Annual report pursuant to Section 13 and 15(d)

Quarterly Financial Data (Unaudited) - Summary of Quarterly Financial Information (Detail)

v3.19.1
Quarterly Financial Data (Unaudited) - Summary of Quarterly Financial Information (Detail) - USD ($)
$ / shares in Units, $ in Thousands
3 Months Ended 12 Months Ended
Dec. 31, 2018
Sep. 30, 2018
Jun. 30, 2018
Mar. 31, 2018
Dec. 31, 2017
Sep. 30, 2017
Jun. 30, 2017
Mar. 31, 2017
Dec. 31, 2018
Dec. 31, 2017
Dec. 31, 2016
Uncategorized [Abstract]                      
Revenue $ 2 $ 27 $ 196 $ 11 $ 186 $ 44 $ 223 $ 55 $ 236 $ 508 $ 399
Operating expenses (8,630) (7,726) (7,688) (4,307) (6,999) (12,991) (3,463) (2,844) 28,351 26,297 12,508
Net loss $ (8,468) $ (7,483) $ (7,576) $ (4,370) $ (6,849) $ (12,904) $ (3,395) $ (2,832) $ (27,897) $ (25,980) $ (12,086)
Net loss per share $ (0.27) $ (0.23) $ (0.25) $ (0.16) $ (0.30) $ (0.51) $ (0.17) $ (0.14)