Merck & Co. told U.S. Food and Drug Administration advisers today that research linking its withdrawn Vioxx to heart attacks and strokes may apply to the entire class of painkillers known as Cox-2 inhibitors.
Merck’s testimony came on the first day of a three-day hearing in Gaithersburg, Maryland in which FDA advisers are examining whether the risks of Cox-2 drugs such as Pfizer Inc.’s Celebrex and Bextra outweigh their benefits. The panel will make a recommendation at the end of the hearing that could range from calling for the drugs’ withdrawal to stronger safety labels.
“We believe the data strongly suggest a class effect from Cox-2 inhibitors,” said Ned Braunstein, senior director of Merck’s research labs, whose voice grew slightly hoarse during his testimony. “We would argue that long-term studies are needed” to determine class effects.
Pfizer, which will testify later today, has argued its drugs don’t carry the same risks as Vioxx. At stake is the more than $4 billion in sales New York-based Pfizer generated from the painkillers, once thought to be more effective than anti- inflammatory medicines such as aspirin and ibuprofen and easier on the stomach.
The advisory panel is unlikely to recommend that the FDA take Celebrex and Bextra off the market, Lehman Brothers analyst Tony Butler wrote in a note to clients this morning.
“Although it is unlikely that the committee will recommend discontinuation of these products from the market, it remains a possibility that it will consider labeling changes,” Butler, who rates Pfizer “overweight” and owns some shares, wrote.
The FDA isn’t obligated to follow the recommendations of its advisory panels, although it usually does.
Shares of New York-based Pfizer, the world’s largest drugmaker, fell 36 cents, or 1.4 percent, to $24.86 at 12:57 p.m. in New York Stock Exchange composite trading. They have plunged 33 percent in the past year. Merck slipped 35 cents to $29.
Amid questioning from panel members and participants, Merck’s Braunstein defended the timing of Merck’s Sept. 30 decision to pull Vioxx, saying the existing label on the drug warned doctors to take cardiovascular side effects into consideration before prescribing the drug.
“What was I supposed to do with this Vioxx warning?” asked Alastair Wood, a professor of pharmacology at Vanderbilt University and chairman of the FDA advisory panel. “What did you intend me to do with that information?”
Braunstein said the intent was for doctors to evaluate a patient’s heart and gastrointestinal risks on an individual basis before prescribing a type of pain therapy such as Vioxx.
The FDA has asked the panel to determine which patients benefit most from Cox-2 painkillers and what actions can be taken to ensure their safe use, according to an agenda released before the meeting started.
The hearing began with presentations from researchers including Garret FitzGerald of the University of Pennsylvania, who has published some of the earliest research linking the Cox-2 painkillers to potential heart risks.
“We’re likely to subject new drugs that might be approved in this class to significant hurdles before they are approved,” FitzGerald told the panel. “Existing drugs in this class should be subject to the same hurdles,” especially when used long-term, he said.
Research released yesterday by the New England Journal of Medicine suggested the entire class of Cox-2 medicines may pose some level of risk to patients’ hearts.
Effect on Sales
A recommendation that Cox-2 painkillers carry the FDA’s strictest warning, highlighted in a black box on their labels, has the potential to cut Celebrex sales in half, according to William Blair & Co. analyst Winton Gibbons, who has an “outperform” rating on Pfizer shares.
It also might limit Pfizer’s ability to market Celebrex and Bextra, making it difficult for Chief Executive Officer Henry McKinnell to make good on his prediction that sales of the painkillers will eventually rebound.
The FDA in December told doctors to consider alternatives to Celebrex after data from a National Cancer Institute study showed that higher doses of the drug more than doubled patients’ risk of heart attacks. The consumer group Public Citizen has called for the medicine’s withdrawal from the market.
“The dirty secret about Celebrex, Bextra and Vioxx is they were just Advil that was easier on the stomach,” said Steven Lampe, who helps manage about $8 billion in assets at Delaware Investments in Philadelphia. “If they’re now harder on the heart, why not just take Advil?”
In addition to Celebrex and Bextra, FDA reviewers will be looking at Merck’s Arcoxia and Novartis AG’s Prexige. Arcoxia is sold in more than 40 countries outside of the U.S. Prexige has been cleared in the U.K. It has not been introduced yet.
The FDA panel includes Wake Forest University researcher Curt Furberg, who has questioned the safety of the Cox-2 class of drugs, and Cleveland Clinic heart specialist Steve Nissen, who in 2001 called for more research on the Cox-2’s in an article published in the Journal of the American Medical Association. Furberg said the FDA had considered asking him not to serve because of his published views on the medicines.