Summary of Significant Accounting Policies - Additional Information (Detail) $ in Thousands	12 Months Ended
Dec. 31, 2024 USD ($) item	Dec. 31, 2023 USD ($) item	Dec. 31, 2022 USD ($) item
Basis of Presentation [Line Items]
Prepaid R&D expense	$ 13	$ 7,245
Expected dividend yield	0.00%	0.00%	0.00%
Impairment of long-lived assets	$ 4,274	$ 0	$ 0
Inventory write-down	2,963
Unrecognized tax provisions	0	0
Unrecognized tax benefits, related interest and penalties	0	0	0
Depreciation and amortization	$ 192	$ 259	$ 248
CSL Vifor and CKDP Agreements [Member] \| License and milestone fees [Member]
Basis of Presentation [Line Items]
Number of performance obligations for revenue recognized \| item	1	1	1
Employee Stock Option
Basis of Presentation [Line Items]
Expected life of options (in years)	6 years 3 months	6 years 3 months	6 years 3 months
Expected dividend yield	0.00%	0.00%	0.00%

Number of performance obligations for revenue recognized.

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Summary Of Significant Accounting Policies [Line Items]

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The aggregate expense recognized in the current period that allocates the cost of tangible assets, intangible assets, or depleting assets to periods that benefit from use of the assets.

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Amount of unrecognized tax benefits.

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