EXHIBIT 10.23 August 1, 2005 Ms. Barbara Pifel Ms. Audrey Schwimmer Mr. Derek Spears Weill Medical College of Cornell University Office of Research & Sponsored Programs 1300 York Avenue, Room A-131 New York, NY 10021 Dr. Brij Saxena Weill Medical College of Cornell University 515 East 71st Street, Room 412 New York, NY 10021 Re: Sponsored Research Agreement between Marc Pharmaceuticals, Inc. and Weill Medical College of Cornell University dated January 22, 2004 (the "Agreement") Dear Ladies and Gentlemen: This letter is to confirm our understanding that the second payment to be made under the Agreement, pursuant to section 4.1 which provided that $187,500 shall be paid by July 1, 2005, shall be revised as follows: $50,000 shall be paid by August 16, 2005, $68,750 shall be paid by September 16, 2005 and $68,750 shall be paid by October 16, 2005. We trust that the foregoing represents the understanding between us. Please indicate your confirmation by signature and return of the enclosed copy. Sincerely, Marc Pharmaceuticals, Inc. By: ______________________ Name: Robert M. Cohen Title: CEO & President We hereby confirm our agreement and understanding of the foregoing: Weill Medical College of Cornell University By: ________________________ Name:______________________ Title: _______________________
