Annual report pursuant to Section 13 and 15(d)

Equity Incentive Plans, Employee Stock Purchase Plan and Stock-Based Compensation - Schedule of Stock-Based Compensation Expense Recognized (Details)

v3.19.1
Equity Incentive Plans, Employee Stock Purchase Plan and Stock-Based Compensation - Schedule of Stock-Based Compensation Expense Recognized (Details) - USD ($)
$ in Thousands
 12 Months Ended
Dec. 31, 2018
Dec. 31, 2017
Dec. 31, 2016
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]      
Total stock-based compensation expense $ 2,872 $ 1,391 $ 968
Research and Development      
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]      
Total stock-based compensation expense 619 119 104
General and Administrative      
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]      
Total stock-based compensation expense $ 2,253 $ 1,272 $ 864