Convertible Preferred Stock, Common Stock and Stockholders' Equity (Deficit) (Tables)

12 Months Ended

Dec. 31, 2013

Equity [Abstract]

Summary of Stock Option Activity

A summary of the Company’s stock option activity under the 2007 Plan and 2013 Plan is as follows:

	Shares		Weighted Average Exercise Price		Weighted Average Remaining Contractual Term (Years)		Aggregate Intrinsic Value
Outstanding at December 31, 2012		123,250	$	0.40		7.84	$	578
Granted		501,500	$	9.39		9.88		—
Exercised		—		—		—		—
Canceled/Forfeited		—		—		—		—
Outstanding at December 31, 2013		624,750	$	7.61		8.41	$	869,490
Exercisable at December 31, 2013 (1)		90,540	$	0.39		5.01	$	638,881
Vested or expected to vest at December 31, 2013		624,750	$	7.61		8.41	$	869,490

(1) Includes awards with early exercise provisions that permit optionee to exercise unvested options.

Summary of Estimated Fair Value of Stock Option Award Granted

The estimated fair value of each 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 years ended December 31, 2013:

	Year Ended December 31,
	2013	2012		2011
Stock Options
Risk free interest rate	1.75% - 1.8%		—	2.33%
Expected option term	6.0 years		—	5.0 years
Expected volatility of common stock	70.8% - 79.4%		—	80.0%
Expected dividend yield	—%		—	—%

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:

	Year Ended December 31,						Period from January 29, 2007 (Inception) to December 31,
	2013		2012		2011		2013
Research and development	$	39,638	$	10,004	$	15,360	$	93,435
General and administrative		106,328		2,501		7,345		142,243
Total stock-based compensation expense	$	145,966	$	12,505	$	22,705	$	235,678

Summary of Common Stock Reserved for Future Issuance

Common stock reserved for future issuance consists of the following at December 31, 2013 and 2012:

	December 31,
	2013		2012
Conversion of preferred stock		—		2,439,002
Stock options issued and outstanding		624,750		123,250
Authorized for future option grants		8,500		—
Warrants for convertible preferred stock		—		14,000
Warrants for common stock		106,000		—
Authorized for Employee Stock Purchase Plan		330,000		—
Total common stock reserved for future issuance		1,069,250		2,576,252