Enbrel Moves to Once-Weekly Dose
First posted Oct. 22, 2003
On Oct. 20, Amgen announced dosing changes for the drug Enbrel (generic name etanercept) for psoriatic arthritis in adult patients. Previously, Enbrel was self-injected twice per week three or four days apart; the new dosing allows patients to take both doses on the same day, within a 24-hour period.
According to Amgen, patients can determine which schedule they would prefer based on their comfort level. The amount is still 50 milligrams (mg) per week delivered in two 25 mg doses.
Efficacy and safety are not changed with the new dosing; the data supporting the change involved 420 patients with active rheumatoid arthritis. Side effects were similar to those in previous studies. Amgen does not expect costs to change for insurance reimbursement.
The change follows a new dosing kit, including a smaller needle and vial adapter that punctures the vial containing the drug. The previous kit had no adaptor, and the needle was at risk of being bent or broken as it punctured the vial.
Enbrel, manufactured by Amgen and co-marketed by Wyeth, is given by self-injection under the skin. The medicine 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.
It is approved for psoriatic arthritis, rheumatoid arthritis, juvenile rheumatoid arthritis and ankylosing spondylitis, a disease that causes inflammation in the spine. The company also filed in June for approval for psoriasis treatment.
Injection site reactions (redness, itching, pain, and 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. Enbrel�s safety and side effects continue to be monitored by Amgen and Wyeth and the FDA.
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