Psoriatic arthritis drug on the fast track
First posted Sept. 21, 2001
The U.S. Food and Drug Administration (FDA) has granted "priority review" to the injectable drug etanercept (brand name Enbrel), meaning the drug could be available for the treatment of psoriatic arthritis in January 2002.
Developed by Immunex of Seattle, Enbrel would be the first drug approved as a treatment for psoriatic arthritis. 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 usually reserved for drugs and biologic products (which Enbrel is) that treat serious and life-threatening conditions and that demonstrate the potential to address unmet medical needs.
Enbrel would be indicated for reducing the signs of symptoms of psoriatic arthritis, with the drug used alone or in combination with methotrexate. The drug is already approved for the treatment of rheumatoid arthritis, an inflammatory disease with similar symptoms to psoriatic arthritis.
Enbrel inhibits tumor necrosis factor-alpha (TNF-alpha), an immune-system cell. In people with psoriatic arthritis, TNF-alpha is present in increased levels, which causes inflammation and can lead to tissue and joint damage.
In a study of Enbrel in 205 people with psoriatic arthritis, patients experienced "significant improvement in signs and symptoms of their disease compared to placebo [a non-drug]," according to Immunex. Patients took either 25 milligrams of Enbrel or placebo by injection under the skin twice weekly for six months. Full details on the trial will be released at a scientific meeting in November 2001.
According to a company official, plans also are moving forward to test Enbrel for the treatment of psoriasis alone. In August, Immunex announced positive results of a phase II trial of Enbrel in 112 people with moderate to severe plaque psoriasis. Patients received either 25 milligrams of Enbrel or placebo twice a week.
After three months, 30 percent of patients on Enbrel achieved a 75 percent improvement of psoriasis, compared to 2 percent of placebo patients. After six months, about half of the patients achieved an improvement of 75 percent or better. About 20 percent of patients who took the drug for six months improved by 90 percent or better.
Injection site reactions and mild infections occurred more frequently in patients who received Enbrel over those who received placebo. The majority of infections were upper respiratory infections similar to colds.
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