Relenza™ is GlaxoSmithKline's brand of zanamivir, a first in-class antiviral drug for the treatment and prevention of influenza. Zanamivir was licensed to GlaxoSmithKline by Biota in 1990 and launched worldwide in 1999.
Relenza is delivered directly to the primary site of infection on the lungs, using a Disk Inhaler™ device. The drug works by destroying an enzyme, neuraminidase, on the surface of the virus, essential for the multiplication and spread of influenza. Relenza is not a vaccine.
Zanamivir was the first of a new generation of drugs known as neuraminidase inhibitors, capable of treating or preventing infection from the influenza virus.
Neuraminidase is essential for the replication of all influenza viruses. It is an enzyme which allows new viruses to be released from the infected lung cells, further extending the infection. Neuraminidase inhibitors block this activity, preventing the release and spread of new viruses.
Development and commercialisation
Zanamivir was the result of research and development initiated by Biota in the 1980's and was discovered in 1989 by a joint team of scientists from the Commonwealth Scientific and Industrial Research Organisation (CSIRO) and the Victorian College of Pharmacy, using the technique of three dimensional structure based drug design.
Relenza is approved in over 50 countries for the treatment of influenza, including in the United States, the European Union, Japan and Australia. Relenza is also widely approved for use as a preventative (prophylactic) treatment against influenza.
A number of national governments are stockpiling Relenza™, as part of their pandemic planning strategy. GlaxoSmithKline (GSK) has indicated that its production capacity is 90 million Diskhaler packs per year and 100 million Rotahaler packs per year.