Vioxx debacle prompts Pfizer to review painkiller

Pfizer, the US drugs giant, said yesterday it would launch a study to evaluate whether its arthritis painkiller, Celebrex, had an adverse impact on patients with heart problems.

Pfizer, the US drugs giant, said yesterday it would launch a study to evaluate whether its arthritis painkiller, Celebrex, had an adverse impact on patients with heart problems.

The move comes after another US pharmaceutical company, Merck, recently withdrew Vioxx - a rival drug aimed at helping people with arthritis - from the market.

Merck stunned the market when it announced three weeks ago that it had found in a trial that patients taking Vioxx over an 18- to 36-month period had twice as many heart attacks and strokes compared with those taking placebos.

Pfizer stressed that its trial, which will begin next year, would have a broad remit, including looking at whether Celebrex had a positive impact on those with heart conditions.

The trial will enroll more than 4,000 patients who have had a recent heart attack and have a history of osteoarthritis. It will last at least two years. The outcome is likely to have a major impact on Pfizer as Celebrex is the market leader among drugs known as Cox-2 inhibitors, which are mainly painkillers.

Drugs companies which manufacture this class of drug are also facing a possible clamp-down by the European Medicines Agency. The body, which monitors all drugs licensed for use in the European Union, met yesterday to consider the evidence surrounding Cox-2 drugs. It is expected to make an announcement on Thursday.

To act, the agency will need a member country of the European Commission to ask it to carry out a formal review of the market. If the body believes there is a risk to health from taking Cox-2 drugs, it could suspend them for a period of time, require doctors to hand them out only in extreme cases or withdraw them from the market altogether. The ruling would affect all drugs sold in the EU, even if they are produced by an American company.

The agency was asked by France last year to investigate Cox-2 drugs, with the result that it told doctors to consider carefully the possible side effects when prescribing them.

Pfizer said it was confident that Celebrex did not pose a heart risk based on its experience in multiple studies over several years and said some small trials suggest the drug may protect against certain heart problems.

The study will specifically look at inflammation and cardiovascular events in osteoarthritis patients at high risk of heart disease, and will compare Celebrex with a placebo.

Celebrex has been on the market since 1999 and its sister drug, Bextra, was introduced in 2001. Vioxx is used by 2 million people around the world including 400,000 patients in the UK.