Experts Predict Tamiflu Could Halve the Pandemic Influenza Death Toll Versus no Intervention

Basel, Switzerland (ots/PRNewswire) -

- First Ever Economic Analysis Shows Tamiflu Use in a Pandemic
Could Save Significant Costs to Society

Treatment with the oral antiviral Tamiflu (oseltamivir) and
prophylaxis for people exposed to infected patients could be one of
the most cost-effective strategies for reducing illness and death
during an influenza pandemic. According to modelling research
presented by Beate Sander, University of Toronto, Canada, a stockpile
of Tamiflu sufficient to cover 65% of a country's population could
cut deaths by approximately half. This study was announced at the
leading influenza conference, Options for the Control of Influenza
VI, in Toronto.(1)

The reality is that country stockpiles of Tamiflu are limited and
are targeted at treatment only rather than treatment and
prevention.(2) However, some governments are now planning for
sufficient antiviral stockpiles that will allow them to provide
Tamiflu preventatively to close contacts of infected individuals.

The disease modelling research analysed for the first time the
cost-effectiveness of strategies to reduce the spread of pandemic
influenza using Tamiflu prophylactically. It was predicted that this
preventative approach is likely to be more cost-effective than
treating symptomatic patients alone and may be an effective and
cost-saving measure for reducing the impact of pandemic influenza.(1)
This research is supported by an earlier analysis that indicates that
a prevention strategy using Tamiflu may help contain a pandemic
outbreak.(3)

The study also predicts that if the stockpile is increased so that
there is an unlimited supply of Tamiflu for treating symptomatic
patients and for preventing infection in people exposed to these
patients (household contacts and school/work contacts), illness
attack rates and deaths could potentially be reduced by more than
half when compared to no intervention. This equates to a cost saving
of US$70,000 per 1,000 population which would save US$21 billion in
the US alone versus no intervention. Adding other strategies such as
school closures further reduces the attack and death rate and
provides a health benefit at a reasonable cost. The research also
showed that pre-pandemic vaccination programmes would play an
important role but their effectiveness would be dependent upon how
well the vaccine was matched to the virus.(1)

"The World Health Organisation provides a strong recommendation
for the use of Tamiflu for the prevention of avian flu in people who
have been in contact with someone who is known, or suspected of being
infected with the virus," commented Professor Ira Longini, Professor
of Biostatistics and Mathematics at the University of Washington,
Seattle, USA. "This research suggests that a similar approach may
also be an effective strategy in the event of an actual pandemic
outbreak, especially as it is unlikely that a vaccine fully matched
to the strain will be available in the initial wave of a pandemic."

Prophylaxis with antivirals or vaccines

Vaccination is the primary means of preventing influenza. However,
at the beginning of a pandemic, supplies of vaccines which are fully
matched to the pandemic strain will be limited or non-existent. This
is because vaccine production can only start once the specific
pandemic virus has been determined. The first doses of a matched
vaccine are unlikely to become available within the early months of
the pandemic, making prophylaxis and treatment with antivirals a
crucial part in the efforts to reduce the burden of pandemic
influenza.(4)

"In an environment full of uncertainties, it is best to have a
comprehensive plan in place," said Arnold Monto, professor of
epidemiology and influenza expert at the University of Michigan.
"Tamiflu is active against all types of influenza virus and will be
immediately available during a pandemic if stockpiles are adequate.
The big question is, should we be stockpiling for treatment only or
for both treatment and prophylaxis?"

Note to editors:

About the study

The objective of the study was to project the potential impact of
pandemic influenza mitigation strategies on health outcomes, cost and
cost effectiveness from a societal perspective in the US. The
population was based on 1,632,000 people of approximate household
size distributions from the 2000 US census. The analysis compared no
intervention with 16 single and combination strategies including
antiviral post-exposure prophylaxis (PEP) with Tamiflu; treatment
with Tamiflu; pre-vaccination before the outbreak of the pandemic
with a partially active vaccine; and school closure. It was assumed
that Tamiflu stockpiles of varying quantities were available from the
start of the pandemic, ranging from covering 25% of the population to
unlimited stockpile. The model was based upon assumptions regarding
the efficacy of Tamiflu and of vaccines in reducing mortality and
morbidity during a pandemic. Illness attack rate was reduced from 500
cases per 1000 population with no intervention to 230 cases per 1000
population in the Tamiflu PEP group. Deaths were reduced from 13
deaths per 1,000 population to 5 deaths per 1,000 population. This
study was supported by an unrestricted educational grant from Roche.

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 30
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
the 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:
www.health-kiosk.ch/start_grip.htm

- About Tamiflu: www.roche.com/med_mbtamiflu05e.pdf

- About influenza: www.roche.com/med_mbinfluenza05e.pdf

- WHO: Global influenza programme:
www.who.int/csr/disease/influenza/en/

- WHO: Avian flu:
www.who.int/mediacentre/factsheets/avian_influenza/en/

References

(1). B Sander et al. Economic Evaluation of Influenza Pandemic
Mitigation Strategies in the US Using a Stochastic Microsimulation
Influenza Model. Data presented at OPTIONS VI 2007. (Abstract
Tracking Number O82)

(2). Public pandemic plans and media reporting

(3). Germann TC et al. Mitigation strategies for pandemic
influenza in the United States, PNAS 2006; 103:5935-5940

(4). Department of Communicable Disease Surveillance and Response,
World Health Organisation, WHO Guidelines on the Use of Vaccines and
Antivirals during Influenza Pandemics, http://www.who.int/csr/resourc
es/publications/influenza/11_29_01_A.pdf ,Accessed 25 May, 2007

For further information, or to arrange an interview with David
Reddy, Global Influenza Pandemic Task Force Leader for Roche, or
Professor Monto, University of Michigan, please contact:

Onsite in Toronto:
Helen Walicka, Roche, +41-79-263-9701
Peter Impey, Ketchum, +44-79-7673-4493
Office: Lucy Rispin, Ketchum, +44-207-611-3621 / +44-77-8991-4901

ots Originaltext: Roche Pharmaceuticals
Im Internet recherchierbar: http://www.presseportal.de

Contact:
For further information, or to arrange an interview with David Reddy,
Global Influenza Pandemic Task Force Leader for Roche, or Professor
Monto, University of Michigan, please contact: Onsite in Toronto:
Helen Walicka, Roche, +41-79-263-9701; Peter Impey, Ketchum,
+44-79-7673-4493; Office: Lucy Rispin, Ketchum, +44-207-611-3621 /
+44-77-8991-4901