XML 46 R32.htm IDEA: XBRL DOCUMENT v3.7.0.1
Stock-Based Compensation (Tables)
 12 Months Ended
Dec. 31, 2016
Stock-Based Compensation Arrangements  
Schedule of stock based compensation expense
     
Year Ended December 31,
  
     
2015
    
2016
  
Research and development
       $ 240         $ 305    
General and administrative
         505           477    
Total
       $ 745         $ 782    
 
Schedule of stock option activity
​ ​ ​
Number of
Options
Outstanding
 ​ ​
Weighted
Average
Exercise Price
Per Share
 ​ ​
Weighted
Average 
Remaining
Life in Years
 ​ ​
Aggregate
Intrinsic
Value
Options outstanding at December 31, 2014
 ​ ​ ​ ​ 84,192 ​ ​ ​ ​ $ 170.88 ​ ​ ​ ​ ​ 6.58 ​ ​ ​ ​ $ —
Granted
 ​ ​ ​ ​ 122,523 ​ ​ ​ ​ $ 7.60 ​ ​ ​ ​
Exercised
 ​ ​ ​ ​ — ​ ​ ​ ​ $ — ​ ​ ​ ​ ​ ​ ​ ​ ​
Cancelled/forfeited
 ​ ​ ​ ​ (417) ​ ​ ​ ​ $ 813.84 ​ ​ ​ ​ ​ ​ ​ ​ ​
Options Outstanding at December 31, 2015
 ​ ​ ​ ​ 206,298 ​ ​ ​ ​ $ 72.60 ​ ​ ​ ​ ​ 8.09 ​ ​ ​ ​ $ —
Granted
 ​ ​ ​ ​ 197,841 ​ ​ ​ ​ $ 4.68 ​ ​ ​ ​
Exercised
 ​ ​ ​ ​ — ​ ​ ​ ​ $ — ​ ​ ​ ​ ​ ​ ​ ​ ​
Cancelled/forfeited
 ​ ​ ​ ​ (14,761) ​ ​ ​ ​ $ 396.83 ​ ​ ​ ​ ​ ​ ​ ​ ​
Options Outstanding at December 31, 2016
 ​ ​ ​ ​ 389,378 ​ ​ ​ ​ $ 25.80 ​ ​ ​ ​ ​ 5.83 ​ ​ ​ ​ $ 121.40
Unvested at December 31, 2016
 ​ ​ ​ ​ (267,582) ​ ​ ​ ​ $ 5.37 ​ ​ ​ ​ ​ 5.44 ​ ​ ​ ​ $ 121.40
Vested and exercisable at December 31, 2016
 ​ ​ ​ ​ 121,796 ​ ​ ​ ​ $ 70.67 ​ ​ ​ ​ ​ 6.68 ​ ​ ​ ​ $ —
​
Schedule of assumptions for stock option grants to employees and directors
     
Year Ended December 31,
  
     
2015
    
2016
  
Expected term (in years)
    
5 – 6
    
5 – 6
  
Risk-free interest rate
    
1.52% – 1.845%
    
1.37% – 1.50%
  
Volatility
    
96% – 108%
    
98% – 104%
  
Expected dividend yield over expected term
    
0.00%
    
0.00%
  
Resulting weighted average grant date fair value
    
$6.16
    
$3.66