Lexeo Therapeutics, Inc.

Adoption of Inducement Plan

On November 4, 2025, our board of directors adoptedthe Lexeo Therapeutics, Inc. 2025 Inducement Equity Incentive Plan, or the Inducement Plan, and, subject to the adjustment provisions of the Inducement Plan, reserved 2,000,000 shares of our common stock for issuance pursuant to equity awards granted under the Inducement Plan.

The Inducement Plan was adopted without stockholder approval pursuant to Rule 5635(c)(4) of the Nasdaq Listing Rules. The Inducement Plan provides for the grant of equity-based awards, including nonstatutory stock options, stock appreciation rights, restricted stock, restricted stock units, performance awards and other awards, and its terms are substantially similar to our 2023 Equity Incentive Plan, including with respect to treatment of equity awards in the event of a “Corporate Transaction” as defined under the Inducement Plan, but with such other terms and conditions intended to comply with the Nasdaq inducement award exception.

In accordance with Rule 5635(c)(4) of the Nasdaq Listing Rules, awards under the Inducement Plan may only be made to individuals not previously employees or non-employee directors of the Company (or following such individuals’ bona fide period of non-employment with the Company), as an inducement material to the individuals’ entry into employment with the Company.

A copy of the Inducement Plan and related form agreements under the Inducement Plan are attached as Exhibit 10.5 hereto and incorporated by reference herein. The above description of the Inducement Plan does not purport to be complete and is qualified in its entirety by reference to such exhibit.