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License Agreements - Additional Information (Detail) - University of Bristol [Member] - USD ($) |  | 6 Months Ended |
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Jan. 22, 2018 | Jun. 30, 2021 | Jul. 31, 2016
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items] |  |  |
Maximum amount payable under license agreement, tied to milestones |  |  | $ 3,200,000
Payments under license agreement |  | $ 125,000 |
Amendment to the University of Bristol License Agreement [Member] |  |  |
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items] |  |  |
Maximum amount payable under license agreement, tied to milestones | $ 1,700,000 |  |
Payments under license agreement | $ 37,500 |  |

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- Details
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- Details
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