If you have any symptoms you are concerned about you should talk to your neurologist office ASAP. This is not one of the drugs I have taken but if you use the little magnifying glass in the upper left you will see many discussions on this treatment by others in the group. There is also a lot of information and sites that come up in a simple google search. In this one I don't see multiple myeloma listed specifically but other side effects- https://www.gilenyahcp.com/tolerability-adverse-events?site=SO080062 Your system likely works differently than ours in the US but I would need to start with my Neurologist and they would refer me to the Oncologist if there were symptoms that pointed towards multiple myeloma There is also a support line for this drug https://www.gilenyahcp.com/gilenya-go-program I actually see a post of "In a recent study published in the Journal of Experimental Medicine, researchers found that fingolimod (sold as Gilenya), an FDA-approved orally administered drug to treat multiple sclerosis, could reduce painful side effects of multiple myeloma treatments."

They screen for serious side effects when you're on the drug. There are six-monthly blood tests for kidney and liver function plus they monitor the white blood cell count (which naturally reduces when on the drug) ... plus likely lots of other analysis. I have to have an annual skin screening, because there is a known - although small - increased likelihood of skin cancer. Hope that helps, x