Dermatomyositis (DM) is a rare and disabling condition with an important impairment of quality of life and possible life-threatening complications.~Treatment is based on high doses of corticosteroids but this exposes patients to adverse events (cardiovascular mortality, glucocorticoids-induced muscle and skin damages). Corticosteroids taper is associated with disease relapses. Although there is no evidence from the literature, clinical practice guidelines recommends the use of DMARDs such as methotrexate. However, response is not complete and these DMARDS take time to act.The interferon type I (IFN-I) pathway is involved in the pathophysiology of DM. Janus kinase 1 and 2 transduces IFN-I signals. In addition, JAK2 inhibition enhances muscle repair and force generation .~JAK 1/2 inhibitors permitted to dramatically and rapidly improve relapsing DM patients (n=4, case series) .~BIRD is a multicenter phase III double blind randomized placebo-controlled trial with two parallel arms (1:1). This is an add-on trial to usual care with rapid corticoid taper. Both groups (experimental and control groups) will receive corticosteroids and the conventional immunosuppressive drug (either azathioprine or methotrexate)~Our primary objective is to evaluate the efficacy of baricitinib (JAK1/2 inhibitor) to obtain prednisone-free DM moderate improvement as compared to placebo, in addition to usual care.~Primary endpoint: moderate improvement (defined as a total improvement score superior or equal to 40 following ACR/EULAR definition) without corticosteroids at week 24 (prednisone-free moderate improvement).~This multicenter trial involves different medical departments in hospitals across France in different regions. Out- and in patients will be recruited in hospital departments involved in management and diagnosis of DM: departments of dermatology, rheumatology and internal medicine.~Eligible patients will sign a written informed consent after full oral and written information about the trial. They will be randomized in 1:1 ratio to receive baricitinib plus prednisone taper plus one immunosuppressive drug (either methotrexate or azathioprine) (experimental group) or placebo plus prednisone taper plus one immunosuppressive drug (either methotrexate or azathioprine) (control group) for a duration of 24 weeks. In both groups, corticosteroids are tapered following a predefined protocol.~5 visits are planned:~screening visit (W-4 to D-1)~baseline visit (W0)~follow-up visit 1 (W5 +/-5 days)~follow-up visit 2 (W12 +/-5 days)~end of study visit 3 (W24+/-5 days) Data will be collected by investigator and clinical research associate on an electronic case report form (eCRF) via a web browser.~The primary analysis will be the comparison between experimental and control groups of the rate of prednisone-free moderate improvement at 24 weeks in the intent to treat population. In order to demonstrate a difference in the rate of primary outcome at 24 weeks from 30% in the control group to 70% in the experimental group, with a power of 80%, a bilateral alpha risk of 5%, and a 15% rate of loss of follow-up, 62 patients are necessary.
Dermatomyositis (DM) is a rare and disabling condition with an important impairment of quality of life and possible life-threatening complications.~Treatment is based on high doses of corticosteroids but this exposes patients to adverse events (cardiovascular mortality, glucocorticoids-induced muscle and skin damages). Corticosteroids taper is associated with disease relapses. Although there is no evidence from the literature, clinical practice guidelines recommends the use of DMARDs such as methotrexate. However, response is not complete and these DMARDS take time to act.~The interferon type I (IFN-I) pathway is involved in the pathophysiology of DM. Janus kinase 1 and 2 transduces IFN-I signals. In addition, JAK2 inhibition enhances muscle repair and force generation.~JAK 1/2 inhibitors permitted to dramatically and rapidly improve relapsing DM patients (n=4, case series).~Our hypothesis is that Janus kinase 1 and 2 (JAK1/2) inhibitors (baricitinib) will permit to obtain dermatomyositis (DM) improvement with a steroid sparing effect as compared to usual care.~Our primary objective is to evaluate the efficacy of baricitinib (JAK1/2 inhibitor) to obtain prednisone-free moderate improvement (ACR/EULAR ≥ 40) of DM as compared to placebo in addition to usual care.~BIRD is a multicenter phase III double blind randomized placebo-controlled trial with two parallel arms (1:1). This is an add-on trial to usual care with rapid corticoid taper.~This is a multicenter trial in different medical departments in hospitals across France in different regions.~Out- and in patients will be recruited in hospital departments involved in management and diagnosis of DM: departments of dermatology, rheumatology and internal medicine.