In a new clinical study being presented at the annual meeting of the American College of Rheumatology in San Antonio, Arcoxia (etoricoxib) demonstrated significantly fewer discontinuations due to gastrointestinal (GI) side effects compared to diclofenac sodium, a commonly prescribed non-steroidal anti-inflammatory drug (NSAID).

In this one-year study, known as the EDGE (Etoricoxib Diclofenac Gastrointestinal Evaluation) study, the rates of confirmed thrombotic cardiovascular events were similar for Arcoxia and diclofenac sodium.

Arcoxia is Merck & Co Inc.'s investigational COX-2 specific inhibitor for arthritis and pain currently under review by the US Food and Drug Administration. The goal Prescription Drug User Fee Act date for the New Drug Application for Arcoxia is Oct. 30.

"The gastrointestinal and cardiovascular safety results from the EDGE study are consistent with data from the ongoing clinical development program for Arcoxia, and add to the data already available on the safety profile of Arcoxia," said Sean Curtis, senior director, clinical research, Merck & Co, Inc.

The EDGE study was a randomized, double-blind, multi-centre clinical trial that included osteoarthritis patients who were assigned to either Arcoxia 90 mg once daily (n=3,593) - 1.5 times the maximum recommended dose for osteoarthritis - or diclofenac sodium 50 mg three times daily (n=3,518) for one year. Patients were treated for up to 16.5 months (mean duration of nine months), and were evaluated at screening, baseline, and months 1, 4, 8 and 12.

The primary endpoint of the study was GI tolerability, defined as the cumulative incidence of patients who discontinued from the study due to either a clinical or laboratory GI adverse experience.

Arcoxia reduced risk of discontinuations due to GI side effects by 50 per cent In the EDGE study, Arcoxia significantly reduced the rate of discontinuations due to GI adverse events (clinical and laboratory) compared to diclofenac. There were 9.4 events per 100 patients per year for patients taking Arcoxia versus 19.2 events for patients taking diclofenac sodium, for a risk reduction of 50 per cent (p<0.001). Differences in GI discontinuation rates between the treatment groups remained significant when clinical and laboratory GI adverse events were evaluated separately, and the risk reduction favouring Arcoxia was maintained in all subgroups evaluated, including the GPA and low-dose aspirin subgroups.

"The EDGE study showed there were similar rates of thrombotic cardiovascular events between Arcoxia and diclofenac in a patient population that appropriately represents the actual clinical setting," Dr. Curtis said adding, "This observation was made in a broad group of patients who had a number of different medical conditions, including pre-existing cardiovascular disease."

The Food and Drug Administration currently is reviewing Merck's New Drug Application for Arcoxia, which seeks indications for the treatment of osteoarthritis, rheumatoid arthritis, chronic low back pain, acute pain, dysmenorrhoea (menstrual pain), acute gouty arthritis and ankylosing spondylitis. Arcoxia has been launched in 48 countries worldwide in Europe, Latin America and the Asia-Pacific region.