"We can say that it does as well if not better than the other immunosuppressive drugs we have now," said Dominic Borie, MD, PhD, senior research scientist and director of transplantation immunology in Stanford's Department of Cardiothoracic Surgery, and senior author of the study that appears in the Oct. 31 issue of Science. The Stanford team showed that the drug, discovered by Pfizer, Inc., and called CP-690,550, prevents organ transplant rejection in monkeys for longer periods of time with fewer of the troublesome side effects seen in traditional drugs.
Transplanted organs are recognized by the recipient's immune system as foreign objects, triggering an attack that can lead to organ failure. Immunosuppressive drugs curtail the rejection process but at a price. Current therapies affect a variety of cell types, leading to side effects that include a weakened ability to fight off infection; an increased rate of cancer, diabetes and high blood pressure and cholesterol; and damage to the nervous system and kidneys.
The ideal immunosuppressant would block the actions of the immune cells that cause organ rejection without interfering with other cells. CP-690,550 appears to be on that track. "Theoretically, the molecule that we are targeting with the drug is present only on immune cells, not throughout the body," said Borie. "We have shown that targeting a pathway that is specific to immune cells provides efficacy. And on the basis of the data we have now, we feel that very likely the side effects of the drug in humans will be limited."'"/>