Share-Based Payments (Tables)

6 Months Ended

Jun. 30, 2014

Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]

Summary of Stock Option Activity and Related Information

A summary of the Company’s stock option activity and related information follows:

	Shares			Weighted-Average Exercise Price		Remaining Contractual Life (in years)
Outstanding at December 31, 2013		1,346,238		$	3.39		8.59
Granted		186,115			14.66
Exercised		(36,612	)		0.49
Cancelled or forfeited		(4,762	)		7.37
Outstanding at June 30, 2014		1,490,979		$	4.86		8.33
Exercisable at June 30, 2014		470,531		$	2.20		7.66
Vested and expected to vest at June 30, 2014(1)		1,126,768		$	5.35		8.50

(1) Represents the number of vested options, plus the number of unvested options expected to vest.

Summary of Status and Changes of Unvested Restricted Stock

A summary of the status of unvested restricted stock is presented below:

	Restricted Stock			Weighted-Average Grant Date Fair Value
Unvested at December 31, 2013		163,353		$	0.06
Granted		70,879			11.43
Vested		(57,054	)		0.95
Unvested at June 30, 2014		177,178		$	4.33

Summary of Stock-based Compensation Expense

During the three and six months ended June 30, 2014 and 2013, the Company recorded stock-based compensation expense for employee and non-employee stock options and restricted stock, which was allocated as follows in the statements of operations (in thousands):

	Three Months Ended June 30,				Six Months Ended June 30,
	2014		2013		2014		2013
Research and development expense	$	144	$	375	$	499	$	408
General and administrative expense		357		15		638		21
	$	501	$	390	$	1,137	$	429