Inclusion body myositis – what are new lines of pathogenesis and therapy?

Purpose of review Although inclusion body myositis (IBM) is considered a rare disease, it is the most prevalent inflammatory myopathy in adults over 50 years of age. Its complex pathophysiological background includes inflammatory and degenerative features, but it remains poorly understood. As a result, no effective therapy is currently available. In this review, we provide an update on the relevant contemporary literature addressing the clinical and pathophysiological aspects of IBM. Recent findings Recent studies have investigated drugs for IBM, including the immunosuppressant sirolimus, but haven’t shown satisfactory results. Some advancements have been made in investigating IBM pathophysiology: a cell culture model recapitulating key disease features has been established. Multiple studies have used RNA sequencing to elucidate disease-specific pathways, including selective type 2 fiber vulnerability. The importance of TDP-43 deposition and subsequent mis-splicing as a disease mechanism has been demonstrated. Further studies have shown the value of patient-reported outcome measures (PROM) and quantitative MRI as investigation tools. Research has also investigated and demonstrated the complex genetic susceptibility related to IBM. Summary In conclusion, significant discoveries have been made in the past year that enhance our clinical and pathophysiological insights into IBM. Due to the persistent lack of effective therapeutic options, additional research is essential – not only to investigate potential treatments but also to reveal the disease's underlying mechanisms.