FDA issues COX-2 changes

Companies seeking to market non-steroidal anti-inflammatory drugs, including COX-2 inhibitors, need to abide by a series of changes implemented by the US Food and Drug Administration (FDA) in a bid to “protect the health of the millions who rely on these drugs”.

The move by the FDA arrived along with a surprise request for Pfizer to withdraw its arthritis treatment COX-2 inhibitor, Bextra (valdecoxib), from the market with immediate effect, though “pending further discussions”. Pfizer has agreed to undertake this action, as well as to suspend sales of the drug in the European Union, at the behest of the European Medicines Agency, although it has also made clear that it “respectfully disagrees” with the decision.

The firm is also in talks with other regulatory agencies around the world.

The FDA said it made its decision to withdraw Bextra as “the overall risk versus benefit profile for the drug is unfavourable”. Notably, there exists the risk of rare but serious skin reactions. The agency also demanded that a boxed warning over the potential cardiovascular and gastrointestinal side effects is displayed on the label for Pfizer's Celebrex, as well as for all other prescription NSAIDs.

It assured the industry that the actions are “based on the available scientific data” and that “the FDA has carefully considered the presentations, discussions, and recommendations from the joint meeting of the Agency's Arthritis and Drug Safety, and Risk Management Advisory Committees”.

The decision to withdraw Bextra may have caught Pfizer a little on the back foot, albeit that the industry is well aware of the investigations into the safety of COX-2 inhibitors following the withdrawal of Merck's Vioxx in September 2004, though it is not expected to become an excessive concern for the company. Shares slid 1.6 per cent (to $26.43) on the news.

However, Pfizer is facing a number of patent expiries on significant products over coming years, and Bextra, which amassed sales of some $1.3bn (£690m) in 2004, featured as part of CEO Hank McKinnell's positive three-year financial outlook presented to Wall Street earlier in April. The company stated that it `will explore options with the FDA under which [Pfizer] might be permitted to resume making Bextra available to physicians and patients'.

In the meantime, the UK's Medicines and Health products Regulatory Agency (MHRA) has advised British patients to seek an alternative medication to Bextra, and one option may be Celebrex, which remains on the market along with several other COX-2 inhibitors at this time.

Lawyers in Germany and the US have reportedly begun the preparation of a class action suit against Pfizer over claims relating to Bextra.