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Summary of Significant Accounting Policies - Schedule of Significant Balance of Accounts Receivable (Detail) - Accounts Receivable [Member] - Credit Concentration Risk [Member] | 12 Months Ended
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Dec. 31, 2021 | Dec. 31, 2020
Astellas Agreement [Member] |  |
Accounting Policy [Line Items] |  |
Concentration risk, percentage | 63.00% | 10.00%
AstraZeneca Agreements [Member] |  |
Accounting Policy [Line Items] |  |
Concentration risk, percentage | 34.00% | 26.00%

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- Definition Accounting policy. + References No definition available. + Details
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