Treatment Response in Immune-mediated Myositis Associated Rapidly-progressing Interstitial Lung Disease

Idiopathic inflammatory myopathies (IIM) are a group of autoimmune conditions characterized by inflammation of muscles with possible extra-muscular manifestations which can include skin and interstitial lung disease (ILD). IIM-associated ILD carries poor prognosis. Particular subtypes of IIM such as anti-melanoma differentiation-associated protein 5 positive (anti-MDA5+) dermatomyositis with ILD are most commonly associated with rapidly progressive-interstitial lung disease (RP-ILD). RP-ILD is defined as worsening dyspnoea on exertion, hypoxaemia, and presence of newly emerging or expanding ground glass opacities on radiographic or computed topography of chest imaging excluding drug or infectious cause. Particularly, patients with anti-MDA5+ dermatomyositis often have RP-ILD with high mortality of over 60% in the first six months of diagnosis. The mainstay of treatment is immunosuppression though there has been no highly efficacious therapy proven to date. Therefore, the overall goal is to improve patient outcomes in IIM-associated RP-ILD including those with anti-MDA5+ dermatomyositis through the development of better treatment regimens. The objective of this research study is to evaluate the efficacy and safety of a combined immunosuppressive regime in patients with IIM-associated RP-ILD. The investigators hypothesize that the simultaneous inhibition of particular targets in the innate and adaptive immune system will improve efficacy and patient survival. The approach involves a combination of four immunosuppressive medications targeting different pathways implicated in IIM associated ILD. If successful, this study could contribute significantly to improving clinical outcomes for patients with IIM-associated RP-ILD.