Annual report pursuant to Section 13 and 15(d)

Stock-based Compensation - Stock Option Activity (Details)

v3.19.1
Stock-based Compensation - Stock Option Activity (Details) - USD ($)
$ / shares in Units, $ in Thousands
12 Months Ended
Dec. 31, 2018
Dec. 31, 2017
Dec. 31, 2016
Number of Shares      
Beginning balance - Outstanding (shares) 3,075,994 1,819,444  
Granted (shares) 1,259,530 1,256,770  
Exercised (shares) 0 0  
Forfeited/expired (shares) (282,611) (220)  
Ending balance - Outstanding (shares) 4,052,913 3,075,994 1,819,444
Exercisable (shares) 2,323,907 1,602,114  
Vested or expected to vest (shares) 4,052,913 3,075,994  
Weighted- Average Exercise Price      
Beginning balance - Outstanding (in dollars per share) $ 5.59 $ 7.52  
Granted (in dollars per share) 1.73 2.80  
Exercised (in dollars per share) 0 0  
Forfeited/expired (in dollars per share) 5.81 9.64  
Ending balance - Outstanding (in dollars per share) 4.37 5.59 $ 7.52
Exercisable (in dollars per share) 5.77 7.19  
Vested or expected to vest (in dollars per share) $ 4.37 $ 5.59  
Weighted- Average Remaining Contractual Life (in years)      
Balance - Outstanding 7 years 2 months 23 days 7 years 2 months 23 days 6 years 11 months 23 days
Exercisable 6 years 2 months 26 days 5 years 9 months 10 days  
Vested or expected to vest 7 years 2 months 23 days 7 years 2 months 23 days  
Aggregate Intrinsic Value ($000)      
Balance - Outstanding $ 0 $ 151 $ 32
Exercisable 0 15  
Vested and expected to vest $ 0 $ 151