FDA panel clears Vioxx return to market
pharmafile | February 21, 2005 | News story | Sales and Marketing |
An FDA panel has narrowly voted in favour of allowing Vioxx to return to the market, after concluding it carries similar side-effect risks to other still available Cox-II drugs.
Members of the joint Arthritis Drugs/Drug Safety & Risk Management advisory committee voted 17 to 15 on the balance of Vioxx's benefit/risk profile, while Pfizer's Bextra also just scraped through the crucial test, with 17 votes to 13 (plus two abstentions) in its favour.
News of Vioxx's possible return has come as a considerable surprise to many observers, but Merck may still need formal FDA approval to re-introduce the drug it voluntarily withdrew in September.
The expert committee was specially convened to consider the latest evidence on all the drugs in the class which have suffered from the emergence of data suggesting all Cox-IIs carry increased risk of heart attack or stroke.
Celebrex, which earned Pfizer $3.3 billion last year gained an almost unanimous vote of confidence from the committee, with just one of the 33 experts voting against its continued marketing.
The committee failed to agree entirely on the huge amount of clinical data before them, but jointly concluded that lower doses for shorter durations should be recommended, in addition to stronger warnings about the possible side-effects.
One member of the committee, Curt Furberg, is an epidemiologist at Wake Forest and is also co-author of one of the latest studies published on the drugs.
"If a Cox-II were necessary, patients would have to be informed of the potential risks, and the lowest possible dose should be used for the shortest possible time," the study stated.
The decisions of the committee should go some way to ending uncertainty about how the drugs should be used but are likely to have condemned them to static or dwindling sales.
Having already suffered the most, Merck has benefited most from the rulings, though even after a rally the company's share price remains 30% below its pre-Vioxx withdrawal level.
In a statement made before the vote Peter Kim, Merck's head of R&D said the company had always believed the drug could return with the appropriate labelling, but said the evidence had "continued to evolve" suggesting other Cox-IIs carried similar risks.
"We do know that Vioxx offers unique benefits among coxibs marketed in the US. It was the only coxib with proven risk reductions in GI events versus naproxen as demonstrated in the VIGOR study. Also, it was the only coxib that was not contraindicated in patients with sulfonamide allergies," he said.
He added that response to pain medication varies from patient to patient. "What works well for one patient may not work at all for others. We have heard numerous reports from patients, including patients with chronic, debilitating pain, that Vioxx was the only medicine that relieved their pain."
Despite Merck's confidence that the drug has a comparable profile to Celebrex and the other Cox-IIs, the closeness of the vote belied a lack of consensus on Vioxx.
Panel chairman Alastair Wood said: "There's a clear signal this drug appears substantially worse than the others."
The US decision coincided with a similar conclusion by the European Union regulator the EMEA. It announced that all Cox-IIs would now be contraindicated in patients with ischaemic heart disease or stroke. A new warning of caution was also added when prescribing to patients with heart disease, such as hypertension, high cholesterol, diabetes and smoking, as well as for patients with peripheral arterial disease, with doctors advised to use the lowest effective dose for the shortest possible duration of treatment
Finally, Merck Sharp & Dohme's Arcoxia will be contraindicated in patients with hypertension whose blood pressure is not under control.
The EMEA stressed that these were only interim guidance, with a final class review expected in April.