Quarterly report pursuant to Section 13 or 15(d)

Stock Plans (Tables)

Stock Plans (Tables)

3 Months Ended

Mar. 31, 2020

The following table summarizes option activity:


				Weighted
		Weighted		Average
		Average		Remaining	Aggregate
		Exercise		Option	Intrinsic
	Options (in	Price per		Term (in	Value (in
	thousands)	share		years)	thousands)
Outstanding at December 31, 2019	1,192	$	6.23	7.9	$	—
Granted	—		—
Forfeited or expired	(288)		1.71
Outstanding at March 31, 2020	904	$	7.67	7.2	$	—
Exercisable at March 31, 2020	748	$	8.95	6.8	$	—

Schedule of the stock-based compensation expense

The following table summarizes the stock-based compensation expense recorded for awards under our stock option plans (in thousands):


	Three Months Ended
	March 31,
	2020		2019
Research and development	$	—	$	77
Selling, general and administrative		(84)		59
Total stock-based compensation expense	$	(84)	$	136

Schedule of assumptions to estimate the fair value of options


	Three Months Ended
	March 31,
	2020		2019
Weighted-average risk-free interest rate	—	%	2.58	%
Expected dividend payments	—		—
Expected holding period (years) (1)	—		6.3
Weighted-average volatility factor (2)	—		0.91
Estimated forfeiture rates for options granted (3)	—	%	25	%

(1)

Expected holding period is based on historical experience of similar awards, giving consideration to the contractual terms of the stock-based awards, vesting schedules and the expectations of future employee behavior.

(2)

Weighted average volatility is based on the historical volatility of our common stock.

(3)

Estimated forfeiture rates are based on historical data.