Background/Purpose:  Corticosteroids in juvenile dermatomyositis (JDM) alone or in association with other immunosuppressive drugs, namely methotrexate (MTX) and cyclosporine (CSA), represent the first-line treatment option for new onset JDM. No clear evidence based guidelines are actually available to standardize the tapering and discontinuation of corticosteroids in JDM. The purpose of the study was to provide an evidence-based approach for corticosteroid tapering/discontinuation through the analysis of the patients in the PRINTO new onset JDM trial.

Methods:  New onset JDM children were randomized to receive either prednisone (PDN) alone or in combination with MTX or CSA. All children were given initially three daily pulses of intravenous methylprednisolone (30 mg/kg/pulse), and then PDN 2 mg/kg/day. After 1 month PDN was tapered to 1 mg/kg/day, from month 2 to 6 was tapered to 0.2, at month 12 to 0.1, and then discontinued at month 24. Major therapeutic changes were defined as the addition or major increase in the dose of MTX/CSA/other drugs or any other reasons for which the patient was dropped from the trial (adverse events, lost to follow-up, etc). Patients who followed the steroid tapering protocol and discontinued PDN at month 24 with no major therapeutic change (group 1) represented the reference standard for the best clinical outcome. Group 1 was compared with those following the steroid protocol, but with other major therapeutic changes (group 2), and with the group who deviated from the steroid protocol with/without major therapeutic changes (group 3). JDM core set measures (CSM) were compared in the 3 groups at 6-12-18 and 24 months (Table).

Results:  139 children were enrolled in the trial: 47 on PDN, 46 on PDN+CSA and 46 on PDN+MTX. We identified 57 (41%) patients for group 1, 24 (17%) for group 2 and 58 (42%) for group 3. At baseline all 3 groups had a high level of disease activity with no differences in the CSM. In group 1 (PND off no failure) there were 12 (21%) patients randomized to PDN alone, 21 (37%) to PDN+CSA and 24 (42%) to PDN+MTX. When we compared the three groups, significant differences were found in all CSM at each time point of analysis (p<0.0001). In particular Group 1, when compared to Group 2 and 3, had the lowest level of disease activity at all time points; the decrease of disease activity was primarily within the first 6 months of treatment. Group 2 and 3 were overlapping in the levels of disease activity reached at all the time points and were globally higher when compared to group 1. Table: Core set measures values at different time points in the 3 groups of patients (only key results are reported).   

Conclusion: The PRINTO protocol from the trial in new onset JDM might constitute the reference evidence-based approach for corticosteroid tapering for possible use in current clinical practice.