Leases

12 Months Ended

Dec. 31, 2020

Leases

Leases

5.           Leases

Kiniksa US leases office and laboratory space under operating leases. Leases with an initial term of 12 months or less are not recorded on the balance sheet; the Company recognizes lease expense for these leases on a straight-line basis over the lease term. For lease agreements entered into or reassessed after the Company’s adoption of ASC 842, the Company will combine lease and non-lease components. Kiniksa US’s leases have remaining lease terms of less than 2 years.

On March 13, 2018, Kiniksa US entered into an operating lease in Lexington, Massachusetts for office and laboratory space that comprises the headquarters for Kiniksa US and on June 26, 2018, Kiniksa US entered into an amendment to the lease expanding the rentable space to a total of 27,244 square feet. On November 7, 2018, Kiniksa US entered into an amendment (the “Third Amendment”) to the lease expanding the rentable space to a total of 55,924 square feet which were occupied in phases through December 2019. On November 6, 2020, Kiniksa US entered into an amendment (the “Fourth Amendment”) to extend the term of the sublease by one month to August 31, 2021 and entered into a Recognition and Attornment Agreement and Amendment of Sublease (the “2020 Agreement”) directly with the prime landlord to continue to lease the space upon the expiration of the Fourth Amendment through August 31, 2023. Monthly lease payments include base rent, as well as, ancillary charges such as the share of operating expenses and real estate taxes. Base rent under the Third Amendment and Fourth Amendments were $139 per month and increased to $153 per month in November 2020 with subsequent increases to $233 per month in September 2021 and $240 per month in September 2022 through the end of the lease. Further, a letter of credit to secure the lease is not required under the 2020 Agreement.

On December 21, 2018, Kiniksa US entered into an operating lease in San Diego, California for office space comprising a total of 4,400 square feet. The lease commenced on January 1, 2019 and expires on January 31, 2021. On July 17, 2020, Kiniksa US entered into an amendment to extend the lease through January 31, 2022. Monthly lease

payments for base rent are $13 and increase to $14 in February 2021 in accordance with the extension. Additional fees for ancillary charges such as the share of operating expenses, parking and real estate taxes are not included in the base rent.

On December 1, 2020, Kiniksa UK entered into an operating lease in London, UK for office space comprising a total of 164 square meters. The lease commenced on December 1, 2020 and expires on November 30, 2025 with an option to terminate on November 30, 2023. Quarterly lease payments for base rent are £20 as of December 2020 and will increase periodically until the termination of the lease. Additional fees for ancillary charges such as the share of operating expenses, parking and real estate taxes are not included in the base rent. The lease also includes a requirement to restore the property to original condition and is estimated to be approximately £22.

	Years Ended
	December 31,
	2020		2019
Operating lease cost	$	1,578	$	1,443
Variable lease cost		167		152
Total lease cost	$	1,745	$	1,595

	December 31,
	2020
Weighted-average remaining lease term (years)		2.64
Weighted-average discount rate		5.60%

Maturities of operating leases liabilities were as follows:

As of December 31,
2021	$	2,419
2022		3,055
2023		2,065
2024 and thereafter		—
Total future minimum lease payments	$	7,539
Less imputed interest		(554)
Present value of lease liabilities	$	6,985