PentaLyte® STATUS: PHASE I TRIAL COMPLETED

BLOOD PLASMA VOLUME EXPANSION CARDIOPULMONARY BYPASS SURGERY

BioTime, Inc. announced on June 15, 1998 that in a laboratory study in rabbits, PentaLyte® substantially improved protection of the stomach and lung from damage in the treatment of hypovolemia. PentaLyte®, currently in preparation for clinical trials, was compared to Ringer's lactate - the crystalloid most often employed in surgical procedures. The research was conducted by a team led by Dr. Vance G. Nielsen of the Department of Anesthesiology at the University of Alabama at Birmingham, one of the nation's leading centers for cardiac surgery. The study is published in the June issue of the American Journal of Respiratory and Critical Care Medicine (Am J Respir Crit Care Med Vol 157, pp 1982-1990, 1998). Reprints of the report will be available from BioTime and can be found on the Internet at http://www.ajrccm.org.

PentaLyte is BioTime's proprietary pentastarch-based synthetic plasma expander, designed especially for use when a faster elimination of the starch component is desired and acceptable. Of the approximately 10,000,000 surgeries that occur within U.S. hospitals each year, about 25% require blood transfusions. A substantial portion of the remaining surgeries, while not requiring transfusions, do cause blood loss. In addition, many patients are treated for injuries that result in significant bleeding. Although Hextend can be used in these cases, some physicians appear to prefer a solution which could be metabolized faster and excreted earlier when the longer term protection provided by Hextend is not required. PentaLyte combines the physiologically balanced Hextend formulation with pentastarch, a medical starch currently available in the U.S., with a lower molecular weight and degree of substitution (see diagram below) than the hetastarch used in Hextend. By testing and bringing both Hextend and PentaLyte to the market, BioTime can increase its market share by providing the medical community with solutions to match patients' needs.

PentaLyte® is a solution almost identical to Hextend® but containing a lower molecular weight starch (called pentastarch) which is substituted with fewer hydroxyethyl groups. Its lower molecular weight and degree of substitution results in its removal from the blood more rapidly than hetastarch.