Supplemental Balance Sheet Information - Prepaid expenses and other current assets (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Supplemental Balance Sheet Information [Abstract]
Prepaid clinical, contract research and manufacturing costs	$ 4,548	$ 2,336
Interest receivable	224	161
Prepaid insurance	472	694
Other	1,307	1,040
Prepaid expenses and other current assets	$ 6,551	$ 4,231

Carrying amount as of the balance sheet date of interest earned but not received. Also called accrued interest or accrued interest receivable.

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Amount of asset related to consideration paid in advance for other costs that provide economic benefits within a future period of one year or the normal operating cycle, if longer.

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Amount of asset related to consideration paid in advance for costs that provide economic benefits in future periods, and amount of other assets that are expected to be realized or consumed within one year or the normal operating cycle, if longer.

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Amount of asset related to consideration paid in advance for insurance that provides economic benefits within a future period of one year or the normal operating cycle, if longer.

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Supplemental Balance Sheet Information [Abstract]

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