Balance Sheet Details -Summary of Property and Equipment (Details) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Property Plant And Equipment [Line Items]
Property and equipment, gross	$ 2,224	$ 1,784
Less accumulated depreciation and amortization	(596)	(402)
Property and equipment, net	1,628	1,382
Laboratory Equipment
Property Plant And Equipment [Line Items]
Property and equipment, gross	1,797	1,635
Leasehold Improvements
Property Plant And Equipment [Line Items]
Property and equipment, gross	126	72
Computer Equipment and Software
Property Plant And Equipment [Line Items]
Property and equipment, gross	63
Furniture and Fixtures
Property Plant And Equipment [Line Items]
Property and equipment, gross	55	36
Construction in Progress
Property Plant And Equipment [Line Items]
Property and equipment, gross	$ 183	$ 41

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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