Some of the views expressed in the following notes on newly approved products should be regarded as preliminary, as there may have been limited published data at the time of publication, and little experience in Australia of their safety or efficacy. However, the Editorial Executive Committee believes that comments made in good faith at an early stage may still be of value. Before new drugs are prescribed, the Committee believes it is important that more detailed information is obtained from the manufacturer's approved product information, a drug information centre or some other appropriate source.
Simulect (Novartis Pharmaceuticals)
vials containing 20 mg as lyophilised powder
Approved indication: organ transplant
Australian Medicines Handbook Section 14.1.4
Episodes of acute rejection occur in 30-50% of patients after a renal allograft. This rejection involves T lymphocytes which are specific for the antigens on the donor kidney. The signal for the proliferation of T cells is the binding of the cytokine interleukin-2 to its receptor on the surface of the lymphocyte. Basiliximab is a chimeric (mouse/human) monoclonal antibody which acts as an immunosuppressant by blocking the interleukin-2 receptor.
The antibody is given intravenously two hours before transplant surgery and 4 days afterwards. This suppresses the immune response for 4-6 weeks. The half-life of basiliximab is approximately one week.
Basiliximab has been studied in trials which investigated if it had any additional effect on patients given cyclosporin and steroids. One study randomised 193 renal transplant patients to receive basiliximab and 187 to be given a placebo. Acute rejection occurred in 51 of the patients given basiliximab and in 73 of the placebo group. There was also a significantly lower incidence of steroid-resistant rejection episodes which required antibody therapy in the patients given basiliximab.1
In patients taking a combination of immunosuppressant drugs, it can be difficult to attribute adverse effects to one particular drug. Data from the 363 patients given basiliximab in clinical trials show that the pattern of adverse reactions is similar to that seen in the 359 patients given a placebo. The commonly reported adverse events in the trials included nausea, constipation, pain and urinary tract infection. Some patients will develop antibodies e.g. human anti-mouse antibodies. Post-transplant lymphoproliferative disorders have also been reported.
The evidence is that basiliximab is efficacious at reducing graft rejection in the first 6 months. After a year, however, there is no difference in graft survival. As other drugs such as tacrolimus and mycophenolate are now available for use in transplant patients, further research will be needed to determine the best regimens for allograft recipients.
