Analysts puzzle over plan to sell a Vioxx-like drug

WASHINGTON -- Some analysts are scratching their heads at the move Merck & Co. is planning : The drug maker wants to sell a new painkiller that is just like Vioxx , the blockbuster drug it pulled from the market in 2004 because the treatment doubled heart risks.

Members of Congress have characterized the Food and Drug Administration as being powerless to do anything about Vioxx after it was approved. They said Merck was slow to make label changes that would have alerted consumers to heart risks and that the FDA did not halt aggressive advertising that drove sales higher even as safety concerns grew. Pending legislation aimed at avoiding another Vioxx fiasco would make it easier to curb advertising for new drugs and to restrict the number of doctors who can prescribe such medications when safety questions flare after FDA approval.

But that's not causing Merck to hesitate on its new painkiller, Arcoxia, already for sale in 62 countries.

"We believe Arcoxia has the potential to become a valuable treatment option for many Americans suffering from osteoarthritis," Chris Loder , a Merck spokesman , said in a statement. "As long as people suffer from pain, either from arthritis or other chronic conditions, there will always be a need for additional treatments to combat it."

Merck will present its case for Arcoxia's approval during an FDA advisory meeting scheduled for April 12 .

Morgan Stanley analyst Jami Rubin , who follows Merck, said she doubts the FDA will approve Arcoxia.

Merck is "comfortable with the data and believes that in a normal environment -- where common sense is used to weigh positives and negatives -- this drug would probably get approved," Rubin said. "But we're not in a normal environment. We're in a politicized environment."

Indeed, the US House of Representatives is taking a tougher stance on FDA reform than proposed legislation cosponsored in the Senate by Senator Edward M. Kennedy , Democrat of Massachusetts . A House bill, cosponsored by Representative Edward J. Markey , Democrat of Malden , would mark brand new drugs with a symbol that warns of their uncertain safety and ban ads for new drugs for three years, compared with a two-year moratorium possible under the Senate bill.

Right now, the FDA has more power to demand action from drug makers prior to approval. But the clinical trials that guide FDA action usually involve just a few thousand patients, providing an incomplete picture of a drug's safety. New side effects can crop up once the drug is on sale and used by millions of people -- including older and sicker patients than those involved in pre-approval trials.

Bextra , Celebrex, and Vioxx , the new-generation painkillers known as cox-2 inhibitors, were introduced with a blaze of direct-to-consumer advertising amid the promise that they would ease pain without causing the serious gastrointestinal distress associated with older therapies. Of the three drugs, only Celebrex remains on sale, and a recent American Heart Association advisory tells doctors to prescribe Celebrex to people with vulnerable hearts only as a last resort.

The same advice would apply to Arcoxia if it wins FDA approval, said a Harvard Medical School professor who was the lead author of the heart association advisory.

Arcoxia is better than Celebrex or Vioxx at protecting against certain gastrointestinal woes, such as stomach upset and burning, but there's a serious downside -- it also makes blood stickier and more prone to forming blood clots that can trigger heart attacks and strokes .

"Use these drugs in the lowest-risk patients. Find the lowest-risk drug. Give it in the lowest dose possible for the shortest period of time required to control the patient's symptoms," said Dr. Elliott M. Antman , a professor of medicine at Harvard Medical School and Brigham and Women's Hospital in Boston.

Dr. Bruce Psaty said he would not prescribe Arcoxia. "I didn't prescribe Vioxx. I didn't prescribe Celebrex," said Psaty, a University of Washington researcher who testified before Congress last week about bolstering drug safety.

But Dr. Patience White , chief public health officer at the Arthritis Foundation , said if the FDA considers Arcoxia safe enough to be sold, some doctors would likely prescribe it.

"I can't tell you the numbers," said White, former chair of the FDA arthritis advisory panel that will consider Merck's application. "I think it's important to have options for people with arthritis. I think the hard thing here is that most people don't realize how serious arthritis is. It really devastates people's lives."

Dr. Eric Topol , a leading cardiologist who was among the first to raise a red flag about Vioxx, expects Arcoxia would never attain the blockbuster status of the drug it replaces and would be used only by a small group of patients who are unable to find pain relief from anything else on the market

"I can't imagine, with all that has happened over the last several years, that any new [cox-2 inhibitor] is going to come out and wind up being used in tens of millions" of patients, said Topol, chief academic officer at Scripps Health .

Diedtra Henderson can be reached at dhenderson@globe.com.