FAIR VALUE MEASUREMENTS (Tables)

12 Months Ended

Dec. 31, 2019

Fair Value Disclosures [Abstract]

Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis

The following tables present information about the Company’s financial assets and liabilities measured at fair value on a recurring basis and indicate the level of the fair value hierarchy used to determine such fair values:

	Fair value measurements at December 31, 2019 using:
	Level 1		Level 2		Level 3		Total
Assets:
Money market funds	$	24,157	$	—	$	—	$	24,157
Total	$	24,157	$	—	$	—	$	24,157
Liabilities:
Derivative liabilities	$	—	$	—	$	16	$	16
Total	$	—	$	—	$	16	$	16

	Fair value measurements at December 31, 2018 using:
	Level 1		Level 2		Level 3		Total
Liabilities:
Derivative liabilities	$	—	$	—	$	4,023	$	4,023
Total	$	—	$	—	$	4,023	$	4,023

Schedule of Fair Value Measurement Inputs

The following table presents the key inputs of the tranche rights derivative liabilities, which were extinguished in August 2019:

	December 31,
	2019		2018
Risk-free interest rate	0.0	%	2.6	%
Expected term (in years)	0.0		2.0
Expected volatility	0.0	%	65.0	%
Expected dividend yield	0.0	%	0.0	%

Reconciliation of Fair Value Liabilities

	Derivative liabilities
Balance - December 31, 2017	$	8
Issuance of series B preferred stock tranche right	4,000
Change in fair value	15
Balance - December 31, 2018	4,023
Change in fair value	6,393
Exercise of series B preferred stock tranche right	(10,400)
Balance - December 31, 2019	$	16