Share-Based Compensation (Tables)

12 Months Ended

Dec. 31, 2018

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

Share-Based Compensation Expense by Types of Awards

During the years ended December 31, 2018 and 2017, we recognized share-based compensation expense which consisted of the following types of awards (in thousands):

	2018		2017
Restricted stock	102		1,015
Options	6,267		4,731
Total share-based compensation expense	$	6,369	$	5,746

Summary of Share-Based Compensation Expense

The following table summarizes share-based compensation expense for the years ended December 31, 2018 and 2017, which was allocated as follows (in thousands):

	2018		2017
Research and development	$	1,950	$	911
Selling, general and administrative	4,419		4,835
Total share-based compensation expense	$	6,369	$	5,746

Schedule of Black Scholes Stock Option Pricing Model Weighted Average Assumptions

Fair value for stock options was estimated at the date of grant using the Black-Scholes pricing model, with the following weighted average assumptions:

	Year Ended December 31,
	2018		2017
Risk-free interest rate	2.9	%	1.9	%
Expected dividend yield	None		None
Expected life (in years)	5.4		5.2
Volatility	82	%	83	%

Stock Option Activity for All Stock Plans

The following table summarizes stock option activity for all of our stock option plans:

	Options		Weighted Average Exercise Price		Weighted Average Remaining Contractual Term (Years)	Aggregate Intrinsic Value (Thousands)
Outstanding at December 31, 2016 (1,913,000 exercisable)	2,806,000		$	11.44
Granted	4,450,000		$	3.68
Exercised	—		$	—
Forfeited	(378,000	)	$	6.27
Cancelled and expired	(210,000	)	$	24.33
Outstanding at December 31, 2017 (2,500,000 exercisable)	6,668,000		$	6.15
Granted	3,100,000		$	3.04
Exercised	(12,000	)	$	3.89
Forfeited	(408,000	)	$	3.48
Cancelled and expired	(2,129,000	)	$	9.18
Outstanding at December 31, 2018 (2,597,000 exercisable)	7,219,000		$	4.08	8.1	$	—
Vested or expected to vest at December 31, 2018	6,321,000		$	4.32	7.7	$	—
Exercisable at December 31, 2018	2,597,000		$	5.49	6.4	$	—

Summary of Status of Nonvested Restricted Stock Awards and Units

A summary of the status of nonvested restricted stock units as of December 31, 2018 and 2017 and changes during the periods then ended, is presented below:

	Nonvested Units		Weighted Average Grant-Date Fair Value Per Unit
Nonvested at December 31, 2016	187,000		$	5.35
Issued	20,000		$	4.97
Vested	(187,000	)	$	5.35
Forfeited	—		$	—
Nonvested at December 31, 2017	20,000		$	4.97
Issued	—		$	—
Vested	(20,000	)	$	4.97
Forfeited	—		$	—
Nonvested at December 31, 2018	—		$	—

A summary of the status of nonvested restricted stock awards as of December 31, 2018 and 2017 and changes during the periods then ended, is presented below:

	Nonvested Shares		Weighted Average Grant-Date Fair Value Per Share
Nonvested at December 31, 2016	183,000		$	12.76
Issued	2,000		$	5.78
Vested	(83,000	)	$	9.43
Forfeited	(39,000	)	$	14.39
Nonvested at December 31, 2017	63,000		$	15.93
Issued	—		$	—
Vested	(35,000	)	$	12.00
Forfeited	(15,000	)	$	16.12
Nonvested at December 31, 2018	13,000		$	26.23