Merck fails to win FDA approval for Vioxx successor

Nearly three years after recalling its blockbuster arthritis painkiller Vioxx, the global pharmaceutical company, Merck experienced yet another setback when the Food and Drug Administration on Friday rejected company's bid to win approval for the pain reliever Arcoxia, a successor to withdrawn pain-reliever Vioxx.

The move had been highly anticipated after an FDA advisory panel of medical experts earlier this month recommended that the painkiller not be approved, and voted 20-1 at a meeting on April 12 against approval of Arcoxia to treat osteoarthritis because of a possible link to increased risks of heart attacks and strokes.

Whitehouse Station, New Jersey-based Merck said early Friday that the FDA has issued a non-approvable letter for Arcoxia, stating the company must provide additional safety and efficacy data, including information from ongoing clinical trials before it will consider approving Arcoxia.

"At this time we are evaluating the FDA's letter," company spokesman Ron Rogers said.

Arcoxia is on the market in 63 countries, and had sales of $265 million last year. According to market analysts, Arcoxia could have brought in $1 billion in U.S. sales if it had been approved. Merck said it would continue selling the drug outside the United States.

Arcoxia is, however, designed to treat the pain of osteoarthritis without the harsh stomach effects associated with painkillers such as aspirin, but in his testimony before the agency's advisory panel, FDA scientist Dr. David Graham said drug safety studies performed on Arcoxia were neither adequate nor reasonable to support its approval.

Distressed with FDA’s decision, Peter S. Kim, president of Merck Research Laboratories said, "We are disappointed with today's decision," adding that "We pursued FDA approval of Arcoxia because we believe strongly that new medicines are needed for patients whose osteoarthritis pain is inadequately managed with currently available therapies."

Although FDA is not bound to follow its advisory panel's recommendations, it generally follows their guidance. The agency makes a decision on whether a product should be approved after evaluating all data and considering the recommendations of the advisory committee.

The U.S. regulators’ recent decision reflects a new standard for all drugs in a class of medicines called non-steroidal anti-inflammatory drugs, or NSAIDs, which includes which include cox-2 painkillers like naproxen, aspirin, ibuprofen and Pfizer Inc.'s Celebrex. The agency mandated in 2005 that these drugs carry its strictest warning about an increased risk of heart attacks, strokes and death.

FDA has said any new non-steroidal anti-inflammatory drugs must be safer or significantly more effective than existing treatments before it can come on the US market.

Arcoxia (etoricoxib) is a cox-2 inhibitor and is chemically similar to Bextra, Celebrex and Vioxx, a painkiller that Merck withdrawn from the market in September 2004 after researches linked the long-term use of the drug to a higher risk of heart attack and stroke.

Bextra too was pulled for similar reasons early in 2005, while Celebrex still remains on drug store shelves, though carrying a strong warning label highlighting potential heart risk. Although the FDA has said Vioxx, the arthritis and pain-relief drug, could be returned to the market with certain restrictions, Merck has yet to work on it.

Vioxx is known to have been taken by more than 20m people in more than 80 countries worldwide before it was withdrawn. It has been estimated that the drug could have caused 27,785 heart attacks or deaths since it was approved for use in 1999. Since pulling Vioxx from the market, Merck has faced more than 10,000 lawsuits from former patients and their families.

Shares of Merck dipped 57 cents, or 1.1 percent, to $51.86 in New York Stock Exchange composite trading. The stock has gained 50 percent in the past year.