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.

Zenapax (Roche)

vials containing 25 mg/5 mL

Approved indication: renal transplant

Australian Medicines Handbook Section 14

Despite advances in immuno suppression, acute rejection remains a major problem for patients receiving a kidney transplant. The chances of a successful transplant may be increased by interfering with cellular immunity. Monoclonal antibodies such as basiliximab (see 'New drugs' Aust Prescr 1999;22:95)and daclizumab inhibit the proliferation of T lymphocytes by binding to theinterleukin-2 receptor on these cells.

Daclizumab is infused before surgery. The dose is then repeated every two weeks for a total of five doses with the aim of saturating the receptors. The half-life of daclizumab is 20 days, resembling that of IgG.

In one trial, 126 patients given daclizumab were compared with 134 who received an intravenous placebo. Both groups were also given cyclosporin, azathioprine and prednisone. Acute rejection occurred in 35% of the patients given a placebo, but in only 22% of patients given daclizumab. After a year, the graft survival was 90% in the placebo group and 95% in the daclizumab group.1

The toxicity of the other immunosuppressive drugs is not increased by daclizumab. Treatment did not cause significantly more adverse effects than placebo.1

While daclizumab reduces the incidence of acute rejection its long-term effectiveness requires further study. Although 90% of the daclizumab molecule contains a human antibody sequence this does not appear to make it significantly superior to basiliximab.