Property and equipment, net (Details) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Property and equipment, net
Property and equipment, gross	$ 4,975	$ 3,751
Less: Accumulated depreciation and amortization	(2,683)	(1,933)
Property and equipment, net	2,292	1,818
Depreciation expense	1,000	700	$ 300
Laboratory equipment
Property and equipment, net
Property and equipment, gross	4,326	3,356
Leasehold improvements
Property and equipment, net
Property and equipment, gross	300	75
Computer equipment and software
Property and equipment, net
Property and equipment, gross	229	221
Furniture and office equipment
Property and equipment, net
Property and equipment, gross	$ 120	$ 99

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.

+ References

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