Merck & Co’s COX-2 inhibitor Arcoxia (etoricoxib), the follow-up to the company’s withdrawn painkiller Vioxx (rofecoxib) [[01/10/04a]], should continue in two Phase III clinical trials, according to the advisory group monitoring the studies.

The Phase III trials have been undertaken in a bid to secure US approval for Arcoxia, which has proved elusive despite the drug being already launched in 48 countries worldwide including in Europe, Latin America and the Asia-Pacific region. Last October, the US Food and Drug Administration issued Merck with an “approvable” letter for Arcoxia, indicating that the agency needed additional safety and efficacy data for the drug before it would give the green light to the drug [[01/11/04a]].

The company has insisted that it is fully behind the product, despite continuing probes into the safety of the COX-2 inhibitors class and other non-steroidal anti-inflammatory drugs in the wake of Vioxx’s withdrawal over its link to an increased risk of heart attack and stroke [[01/10/04a]]. Just last week, the FDA recommended that the labelling of the COX-2 inhibitors, including Pfizer’s Celebrex (celecoxib) and Bextra (valdecoxib) and 18 non-selective NSAIDs, be changed to emphasise the cardiovascular risks [[17/06/05a]].

Merck said that the advisory group's recommendations mean that it will press on with testing, with a view to filing for US approval of Arcoxia sometime in 2006.

The US firm re-submitted a New Drug Application to the FDA for Arcoxia at the beginning of 2004 [[05/01/04b]], after withdrawing its original dossier for the drug in 2002 to allow it to include additional data that it said at the time would enhance its safety and efficacy profile [[18/03/02b]].