Monte Rosa Therapeutics, Inc.

Our principal offices occupy approximately 63,327 square feet of office and laboratory space at 321 Harrison Avenue, Suite 900, Boston, Massachusetts, 02118, which has served as our headquarters since the second quarter of 2023. Our obligation to pay rent pursuant to the lease began on December 21, 2022. The initial term of the lease is 128 months following April 1, 2022. The annual base rent under the lease is $95 per square foot for the first year, which is subject to scheduled annual increases of 3%, plus certain costs, operating expenses and property management fees. We have the option to extend the lease once for five years upon notice to the Landlord at least one year prior to the end of the then-current term. We also have the option to sublet the Premises on the terms and conditions set forth in the lease.

We have an additional location used for office and laboratory space that occupies approximately 21,422 square feet located in Basel-City, Switzerland. In April 2023, we amended the lease to increase the square footage of the office and laboratory space to 44,685 square feet and extended the lease term through June 2027.

We believe that our facilities are adequate for our current needs and for the foreseeable future. To meet the future needs of our business, we may lease additional or alternate space. We believe that suitable additional or substitute space at commercially reasonable terms will be available as needed to accommodate any future expansion of our operations.