FAIR VALUE OF FINANCIAL INSTRUMENTS (Tables)

9 Months Ended

Sep. 30, 2021

Fair Value Disclosures [Abstract]

Schedule of Fair Value of Financial Liabilities

The following table sets forth the fair value of the Company’s financial liabilities by level within the fair value hierarchy (in thousands):

	At September 30, 2021
	Level 1		Level 2		Level 3		Total
2017 Placement Warrants Liability	$	—	$	—	$	7,449	$	7,449
2016 Placement Warrants Liability	—		—		2,639		2,639
Total	$	—	$	—	$	10,088	$	10,088

	At December 31, 2020
	Level 1		Level 2		Level 3		Total
2017 Placement Warrants Liability	$	—	$	—	$	3,675	$	3,675
2016 Placement Warrants Liability	—		—		1,189		1,189
Total	$	—	$	—	$	4,864	$	4,864

Summary of Changes in Fair Value of Level 3 Financial Liabilities

The following table sets forth a summary of the changes in fair value of the Company’s Level 3 financial liabilities (in thousands):

	Three Months Ended September 30,				Nine Months Ended September 30,
	2021		2020		2021		2020
Fair value, beginning of period	$	9,212	$	2,072	$	4,864	$	5,373
Change in fair value of Level 3 financial liabilities	876		2,020		5,577		(1,281)
Fair value of 2016 Placement Warrants at exercise	—		—		(2)		—
Fair value of 2017 Placement Warrants at exercise	—		—		(351)		—
Fair value, end of period	$	10,088	$	4,092	$	10,088	$	4,092