Pfizer could be in for a rough ride later today when a US Food and Drug Administration advisory panel sits to decide whether the firm’s painkiller Celebrex (celecoxib) should be approved as a treatment for juvenile rheumatoid arthritis.

The pre-hearing briefings reveal that agency staff are concerned about giving the green light to a COX-2 agent, given that two drugs in the same class – Merck & Co’s Vioxx (rofecoxib) and Pfizer’s own Bextra (valdecoxib) – have been withdrawn over links to cardiovascular problems.

Nevertheless, in recent months the COX-2 class has experienced something of a recovery and Pfizer argues that Celebrex has been proved to be as effective as the NSAID naproxen in treating juvenile rheumatoid arthritis in trials.

However the FDA documents claim that “there are limitations to the design of this non-inferiority trial that raise questions about whether it provides adequate evidence of efficacy of celecoxib,” in children. They also suggest that more study is required into the cardiovascular risks of long-term use of the drug in children.

Pfizer’s briefing document accepts these points as valid but stresses that the uncertainty over long-term cardiovascular risk applies to all the drugs used to treat arthritis in children. The company said that the benefit/risk balance is favourable to approval, adding that it would be "supportive" of any labelling changes the FDA may request.