The FDA has issued a non-approvable letter for Merck’s Arcoxia. Merck was seeking approval of the Vioxx-like drug as a treatment for osteoarthritis. Vioxx was pulled off the market in September 2004 after being linked to an increased risk of heart attack and stroke in patients taking the drug. Arcoxia had been under review by the FDA as an investigational selective COX-2 inhibitor since the NDA was submitted in December 2003 for a 60 mg once-daily dose along with review of a separate related NDA for a 30 mg once-daily dose submitted in April 2004. In its non-approvable letter, the FDA indicated the drugmaker would need to provide additional data in support of the benefit-to-risk profile for the proposed doses of Arcoxia in order to gain approval. “We are disappointed” with the decision, said Peter Kim, president, Merck Research Laboratories. Arcoxia is currently marketed in 63 other countries. Pfizer’s Celebrex is the only COX-2 currently available on the US market.