I just had an appointment with my neurologist and don't have to go back for 6 months (had been every 3 months). I have been on IVIG every 3 weeks for 10 months now and have just really started noticing the effects in the last month or so. I have less pain now than I've had for years. He said most insurers want to try a withdrawal from the therapy after 2 years to make sure it is still needed. The Gamunex seems to be working for me, it just took a while to have an impact.