5.76 years		5.63 years
Forfeiture rate*	5.00	%	5.00	%
Expected dividend yield	0.00	%	0.00	%

* - Authoritative guidance requires forfeitures to be estimated at the time of grant and revised, if necessary, in subsequent periods if actual forfeitures differ from those estimates. During the six- month periods ended June 30, 2013 and 2012, forfeitures were estimated at 5%.

Schedule of Share-based Compensation, Stock Options, Activity [Table Text Block]

A summary of the Company’s stock option plans and of changes in options outstanding under the plans for the six months ended June 30, 2013 is as follows:

	Number of Options		Weighted Average Exercise Price
Outstanding at January 1, 2013		1,636,544	$	5.07
Granted		1,934,500	$	1.79
Exercised		(3,817)	$	1.88
Expired		(75,975)	$	25.43
Forfeited		-	$	-
Outstanding at June 30, 2013		3,491,252	$	2.79
Vested and expected to vest at June 30, 2013		3,396,030	$	2.82
Exercisable at June 30, 2013		1,586,809	$	3.90