Leases

12 Months Ended

Dec. 31, 2021

Leases

Leases

6. Leases

We have entered into one operating lease for real estate. This lease has a term of 78 months, and includes renewal terms which can extend the lease term by 60 months, which is included in the lease term when it is reasonably certain that we will exercise the option.  As of December 31, 2021, our operating lease had a weighted average remaining lease term of 45 months. The right-of-use (ROU) asset is included in "Other assets" on our balance sheets as of December 31, 2021 and 2020, and represents our right to use the underlying asset for the lease term. Our obligations to make lease payments are included in "Accrued expenses" and "Other long-term liabilities" on our balance sheets as of December 31, 2021 and 2020.  The ROU asset was initially measured at cost, which comprises the initial amount of the lease liability adjusted for lease payments made at or before the lease commencement date, plus any initial direct costs incurred, less any lease incentives received. The ROU asset is subsequently measured throughout the lease term at the carrying amount of the lease liability, plus initial direct costs, plus (minus) any prepaid (accrued) lease payments, less the unamortized balance of lease incentives received.

As of December 31, 2021 and 2020, ROU assets were $1.7 million and $2.0 million, respectively, and operating lease liabilities were $2.5 million and $3.0 million, respectively. We have entered into various short-term operating leases, primarily for clinical trial equipment, with an initial term of twelve months or less. These leases are not recorded on our balance sheets. All operating lease expense is recognized on a straight-line basis over the lease term. During the years ended December 31, 2021 and 2020, we recognized $0.6 million and $0.6 million, respectively, in total lease costs, which included less than $0.1 million in short-term lease costs related to short-term operating leases in each year.

Because the rate implicit in the lease is not readily determinable, we use our incremental borrowing rate to determine the present value of the lease payments. The weighted average incremental borrowing rate used to determine the initial value of the ROU asset and lease liability was 11.0%, derived from a corporate yield curve based on a synthetic credit rating model using a market signal analysis. We have certain contracts for real estate which may contain lease and non-lease components which we have elected to treat as a single lease component.

ROU assets for operating leases are periodically reduced by impairment losses. We use the long-lived assets impairment guidance in ASC Subtopic 360-10, Property, Plant, and Equipment – Overall, to determine whether an ROU asset is impaired, and if so, the amount of the impairment loss to recognize.  As of December 31, 2021 and 2020, we have not recognized any impairment losses for our ROU assets.

We monitor for events or changes in circumstances that require a reassessment of one of our leases. When a reassessment results in the remeasurement of a lease liability, a corresponding adjustment is made to the carrying amount of the corresponding ROU asset unless doing so would reduce the carrying amount of the ROU asset to an amount less than zero. In that case, the amount of the adjustment that would result in a negative ROU asset balance is recorded in our statements of operations and comprehensive loss.

Maturities of operating lease liabilities as of December 31, 2021 were as follows (in thousands):

2022	$	807
2023		823
2024		840
Thereafter		643
		3,113
Less: imputed interest		(578)
Total lease liabilities	$	2,535
Current operating lease liabilities	$	556
Non-current operating lease liabilities		1,979
Total lease liabilities	$	2,535