Wyeth Pharmaceuticals, a division of Wyeth, announced that the European Commission has approved Enbrel (etanercept) (25 mg twice weekly) for the treatment of adults with severe active ankylosing spondylitis (AS) who have had an inadequate response to conventional therapy.

Ankylosing spondylitis is the fifth indication for Enbrel in the European Union. It is also approved in the EU for rheumatoid arthritis in adults with inadequate response to methotrexate (MTX), for rheumatoid arthritis in adults not previously treated with MTX, for adults with psoriatic arthritis, and for children with juvenile chronic arthritis.

"We are pleased that Enbrel is now approved in the European Union for the treatment of ankylosing spondylitis," says Robert Power, president, International, Wyeth Pharmaceuticals. "Clinical studies show that Enbrel offers many patients relief of symptoms such as back pain, morning stiffness, and fatigue as rapidly as two weeks after initiation of therapy."

Ankylosing spondylitis is a painful and potentially progressive inflammatory disease affecting the spine and the joints and ligaments that normally allow a person's back to move and flex. The disease most often occurs in the lower back but can affect the upper spine and neck. The spine can fuse, causing deformity and loss of motion. Ankylosing spondylitis may also involve other joints, such as the hips, shoulders, knees, and ankles. The disease frequently strikes people in their late teens and twenties, and tends to affect more men than women. It is estimated that there are more than 600,000 patients with AS in Europe and 350,000 in the United States.

"For the first time, with the use of Enbrel we see improvement in spinal mobility, the loss of which is a debilitating symptom of ankylosing spondylitis," said Dr Peter Brock, vice president of Global Medical Affairs and European Medical Director of Wyeth Pharmaceuticals. "Enbrel has proven to be an effective and generally well-tolerated treatment for a broad range of rheumatoid arthritis patients, which will be important to physicians introducing the therapy to a new group of patients."

In a pivotal phase III study (n=277), after 12 weeks 60 per cent of patients treated with Enbrel (n=138) achieved a 20 per cent improvement in the Assessment in Ankylosing Spondylitis Response Criteria (ASAS 20), a composite measure that includes back pain, morning stiffness, global patient assessment, and physical function, compared with 27 percent of patients receiving placebo. At 24 weeks, 58 per cent of patients treated with Enbrel achieved this reduction compared with 23 per cent of the placebo patients.

Adverse events were similar to those reported in previous clinical trials of Enbrel, with injection site reactions occurring more frequently than in the placebo group. The most frequent adverse events in placebo-controlled rheumatoid arthritis (RA) clinical trials (n=349) were injection site reactions (ISRs) (37 per cent), infections (35 per cent), and headache (17 per cent). Only the rate of ISRs was higher than that of placebo.