Appeal type: Medical necessity
Decision: Upheld

Diagnosis: Myositis. 
Treatment: Gammagard Liquid 10% Vial. 

The insurer denied: Gammagard Liquid 10% Vial. 
The denial is upheld. 

The patient is an adult male with necrotizing myositis. Per the attending physician (AP) appeal letter, this patient presented with left leg pain 8 months ago. Magnetic resonance image (MRI) of the patient's left lower extremity demonstrated diffuse intramuscular edema and muscle biopsy demonstrated necrotizing myopathy. He now has profound left leg weakness requiring a cane and is developing right leg symptoms. Per the attached progress notes, the patient was hospitalized for left thigh pain and weakness and acute kidney injury, felt initially to be due to lumbar radiculopathy and diabetic nephropathy, respectively. Ultimately, a left thigh muscle biopsy showed necrotizing myopathy with no inflammatory infiltrate. The muscle biopsy report is not attached. Muscle enzymes (creatine phosphokinase [CPK]/aldolase) were normal and hydroxymethylglutaryl-coenzyme A (HMG-CoA) reductase antibody was negative. Given the atypical unilateral involvement, steroids were not recommended at that time. The plan was to treat with intravenous immunoglobulin (IVIG) (i.e., Gammagard), which was denied by insurance. At his office visit 4 months ago, the patient stopped prednisone due to gastritis, with no change in his symptoms. There were no systemic symptoms. The patient's sedimentation rate was 32. Due to chronic kidney disease (creatinine of 4.25), methotrexate was contraindicated, and azathioprine 50 milligrams daily was started. At the patient's last office visit, he reported continued weakness and pain in his bilateral lower extremities, with strength of 3/5. Azathioprine dose was increased to 100 milligrams daily. No additional follow up data are provided. The appeal is for Gammagard for the treatment of necrotizing myositis. 

The proposed Gammagard for the treatment of necrotizing myositis is not medically necessary. 

Necrotizing myositis is an idiopathic inflammatory myopathy that may be treated similarly to dermatomyositis and polymyositis, and intravenous immunoglobulin (IVIG) (i.e., Gammagard) may be considered as part of the treatment regimen. Per a recent UpToDate review, for immune-mediated necrotizing myopathy, "management of this condition includes immediate statin discontinuation...Treatment with oral steroid, methotrexate, intravenous immunoglobulin (IVIG), and/or rituximab appears to be reasonable and safe, and these agents are commonly used". 

Based upon the attached progress notes, this patient with diabetes and stage IV chronic kidney disease has worsening bilateral lower extremity pain and weakness. There was no worsening of his symptoms off of prednisone and it is unclear whether he is responding to treatment with azathioprine 100 milligrams daily, as no additional follow up information is provided. Laboratory evaluations and muscle biopsy are not entirely consistent with an idiopathic inflammatory myopathy. It is unclear whether the patient's muscle pathology could be consistent with a diabetic muscle infarction, which would not be expected to respond to immunotherapy. In addition, it is unclear whether this patient's ongoing lower extremity weakness and pain may be due to lumbar radiculopathy, and further imaging may be appropriate. Finally, Gammagard may be associated with acute renal failure, and carries significant increased risk in this diabetic patient with stage IV kidney disease. For all of these reasons, treatment with Gammagard in this patient would not be clinically appropriate or in accordance with standard of care in the rheumatology community and is not medically necessary at this time.