Leases classified as operating leases are included in operating lease right-of-use assets ("ROU"), operating lease liabilities, current portion and operating lease liabilities, net of current portion, in the Company's condensed consolidated balance sheets. Cash paid for operating lease liabilities was $0.2 million during the three months ended March 31, 2023 and 2022, respectively, which is included in operating cash flows. During the three months ended March 31, 2023 and 2022, the Company incurred $0.7 million and $0.2 in rent expense, respectively.

On February 2, 2023, the Company entered into a sublease agreement for approximately 17,729 square feet of office and laboratory space in the building located at 321 Harrison Avenue, Boston, Massachusetts. The sublease included a rent-free period, with rent payments commencing on May 24, 2023. Under the terms of the sublease, the sublessee is to pay the Company approximately $1.5 million in year one and $1.9 million per year thereafter, which is subject to a 3.0% annual rent increase, plus certain other costs under the sublease, such as operating expenses, taxes, insurance, property management fee and utilities. The Company remains jointly and severally liable under the head lease and accounts for the sublease as an operating lease. The lease term commenced on March 24, 2023 and is expected to end in March 2026. The sublessee has the option to extend the sublease for a one-year period on the same terms and conditions as the current sublease, subject to a change in base rent for the extended period equal to a 3% increase to the then current rent. Upon execution of the sublease agreement, the sublessee provided the Company a security deposit of $0.4 million which is held in the form of a letter of credit. During the three months ended March 31, 2023, the Company recognized sublease income of $38 thousand.

The components of lease expense were as follows (in thousands):


	Three Months Ended March 31,
	2023		2022
Lease cost
Operating lease cost	$	656	$	—
Short-term lease cost		488		165
Total	$	1,144	$	165

Variable lease costs primarily relate to common area costs and other operating costs, which are assessed based on the Company’s proportionate share of such costs for the leased premises. Variable lease expense for the three months ended March 31, 2023 and 2022, respectively, was not material.

The weighted-average remaining lease term and weighted-average discount rate for operating leases were:


	As of March 31, 2023
Weighted-average remaining lease term (in years)		9.70
Weighted-average discount rate		9.40	%