Retrospective analysis of infliximab and adalimumab treatment in a large cohort of juvenile dermatomyositis patients.

Background: Anti-TNF treatment may be useful for the treatment of patients with refractory juvenile dermatomyositis (JDM). The aim of this study was to describe the use of infliximab and adalimumab therapy in juvenile dermatomyositis as an adjunctive treatment.

Methods: Sixty children recruited to the UK JDM Cohort and Biomarker Study that had received at least 3 months of anti-TNF treatment (infliximab or adalimumab) were studied. Childhood Myositis Assessment Scale (CMAS), Manual Muscle Testing (MMT8) and physician's global assessment (PGA) were recorded. Skin disease was assessed using the modified skin disease activity score (DAS). Data were analysed using Friedman's test for repeated measures analysis of variance.

Results: Compared to baseline, there were improvements at 6 and 12 months in skin disease (χ(2) = 15.52, p = 0.00043), global disease (χ(2) = 8.14, p = 0.017) and muscle disease (CMAS χ(2) = 17.02, p = 0.0002 and MMT χ(2) = 10.56, p = 0.005) in infliximab patients. For patients who switched from infliximab to adalimumab, there was improvement in global disease activity (χ(2) = 6.73, p = 0.03), and trends towards improvement in CMAS, MMT8 and modified DAS. The median initial prednisolone dose was 6 [0-10] mg, and final was 2.5 [0-7.5] mg (p < 0.0001). Fifty-four per cent of patients had a reduction in the number and/or size of calcinosis lesions. Twenty-five per cent switched their anti-TNF treatment from infliximab to adalimumab. 66.7%of the switches were to improve disease control, 26.7% due to adverse events and 6.6% due to patient preference. A total of 13.9 adverse reactions occurred in 100 patient-years, of which 5.7 were considered serious.

Conclusion: Reductions in muscle and skin disease, including calcinosis, were seen following treatment with infliximab and adalimumab.