In the end, rejection was not unexpected but the fierce criticism from US regulatory advisors that accompanied their decision to turn down Merck & Co's painkiller Arcoxia was a little surprising.

A US Food and Drug Administration panel advisory committee voted 20-1 against recommending approval of Merck’s New Drug Application of Arcoxia (etoricoxib), a COX-2 inhibitor, for the treatment of osteoarthritis saying that potential cardiovascular risks outweighed the possible benefits. The FDA is not bound by the recommendations, but usually follows them and nobody is betting on an approval at the end of the month.

Merck had submitted data from what it described as “a comprehensive and robust clinical programme” that included efficacy and safety findings for Arcoxia 30mg and 60mg once daily from 11 studies in patients with osteoarthritis and results from its large 34,000-patient, long-term MEDAL study which showed that Arcoxia posed the same cardiovascular risk as the older non-steroidal anti-inflammatory drug diclofenac. Merck withdrew its original marketing application for Arcoxia in 2002, at a time when concern over the tendency of COX-2 inhibitors to cause heart attacks and strokes, which led to the withdrawal of the firm’s Vioxx (rofecoxib) from the market in 2004, was starting to build.

The panel accepted the MEDAL data but were highly critical of the choice of comparator drug, arguing that diclofenac has higher heart risks than similar treatments, such as naproxen. Merck said it chose diclofenac because it is the world's most popular pain reliever.

That argument cut little ice with the panel who were told by David Graham of the FDA’s Office of Drug Safety (best-known as the whistleblower who first raised concerns over the safety of Vioxx) that approving Arcoxia would be “a potential public health disaster.” He added that “we could have a replay of what we had with rofecoxib.”

Need better drugs, not just new drugs

His views were already echoed by the panel members, one of whom, Arthur Levin, director of the Center for Medical Consumers in New York, said: “Based on the history and based on the evidence, my question is, why are we even having this meeting?" Martha Solonche, the advisory panel's patient representative, said “the idea should not be that we need new drugs. The idea should be that we need better drugs,” while another panel member, David Felson, noted that "there is nothing special about this drug that would warrant giving it to patients and putting them at risk of a cardiovascular death, period."

In response, Peter Kim, president of Merck Research Laboratories, said that the company is "disappointed" with the committee's decision and added that “we continue to believe that Arcoxia has the potential to become a valuable treatment option for many Americans suffering from osteoarthritis."

He concluded by saying that the drugmaker will continue to work with the FDA over Arcoxia but its efforts would appear to be in vain. The treatment is, however, already approved in 63 countries and brought in $265 million in revenues in 2006.