Equity (Tables)

6 Months Ended

Jun. 30, 2015

Equity [Abstract]

Summary of Stock Option Activity

A summary of the stock option activity under the Company’s plans for the six months ended June 30, 2015 is as follows:

	Number of shares		Weighted average exercise price
Options outstanding at December 31, 2014		4,012,096	$	2.04
Options granted		1,723,500		4.77
Less:
Options exercised		207,625		1.54
Options canceled or expired		5,000		2.48
Options outstanding at June 30, 2015		5,522,971		2.91
Exercisable at June 30, 2015		2,739,622	$	1.51

Summary of Stock-Based Compensation Expense Recognized for Stock Options and Restricted Stock Included in Consolidated Statements of Operations

Stock-based compensation expense recognized for stock options and restricted stock and included in the consolidated statements of operations was allocated as follows:

	Three months ended June 30,				Six months ended June 30,
(in thousands)	2015		2014		2015		2014
Research and development expense	$	123	$	27	$	178	$	69
General and administrative expense		385		130		635		177
Total stock-based compensation expense	$	508	$	157	$	813	$	246

Summary of Warrant Activity

A summary of the warrant activity for the six months ended June 30, 2015 is as follows:

	Number of shares		Weighted average exercise price
Warrants outstanding at December 31, 2014		650,000	$	1.48
Warrants granted		—		—
Less:
Warrants exercised		—		—
Warrants canceled or expired		—		—
Warrants outstanding at June 30, 2015		650,000		1.48
Exercisable at June 30, 2015		530,000	$	1.49