I know that there are trials right now looking at the use of cellcept in combination with Avonex. I almost joined one right after I got diagnosed in the fall of 2007 but decided I didn't want to be in a study without having tried a standard therapy first. Turns out the interferon made me quite sick. The MS clinic I spoke to that was doing the trial said the doctor in charge had been quite pleased with some of the results-- but who knows, they could have been telling me that to convince me to join the study!
I have a friend who takes cellcept for lupus and an autoimmune blood disorder. She seems to tolerate it fairly well except for some digestive issues.
Good luck Barb making a decision about what to do. Wish I could give you more information.