Debt (Tables)

12 Months Ended

Dec. 31, 2019

Debt Disclosure [Abstract]

Schedule of debt valuation assumptions

The assumptions used in the Black-Scholes option-pricing model are determined as follows:

	December 31, 2019		December 31, 2018
Volatility	98.04	%	102.90	%
Risk-free interest rate	1.81	%	2.63	%
Weighted average expected life (in years)	6.25		1.29
Dividend yield	0	%	0	%

The assumptions used in the Black-Scholes option-pricing model are determined as follows:

	December 31, 2019
Volatility	98.01	%
Risk-free interest rate	1.58	%
Expected life (in years)	7
Dividend yield	0	%

Schedule of carrying amounts of debt

The 2024 Notes and 2022 Loan consist of the following (in thousands):

	December 31,		December 31,
Liability component	2019		2018
Principal	$	36,502	$	7,950
Less: debt discount	(4,905)		(478)
Net carrying amount	$	31,597	$	7,472

Schedule of interest expense recognized

The following table sets forth total interest expense recognized related to the 2024 Notes and 2022 Loan (in thousands):

	December 31,		December 31,
	2019		2018
Contractual interest expense	$	2,653	$	388
Accretion of debt discount	394		182
Total	$	3,047	$	570