Download Pfizer Research Compounds May be Effective Aghaibnublic

Embargoed until 2:00pm (EST)
June 26, 2003
Contact: Stephen Lederer
(860) 732-9783
Mariann Caprino
(212) 733-4554
PFIZER REPORTS IMPORTANT RESEARCH DEVELOPMENTS AGAINST MALARIA,
SARS AND SMALLPOX
--Malaria: Pfizer to Conduct Phase III Trials with
Zithromax/Chloroquine Combination in Asia, Africa, Latin America
--SARS: More than 350 Pfizer Compounds Tested Against SARS; Pfizer
to Identify Best Active Candidates for Potential Development
--Smallpox: Pfizer Experimental Compound Being Investigated
For Utility in Smallpox
NEW YORK, June 26 -- Pfizer Inc said today that a number of the
company’s compounds have shown activity against some of the
world’s leading infectious diseases -- malaria, severe acute
respiratory syndrome (SARS), and pox viruses.
The research programs involve compounds discovered by Pfizer
scientists that range from a marketed medicine – the leading
antibiotic Zithromax – to untested molecules selected from the
company’s vast chemical library.
Pfizer announced:

Phase II clinical trials against drug-resistant malaria
using a combination of Zithromax and chloroquine, an older,
commonly used malaria treatment, have shown very promising
results.
The combination has been shown to be three times
more effective than chloroquine alone. Based on these
encouraging data, Pfizer plans to conduct much larger,
Phase III clinical trials worldwide.

At least
10 Pfizer compounds have shown significant
activity against the SARS virus in laboratory tests. The
company will now selected the best candidates for
continuing development and potential studies in humans.

Pfizer said it has shared an experimental medicine with
Harvard Medical School because of potential utility in
treating smallpox.
“Taken together, we are making inroads against three of the
world’s most-feared diseases,” said Pfizer Chairman and Chief
Executive Hank McKinnell.
“We are able to do because our
scientific operations are unmatched in their global scale.
With
more than two million compounds in our research library and the
ultra-high throughput systems to rapidly screen them against
diseases, we have a very good chance of emerging with at least
some credible candidates against these and other unexpected
threats.”
For malaria, Pfizer will begin Phase III clinical trials, the
final stage of human testing, on three continents to definitively
demonstrate the efficacy of Zithromax combined with chloroquine.
Pfizer cautioned that there are no guarantees that any of these
compounds will result in a viable medicine for patients.
“There are tremendous risks and high costs involved in any
pharmaceutical research and development project,” McKinnell said.
“The complexity of this research is enormous, and my best guess
is that none of these candidates has a significant commercial
market. But the human stakes are so high that we must continue
our investment and seek partnerships through all phases of
development and distribution if we are to save lives.”
Zithromax® / Chloroquine Combination Against Malaria
Plasmodium falciparum is the most common form of malaria – a
mosquito-borne disease that affects 300 million people worldwide
and results in approximately 1.5 million deaths each year. “If
untreated, it can cause cerebral malaria and death,” said Dr
Solomon Nwaka Scientific Officer and Project Manager at the
Medicines for Malaria Venture, a not-for-profit organization
founded by the World Health Organization and other agencies.
“This is a global crisis that is becoming more alarming with
increased resistance to older drugs,” he said.
“We desperately
need new scientific approaches, increased investment and
collaboration between industry, governments and academic
medicine. In this regard, the chloroquine/Zithromax combination
Phase III clinical trials represent an important scientific
undertaking.”
Chloroquine, introduced more than 30 years ago, remains a
standard treatment. But because the malaria parasite has
developed resistance against chloroquine, the medicine now is
often ineffective.
Pfizer scientists set out to find a more potent therapy. They
found that 28 days after taking chloroquine, only 31 percent of
patients were free of symptoms.
That number was slightly higher
-- 38 percent -- when patients were given Zithromax®.
But when
the two medicines were combined, the success rose to 96 percent.
Dr. Mike Dunne, who is leading Pfizer’s development efforts, said
larger-scale clinical trials are planned and will involve over
1200 patients in India, Indonesia, Kenya, Peru and South Africa,
all countries where the prevalence of malaria is high. Pfizer has
begun discussions about the program with
officials in these
countries and with the U.S. Food and Drug Administration.
[Pfizer recognizes the commercial prospects for this medicine are
limited. The company said it intends to make the medicines
available to those in need in the developing world using models
developed for other Pfizer access programs.]
Pfizer Compounds Act Against SARS virus
Pfizer’s laboratories at La Jolla, Calif., have provided
350
anti-viral compounds for testing against SARS to the National
Institute of Allergy and Infectious Diseases and the U.S. Army
Medical Research Institute of Infectious Diseases.
“Last month, we reported that some of our compounds showed
activity against the SARS virus,” said Dr. Dave Matthews
distinguished research fellow at Pfizer’s R&D site in La Jolla,
California.
“Since then, we have sent many more for laboratory
testing and found some that are five times more effective.”
The SARS virus has a key protein required for replication that is
related to a protein in rhinovirus, primary cause of the common
cold.
In an earlier search for a cold treatment, Pfizer
scientists looked at the molecular structure of this key
rhinovirus protease and found compounds that stop reproduction.
X-ray crystallography, which visualizes individual atoms, shows
how these compounds bind to enzymes that control replication and
make them inactive. It was the realization that the rhinovirus
and SARS virus proteases have similar structure and function that
originally led Pfizer scientists to test selected rhinovirus
inhibitors against SARS.
“We are very encouraged,” Dr. Matthews said. “We believe we can
now go forward with one or two of the most promising candidates.
We know a lot about these compounds.
But first, we will conduct
animal studies to ensure that there are no unforeseen risks. If
these studies are successful, we will design further studies in
humans.”
Dr. Peter Corr, senior vice president, Science and Technology,
Pfizer, said the projects involving SARS and malaria include
strong partnerships with governments, leading academic
institutions and public health organizations. Pfizer’s global
capabilities allow the company to share its findings with other
organizations to rapidly advance development.
As one example, Dr. Corr said Harvard Medical School approached
Pfizer to request one of the company’s experimental medicines for
research in smallpox.
“We sent the first sample on the day the
request came in,” Dr. Corr said.
“This can be a deadly disease,
and immunity through vaccination is waning throughout the world
and we’re all concerned about the threat of bioterrorism.”
Dr. Corr stressed that the smallpox research is at a very early
stage.
“We could move forward with human testing of a compound
in the near future.
Our ability to quickly respond to these
diseases and threats is based on the vast R&D infrastructure
supported by a vibrant pharmaceutical market that encourages
innovation.”
This year alone, Pfizer plans to invest $7.1 billion -approximately $135 million each week -- in research and
development, which is significantly more than any other company.
Pfizer has approximately 14,000 researchers worldwide at major
research facilities in the United States,
Europe and Japan.
Pfizer and partner organizations currently fund and operate
innovative health care programs in the developing world.
Among
them is the International Trachoma Initiative, which has reduced
the incidence of active infection by over 90 percent in Morocco,
50 percent in Tanzania, 75 percent in Vietnam and 45 percent in
Ghana.
To date, Pfizer has donated over $250 million worth of
Zithromax to the ITI.
Through the Diflucan Partnership Program, Pfizer provides its
antifungal medicine, Diflucan, free of charge to governments and
non-governmental organizations to treat opportunistic infections
in HIV/AIDS patients.
The program, which currently operates in
17 countries, also provides for secure distribution and training
for healthcare professionals.