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Acquisitions - Summary of Estimated Relative Fair Values at Date of Acquisition (Detail) - USD ($) |  | 12 Months Ended |  |
--- | --- | --- | --- | ---
Mar. 03, 2015 | Sep. 30, 2015 | Sep. 30, 2014 | Sep. 30, 2013
Asset Acquisition [Line Items] |  |  |  |
Assets acquired |  | $ 23,879,181 | $ 68,538 | $ 123,191
Acquired in-process research and development - Pre-Clinical Candidates |  | $ 10,142,786 |  |
Novartis |  |  |  |
Asset Acquisition [Line Items] |  |  |  |
Acquired in-process research and development - Pre-Clinical Candidates | $ 10,142,786 |  |  |
Total purchase consideration | 35,000,000 |  |  |
Novartis | Patents |  |  |  |
Asset Acquisition [Line Items] |  |  |  |
Assets acquired | 21,728,334 |  |  |
Novartis | License |  |  |  |
Asset Acquisition [Line Items] |  |  |  |
Assets acquired | $ 3,128,880 |  |  |

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