Enbrel filed for approval for psoriasis treatment
First posted July 8, 2003
The biologic drug Enbrel was filed July 8 for approval by the U.S. Food and Drug Administration (FDA) for the treatment of moderate to severe psoriasis. Enbrel became the first biologic approved for psoriatic arthritis in January 2002; recent studies also show it to be effective for psoriasis.
Enbrel, manufactured by Amgen and co-marketed by Wyeth, is approved for rheumatoid arthritis and juvenile rheumatoid arthritis, and is under review for ankylosing spondylitis, a disease that causes inflammation in the spine. FDA approval typically takes about one year; however, some people with psoriasis are already receiving Enbrel treatment from their doctor "off-label" (without FDA approval).
Researchers presented new evidence for Enbrel's use in moderate to severe psoriasis at the International Psoriasis Symposium in late June in New York.
The presentation focused on a phase III study involving 583 patients in 50 centers worldwide. Patients were given 50 milligrams (mg) of Enbrel twice weekly, 25 mg twice weekly or placebo. After 12 weeks, half of those given 50 mg and more than one third of those given 25 mg had the severity of their psoriasis improve by 75 percent.
"A significant number of patients experienced rapid improvement in as quickly as two weeks" after beginning treatment, said Kim Papp, M.D., of Probity Medical Research in Waterloo, Canada.
The response in the first 12 weeks of this study is nearly identical to a study presented by Alice Gottlieb, M.D., Ph.D., at the American Academy of Dermatology in late March 2003. In that study, which went on for 24 weeks, nearly 60 percent of patients receiving 50 mg twice weekly achieved 75 percent improvement in psoriasis severity after 6 months, as did more than one third receiving 25 mg twice weekly. The 24-week data for the study Dr. Papp presented is not yet available.
More treatments to target psoriasis pathway
The psoriasis filing follows the approval in January 2003 of Amevive, another biologic medication, for psoriasis treatment. Although the two target different parts of the inflammatory process involved in psoriasis, they both offer doctors and patients additional treatment options that have the potential to be safer and more effective that existing treatments.
Enbrel is given by self-injection under the skin. Enbrel works by blocking a chemical in the immune system that overstimulates inflammation. This chemical is called "tumor necrosis factor-alpha" (TNF-alpha), an immune-system chemical messenger.
Injection site reactions (redness, itching, pain, swelling) were the most common short-term side effect.
Serious infections, including some fatalities, have been reported with the use of Enbrel. The infections often occurred in patients using other medications that suppress the immune system, like methotrexate. Serious infections are rare in patients taking Enbrel alone. Also, rare cases of tuberculosis have been observed in patients taking medications that target TNF-alpha.
The medication should not be started in someone with an active infection, and it may not be recommended for someone with a history of recurring infections. If a serious infection develops, a doctor will most likely stop Enbrel treatment.
Cases of multiple sclerosis and other central nervous system disorders have been observed in association with Enbrel and medications that target TNF-alpha, although the connection between the disorders and the medications remains unclear. Due to rare reports of blood disorders, people taking Enbrel are advised to contact their doctor if they experience persistent fever, bruising, bleeding or paleness.
Recently, the FDA reviewed the association between TNF-alpha medications like Enbrel and an increased risk of developing lymphoma, a type of cancer. There is not enough data to know if the medication contributed to higher risk. Enbrel�s safety and side effects continue to be monitored by Amgen and Wyeth and the FDA.
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