@shannon_ohara , the main purpose of all the Disease Modifying Therapies (DMTs) is to reduce the frequency and Severity of future relapses. So, a form of insurance for the future.
However, once the brain is prevented from attacking our Central Nervous System (CNS), it does have a chance to try and effect some repair of the residual damage from previous relapses.
This repair is contingent on the neuronal reserve that you have available. This reserve gets depleted as we age.