Prepaid Expenses and Other Current Assets - Schedule of Prepaid Expenses and Other Current Assets (Detail) - USD ($) $ in Thousands |
Dec. 31, 2015 |
Dec. 31, 2014 |
|---|---|---|
| Prepaid Expense and Other Assets, Current [Abstract] | ||
| Deposits | $ 67 | $ 505 |
| Undelivered laboratory and office equipment | 17 | 78 |
| Insurance | 42 | 67 |
| Other current assets | 195 | 146 |
| Prepaid expenses and other current assets | $ 321 | $ 796 |