Property and Equipment, Net - Summary of Property and Equipment, Net (Detail) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Property, Plant and Equipment [Line Items]
Property plant and equipment, gross	$ 3,018	$ 394
Less: Accumulated depreciation and amortization	(384)	(45)
Property plant and equipment, net	2,634	349
Laboratory and Office Equipment [Member]
Property, Plant and Equipment [Line Items]
Property plant and equipment, gross	1,624	126
Leasehold Improvements [Member]
Property, Plant and Equipment [Line Items]
Property plant and equipment, gross	1,260	240
Computer Equipment and Software [Member]
Property, Plant and Equipment [Line Items]
Property plant and equipment, gross	$ 134	$ 28

Amount of accumulated depreciation, depletion and amortization for physical assets used in the normal conduct of business to produce goods and services.

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Amount before accumulated depreciation, depletion and amortization of physical assets used in the normal conduct of business and not intended for resale. Examples include, but are not limited to, land, buildings, machinery and equipment, office equipment, and furniture and fixtures.

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