Pharmaceutical giant Pfizer Inc. says new research has found an increased risk of heart problems with patients taking its painkiller Celebrex, a Cox-2 inhibitor similar to Vioxx, which was removed from the market in September because of concerns about increased risk of heart attack and strokes.
Pfizer said it received new information about the cardiovascular safety of Celebrex based on an analysis of two long-term cancer trials. As reported to Pfizer by the Data Safety and Monitoring Board, one of the studies (the APC cancer trial) demonstrated an increased cardiovascular risk over placebo, while the other trial (the PreSAP cancer trial) revealed no greater cardiovascular risk than placebo.
"These clinical trial results are new. The cardiovascular findings in one of the studies (APC) are unexpected and not consistent with the reported findings in the second study (PreSAP). Pfizer is taking immediate steps to fully understand the results and rapidly communicate new information to regulators, physicians and patients around the world," said Hank McKinnell, Pfizer chairman and chief executive officer.
Celebrex is approved for use in the United States for the treatment of arthritis and pain, at recommended doses of 100mg to 200mg daily for osteoarthritis and 200mg to 400mg a day for rheumatoid arthritis. It is also approved for a rare condition called familial adenomatous polyposis in doses up to 800mg per day. The APC cancer trial studied Celebrex at doses of 400mg to 800mg per day. In the PreSAP cancer trial the dose was 400mg per day.
"In placing this new information in context, it is important to understand that the APC trial results differ from both the PreSAP cardiovascular results as well as the large body of data that we and others have accumulated over time, in which an increased risk of serious cardiovascular events in arthritis patients, even at higher-than-recommended doses, had not been seen," said Dr. Joseph Feczko, president of worldwide development for Pfizer.
A third long-term study involving Celebrex in patients at high-risk for Alzheimer's disease is also under way with about 2,000 patients enrolled, about 750 of whom are on 400mg per day of Celebrex. As with the cancer studies, this study is monitored by independent safety experts who meet regularly to assess adverse events. The company said a review by this board as recent as December 10 did not result in any recommendations to change the conduct of this study.
Pfizer said it will continue to work with the FDA on the company's plans to sponsor a major clinical study to further assess Celebrex in osteoarthritis patients at high-risk for cardiovascular disease.
