Stock-Based Compensation (Tables)

12 Months Ended

Dec. 31, 2014

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

Summary of Share Based Fair Value Assumptions

The fair value of options granted were estimated using the Black-Scholes-Merton option pricing model based on the assumptions in the table below:

Year ended December 31,	2014	2013
Expected dividend yield	0%	0%
Expected volatility	46%-63%	62%-63%
Risk-free interest rate	1.60% - 2.30%	1.64% - 1.98%
Expected life (in years)	5.2 – 7.0	5.7 – 6.1

Schedule of Stock Option Activity

The following table summarizes the Company’s stock option activity, including grants to non-employees, for the years ended December 31, 2014 and 2013:

	Number of Shares			Weighted- Average Exercise Price		Weighted- Average Remaining Contractual Term (Years)
Options outstanding at December 31, 2012		2,584,554		$	0.40		8.70
Options assumed through merger with SafeStitch		709,550			3.75
Granted		603,139			2.20
Forfeited		(6,129	)		0.40
Exercised		(68,227	)		0.80
Options outstanding at December 31, 2013		3,822,887		$	1.30		7.95
Granted		2,422,309			5.40
Forfeited		(670,065	)		3.95
Exercised		(151,390	)		0.49
Options outstanding at December 31, 2014		5,423,741		$	2.82		7.79

Schedule of Stock Options Outstanding

The following table summarizes information about stock options outstanding at December 31, 2014:

	Number of Shares		Weighted- Average Exercise Price		Weighted- Average Remaining Contractual Term (Years)
Exercisable at December 31, 2014		2,721,164	$	1.47		6.65
Vested or expected to vest at December 31, 2014		4,864,038	$	2.38		7.63

Schedule of Unvested Stock Option Activity

The following table summarizes the unvested stock option activity:

	Number of Shares			Weighted-Average Fair Value
Unvested options at December 31, 2012		1,707,536		$	0.40
Unvested options assumed through merger with SafeStitch		223,200			2.45
Granted		603,139			0.95
Vested		(711,818	)		1.25
Forfeited		(5,490	)		0.20
Unvested options at December 31, 2013		1,816,566		$	1.10
Granted		2,422,309			2.87
Vested		(993,888	)		1.04
Forfeited		(542,410	)		2.25
Unvested options at December 31, 2014		2,702,577		$	2.33