Leases

12 Months Ended

Dec. 31, 2021

The Company leases certain office and laboratory space. Additionally, the Company has embedded leases through its agreements with contract manufacturing organizations.

60 Binney Street lease & sublease

In October 2021, the Company entered into a consent to assignment and amendment to its lease agreement for its 60 Binney Street lease (the "Assignment"). The Assignment transfers the Company's interest in the lease to 2seventy bio and releases the Company from its obligation to maintain the $13.8 million collateralized letter of credit required under the original 60 Binney Street lease. Although the lease was legally transferred to 2seventy bio, the lessor required that the Company remain secondarily liable as a guarantor for payment obligations accruing under the 60 Binney Street lease from the date of Assignment until (i) the Company has completely vacated the premises and (ii) 2seventy bio has reached a market capitalization of $900 million. Upon Separation, the lease assignment was accounted for as the termination of the original lease and the Company de-recognized the right-of-use asset and lease liability related to the 60 Binney Street lease and recognized the fair value of the guarantee pursuant to ASC 405, Liabilities. The fair value of the guarantee was not material.

Concurrent with the Assignment of the 60 Binney Street Lease, the Company entered into a sublease agreement with 2seventy bio for office, laboratory and storage space located at 60 Binney Street (the "60 Binney Street Sublease") while it constructs and outfits its new office and laboratory space. Under the terms of the 60 Binney Street Sublease, the Company will lease 72,988 square feet for $0.5 million per month in base rent for the period beginning from the Assignment through March 2022 and 58,004 square feet for $0.4 million per month in base rent for the period from April 2022 through March 2024. The Company accounted for the 60 Binney Street Sublease as a new lease under ASC 842, and in November 2021, recognized a right-of-use asset and lease liability related to the 60 Binney Street Sublease.

50 Binney Street sublease & sub-sublease

In April 2019, the Company entered into a sublease agreement for office space located at 50 Binney Street in Cambridge, Massachusetts (the “50 Binney Street Sublease”) to supplement the Company’s corporate headquarters located at 60 Binney Street in Cambridge, Massachusetts. Under the terms of the 50 Binney Street Sublease, the Company will lease 267,278 square feet of office space for $99.95 per square foot, or $26.7 million per year in base rent subject to certain operating expenses, taxes and annual rent increases of approximately 3%. The lease will commence when the space is available for use by the Company, which is anticipated to be in the first half of 2022, which reflects the sublessor's exercise of its option to postpone the commencement date of the sublease. The lease term will end on December 31, 2030, unless other specific circumstances specified in the 50 Binney Street Sublease occur. The Company will assess the lease classification of the 50 Binney Street Sublease and commence recognition of the associated rent expense at the lease commencement date.

Upon signing the 50 Binney Street Sublease, the Company executed a $40.1 million cash-collateralized letter of credit, which may be reduced in the future subject to the terms of the 50 Binney Street Sublease and certain reduction requirements specified therein. The $40.1 million of cash collateralizing the letter of credit is classified as restricted cash and other non-current assets on the Company’s consolidated balance sheets. Payments will commence at the earlier of (i) the date which is 90 days following the commencement date and (ii) the date the Company takes occupancy of all or any portion of the premises.

In connection with the execution of the 50 Binney Street Sublease, the Company also entered into a purchase agreement for furniture and equipment (the “Furniture Purchase Agreement”) located on the premises upon lease commencement. Upon execution of the Furniture Purchase Agreement, the Company made an upfront payment of $7.5 million, all of which was recorded within restricted cash and other non-current assets on the Company’s consolidated balance sheets and assessed for recoverability on a recurring basis. The Company will be required to make another $7.5 million payment under the Furniture Purchase Agreement upon lease commencement.

In December 2021, the Company entered into a sub-sublease agreement (the "Sub-Sublease") with Meta Platforms, Inc. (“Meta”). Under the terms of the Sub-Sublease, the Company is subleasing the entirety of the 50 Binney Street premises which it has rights to under the 50 Binney Street Sublease. The Company is sub-subleasing the premises for $28.0 million in the first year with 3% annual increases in each subsequent year. Meta will receive access to 50 Binney Street at the lease commencement date, which is the same point that the Company would receive access under the 50 Binney Street Sublease. The Company remains liable under the 50 Binney Street Sublease, including for maintenance of the $40.1 million collateralized

letter of credit. As a result of the execution of the Sub-Sublease, the Company assessed the $7.5 million deposit related to the Furniture Purchase Agreement for recoverability and determined that the amount was not recoverable. As a result, the Company recorded $7.5 million in the Company's consolidated statements of operations and comprehensive loss as selling, general and administrative expense during the year ended December 31, 2021.

Assembly Row lease

In November 2021, the Company entered into a lease agreement with Assembly Row 5B, LLC ("Landlord") for office space located at 455 Grand Union Boulevard in Somerville, Massachusetts to serve as the Company's future corporate headquarters. Under the terms of the arrangement, the Company will lease approximately 61,180 square feet starting at an annual rate of $45 per square foot, subject to annual increases of 2.5%, plus operating expenses and taxes. In addition, the Company will be eligible for a tenant work allowance of $160 per rentable square foot of the premises. The lease will commence on the date on which the Landlord tenders possession of the premises to the Company with any tenant work required to be performed by the Landlord substantially completed, which is anticipated to occur in the first half of 2022.

