Rituxan/rituximab insurance coverage

My wife is about to start Rituxan (rituximab) infusions.

She has been receiving plasmapheresis biweekly for some time, and the plan is to continue/coordinate with rituximab. The epheresis appears to keep her CIDP in check at best, but no improvement; IVIG didn’t have much effect.

Any recommendations on insurance coverage for rituximab/rituxan for CIDP and/or CRPS/RSD, particularly Medicare?