Really depends on your Dr., but i believe the protocol is that you need to have failed at 2 prior ms drugs prior to switching to Lemtrada. It is a fairly caustic drug (reformulated chemotherapy) that requires monthly blood and urine tests for 5 years after treatment (to monitor for adverse side effects like kidney liver issues, blood platelet drops, and tyroid issues). Most of the people at the neuro I go to end up on Tysabri after the Copaxon. I just did my 1st round of Lemtrada after thanksgiving. I continue to be hopeful for results but I'd by lying if I didn't tell you it is a bit if a rough ride. You spend 8 hrs a day for a week in the infusion center reviewing the drug. The 1st 4 months post treatment are rough from what my Dr.'s have told me. Lots of fatigue, headache etc... you literally don't have an immune system for a while so avoiding germs is important. That being said the #'s on the Lemtrada are really good long term. Perfect example if sorry term pain for long term gain. Not trying to talk you out of it, even knowing what I know today I'd do the Lemtrada, but go into it with your eyes wide open. Good luck on whatever you decide.