Shares in drug giant Pfizer plummeted 14.6% in New York on Friday afternoon after a trial showed a higher heart attack rate for patients on its blockbuster Celebrex arthritis and pain medicine. The risks appeared in only one of two studies.
'These clinical trial results are new. The cardiovascular findings in one of the studies are unexpected and not consistent with the reported findings in the second study,' Pfizer chairman and chief executive Hank McKinnell said in a statement.
Pfizer shares plunged $4.23 to $24.75 in the first 15 minutes of trade.
A study into prevention of benign tumours, or adenomas, showed patients taking 400mg and 800mg of Celebrex daily had an approximately 2.5 fold increase in their risk of experiencing a major fatal or non-fatal cardiovascular event compared to those patients taking a placebo, according to the National Cancer Institute.
Based on the 'statistically significant' findings, the sponsor of the trial, the NCI, suspended the dosing of Celebrex. The news was given to Pfizer late on Thursday. A separate study, however, into the prevention of polyps, showed no increased risk for Celebrex patients taking 400mg daily compared with those taking placebo.
Pfizer's rival Merck had already announced a global withdrawal of a similar drug, Vioxx, on September 30, prompted by a study showing that it increased the risk for strokes and heart attacks. Merck's share price has crumbled and it is now engulfed in lawsuits.
Until now, Pfizer's Celebrex - used by 26 million people according to the Pfizer Internet site - had not been shown to produce any increased risk of heart attacks.
'Pfizer is taking immediate steps to fully understand the results and rapidly communicate new information to regulators, physicians and patients around the world,' McKinnell said. Celebrex is approved for use in the US for the treatment of arthritis and pain.
