BIOTIME, INC. 935 Pardee Street Berkeley, CA 94710 Tel: 510-845-9535 o Fax: 510-845-7914 July 29, 1999 Sheldon M. Wecker, Ph.D., Director Hospital Products Division Abbott Laboratories, D-977, AP30 200 Abbott Park Road Abbott Park, IL 60064-3537 Dear Mr. Wecker: This is to confirm in writing a modification of Article 8 of our Exclusive License Agreement, dated April 23, 1997 (the "Agreement"), as follows. The caption, first sentence and table portion of Article 8(a) of the agreement is hereby deleted and replaced with the following: (a) Minimum Amounts. Abbott agrees to the establishment of the following minimum Product sales targets in the Territory for each twelve month period, commencing on and after October 1, 2000, subject to Abbott's option not to market the Product as provided in 8(b) below. [Confidential Information has been omitted and filed separately with the Securities and Exchange Commission] All other terms and conditions of the Agreement remain in full force and effect. If this modification is acceptable, each party shall so signify by having an authorized officer counter sign this letter in the place provided below. Thank you. Very truly yours, /s/Ronald S. Barkin -------------------- President and COO ABBOTT LABORATORIES July 29, 1999 Page 2 ACCEPTED AND AGREED: Abbott Laboratories BioTime, Inc. By: /s/Richard A. Gonzalez By: /s/Ronald S. Barkin ----------------------------- ------------------------- Title: President HPD Title: President --------------------------- ------------------------- D ate: August 3, 1999 Date: July 29, 1999