Until H1N1/2009 develops Tamiflu resistance and proves Tamiflu was a better snake oil than it was an antiviral, the world can stop pretending Tamiflu is effective against H5N1. At last, the understudy iv zanamivir (im/iv peramivir seems to have imploded) will be tested. Studies that have been delayed for years are finally at the recruitment stage and the South East Asian Infectious Disease Clinical Research Network have published the protocol which also contains fascinating background information.
"Précis
The emergence of the H5N1 strain of avian influenza A over the last several years poses a direct threat to human health and may be the source of a novel influenza virus capable of erupting into a human pandemic.
The oral neuraminidase inhibitor oseltamivir is considered standard therapy for the treatment of avian influenza but this is not based on prospective or comparative clinical trials. Compared to human influenza, H5N1 avian influenza has a significantly higher mortality rate, a higher rate of viral replication with greater viral shedding and for a longer time. Despite the widespread availability and use of oseltamivir, the case fatality rates for H5N1 infection remain high, at approximately 60% and 80% in Indonesia.
Recently, an intravenous neuraminidase inhibitor, zanamivir, has been developed and shown to be active in human influenza. This route of administration route is preferred in severely diseased subjects, like those infected with avian influenza. Inhaled zanamivir is already approved in many countries for the prevention and treatment of human influenza but the inhaled route of administration has not been tested in seriously ill subjects or those with pneumonia.
The primary purpose of this protocol is to evaluate zanamivir administered intravenously against H5N1 influenza A in humans, testing the hypothesis that this therapy will result in a reduction in all cause, hospital mortality compared to historical controls. This protocol will also attempt to better define the clinical manifestation of this infection, the relationship between antiviral plasma concentrations and viral dynamics, the safety and tolerability of IV Zanamivir, and the pathogenesis of avian influenza, which may help to improve the treatment of these diseases."
A Historically Controlled Open-label, Phase II, Efficacy Study to Evaluate Intravenous Zanamivir for Treatment of Avian Influenza in Adults and Children Infected with H5N1
