Lexeo Therapeutics, Inc.

Our corporate headquarters is located at 345 Park Avenue South, 6 th Floor, New York, NY 10010, where we lease a total of approximately 15,839 square feet of office and laboratory space used for our research and development activities, general and administrative activities and other activities. This lease agreement began in April 2022 and expires in July 2029 with an additional five-year option to extend at the then-prevailing effective market rental rate. We also lease up to 3,000 square feet of laboratory and related office space used for our research and development activities at BioLabs San Diego, 9276 Scranton Road, Suite 500, San Diego, CA 92121. This lease agreement began in September 2024 and expires in September 2026 and is terminable by either party with 30 days' notice.

We believe that our current facilities are sufficient to meet our current and near term needs and that suitable additional or substitute space will be available at commercially reasonable terms as and when needed.