The MIGHT Trial - An Exploratory Clinical Trial of IVIG in Anti-HMGCR Immune Mediated Necrotizing Myopathy

Inclusion criteria

• Age > 16 years
• Anti-HMGCR antibody positive
• MMT-8 score < 142 (range 0-160)
• Serum CK > 5x upper limit of normal
• Anti-HMGCR IMNM disease duration < 36 months at screening
• No moderate or severe respiratory or swallowing dysfunction due to anti-HMGCR IMNM at screening
• No history of dermatomyositis rash
• Must reside in a state with a participating research site

Exclusion criteria

• Oral glucocorticoid (GC) daily dose > 15mg at screening
• Change in oral GC dose < 2 weeks prior to screening
• Prior IVIG treatment for anti-HMGCR IMNM

->1 oral conventional synthetic DMARD (e.g. methotrexate, mycophenolate mofetil, azathioprine) use at screening

• Change in concomitant DMARD dose < 4 weeks prior to screening
• Rituximab < 6 months prior to screening
• Plasma exchange, cyclophosphamide, or biologic immunosuppressive medication < 3 months prior to screening
• Use of statin medication at screening
• History of anaphylactic reaction to IVIG
• History of angina pectoris, myocardial infarction, transient ischemic attack, or stroke < 12 months prior to screening
• Females of child-bearing potential who are pregnant, breastfeeding, or are unwilling to practice a highly effective method of contraception during the study
• Wells Criteria for DVT score of 2 or more at screening
• Wells Criteria for PE score of 4 or more at screening
• Weight >120kg
• History of cancer (excluding non-melanomatous skin cancer) < 5 years prior to screening
• History of pulmonary embolism or deep venous thromboembolism < 3 years prior to screening
• History of hyperviscosity or hypercoagulable state
• Currently receiving anti-coagulation therapy (vitamin K antagonists, non-vitamin K oral anticoagulants [e.g. dabigatran, rivaroxaban, apixaban], parenteral anticoagulants [e.g. fondaparinux]. Note that oral anti-platelet agents are allowed (e.g. aspirin, clopidogrel, ticlopidine).
• Glomerular filtration rate (GFR) <60mL/min at the time of screening
• Any medical condition which, in the investigator's judgment, makes participation in the clinical trial unadvisable or which would interfere with evaluation of the study treatment.