0000950170-25-043486 Sample Contracts

LEXEO THERAPEUTICS, INC. Shares of Common Stock ($0.0001 par value per share) SALES AGREEMENT
Sales Agreement • March 24th, 2025 • Lexeo Therapeutics, Inc. • Biological products, (no disgnostic substances) • New York

Lexeo Therapeutics, Inc., a Delaware corporation (the “Company”), confirms its agreement (this “Agreement”) with Leerink Partners LLC (the “Agent”), as follows:

EMPLOYMENT AGREEMENT for KYLE RASBACH
Employment Agreement • March 24th, 2025 • Lexeo Therapeutics, Inc. • Biological products, (no disgnostic substances) • New York

This Employment Agreement (the “Agreement”) is made between Lexeo Therapeutics, Inc. (the “Company”) and Kyle Rasbach (the “Executive”) (collectively, the “Parties”).

*** ] = CERTAIN CONFIDENTIAL INFORMATION CONTAINED IN THIS DOCUMENT, MARKED BY BRACKETS, HAS BEEN OMITTED BECAUSE IT IS BOTH (I) NOT MATERIAL AND (II) IS THE TYPE THAT THE REGISTRANT TREATS AS PRIVATE OR CONFIDENTIAL. RESEARCH AGREEMENT
Research Agreement • March 24th, 2025 • Lexeo Therapeutics, Inc. • Biological products, (no disgnostic substances) • California

This Agreement is made by and between Lexeo Therapeutics, Inc. (“Company”) with offices at 345 Park Avenue South, Sixth Floor, New York, NY 10010, and The Regents of the University of California on behalf of its San Diego campus, having its office at 9500 Gilman Drive, La Jolla, CA 92093-0934, (“University”), (each may be individually referred to as a “Party” and collectively, as the “Parties”), effective as of the date of last signature below (“Effective Date”).

SECOND AMENDMENT TO THE RESEARCH AGREEMENT BETWEEN LEXEO THERAPEUTICS, INC. AND THE REGENTS OF THE UNIVERSITY OF CALIFORNIA ON BEHALF OF ITS SAN DIEGO CAMPUS
Research Agreement • March 24th, 2025 • Lexeo Therapeutics, Inc. • Biological products, (no disgnostic substances)

This Second Amendment (“Amendment”) by and between LEXEO Therapeutics, Inc. located at 345 Park Avenue South, Sixth Floor, New York, NY 10010 (“Sponsor”) and The Regents of the University of California on behalf of its San Diego Campus, located at 9500 Gilman Drive #0934, La Jolla, CA 92093-0934 (“Institution”) is made and effective as of the last date of signature (“Effective Date”).

THIRD AMENDMENT TO THE RESEARCH AGREEMENT BETWEEN LEXEO THERAPEUTICS, INC. AND THE REGENTS OF THE UNIVERSITY OF CALIFORNIA ON BEHALF OF ITS SAN DIEGO CAMPUS
Research Agreement • March 24th, 2025 • Lexeo Therapeutics, Inc. • Biological products, (no disgnostic substances)

This Third Amendment (“Amendment”) by and between Lexeo Therapeutics, Inc. located at 345 Park Avenue South, Sixth Floor, New York, NY 10010 (“Sponsor”) and The Regents of the University of California on behalf of its San Diego Campus, located at 9500 Gilman Drive #0934, La Jolla, CA 92093-0934 (“Institution”) is made and effective as of the last date of signature (“Effective Date”).

*** ] = CERTAIN CONFIDENTIAL INFORMATION CONTAINED IN THIS DOCUMENT, MARKED BY BRACKETS, HAS BEEN OMITTED BECAUSE IT IS BOTH (I) NOT MATERIAL AND (II) IS THE TYPE THAT THE REGISTRANT TREATS AS PRIVATE OR CONFIDENTIAL. SECOND AMENDMENT TO THE RESEARCH...
Research Agreement • March 24th, 2025 • Lexeo Therapeutics, Inc. • Biological products, (no disgnostic substances)

This Second Amendment (“Second Amendment”) by and between Lexeo Therapeutics, Inc. located at 345 Park Avenue South, Sixth Floor, New York, NY 10010 (“Sponsor”) and The Regents of the University of California on behalf of its San Diego Campus, located at 9500 Gilman Drive #0934, La Jolla, CA 92093-0934 (“Institution”) is made and effective as of the last date of signature (“Effective Date”).

FOURTH AMENDMENT TO THE RESEARCH AGREEMENT BETWEEN LEXEO THERAPEUTICS, INC. AND THE REGENTS OF THE UNIVERSITY OF CALIFORNIA ON BEHALF OF ITS SAN DIEGO CAMPUS
Research Agreement • March 24th, 2025 • Lexeo Therapeutics, Inc. • Biological products, (no disgnostic substances)

This Fourth Amendment (“Amendment”) by and between LEXEO Therapeutics, Inc. located at 345 Park Avenue South, Sixth Floor, New York, NY 10010 (“Sponsor”) and The Regents of the University of California on behalf of its San Diego Campus, located at 9500 Gilman Drive #0934, La Jolla, CA 92093-0934 (“Institution”) is made and effective as of the last date of signature (“Effective Date”).