Long-Term Debt (Tables)

12 Months Ended

Dec. 31, 2021

Debt Disclosure [Abstract]

Schedule of Debt

Long-term debt consisted of the following:

(in thousands)	December 31, 2021		December 31, 2020
Principal amount of long-term debt	$	32,500	$	32,500
Debt premium, net of accretion	277		223
Cumulative accrual of end of term payments	1,157		455
Long-term debt	33,934		33,178
Less: current portion of long-term debt	(795)		—
Long-term debt, net of current portion	$	33,139	$	33,178

Schedule of Maturities of Long-term Debt

As of December 31, 2021, future principal payments and accrued end-of-term payments due under the Hercules Loan Agreement were as follows (in thousands):

Year Ending December 31	Total
2022	$	795
2023	21,471
2024	11,391
Long-term debt, including end-of-term payments	$	33,657