European Commission Approves ReFacto AF(TM) as a Variation to the Refacto(R) Marketing Authorisation

MAIDENHEAD, England - Improvements in Purification Process Represent Important Advance in the
Treatment of Haemophilia A

Wyeth announced today it has received a positive decision from the
European Commission for a variation of the marketing authorisation for
ReFacto moroctocog alfa (Recombinant Coagulation Factor VIII), a treatment
for haemophilia A. The manufacturing process for ReFacto has been modified,
and the name has been changed to ReFacto AF moroctocog alfa (Recombinant
Coagulation Factor VIII). The decision by the European Commission follows a
positive recommendation from the Committee for Medicinal Products for Human
Use on 18 December 2008.

ReFacto AF - indicated for the treatment and prophylaxis of bleeding in
adults and children of all ages with haemophilia A - is a recombinant factor
VIII product free of added exogenous human- or animal-derived protein in its
cell culture, manufacturing, purification processes and final formulation.

“This milestone is an important step in the evolution of haemophilia A
treatment and establishes a new standard in recombinant factor VIII product
purification,” says Andreas Krebs, President, Wyeth Europe. “We believe the
state-of-the-art manufacturing and purification process used for ReFacto AF
make it an exciting new therapeutic option for many patients with Haemophilia
A.”

Wyeth is planning to make ReFacto AF available in the European Union
(EU), where the predecessor product ReFacto is currently commercially
available, in June 2009. The product will be launched in most EU member
countries at the same time to ensure that haemophilia A patients have access
to the therapy as soon as possible. Once ReFacto AF is introduced, Wyeth will
no longer supply ReFacto. The company will work with health care
professionals, haemophilia treatment centres and home health care companies
to help them manage their supply while transitioning from ReFacto to ReFacto
AF.

Improvements in Purification Technology

Until now, the purification process for all recombinant factor VIII
products used monoclonal antibodies derived from mouse cell lines. ReFacto AF
is completely albumin-free, uses a synthetic peptide ligand that is totally
free of animal materials and includes a viral-retaining nanofiltration
purification step to further reduce the risk of potential viral
contamination.

“Reducing the risk of transmitted infection is a major consideration.
ReFacto AF was developed in response to the community’s desire to completely
remove albumin as a theoretical source of pathogen transmission. We believe
that by having access to a product which in its production process is both
free of exogenous animal or human-derived proteins and relies on a
sophisticated purification process will give both health care providers and
patients a greater sense of security,” says Mikael Dolsten, MD, PhD,
President, Wyeth Research.

About Haemophilia A

Haemophilia A is a rare, inherited blood clotting disorder, which
affected approximately 30,000 people in the European Union in 2005. People
with haemophilia A are deficient in a key protein - factor VIII - which is
vital in the clotting mechanism to prevent bleeding. This condition can be
characterized by spontaneous haemorrhages or prolonged bleeding, typically
into joints and soft tissue. Most patients with haemophilia A are dependent
on factor VIII replacement therapy.

Wyeth and Haemophilia

Wyeth is a leader in hemophilia science, having developed the first and
only albumin-free recombinant factor IX therapy for the treatment of
haemophilia B, and continues to research new recombinant products for the
treatment of bleeding disorders. With the introduction of ReFacto AF, Wyeth
is the only company to offer state-of-the-art recombinant factor VIII and IX
therapies for the treatment of haemophilia A and B, respectively. Wyeth also
works to help improve the health of haemophilia patients through education,
patient assistance programs, and by supporting associations such as the World
Federation of Haemophilia, the European Association for Haemophilia and
Allied Disorders, and the European Haemophilia Consortium.

ABOUT WYETH:

Wyeth is one of the world’s largest research-based pharmaceutical and
health care products companies. It is a leader in the discovery, development,
manufacturing, and marketing of prescription drugs and over-the-counter
medications. It is also a global leader in vaccines, biotechnology and animal
health care.

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Source: Wyeth Pharmaceuticals Limited

For further information, please contact: Wyeth: Gill Markham, Communications - Europe, Middle East and Africa, Direct Tel: +44-1628-692536, Email: markhagl at wyeth.com; Danielle Halstrom, Communications - Global, Direct Tel: +1-484-865-2020, Email: halstrd at wyeth.com