People with psoriatic arthritis achieved considerable relief from symptoms of the disease, as well as significant reduction of skin psoriasis, after six months of treatment with etanercept (brand name Enbrel), according to a study presented Nov. 13, 2001, in San Francisco at the American Academy of Rheumatology's (ACR) annual meeting.
"Etanercept provides significant benefit for joint manifestations, skin disease and quality of life," said Philip Mease, M.D., of Seattle's Minor & James Medical Center, who led the study.
According to Dr. Mease, 62 percent of patients on low doses of methotrexate who received Enbrel injections under the skin achieved at least a 20 percent improvement in symptoms of psoriatic arthritis (tender and swollen joints, stiffness, pain, etc.) after three months. Among those patients who received Enbrel without methotrexate, 58 percent had at least a 20 percent improvement in their psoriatic arthritis. All patients received 25 milligrams of the drug twice a week and were compared to an equal number of patient who received no Enbrel.
In addition, after six months, 43 percent of patients with moderate to severe psoriasis achieved a 50 percent improvement in a typical lesion, and a 47 percent improvement in their psoriasis overall. "These are very good responses in the skin," Dr. Mease said.
Dr. Mease presented details of the study -- a phase III trial in 205 patients at 17 clinics across the country -- for the first time to the public in front of several hundred clinical rheumatologists and researchers at a symposium held during the ACR meeting. The U.S. Food and Drug Administration (FDA) is currently reviewing the results of the study to determine whether to approve Enbrel for patients with psoriatic arthritis. If approved, Enbrel would be the first drug ever approved specifically for treating psoriatic arthritis.
Enbrel inhibits the action of a cytokine called tumor necrosis factor (TNF) alpha, which is overproduced in the synovial fluid (lubricating fluid of the joints) and skin of people with psoriatic arthritis. TNF-alpha promotes inflammation, which leads to painful damage of the joints and connective tissue, as well as contributes to development of lesions on the skin.
Adverse events and side effects of Enbrel included reactions at the site of injection (36 percent of patients) and infections events (40 percent of patients; events included upper respiratory infections, sinusitis and urinary tract infections).
Enbrel is already approved for the treatment of rheumatoid arthritis, an inflammatory disease with similar symptoms to psoriatic arthritis. Long-term use by patients also appears to be safe and effective. Many patients with psoriatic arthritis are already receiving Enbrel "off label."
The FDA granted "priority review" to Etanercept in September 2001, meaning the drug could be available for the treatment of psoriatic arthritis in January 2002, if approved. Under priority review, the FDA must act on a drug application within six months of when it was submitted; Immunex submitted Enbrel to the FDA on July 16, 2001.
Priority review is reserved either for drugs that treat serious and life-threatening conditions or that demonstrate the potential to address unmet medical needs.
