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Reverse Merger - Additional Information (Detail) $ / shares in Units, $ in Thousands |  |  |  | 12 Months Ended |
--- | --- | --- | --- | --- | ---
Aug. 17, 2017 USD ($) | Aug. 01, 2017 Right $ / shares shares | Jan. 05, 2015 | Dec. 31, 2017 USD ($) shares | Dec. 31, 2016 shares
Business Acquisition [Line Items] |  |  |  |  |
Common stock, shares outstanding | shares |  |  |  | 11,947,932 | 21,230
Contingent value rights recovery | $ |  |  |  | $ 200 |
OncoGenex Pharmaceuticals, Inc [Member] |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |
Reverse stock split ratio |  | 0.0909 | 0.0909 |  |
Share price |  | $ 4.62 |  |  |
Common stock, shares outstanding | shares |  | 2,736,703 |  |  |
Number of contingent value rights to be issued for each share of common stock outstanding | Right |  | 1 |  |  |
Contingent value rights recovery | $ | $ 200 |  |  |  |
OncoGenex Pharmaceuticals, Inc [Member] | Contingent Value Rights [Member] |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |
Combined company acquisition period results |  | 5 years |  |  |
Aggregate consideration distributed to the holders, consideration received percent |  | 80.00% |  |  |
OncoGenex Pharmaceuticals, Inc [Member] | Warrant [Member] |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |
Share price |  | $ 4.62 |  |  |
OncoGenex Pharmaceuticals, Inc [Member] | Warrant [Member] | Minimum [Member] |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |
Volatility rate |  | 90.33% |  |  |
Risk-free interest rate |  | 1.32% |  |  |
Expected lives |  | 1 year 10 months 28 days |  |  |
OncoGenex Pharmaceuticals, Inc [Member] | Warrant [Member] | Maximum [Member] |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |
Volatility rate |  | 106.08% |  |  |
Risk-free interest rate |  | 1.53% |  |  |
Expected lives |  | 3 years 2 months 27 days |  |  |
OncoGenex Pharmaceuticals, Inc [Member] | Stock Options [Member] |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |
Share price |  | $ 4.62 |  |  |
OncoGenex Pharmaceuticals, Inc [Member] | Stock Options [Member] | Minimum [Member] |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |
Volatility rate |  | 97.23% |  |  |
Risk-free interest rate |  | 1.31% |  |  |
Expected lives |  | 1 year 9 months 25 days |  |  |
OncoGenex Pharmaceuticals, Inc [Member] | Stock Options [Member] | Maximum [Member] |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |
Volatility rate |  | 106.63% |  |  |
Risk-free interest rate |  | 1.54% |  |  |
Expected lives |  | 3 years 3 months 22 days |  |  |

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