Fair Value of Financial Instruments (Tables)

9 Months Ended

Sep. 30, 2020

Fair Value Disclosures [Abstract]

Summary of Financial Instruments Measured at Fair Value on Recurring Basis

The following table sets forth the Company’s financial instruments that were measured at fair value on a recurring basis by level within the fair value hierarchy (in thousands).

	Fair Value Measurements at September 30, 2020
	Total		Level 1		Level 2		Level 3
Liabilities
2017 PIPE warrant liability	$	4,777	$	—	$	—	$	4,777
2018 PIPE warrant liability		867		—		—		867
Essentialis purchase price contingency liability		10,138		—		—		10,138
Total common stock warrant and contingent    consideration liability	$	15,782	$	—	$	—	$	15,782

	Fair Value Measurements at December 31, 2019
	Total		Level 1		Level 2		Level 3
Liabilities
2017 PIPE warrant liability	$	10,822	$	—	$	—	$	10,822
2018 PIPE warrant liability		1,354		—		—		1,354
Essentialis purchase price contingency liability		5,938		—		—		5,938
Total common stock warrant and contingent    consideration liability	$	18,114	$	—	$	—	$	18,114

Summary of Changes in Fair Value of Level 3 Financial Instruments

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

	Series C Warrants					2017 PIPE Warrants					2018 PIPE Warrants					Purchase Price
	Number of Warrants			Liability		Number of Warrants		Liability			Number of Warrants		Liability			Contingent Liability
Balance at December 31, 2019		118,083		$	—		6,024,425	$	10,822			513,617	$	1,354		$	5,938
Expiration of Series C Warrants		(118,083	)		—		—		—			—		—			—
Change in value of 2017 PIPE Warrants		—			—		—		(6,045	)		—		—			—
Change in value of 2018 PIPE Warrants		—			—		—		—			—		(487	)		—
Change in value of contingent liability		—			—		—		—			—		—			4,200
Balance at September 30, 2020		—		$	—		6,024,425	$	4,777			513,617	$	867		$	10,138