Fair Value Measurements (Tables)

9 Months Ended

12 Months Ended

Sep. 30, 2020

Dec. 31, 2019

Fair Value Disclosures [Abstract]

Summary of Financial Assets and Liabilities are Measured at Fair Value on Recurring Basis

The following tables present information about the Company’s financial assets and liabilities that are measured at fair value on a recurring basis and indicate the level of the fair value hierarchy utilized to determine such fair values (in thousands):

	Fair Value Measurements as of September 30, 2020 Using:
	Quoted Prices in Active Markets for Identical Assets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)		Fair Value
Assets
Cash equivalents—money market funds	$	52,175	$	—	$	—	$	52,175
Restricted cash		—		263		—		263
Total assets	$	52,175	$	263	$	—	$	52,438
Liabilities
Derivative liability related to loan	$	—	$	—	$	—	$	—
Total liabilities	$	—	$	—	$	—	$	—

	Fair Value Measurements as of December 31, 2019 Using:
	Quoted Prices in Active Markets for Identical Assets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)		Fair Value
Assets
Cash equivalents—money market funds	$	22,784	$	—	$	—	$	22,784
Restricted cash		—		263		—		263
Total assets	$	22,784	$	263	$	—	$	23,047
Liabilities
Derivative liability related to loan	$	—	$	—	$	494	$	494
Total liabilities	$	—	$	—	$	494	$	494

The following tables present information about the Company’s financial assets and liabilities that are measured at fair value on a recurring basis and indicate the level of the fair value hierarchy utilized to determine such fair values (in thousands):

	Fair Value Measurements as of December 31, 2019 Using:
	Quoted Prices in Active Markets for Identical Assets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)		Fair Value at December 31,
Assets
Cash equivalents—money market funds	$	22,784	$	—	$	—	$	22,784
Restricted cash		—		263		—		263
Total assets	$	22,784	$	263	$	—	$	23,047
Liabilities
Derivative liability related to loan	$	—	$	—	$	494	$	494
Total liabilities	$	—	$	—	$	494	$	494

	Fair Value Measurements as of December 31, 2018 Using:
	Quoted Prices in Active Markets for Identical Assets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)		Fair Value at December 31,
Assets
Cash equivalents—money market funds	$	55,291	$	—	$	—	$	55,291
Restricted cash		—		262		—		262
Total assets	$	55,291	$	262	$	—	$	55,553
Liabilities
Long term call right liability	$	—	$	—	$	390	$	390
Total liabilities	$	—	$	—	$	390	$	390

Schedule of Fair Value Inputs Quantitative Information

The following table provides a rollforward of the cumulative fair values of the Company’s call right liability for which fair value is determined by Level 3 inputs (in thousands):

Balances at December 31, 2017	$	313
Decrease in fair value of call right liability at issuance of Series A-5		(313	)
Balances at December 31, 2018	$	—

Schedule of Aggregate Fair Values of Derivative Liability

The following table provides a roll forward of the aggregate fair values of the Company’s derivative liability (in thousands):

	Derivative Liability
Balance at December 31, 2019	$	494
Change in fair value		556
Payment of success fee		(1,050	)
Balance at September 30, 2020	$	—

The following table provides a roll forward of the aggregate fair values of the Company’s derivative liability, for which fair value is determined using Level 3 inputs (in thousands):

Balances at December 31, 2017	$	—
Initial fair value of derivative liability in connection with loan		323
Change in fair value		67
Balances at December 31, 2018		390
Change in fair value		104
Balances at December 31, 2019	$	494