Switch to IVIG as medication for Clippers

My rheumatologist and neurologist are preparing to for me to try IVIG (such as Gamunix C) as a medication that could replace prednisone. I have been on 20 mg prednisone for 6 months steady and it has stabilized me but they think it would be better to move away from it if possible, I would start with both medications and gradually taper off the prednisone. Does anyone have experience doing this that you could share?