Treatment of refractory immune-mediated necrotizing myopathy with abatacept and tacrolimus: A case-based review

Idiopathic inflammatory myopathies are characterized by muscle weakness, elevation in serum muscle enzyme levels, electromyography abnormalities, presence of Myositis Specific Autoantibodies (MSAs) and findings of inflammation on muscle biopsy. Immune-mediated necrotizing myopathy (IMNM) is a subset of IIM that is often resistant to standard immunosuppressive therapy, requiring multiple combinations of therapeutic agents. We present a case of a middle-aged man with positive anti-Signal Recognition Particle (SRP) IMNM who responded to abatacept and tacrolimus after failing standard of care treatment.