Stockholders' Equity (Tables)

3 Months Ended

Mar. 31, 2014

Summary of Non-Cash Share-Based Compensation Expense

The Company recognized non-cash stock-based compensation expense to employees and directors in its research and development and its general and administrative functions as follows:

	Three Months Ended March 31,				Period from January 29, 2007 (Inception) to March 31, 2014
	2014		2013
Research and development	$	92,665	$	2,501	$	186,100
General and administrative		130,645		625		272,887
Total stock-based compensation expense	$	223,310	$	3,126	$	458,987

Common stock options [Member]

Summary of Estimated Fair Value of Stock Option Award and Employee Stock Purchase Plan Award

The estimated fair value of each stock option award granted was determined on the date of grant using the Black-Scholes option-pricing valuation model with the following weighted-average assumptions for options grants during the three months ended March 31, 2014. No options were granted during the three months ended March 31, 2013.

	Three Months Ended March 31,
	2014			2013
Stock Options
Risk free interest rate		1.77	%		—
Expected option term		6.0 years			—
Expected volatility of common stock		73.21	%		—
Expected dividend yield		0.0	%		—

Employee stock purchase plan [Member]

Summary of Estimated Fair Value of Stock Option Award and Employee Stock Purchase Plan Award

The estimated fair value of each employee stock purchase plan award was determined on the date of grant using the Black-Scholes option-pricing valuation model with the following weighted-average assumptions for options grants during the three months ended March 31, 2014. The employee stock purchase plan did not become active until March 2014.

	Three Months Ended March 31,
	2014			2013
Employee Stock Purchase Plan
Risk free interest rate		0.08	%		—
Expected option term		6.0 months			—
Expected volatility of common stock		73.21	%		—
Expected dividend yield		0.0	%		—