Quarterly report pursuant to Section 13 or 15(d)

Accounting for Shared-based Payments (Tables)

v3.10.0.1
Accounting for Shared-based Payments (Tables)
9 Months Ended
Sep. 30, 2018
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]  
Schedule of stock-based compensation expense
Stock-based compensation has been recognized in operating results as follows:

Three Months Ended
September 30, 
Three Months Ended
September 30, 
Nine Months Ended
September 30, 
Nine Months Ended
September 30, 
($ in thousands)  2018 2017 2018 2017
Included in research and development  $ 459  $ 477  $ 1,634  $ 2,270 
Included in selling, general and administrative  2,525  3,411  7,737  17,812 
Total stock-based compensation expense(1)
$ 2,984  $ 3,888  $ 9,371  $ 20,082 
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(1) Stock based compensation expense for the nine months ended September 30, 2018 includes $193,000 recorded as a liability.
Schedule of weighted-average assumptions used to estimate fair value of stock option awards using the Black-Scholes option valuation model
The estimated fair value of stock option awards was determined on the date of grant using the Black-Scholes option valuation model with the following weighted-average assumptions during the periods indicated.
Nine Months Ended
September 30, 2018 
Nine Months Ended
September 30, 2017 
Risk-free interest rate  2.33-2.85%  1.85%-2.24% 
Dividend yield  —  — 
Expected volatility  63%-68%  62%-73% 
Expected term  6 years 6 years
Summary of stock option activity and of changes in stock options outstanding under the Plan
A summary of stock option activity and of changes in stock options outstanding under the Plans is presented below:


Number of
Options
Exercise Price
Per Share
Weighted Average
Exercise Price
Per Share
Intrinsic
Value
(in thousands)
Weighted Average
Remaining
Contractual Term
Balance outstanding, December 31, 2017  29,868,291  $0.44-9.12  $ 3.83  $ 5,346  6.09 years
Granted  7,917,700  $1.56-2.40  $ 2.12  $ — 
Exercised (1)
(1,805,081) $0.50-1.20  $ 0.56  $ 2,153 
Forfeited  (2,680,222) $0.50-7.91  $ 2.78  $ — 
Balance outstanding, September 30, 2018  33,300,688  $0.44-9.12  $ 3.61  $ 714  6.60 years
Exercisable, at September 30, 2018  22,056,762  $0.44-9.12  $ 4.00  $ 692  5.41 years
____________________
(1) Options exercised includes 428,147 shares withheld for payment of exercise price and related taxes.