Property and Equipment, Net - Summary (Details) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Property and equipment
Gross property and equipment	$ 2,805	$ 1,253
Less: Accumulated depreciation	(1,029)	(780)
Property and equipment, net	1,776	473
Depreciation expenses	249	175	$ 184
Computer equipment
Property and equipment
Gross property and equipment	201	201
Office and other equipment
Property and equipment
Gross property and equipment	329	260
Laboratory equipment
Property and equipment
Gross property and equipment	2,212	729
Leasehold improvements
Property and equipment
Gross property and equipment	$ 63	$ 63

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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The amount of expense recognized in the current period that reflects the allocation of the cost of tangible assets over the assets' useful lives. Includes production and non-production related depreciation.

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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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