Quarterly report pursuant to Section 13 or 15(d)

Stock Plans

v3.7.0.1
Stock Plans
3 Months Ended
Mar. 31, 2017
Stock Plans [Abstract]  
Stock Plans [Text Block]
2. Stock Plans
 
The following table summarizes the stock-based compensation expense recorded for awards under the stock option plans for the three month periods ended March 31, 2017 and 2016:
 
 
 
Three Months Ended
 
 
 
March 31,
 
(in thousands, except per share amounts)
 
2017
 
2016
 
Research and development
 
$
117
 
$
132
 
General and administrative
 
 
304
 
 
200
 
 
 
 
 
 
 
 
 
Total stock-based compensation expenses
 
$
421
 
$
332
 
 
No tax benefit was recognized related to stock-based compensation expense since we have incurred operating losses and we have established a full valuation allowance to offset all the potential tax benefits associated with our deferred tax assets.
 
We use the Black-Scholes-Merton option-pricing model with the following assumptions to estimate the stock-based compensation expense for the three month period ended March 31, 2017 and 2016:
 
 
 
Three Months Ended
 
 
 
March 31,
 
 
 
2017
 
 
2016
 
Weighted-average risk-free interest rate
 
 
2.16
%
 
 
1.53
%
Expected dividend payments
 
 
 
 
 
 
Expected holding period (years)1
 
 
6.6
 
 
 
6.5
 
Weighted-average volatility factor2
 
 
0.88
 
 
 
0.92
 
Estimated forfeiture rates for options granted3
 
 
28
%
 
 
29
%
 
(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.
 
Options to purchase approximately 436,000 and approximately 168,000 common shares were granted during the three month periods ended March 31, 2017 and 2016, respectively.
  
The following table summarizes option activity for the three month period ended March 31, 2017:
 
 
 
 
 
 
 
 
 
Weighted
 
 
 
 
 
 
 
 
 
Weighted
 
 
Average
 
 
 
 
 
 
 
 
 
Average
 
 
Remaining
 
 
Aggregate
 
 
 
 
 
 
Exercise
 
 
Option
 
 
Intrinsic
 
(in thousands, except per share amounts)
 
Options
 
 
Price
 
 
Term
 
 
Value
 
Outstanding at January 1, 2017
 
 
2,002
 
 
$
5.67
 
 
 
5.68
 
 
$
203
 
Granted
 
 
436
 
 
 
3.89
 
 
 
 
 
 
 
 
 
Exercised
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Expired or cancelled
 
 
(14)
 
 
 
17.21
 
 
 
 
 
 
 
 
 
Forfeited
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Outstanding at March 31, 2017
 
 
2,424
 
 
$
5.29
 
 
 
6.27
 
 
$
8
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Exercisable at March 31, 2017
 
 
1,823
 
 
$
5.60
 
 
 
5.21
 
 
$
8
 
  
No shares of restricted stock were awarded to employees, directors and consultants during the three month periods ended March 31, 2017 and 2016.
 
As of March 31, 2017, there was approximately $1,302,000 of total unrecognized compensation expense related to non-vested stock options. This expense is expected to be recognized over a weighted-average period of approximately 1.3 years.