Wyeth Pharmaceuticals, the pharmaceutical division of Wyeth, announced that the U.S. Food and Drug Administration (FDA) approved a new indication for the Company's immunosuppressant agent, Rapamune (sirolimus). Rapamune was approved in 1999 for the prophylaxis of organ rejection in renal transplant patients in combination with cyclosporine and corticosteroids. The new indication provides for withdrawal of cyclosporine from the immunosuppressive regimen two to four months after renal transplantation in patients at low to moderate immunologic risk. The safety and efficacy of cyclosporine withdrawal in high-risk patients have not been adequately studied and it is therefore not recommended. The new indication is supported by data from the Rapamune Maintenance Regimen (RMR) pivotal study.
"The RMR indication is important to physicians, patients, and the renal transplant community," says Victoria Kusiak, Vice President, Global Medical Affairs and North American Medical Director, Wyeth Pharmaceuticals. "Current immunosuppressive regimens involving the use of calcineurin inhibitors, such as cyclosporine, have long been associated with nephrotoxic effects. These damaging effects on the kidney may impact survival of both the transplanted organ and the patient. When patients lose their grafts, pressure is placed on already scarce resources, namely donated organs."
Kidney transplantation is the most common type of organ transplant procedure in the United States. Following an organ transplant, patients are given a combination of drugs to suppress the body's normal immune reaction and prevent rejection of the transplanted organ. Data from the pivotal clinical trial demonstrates that in kidney transplant patients at low to moderate immunological risk, cyclosporine withdrawal from a Rapamune regimen has been shown to improve kidney function with excellent overall graft and patient survival. This open-label study, conducted at 57 transplant centers in Europe, Australia, and Canada, is the largest randomized cyclosporine-withdrawal trial undertaken to date.
A total of 525 kidney transplant patients were started on a regimen of Rapamune, cyclosporine, and corticosteroids, and then randomly assigned to either of two treatment groups three months following transplantation. One group was maintained on the three-drug combination regimen; in the other group, cyclosporine was gradually withdrawn.
At three years, renal function and blood pressure were significantly improved in patients in whom cyclosporine was withdrawn compared with patients who remained on the combination regimen. In an analysis of the three-year data, the graft survival rate in patients who underwent cyclosporine withdrawal was reported to be 91.2 percent. In patients maintained on the combination of Rapamune, cyclosporine, and corticosteroids, graft survival was reported to be 85.1 percent.