Background Polymyositis (PM) and dermatomyositis (DM) are usually treated with glucocorticoids (GC) and immunosuppressive drugs. Controlled trials are scarce and include low numbers of patients. Early addition of methotrexate (MTX) to GC is often used in clinical practice; however evidence of the benefit for this strategy is lacking.
Objectives The aim of the trial was to assess the efficacy and safety of the combination therapy with MTX as compared to GC treatment only from the early phases of PM and DM.
Methods Patients naïve to methotrexate were randomized into 2 groups treated with GC alone (group A) or with added MTX (group B). This was an open label study with the efficacy assessor being unaware of the treatment assignment. Duration of treatment was 48 weeks with monthly assessments. Primary endpoint was the total dose of GC in mg/kg body weight administered between baseline and the end of treatment in the two groups. GC were initially given at 1 mg/kg and tapered according to a pre-defined scheme if definition of improvement (DOI, IMACS) was achieved. Maximal duration of previous GC treatment was 8 weeks. Maximum dose of MTX was 20 mg/week. Secondary endpoints were individual disease activity core set parameters, muscle endurance, functional disability and safety.
Results Five centers enrolled a total of 31 patients (17 PM, 14 DM). 16 patients were randomized in group A, 15 into group B. Groups A and B showed similar baseline characteristics. There were 4 dropouts during the study (3 in A, 1 in B). 85% (group A) and 86% (group B) of patients fulfilled DOI at week 48. There was no significant difference in the total prednisone dose (124±16 mg/kg in group A vs. 135±14 mg/kg in group B, p=0.6). None of the secondary efficacy parameters differed significantly between the two groups at the end of the study. There were 92 reported adverse events (AE). The overall number of AE in the 2 groups was similar. AE related to GC use were more frequent in the group A (5 cases) than in the group B (2 cases).
Conclusions Patients with PM and DM do not significantly benefit from upfront methotrexate addition to GC during one year treatment, when the two strategies are commenced in the early stages of the disease.
Acknowledgements Supported by EULAR and by Institutional Project No. 00023728.
Disclosure of Interest None declared