X0508 4 2026-02-04 0001907108 Lexeo Therapeutics, Inc. LXEO 0001995218 Townsend Richard Nolan C/O LEXEO THERAPEUTICS, INC. 345 PARK AVENUE SOUTH, FLOOR 6 NEW YORK NY 10010 true true false false Chief Executive Officer 0 Common Stock 2026-02-04 4 A 0 161665 0 A 402656 D Stock Option (right to buy) 7.27 2026-02-04 4 A 0 646665 0 A 2036-02-03 Common Stock 260000 646665 D The reported securities are restricted stock units ("RSUs"). Each RSU represents a contingent right to receive one share of Common Stock of the Issuer. Twenty-five percent (25%) of the RSUs shall vest on February 15, 2027, and 1/16th of the RSUs shall vest in quarterly installments thereafter on the Issuer's standard quarterly vesting dates, subject to the Reporting Person's continued service through each applicable vesting date. Includes 290,022 RSUs. 25% of the shares underlying the option vest and become exercisable on February 4, 2027, and 1/48th of the shares underlying the option shall vest in monthly installments thereafter, subject to the Reporting Person's continuous service. /s/ Youjin Choi, Attorney-in-Fact 2026-02-06