An increased risk of side effects from Merck's potential Vioxx successor Arcoxia indicates the drug should not be approved unless it fills an unmet need, an FDA employee told an advisory committee.

Studies of Arcoxia (etoricoxib) show the drug may increase the risk of high blood pressure and congestive heart failure, but it is as effective as diclofenac in treating arthritis pain, the FDA said.

The agency released reviews of several Arcoxia studies prior to the April 12 meeting of the FDA's Arthritis Advisory Committee to discuss the drug. A large Merck study showed Arcoxia had similar rates of adverse cardiovascular events as diclofenac. However, other smaller studies showed the drug had a higher risk of cardiovascular events than naproxen or a placebo, the FDA said.

In addition, patients in one study taking Arcoxia dropped out at a higher rate because of high blood pressure problems, the agency said. Merck said the risks with Arcoxia are "consistent" with other Cox-2 inhibitors.

Merck also said the drug was less likely to cause gastrointestinal problems than other nonsteroidal anti-inflammatory drugs. However, the FDA's analysis said Arcoxia and diclofenac had similar rates of gastrointestinal problems.

A new product with an increased risk for cardiovascular disease should not be approved unless it serves an unfilled need, Bob Rappaport, director of CDER's Division of Anesthesia, Analgesic and Rheumatology Products, said in a letter to the committee. He warned against approving Arcoxia if it did not show a "reasonable risk to benefit balance" for a patient population lacking safe, approved treatments.

However, a former FDA employee said approving an effective Cox-2 inhibitor pain treatment is important because not all patients respond the same way to medications. "Some patients respond and some patients don't -- so having a choice is very important," former director of CDER's Analgesic, Anti-Inflammatory and Ophthalmologic Drug Product Division Lee Simon said. ( http://www.fdanews.com/did/6_72/ )