Quarterly report pursuant to Section 13 or 15(d)

Stock Based Compensation (Tables)

v3.8.0.1
Stock Based Compensation (Tables)
3 Months Ended
Mar. 31, 2018
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]  
Stock-Based Compensation Expense

Stock-based compensation expense, which consists of the compensation cost for employee stock options granted under the 2009 Stock Plan, as amended (the “2009 Stock Plan”) and under the Company’s 2014 Equity Incentive Plan, as amended (the “2014 Equity Incentive Plan”) and the value of options issued to non-employees for services rendered, was allocated to research and development and general and administrative expenses in the unaudited consolidated statements of operations. Stock-based compensation for the three months ended March 31, 2018 and 2017 were (in thousands):

 

 

Three Months Ended

March 31,

 

 

2018

 

 

2017

 

Research and development

$

180

 

 

$

 

General and administrative

 

463

 

 

 

26

 

Total stock-based compensation

$

643

 

 

$

26

 

 

Weighted-Average Fair Value Valuation Assumptions

The fair value of employee stock options was estimated using the following weighted-average assumptions for the three months ended March 31, 2018 and 2017:

 

 

Three Months Ended

March 31,

 

 

2018

 

 

2017

 

Employee Stock Options:

 

 

 

 

 

 

 

Risk-free interest rate

 

2.68

%

 

 

1.95

%

Expected term (in years)

 

6.02

 

 

 

5.00

 

Dividend yield

 

 

 

 

 

Volatility

 

108

%

 

 

76

%

Weighted-average fair value of stock options granted

$

8.85

 

 

$

0.82

 

 

Stock Option Activity Under Equity Incentive Plan

The following table summarizes stock option activity under the Company’s equity incentive plans:

 

Options

 

Number of

Shares

 

 

Weighted-

Average

Exercise

Price

 

 

Weighted-

Average

Remaining

Contractual

Term

 

 

Aggregate

Intrinsic

Value (in millions)

 

Outstanding at December 31, 2017

 

 

2,768,711

 

 

$

12.07

 

 

 

5.6

 

 

$

11.0

 

Granted

 

 

297,750

 

 

$

10.69

 

 

 

 

 

 

 

Exercised

 

 

(161,705

)

 

$

0.91

 

 

 

 

 

 

 

Forfeitures

 

 

(24,995

)

 

$

31.47

 

 

 

 

 

 

 

Outstanding at March 31, 2018

 

 

2,879,761

 

 

$

12.38

 

 

 

6.2

 

 

$

7.7

 

Exercisable at March 31, 2018

 

 

1,470,533

 

 

$

15.89

 

 

 

2.9

 

 

$

6.6