Pfizer may have hid Celebrex side effects

Public Citizen, a national, non-profit consumer advocacy organization, that called for recall of Celebrex and Bextra earlier, has now presented compelling evidence in support of their request. It is now well-known that both Celebrex and Bextra are no longer considered as safe as FDA thought they were when it approved them. After the recall of Vioxx and disclosure of data from a range of studies, it has been found that Celebrex and Bextra both have adverse side reactions that are simply too high. Accordingly, Kaiser Permanente, the largest HMO in the United States, has already banned Bextra prescriptions. Experts expect that both Celebrex and Bextra may soon face similar bans from other healthcare organizations. (Related article: Pfizer highlights risks of Celebrex recall)

There were 36 million prescriptions written in the U.S. for Celebrex and Bextra last year—thus about three million prescriptions a month. There was a significant jump in prescriptions after Vioxx was recalled, but when evidence about the dangers of Celebrex and Vioxx were pointed out in December 2004 and January this year, prescriptions have dropped rapidly. (Related article: Pfizer's position on safety of Celebrex)

Sidney M. Wolfe, MD, Director of Public Citizen's Health Research Group, in a letter addressed to the acting commissioner of the FDA, writes that they have discovered the results of an unpublished randomized placebo-controlled study by Pfizer, finished more than four years ago, that showed a significantly increased rate (3.6-fold) of serious cardiovascular adverse events and more than a doubling in the rate of cardiovascular deaths in people using Celebrex compared to those using a placebo in a study concerning Alzheimer’s disease. (Related article: FDA sides with drug companies rather than American people in Vioxx recall case)

Despite these older, but previously undisclosed findings, when Pfizer recently announced the results of an ongoing colon polyp prevention trial that was stopped because of a 2.5 to 3.4-fold increased risk of fatal or non-fatal major cardiovascular events in patients using celecoxib, Pfizer CEO McKinnell stated that “these clinical trial results are new.” (Related article: Pfizer stands by the safety of Celebrex)

Dr. Wolfe says that when the results of this study were first posted on the PhRMA web site around the beginning of this month, there was no mention of the statistical significance of these cardiovascular adverse events. But when the posting was modified last Monday (the day Public Citizens' petition to ban celecoxib or Celebrex and valdecoxib or Bextra was filed) the company admitted that “A statistically significant difference favoring placebo in adverse events was observed for certain CV-related body system terms (Cardiovascular Disorders,General; Heart Rate and Rhythm Disorders; Myo, Endo, Pericardial & Valve Disorders)."

Dr. Wolfe also accuses Pfizer of hiding this data, saying that there was certainly no mention of this study in February, 2001 when there was an FDA hearing concerning the results of the CLASS study, finished in 2000, that failed to show any gastrointestinal advantage over older NSAIDs for celecoxib or Celebrex. Nor has FDA ever mentioned it in the context of all of the public discussion of COX-2 dangers, especially in the past four months. If the FDA has had this study for a considerable amount of time and did not make the results public, it has seriously failed, once again, in its mission to protect the public health. If, as is entirely possible, Pfizer did not send these results to the FDA until after the December 17th announcement of similarly increased cardiovascular risk in the polyp-prevention study, the company has set itself up for enormous liability for having failed to inform the outside world of these important findings. (Related article: Celebrex class action lawsuits follow the Vioxx case approach)

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