Composition: Etanercept 25mg.
Presentation: Powder and solution for injection.
Storage and stability: Store at 2-8C. Do not freeze.
Action: Selective immunosuppressant. Etanercept is a human tumour necrosis factor receptor p75 Fc fusion protein. It is a competitive inhibitor of TNF binding to cell surface receptors.
Indications: Treatment of active rheumatoid arthritis in adults when the response to disease modifying antirheumatic drugs, including methotrexate (unless contraindicated), has been inadequate. Treatment of active polyarticular-course juvenile chronic arthritis in children aged four to 17 years who have had an inadequate response to, or who have proved intolerant of, methotrexate.
Contraindications: Hypersensitivity to active substance or excipients; sepsis or risk of sepsis. Treatment should not be initiated in patients with active infections, including chronic or localised infections.
Dosage and administration: Treatment should be initiated and supervised by specialist physicians. Enbrel 25mg is reconstituted with 1ml water for injections.
Adults, recommended dose is 25mg etanercept administered twice weekly as a subcutaneous injection. 25mg administered once weekly gives a slower response and may be less effective.
Elderly (65 years and over), no dosage adjustment required. As for adults.
Children and adolescents (four to 17 years), 0.4mg/kg (up to a maximum of 25mg per dose) twice weekly as a subcutaneous injection, with an interval of three to four days between doses. Children under four years, etanercept has not been studied.
Renal and hepatic impairment, no dose adjustment required.
Pregnancy, use is not recommended. Women of child-bearing potential should be advised not to get pregnant during use. Lactation, excretion in human milk unknown (see SPC).
Overdosage: No dose-limiting toxicities observed in trials. No known antidote.
Precautions: Patients who develop a new infection while undergoing treatment should be monitored closely. Discontinue treatment if a serious infection develops. Caution needed when considering use in patients with a history of recurring infections or with underlying conditions which may predispose to infections, such as advanced or poorly controlled diabetes. Patients with significant exposure to varicella virus should temporarily discontinue etanercept and be considered for prophylactic treatment with varicella zoster immune globulin.
Live vaccines should not be given concurrently with etanercept. Juvenile chronic arthritis patients should, if possible, be brought up to date with all immunisations prior to initiating therapy.
The long term safety of etanercept in combination with other disease-modifying antirheumatic drugs has not been established.
Drug interactions: Interactions between etanercept and other drugs have not been evaluated in formal studies.
Side effects: Adults, injection site reactions, upper respiratory tract infections. No increase in the incidence of serious infections was observed in trials. In postmarketing reports, serious infections have been reported. Impact of long term treatment on the development of autoimmune disease is unknown. See SPC for details of other undesirable effects. Juvenile chronic arthritis, in general, undesirable effects similar in frequency and type to those seen in adults. Severe effects reported (in trial of 69 patients) included varicella with signs and symptoms of aseptic meningitis, gastroenteritis, depression/personality disorder, cutaneous ulcer and oesophagitis gastritis. Headache, nausea, abdominal pain and vomiting were reported more commonly in juvenile chronic arthritis patients than in adults in trials.
Net price: 4 x 25mg vials £325.
Supplier: Wyeth Laboratories, Huntercombe Lane South, Taplow, Maidenhead, Berkshire SL6 0PH (tel 01628 604377, fax 01628 666 368). Wyeth says that supplies of etanercept are currently limited by manufacturing constraints and are unlikely to be sufficient to treat all suitable adult rheumatoid arthritis patients. To ensure continuity of supply the company is maintaining a record of patients prescribed etanercept (by initials only) and a special form has been designed to accompany each order.
Legal class: POM.