Shareholders’ Equity (Tables)

6 Months Ended

Jun. 30, 2014

Summary of Share-based Compensation Expense

The following table summarizes all share-based compensation expense related to stock options, restricted stock and restricted stock units by expense category (in thousands):



	Three Months Ended June 30,				Six Months Ended June 30,
	2014		2013		2014		2013
Research and development:
Stock options	$	36	$	251	$	44	$	647
Restricted stock	146		35		505		43
Research and development share-based compensation expense	182		286		549		690
General and administrative:
Stock options	266		1,892		289		4,962
Restricted stock	1,706		112		4,014		121
Restricted stock units	—		52		—		52
General and administrative share-based compensation expense	1,972		2,056		4,303		5,135
Total share-based compensation expense included in expenses	$	2,154	$	2,342	$	4,852	$	5,825

Stock Options, Valuation Assumptions



	Three Months Ended June 30, 2014
Dividend yield	—
Volatility	199.4	%
Risk-free interest rate	2.24	%
Expected life of options (years)	6.11 - 10.00

Summary of Stock Option Activity and Related Data

A summary of the Company’s stock option activity and related data for the six months ended June 30, 2014 is as follows:



	Outstanding Options
	Number of Shares	Weighted-Average Exercise Price		Weighted-Average Remaining Contractual Term (Years)
Balance at December 31, 2013	54,000	$	6.00	9.63
Granted	55,000	$	7.51	9.90
Balance at March 31, 2014	109,000	$	6.76	9.76
Granted	274,900	$	10.73	9.77
Balance at June 30, 2014	383,900	$	9.60	9.70