Nextran, a Baxter Healthcare Corp. subsidiary specializing inxenotransplantation, and Cytel Corp., of San Diego, said they wouldcollaborate to develop a carbohydrate product to enhance animal-to-human organ transplants.

Under the agreement, Nextran will make an unspecified up-frontpayment to Cytel as well as a $1 million equity investment in thecompany for the right to enter into an exclusive supply agreement.Subsequent product milestone payments over the next few years willbring Nextran's total expenditure to approximately $7.5 million.

Nextran, of Deefield, Ill., currently is trying to develop transgenic pigorgans for transplant into humans. The collaboration with Cytel isdesigned to develop a method for dealing with the primary barrier tosuch transplants _ hyperacute rejection. Pig organs are covered witha carbohydrate that the human immune system rapidly identifies asforeign because antibodies against the carbohydrate are carried inhuman blood. As a result, the human immune system launches a swiftand virulent attack against transplanted pig organs. Nextran willattempt to sidestep such immune responses by depleting theseantibodies from a transplant recipient's blood.

Cytel will produce a column comprised of the offending carbohydrateusing their proprietary enzymatic sugar nucleotide cycling technologywhich Cytel spokeswoman Karin Eastham said can produce"pharmaceutical quantities of the carbohydrate." Prior to transplant, arecipient's blood will be run through the column which willpresumably bind and remove the hyper-reactive antibodies. Baxterspokeswoman Mary Thomas said that Nextran is in the process oftesting the column and that the xenotransplant procedure is likely toenter clinical trials in late 1997 or early 1998. _ Lisa Seachrist

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