Bextra wird nicht geschluckt, sondern intravenös verabreicht. Das Mittel ist deutlich gefährlicher als Celebrex und könnte vom Markt genommen werden. Doch Bextra bringt nur 650 Mio. Umsatz von insgesamt 52 Mrd. - das ist 1,2 %. Das rechtfertigt keinen Kursrückgang, der sich in der Spitze auf 50 % beläuft (Pfizer stand 2000 bei 50 Dollar). Celebrex hingegen dürfte am Markt bleiben. Bei der jetzt ausgekramten Alzheimer-Studie ging es um einen Test, ob Celebrex als Mittel gegen Alzheimer taugt. Die 450 Probanden hatten laut Pfizer ohnehin wegen ihres schwachen Allgemeinzustands eine um den Faktor 4 erhöhte Herzinfarktgefahr. Daher seien die Ergebnisse nicht signifikant. Andere Verträglichkeitsstudien an insgesamt 30.000 (!) Patienten haben keinen Hinweis auf erhöhte Herz-Kreislauf-Gefahren geliefert (siehe unten).
Klar werden Ärzte zurückhaltender werden beim Verschreiben von Celebrex, aber dieser Effekt wird größtenteils dadurch kompensiert, dass Vioxx (Merck) nicht mehr am Markt ist. Im letzten Quartal führte dies zu Umsatzsatzsteigerungen bei Celebrex um 24 % - und dies, obwohl die Vioxx-Risiken bereits bekannt waren.
Es könnte gut sein, dass die Pfizer-Aktie, getrieben vom negativen Momentum, weiter fällt. Auch hasst die Börse Unsicherheit, und die bleibt bis zur FDA-Konferenz Mitte Februar weiter bestehen.
Dies schreibt Pfizer dazu auf der eigenen Webseite:
An Important Message About Recent CELEBREX News
With all of the recent news about CELEBREX, we want to ensure you have the most current information to discuss with your doctor.
On December 17, the National Cancer Institute (NCI) and Pfizer reported new information on two separate long-term colorectal cancer prevention studies of patients treated with high doses of CELEBREX for more than two years.
The NCI reported that the first study showed a significant increase in cardiovascular risk (such as heart attack and stroke) with CELEBREX at 400mg and 800mg per day (2x to 4x the common arthritis dose) compared to placebo (sugar pill).1 The findings are different in the second study that reported no difference in cardiovascular risk between CELEBREX at 400mg per day and placebo.1 Pfizer will evaluate this new safety information.
On December 20, the National Institutes of Health reported new information from a long-term Alzheimer's prevention study investigating CELEBREX (400mg per day) and the over-the-counter dose of naproxen (440mg per day) versus placebo for up to three years. In a preliminary analysis of this study, there was no significant increase in cardiovascular risk for patients on CELEBREX compared to placebo, however there was an apparent increase in risk for patients on naproxen compared to placebo.
What Do These Findings Mean?
Pfizer considers this new safety information important. The new information needs to be put in context with the existing CELEBREX data, which have been gathered over the past 10 years. The cardiovascular safety of CELEBREX has been studied based on data in 15 completed clinical studies, representing nearly 30,000 patients treated up to one year. In this body of data, there was no significant increase in cardiovascular risk in patients taking CELEBREX as compared to conventional non-steroidal anti-inflammatory drugs (NSAIDs) or placebo, according to a cardiovascular endpoint.
How Does This Compare to Other Arthritis Medicines?
Despite being widely used for decades, NSAIDs have not been evaluated for cardiovascular safety in similar large, multi-year studies with the exception of the over-the-counter dose of naproxen used in the long-term Alzheimer’s study described above. It is important to remember that all medicines have risks and benefits.
What Should I Do If I Am Taking CELEBREX?
As always, you should talk with your physician about the risks and benefits of treatment options. Physicians are recommended to consider all available therapies when choosing a medicine for patients. CELEBREX remains one of these options for arthritis and pain treatment at the lowest effective dose for appropriate patients.
Our Commitment
Pfizer is committed to providing important information about its medicines to physicians and patients in a timely fashion. Pfizer stands behind CELEBREX. CELEBREX is an important medicine for millions of people with arthritis. Pfizer is taking immediate steps to evaluate this new safety data and will work closely with the FDA and the medical community to fully understand what this means for people taking CELEBREX.
Additional Important Information.
Prescription CELEBREX is not for everyone. People with aspirin-sensitive asthma or allergic reactions due to aspirin or other arthritis medicines or certain drugs called sulfonamides should not take CELEBREX. In rare cases, serious stomach problems such as bleeding can occur without warning. The most common side effects in clinical trials were indigestion, diarrhea, and abdominal pain. CELEBREX should not be taken in late pregnancy. Tell your doctor if you have kidney or liver problems.
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Pfizer Acted Responsibly In Sharing Celebrex Alzheimer's Study Data With FDA
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Public Citizen Charge is Misleading and Unfair to Patients
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NEW YORK, February 1 -- Pfizer Inc said today that it remains confident in its COX-2 medicines as important treatment options for arthritis patients and that it has acted responsibly in sharing all appropriate data with the U.S. Food and Drug Administration.
Pfizer vigorously refutes claims by Public Citizen that safety data from a 1999 Celebrex study in Alzheimer's patients were "undisclosed." The study was monitored by an independent panel of safety experts, an abstract of the results was presented at a scientific congress in 2000, and the completed study report was submitted to the FDA in June 2001.
"Pfizer acted responsibly in sharing this information in a timely manner with the FDA," said Dr. Joseph Feczko, Pfizer president of worldwide development.
"Public Citizen’s cherry-picking of data is alarmist and misconceived,” he said. “It is not possible to draw clinically meaningful cardiovascular conclusions from this study alone given the variations in patients’ medical history, their advanced age and other significant study limitations. This flawed use of data is misleading and unfair to a reasoned scientific discussion of these issues.”
In fact, this single study is only one piece of information in the vast amount of clinical trial and other data supporting the safety of Celebrex in arthritis patients.
The 12-month study, which was designed to assess the potential of Celebrex in slowing Alzheimer's disease progression, showed that Celebrex did not significantly influence the course of the disease.
While patients who received Celebrex experienced more cardiovascular events versus placebo, there was a large difference in the underlying cardiovascular risk profile of the patients assigned to Celebrex treatment compared with those who received placebo. For example, more patients assigned to Celebrex had hypertension, diabetes, took aspirin or had undergone a previous heart by-pass surgery than those patients taking placebo. Even Public Citizen acknowledged the study "was not large enough to demonstrate a statistically significant increase in any individual serious cardiovascular event."
On February 16, an FDA advisory committee will begin a rigorous scientific evaluation of the risks and benefits of all COX-2 medicines, including Celebrex and Bextra. Pfizer has provided the agency with an extensive analysis of all available safety data for its COX-2 medicines and continues to cooperate fully with worldwide regulatory authorities.
“The FDA advisory meeting is the appropriate forum for these important public health issues to be fully addressed and put into context,” Dr. Feczko said.