Embedded leases

In June 2016, the Company entered into a manufacturing agreement for the future commercial production of the Company’s beti-cel and eli-cel drug products with a contract manufacturing organization. Under this 12-year agreement, the contract manufacturing organization will complete the design, construction, validation and process validation of the leased suites prior to anticipated commercial launch of the product candidates. During construction, the Company paid $12.0 million upon the achievement of certain contractual milestones. Construction was completed in March 2018 and beginning in April 2018, the Company pays $5.1 million per year, subject to annual inflationary adjustments, in fixed suite fees, as well as certain fixed labor, raw materials, testing and shipping costs for manufacturing services. The Company may terminate this agreement at any time upon payment of a one-time termination fee and up to 24 months of fixed suite and labor fees. The Company concluded in prior periods that this agreement contained an embedded lease as the suites are designated for the Company’s exclusive use during the term of the agreement. The Company recorded a right-of-use asset and lease liability for this operating lease on the effective date of ASC 842 and is recognizing rent expense on a straight-line basis throughout the remaining term of the embedded lease.

In November 2016, the Company entered into an agreement for clinical and commercial production of the Company’s beti-cel, lovo-cel, and eli-cel drug products with a contract manufacturing organization at an existing facility. The Company concluded that this agreement contains an embedded operating lease as the clean rooms are designated for the Company’s exclusive use during the term of the agreement. The term of the agreement is five years with subsequent three-year renewals at the mutual option of each party. As a result, the Company recorded a right-of-use asset and lease liability for this operating lease on the effective date of ASC 842, and is recognizing rent expense on a straight-line basis throughout the estimated remaining term of the embedded lease. In March 2020, the Company amended its agreement with the contract manufacturing organization, resulting in a lease modification. Under the terms of the amended agreement, the Company may be required to pay annual maintenance and production fees of up to €16.5 million, depending on its production needs, and may terminate this agreement with twelve months’ notice and a one-time termination fee. In September 2021, the Company reassessed the term of this lease in light of the planned orderly wind down of its operations in Europe. As a result, the Company reduced the right-of-use asset and related lease liability to reflect a shortened expected term of the agreement. In November 2021, the Company exercised its right to terminate the lease agreement, and such termination will be effective in November 2022. Per the terms of the amended agreement, the Company was obligated to pay a one-time termination fee of €1.0 million upon termination, which was paid in December 2021. In connection with this termination, the Company will pay for services properly rendered through the date of termination in accordance with the contract manufacturing agreement, based on work completed and expenses incurred prior to the date of termination.

In July 2020, the Company entered into an agreement reserving manufacturing capacity with a contract manufacturing organization. The Company concluded that this agreement contains an embedded lease as a controlled environment room at the facility is designated for the Company's exclusive use during the term of the agreement, with the option to sublease the space if the Company provides notice that it will not utilize it for a specified duration of time. Under the terms of the agreement, the Company will be required to pay up to $5.4 million per year in maintenance fees in addition to the cost of any services provided and may terminate this agreement with eighteen months' notice. The agreement commenced in March 2021, and it has a term of five years with the option to extend. The Company classified the embedded lease as an operating lease and recognized a right-of-use asset and lease liability upon lease commencement in March 2021 and is recognizing rent expense on a straight-line basis throughout the remaining term of the embedded lease.

In February 2021, the Company entered into another agreement reserving manufacturing capacity with a contract manufacturing organization. The Company concluded that this agreement contains an embedded lease as a controlled

environment room at the facility is designated for the Company's exclusive use during the term of the agreement, with the option to sublease the space if the Company provides notice that it will not utilize it for a specified duration of time. Under the terms of the agreement, the Company will be required to pay up to $4.2 million per year in maintenance fees and an immaterial amount of other annual fees as well as per-batch fees for the cost of any services provided. Either party may terminate this agreement with eighteen months’ notice at any time or with eight months’ notice after stage 5 has commenced. The term of the agreement is five years, with the option to extend, and it commenced in November 2021. The Company classified the embedded lease as an operating lease and recognized a right-of-use asset and lease liability upon lease commencement in November 2021 and is recognizing rent expense on a straight-line basis throughout the remaining term of the embedded lease.

Summary of all lease costs recognized under ASC 842

The following table contains a summary of the lease costs recognized under ASC 842 and other information pertaining to the Company’s operating leases for the years ended December 31, 2021 and 2020 (in thousands):


	For the year ended December 31,
	2021			2020 (2)			2019 (2)
Lease cost (1)
Operating lease cost	$	25,067		$	18,660		$	20,005
Total lease cost	$	25,067		$	18,660		$	20,005

Other information
Operating cash flows used for operating leases	$	22,805		$	17,780		$	17,205
Weighted average remaining lease term	4.7 years			6.3 years			7.3 years
Weighted average discount rate	5.02		%	5.98		%	6.66		%

(1) Short-term lease costs and variable lease costs incurred by the Company for the twelve months ended December 31, 2021, 2020 and 2019 were immaterial.

(2) Prior period amounts have been retrospectively adjusted to reflect the effects of the Separation.

Rent expense is calculated on a straight-line basis over the term of the lease. Rent expense recognized under all leases, including additional charges for utilities, parking, maintenance, and real estate taxes, was $36.2 million, $24.2 million, and $23.3 million for the years ended December 31, 2021, 2020 and 2019, respectively.

As of December 31, 2021, future minimum commitments under ASC 842 under the Company’s operating leases were as follows (in thousands):


	As of
Maturity of lease liabilities	December 31, 2021
2022	$	27,037
2023	21,460
2024	18,009
2025	14,639
2026	8,598
2027 and thereafter	12,356
Total lease payments	102,099
Less: imputed interest	(12,515)
Total operating lease liabilities	$	89,584

The above table excludes legally binding minimum lease payments for leases executed but not yet commenced as of December 31, 2021.