My sister has Lupus, Fibromylagia, and 2 years ago was also diagnosed with MS. To my knowledge, there is no stopping the advance, there may be a breakthrough from stem cell research, but that may be some time away. Don't ask me about her quality of life. She is in constant pain, shits in a bag, lost all her hair, and we can't even hug her unless she is medicated to the twilight zone because the mere touch, let alone the pressure of a hug, causes her serious agony. Most of that is due to the Lupus, not MS.
I called her and read her your question. Her response was:
Take the medications. You may not stop it, but you will most certainly slow it, and manage they sypmtoms somewhat. There are new treatments and breakthroughs all the time, possibly even more with the easing of restrictions on stem cell research. She also said one should always live it up whenever possible in addition to taking your meds.