The drug etanercept alleviates the pain and stiffness associated with ankylosing spondylitis, an inflammatory spinal condition, according to results of a clinical trial supported by the National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS) and published in the May 2nd issue of The New England Journal of Medicine.
According to the study's lead author, Jennifer Gorman, M.D., at the University of California, San Francisco, 20 patients received twice-weekly injections of etanercept and 20 patients received a placebo for four months. At the trial's end, 80 percent (16) of the patients taking etanercept reported less morning stiffness, spinal pain and joint swelling, compared with 30 percent (6) in the placebo group. All patients continued taking their pre-trial medications for ankylosing spondylitis, including nonsteroidal antiflammatory drugs, oral corticosteroids, and disease modifying antirheumatic drugs, during the trial. Etanercept worked faster than these current therapies and slowed the disease process.
Results from this trial suggest that etanercept can be used safely in combination with other anti-inflammatory and immunosuppressive drugs. Long-term studies with larger numbers of patients are necessary to confirm the safety and benefits of etanercept for the treatment of ankylosing spondylitis. A large multicenter phase 3 trial is currently underway.
Etanercept (Enbrel®) belongs to a class of drugs called "biologic agents" that are designed to interfere with the biological disease process. Etanercept is a tumor necrosis factor (TNF) antagonist, a substance that blocks the action of TNF, a naturally occurring protein in the body that contributes to the inflammation found in ankylosing spondylitis.
Ankylosing spondylitis, a chronic inflammatory arthritis characterized by joint stiffness, pain and extra bone growth that can result in partial or complete fusion of the spine, is difficult to treat. It typically strikes adolescent and young adult males. Currently there is no cure, and treatments have not been shown to affect spinal symptoms of the disease.
The trial was also supported by the Immunex Corporation, and funded under NIH contract #N01-AR-9-2244.
Gorman J, Sack K, Davis J. Treatment of ankylosing spondylitis by inhibition of tumor necrosis factor alpha. NEJM 2002;346:1349-56.