Updated WHO Bird Flu (H5N1) Management Guidance Reinforces Tamiflu as First Line Treatment
22/08/2007 14:59
PR Newswire
BASEL, Switzerland, August 22 /PRNewswire/ -- The World Health Organization (WHO) has reinforced that
Tamiflu (oseltamivir) is the primary recommended antiviral of choice in
managing patients infected with H5N1 in updated guidance published on the WHO
website today. Experts believe that a human influenza pandemic is imminent
and could be triggered by the highly pathogenic H5N1 strain, which to date
has infected 321 humans causing 194 deaths worldwide (as of Aug 16 2007).
"Experiences clearly show that to reduce mortality patients
should receive treatment with oseltamivir as early as possible, but treatment
remains effective even when patients present late," commented Professor John
Oxford, Professor of Virology at St Bartholomew's and the Royal London
Hospital, "H5N1 has proven to be an extremely virulent virus in humans and in
some countries we have seen the need to use higher and longer doses of
oseltamivir to gain maximum benefit."
The latest advice is based on evidence presented to the WHO by
experts in countries that have reported human cases of bird flu. Tamiflu is
the only neuraminidase inhibitor to have been used in the management of human
cases of H5N1 and is the only antiviral strongly recommended for treatment of
H5N1 infected patients by the WHO.
With this latest evidence WHO recommends:
- Standardising care and promptly sharing clinical and
treatment information to improve understanding of the disease and
identify appropriate therapy
- Tamiflu remaining the primary antiviral treatment both early and
late in the infection as there is evidence of prolonged replication with
H5N1
- Modified Tamiflu treatment regimens - higher and longer dosing
may be necessary given the virulence of some forms of H5N1 seen recently
- Possible combination therapy with adamantanes (case by case
basis), particularly in patients with pneumonia or progressive disease
The guidance also states that inhaled zanamivir has not been
studied in human H5N1 illness and that the adequacy of inhaled zanamivir
delivery in patients with serious lower respiratory tract or extra pulmonary
disease is a major concern. Ongoing modifications will be made to the WHO
guidance based on continual research findings.
During the clinical development programme Roche carried out
studies looking at higher doses of Tamiflu. The safety profile at these
higher doses was supportive of further investigation A high versus standard
dosage study has recently started in patients with severe influenza, both
H5N1 and seasonal , in conjunction with the National Institutes of Health
(NIH), to determine which is the most effective dose in severe disease.
WHO coordinates the global response to human cases of H5N1
avian influenza and tracks the corresponding threat of an influenza pandemic,
providing access to both technical guidelines and information useful for the
general public.
Tamiflu is an oral neuraminidase inhibitor that is active
against all strains of influenza A and B tested. More than 80 governments
worldwide are now stockpiling Tamiflu in preparation for a pandemic and many
global businesses are in discussions with Roche and are now stockpiling for
their employees and their families in line with local laws and regulations.
Notes to Editors:
About the guidance
http://www.who.int/csr/disease/avian_influenza/guidelines/clinicalmanage07/en/index.html
About pandemic influenza
An influenza pandemic occurs when a new strain of influenza A
virus appears, against which the human population has no immunity resulting
in several, simultaneous epidemics worldwide with enormous numbers of deaths
and illness. The most severe influenza pandemics to date include: 'Spanish
flu' A (H1N1): 1918 caused in excess of 50 million deaths worldwide, 'Asian
flu' A (H2N2): 1958 caused 1 million deaths worldwide, 'Hong Kong flu' A
(H3N2): 1968 caused 800,000 deaths worldwide in six weeks. The WHO believes
that we are as close to the next pandemic as we have been any time in the
past 37 years, with two of the three widely-recognised prerequisites for a
human pandemic met to date in the avian influenza outbreak in East Asia.
Firstly, a new influenza virus strain has emerged (H5N1), and secondly, the
virus has spread to humans. The final barrier will be effective transmission
of the virus from human to human.
About Tamiflu
Tamiflu is designed to be active against all clinically
relevant influenza viruses and works by blocking the action of the
neuraminidase (NA) enzyme on the surface of the virus. When neuraminidase is
inhibited, the spread of the virus to other cells in the body is inhibited.
It is licensed for the treatment and prophylaxis of influenza in children
aged one year and above and in adults.
Roche and Gilead
Tamiflu was invented by Gilead Sciences and licensed to Roche
in 1996. Roche and Gilead partnered on clinical development, with Roche
leading efforts to produce, register and bring the product to the markets.
Under the terms of the companies' agreement, amended in November 2005, Gilead
participates with Roche in the consideration of sub-licenses for the pandemic
supply of Tamiflu in resource-limited countries. To ensure broader access to
Tamiflu for all patients in need, Gilead has agreed to waive its right to
full royalty payments for product sold under these sub-licenses.
About Roche
Headquartered in Basel, Switzerland, Roche is one of the world's leading
research-focused healthcare groups in the fields of pharmaceuticals and
diagnostics. As the world's biggest biotech company and an innovator of
products and services for the early detection, prevention, diagnosis and
treatment of diseases, the Group contributes on a broad range of fronts to
improving people's health and quality of life. Roche is the world leader in
in-vitro diagnostics and drugs for cancer and transplantation, a market
leader in virology and active in other major therapeutic areas such as
autoimmune diseases, inflammation, metabolism and central nervous system.
Additional information
- Roche Health Kiosk, Influenza:
http://www.health-kiosk.ch/start_grip.htm
- About Tamiflu:
http://www.roche.com/med_mbtamiflu05e.pdf
- About influenza:
http://www.roche.com/med_mbinfluenza05e.pdf
- WHO: Global influenza programme:
http://www.who.int/csr/disease/influenza/en/
- WHO: Avian flu:
http://www.who.int/mediacentre/factsheets/avian_influenza/en/
Helen Walicka, International Communications Manager, Tel. +41(0)79-263-9701