Selected Quarterly Financial Data (Unaudited) - Schedule of Quarterly Financial Data (Detail) - USD ($) $ / shares in Units, $ in Thousands |
3 Months Ended | 12 Months Ended | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
Dec. 31, 2015 |
Sep. 30, 2015 |
Jun. 30, 2015 |
Mar. 31, 2015 |
Dec. 31, 2014 |
Sep. 30, 2014 |
Jun. 30, 2014 |
Mar. 31, 2014 |
Dec. 31, 2015 |
Dec. 31, 2014 |
Dec. 31, 2013 |
|
| Statements of Operations Data: | |||||||||||
| Product revenue | $ 394 | $ 388 | $ 334 | $ 238 | $ 193 | $ 143 | $ 97 | $ 27 | $ 1,354 | $ 460 | |
| Collaboration revenue | 42 | 41 | 125 | 188 | 312 | 396 | 312 | ||||
| Revenue | 436 | 429 | 459 | 426 | 505 | 143 | 97 | 27 | 1,750 | 772 | |
| Loss from operations | (10,275) | (11,174) | (9,635) | (7,113) | (7,547) | (6,776) | (5,946) | (6,825) | (38,197) | (27,094) | $ (12,903) |
| Net loss | (10,637) | (11,524) | (10,009) | (7,578) | (7,954) | (7,294) | (6,392) | (7,008) | (39,748) | (28,648) | (13,317) |
| Net loss attributable to common stockholders | $ (10,637) | $ (11,524) | $ (10,009) | $ (7,578) | $ (7,954) | $ (7,294) | $ (6,397) | $ (7,014) | $ (39,748) | $ (28,659) | $ (13,344) |
| Basic and diluted net loss attributable to common stockholders per share | $ (0.43) | $ (0.47) | $ (0.45) | $ (0.35) | $ (0.37) | $ (0.48) | $ (2.10) | $ (2.45) | $ (1.71) | $ (2.69) | $ (5.11) |