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.


Synagis (Abbott)
vials containing 100 mg as powder for reconstitution
Approved indication: prevention of viral infection
Australian Medicines Handbook Section 5.3.2

The respiratory syncitial virus (RSV) commonly infects children. Usually only an upper respiratory tract infection develops, but some children can become seriously ill. The children at risk include those with congenital heart disease, chronic lung disease and premature babies. Palivizumab has been developed as one approach to preventing serious infections in high-risk infants.

The product is a recombinant monoclonal antibody directed against a protein in the RSV. It is injected intramuscularly once a month during the months that RSV is prevalent.

In a double-blind trial, 1002 children were randomised to receive palivizumab and 500 were injected with a placebo. More than 90% of each group received five injections. Approximately 11% of the children in the placebo group were admitted to hospital because of infection with RSV. Only 5% of the palivizumab group needed admission. The largest relative reduction (78%) was in the premature babies; approximately 8% of those given a placebo were admitted compared to2% of those given palivizumab.1

The incidence of adverse effects in the clinical trial was similar for palivizumab and placebo. There was a slightly higher incidence of injection site reactions and altered liver function with palivizumab.1

No interaction studies have been done, but palivizumab is not expected to interfere with immunisations.

Overseas information suggests that one vial may cost nearly $2000. While this implies that palivizumab should only be used for patients with a very high risk of infection, children with severe broncho pulmonary dysplasia get the least benefit.

References

  1. The IMpact-RSV Study Group. Palivizumab, a humanized respiratory syncytial virus monoclonal antibody, reduces hospitalization from respiratory syncytial virus infection in high-risk infants. Pediatrics 1998;102:531-7.