Drug Free Immunosuppression: Progress, But Not Yet "Ready for Prime Time"

Studies presented at the 19th International Congress of The Transplantation Society reported progress toward weaning newly transplanted patients off immunosuppressive drugs, but experts made it clear that the long-sought goal has not been achieved yet.

And most important, leaders in the field of transplantation emphasized that the hundreds of thousands of transplant recipients worldwide who take daily medications to keep from rejecting their organs should not even entertain the idea that a life without pills is in their future.

"The strong message has to be that the die is cast down the line by what you do at the very beginning," said Dr. Thomas Starzl of the University of Pittsburgh. "If a patient taking drugs for four or five years yearns to get off them, that patient has very little chance of profiting from the research being done now."

One reason, added Dr. Megon Sykes of Massachusetts General Hospital, is "we don't yet have a good way of predicting which organ recipients will reject when immunosuppression is tapered off and who will not. Our understanding is rather limited."

"The important message is take your immunosuppressive drugs as recommended by your transplant center," said Dr. Alan Kirk of the National Institute of Health. "The vast majority who stop taking immunosuppressive drugs are going to reject."

Starzl, Kirk, Sykes and others reported on various approaches to weaning patients off the daily immunosuppressive drugs that are a requirement for all but a handful of transplant recipients who were perfectly matched with their donors.

One presentation was made by Dr. Samuel Strober of Stanford University, who reported that by suppressing the recipient's T-cells and injecting blood cells taken from the kidney donor, researchers have managed to withdraw transplant recipients from drugs for up to five months.

At the University of Pittsburgh, researchers reported they are giving transplant recipients a one-time dose of a drug that depletes a subset of T-cells just hours before transplantation and lower-than-usual doses of only one anti-rejection drug beginning the day after transplantation. Ninety days later, if there has been no rejection, the weaning process begins.

But as Dr.Kathryn Wood of the University of Oxford subsequently pointed out, while researchers have succeeded in dramatically lowering the dose and/or frequency of drugs, and even in a few cases weaned patients totally from drugs for a limited time, none of them had permanently freed the recipients from immunosuppressive medications.

Experts also noted that the experiments in reducing immunosuppression are taking place at major research centers, and involve a relatively small number of transplant patients that have been carefully selected as promising candidates.

But on the brighter side, the NIH's Kirk -- unlike Starzl -- held out hope that at some point down the road, new approaches under investigation might offer hope for relief from immunosuppression for patients who had been transplanted years earlier.

However, Kirk emphasized, at present, "None is ready for prime time."

Other sources: International Congress of the Transplantation Society