Additional Balance Sheet Detail - Schedule of Accrued Expenses and Other Current Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Balance Sheet Related Disclosures [Abstract]
External research and development	$ 4,082	$ 2,250
Payroll and benefits	2,928	2,239
Professional services	196	891
Capital lease obligation, current portion	17	50
Restricted stock liability, current portion	6	17
Other	38	49
Total accrued expenses and other current liabilities	$ 7,267	$ 5,496

Accrued liabilities and other current liabilities.

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Accrued research and development expenses.

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- Definition

Accrued restricted stock liability, current.

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Carrying value as of the balance sheet date of obligations incurred through that date and payable for professional fees, such as for legal and accounting services received. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer).

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Amount of capital lease obligation due within one year or the normal operating cycle, if longer.

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Total of the carrying values as of the balance sheet date of obligations incurred through that date and payable for obligations related to services received from employees, such as accrued salaries and bonuses, payroll taxes and fringe benefits. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer).

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Amount of liabilities classified as other, due within one year or the normal operating cycle, if longer.

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