How do you approach further treatment in patients with anti-HMG-COA myopathy who have residual disease activity (ongoing weakness, elevated CK) after >1 year of combination therapy, e.g. IVIG and methotrexate?

The most important question is if the patient still has active disease, or their symptoms of residual weakness are from fatty atrophy. In the latter case, the patient will not benefit from additional immunosuppression but would require aggressive physical therapy.

In anti-HMGCR IMNM, good markers for disease activity include elevated CPK (CPK elevation commonly associated with active disease), as well as muscle MRI (that can help discern between fatty atrophy vs active myositis).

In the case of ...