Cytel and Baxter Announce Collaboration on Xenotransplantation Product.

SAN DIEGO--(BUSINESS WIRE)--Oct. 1, 1996--Cytel Corporation (NASDAQ:CYTL) and Baxter Healthcare Corporation's (NYSE:BAX) Nextran unit, today announced a collaboration to develop a carbohydrate product for use in xenotransplantation.

Xenotransplantation is the process of transplanting animal organs into humans. While 35,000 patients worldwide received human organ transplants in 1995, a critical shortage of organs left as many as 100,000 patients in need. Xenotransplantation holds great promise for making organs available to the thousands of patients currently on waiting lists for donor organs.

Under the agreement, Cytel will manufacture and sell a carbohydrate, which Nextran will incorporate into a xenotransplant product. Nextran will make an up-front payment to Cytel and make an equity investment in the company for the right to enter into an exclusive supply agreement. The agreement also provides for product development milestone payments to Cytel.

John Logan, Ph.D., vice president of research and development at Nextran, who today is presenting at IBC's Xenotransplantation Conference in San Diego, stated "Through this collaboration with Cytel, we expect to minimize the most significant immunological barrier to transplantation of pig organs -- hyperacute rejection."

Without intervention, a pig organ would typically survive less than an hour in a human recipient because human blood contains antibodies that immediately recognize and attack a carbohydrate expressed on the surface of the donor organ, resulting in hyperacute rejection. Nextran's strategy for preventing this hyperacute rejection includes the use of a column which contains an alpha-galactose carbohydrate manufactured by Cytel. Prior to transplant, the recipient's blood will be filtered through this column to remove the rejection-causing antibodies.

To manufacture the column carbohydrate, Cytel will use its proprietary enzymatic sugar nucleotide cycling technology ("SNC Technology"), which enables the large-scale manufacture of bioactive carbohydrates at commercially viable costs. The company has established a broad proprietary position covering its SNC Technology, including 16 issued United States patents and 33 United States patent applications, five with notices of allowance. Cytel also has acquired extensive expertise in the expression, production and purification of enzymes useful in the manufacture of bioactive carbohydrates. In addition to this collaboration with Baxter and a nutritional product collaboration established in early 1996, the company is pursuing development of other bioactive carbohydrates for medical and consumer product markets.

Cytel Corporation is a leader in the discovery, design and development of immunotherapeutics, a class of drugs which the company believes will be more selective and have fewer side effects than drugs currently on the market. Cytel's core technology platforms consist of the Immune Stimulation Program under which the company is developing therapeutic vaccines for infectious diseases and cancers, the Immune Suppression Program which is based on anti-inflammatory cell adhesion inhibitors, and Glycotechnology -- its proprietary SNC Technology enabling the manufacture of large quantities of complex carbohydrates at commercially viable prices.

Baxter's Nextran unit is working to increase the supply of available donor organs through research it is conducting in xenotransplantation. Baxter Healthcare Corp. is the principal domestic operating subsidiary of Baxter International Inc., a Deerfield, Ill.-based global leader in technologies related to the blood and circulatory system. Through its subsidiaries, Baxter has market-leading positions in four global businesses: biotechnology, which develops therapies and products in transfusion medicine; cardiovascular medicine, which develops products and provides service to treat late-stage cardiovascular disease; intravenous systems and medical products, which develops technologies and systems to improve intravenous medication delivery, and renal, which develops products and services to improve therapies to fight kidney disease.

Actual results may differ materially from the above forward- looking statements due to a number of important factors, including but not limited to the risks associated with the timing and cost of conducting human clinical trials, the possibility that testing may reveal undesirable and unintended side effects or other characteristics that may prevent or limit the commercial use of proposed products and the risks associated with negotiating and implementing successful collaborative arrangements. These factors are more fully discussed in Cytel's most recent Form 10-K and Form 10-Qs.

CONTACT: Cytel Corporation

Karin Eastham, 619/552-3000

or

Baxter Healthcare Corp.

Mary Thomas, 847/948-2815