CAR-T therapy for immune-mediated necrotizing myopathy: a review of mechanisms and emerging clinical evidence

Among the heterogeneous group of idiopathic inflammatory myopathies (IIMs), immune-mediated necrotizing myopathy (IMNM) stands out for its hallmark of severe muscle necrosis accompanied by only sparse inflammation. The condition is strongly driven by myositis-specific autoantibodies (MSAs), chiefly anti-HMGCR and anti-SRP, which are central to its pathophysiology. Despite advances in immunosuppressive therapies, many patients remain refractory to conventional treatments. Recent developments in cellular therapies, especially chimeric antigen receptor T cell (CAR-T) therapy, have shown transformative potential in autoimmune diseases. This review aims to synthesize current knowledge on IMNM pathophysiology, elucidate the mechanistic rationale for CAR-T therapy, summarize emerging clinical evidence, and explore the feasibility of CAR-Treg-based approaches for IMNM. Key Points • This review summarizes the unique pathophysiological features and current therapeutic challenges of immune-mediated necrotizing myopathy (IMNM). • The role of anti-HMGCR and anti-SRP autoantibodies in IMNM pathogenesis and their implications for targeted immunotherapy are highlighted. • The mechanistic rationale and emerging clinical evidence supporting CAR-T therapy in IMNM are systematically reviewed. • CAR-Treg-based strategies are explored as a potential precision immunotherapy approach for refractory IMNM.