Supplemental Balance Sheet Information - Schedule of Accrued Expenses (Details) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Payables And Accruals [Abstract]
Accrued clinical trial costs	$ 1,988	$ 2,683
Accrued personnel costs	1,228	1,409
Accrued professional fees	25	30
Accrued other	119	140
Total accrued expenses and other current liabilities	$ 3,360	$ 4,262

Amount of expenses incurred but not yet paid classified as other, due within one year or the normal operating cycle, if longer.

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