Possible role for tumour necrosis factor inhibitors in the treatment of resistant dermatomyositis and polymyositis: a retrospective study of eight patients.

OBJECTIVE To understand the use of tumour necrosis factor (TNF)alpha inhibitors in refractory dermatomyositis and polymyositis in an academic centre. METHODS A retrospective study of eight patients with dermatomyositis or polymyositis refractory to corticosteroids and immunosuppressives who were treated with TNF inhibitors between 1998 and 2004. RESULTS 8 patients with dermatomyositis or polymyositis who were treated with TNF inhibitors as adjunct treatment were identified. The mean (SD) duration of disease before initiation of TNF inhibitors was 8.5 (4.4) years. The patients failed to respond to treatment with corticosteroids (oral and intravenous); intravenous immunoglobulin and immunosuppressants (methotrexate, azathioprine, mycophenolate mofetil and leflunomide); 4.5 (1.4) immunosuppressants had been used before TNF treatment. Six patients were treated with etanercept alone, one with infliximab and one sequentially with both agents. Of the eight patients, six showed a favourable response with improved motor strength and decreased fatigue after 15.2 (6.5) months. Two of the patients did not respond after 4 (1.4) months and TNF inhibitors were discontinued. Responders showed a 54.4% (27.7%) decrease in serum concentration of creatine kinase, which was grossly abnormal (4463.5 (4036.4) U/l). Non-responders had similar reductions in creatine kinase concentration (56.1% (20.4%)), but their pre-treatment concentrations were in the normal range (118.5 (19.1) U/l). CONCLUSION Anti-TNF agents may be useful in some patients with refractory dermatomyositis or polymyositis.