The future facing COX-2 inhibitors may not be as bleak as many are suggesting, according to new analysis published by Datamonitor. However, since Merck & Co’s withdrawal of Vioxx (rofecoxib) for safety reasons [[01/10/04a]], the whole class has come under the spotlight and calls to pull all COX-2 inhibitors are not surprising, says Duncan Emerson, Datamonitor’s senior healthcare analyst.

He notes that worries over the safety of Pfizer’s Celebrex (celecoxib) and Bextra (valdecoxib) have increased pressure on firms which market the COX-2s [[20/12/04e]], and adds that “many are seeing as a serious strategic error by Pfizer” its decision to keep Celebrex on the market, a move which “could increase legal, financial and reputational costs for the company in the future.”

All eyes are now on the US Food and Administration, which has been collecting data on COX-2s ahead of a meeting in February to determine whether additional regulatory action is needed [[20/10/04c]].

Datamonitor puts forward two outcomes. Firstly, Mr Emerson said that “without exception,” if the FDA does not advise withdrawal of the class, this would be good news for all companies in the COX-2 field, namely Pfizer, Novartis, Merck and GlaxoSmithKline. However it predicts that sales will still be hit “as the level of uncertainty regarding the class will still linger on in patients’ and physicians’ minds.”

Still, firms that market COX-2s could see this as an opportunity to prove they take these issues seriously and make sure any studies requested by the FDA “are well designed, answer the key questions about cardiovascular safety and that the data is made available to the general public.”

The second scenario, that the FDA recommends withdrawing the class “would be an unprecedented move”, says the analysis and such an action is unlikely. However, “regardless of what the FDA decides, confidence in the COX-2s has now been dented, possibly irrevocably,” it adds.

Despite this, Datamonitor believes the level of anxiety that has been witnessed regarding the COX-2s is “somewhat unwarranted.” Mr Emerson says that where the products are used according to their labelling, they provide safe, effective relief from the symptoms of both rheumatoid and osteoarthritis. He thinks the FDA will recommend a black-box warning to inform patients of the potential cardiovascular risks associated with taking high doses but “how this will affect future sales of COX-2s will depend greatly on the severity of the warning”.