John Corboy, MD: The Lack of Knowledge on Stopping DMT in MS and the DISCO-MS Trial

John Corboy, MD, a professor of neurology and the co-director of the Rocky Mountain MS Program at the University of Colorado: As we age, we collect, unfortunately, more likelihood of diabetes, high blood pressure, stroke, cancers, and a variety of other conditions, many of those are potentially problems if you're going to use some of our disease-modifying therapies, especially our more effective disease-modifying therapies. So one portion of consideration of discontinuation of disease-modifying therapies is trying to limit the impact on these so-called cortical morbidities, and I think that is an important portion of it.

The biggest portion was just a simple question as to if you're going to use a medication, any medication - for infection, for a headache, anything - after you decide that you should use it, it's appropriate conditions, you know what the side effects, are you know how to pay for it, and everything else, you should clearly ask the question: “What am I going to stop using it?” There are some conditions in our world, and medicine that you continue, if you have type 1 diabetes [for example], you may well use insulin for the rest of your life.

And there are certainly other examples of that as well, but there are quite a few examples of even chronic conditions, where you may well not need to do that. So, some examples of other autoimmune conditions that may change over time as you age are: sarcoidosis, which often burns out; rheumatoid arthritis often burns out; and other conditions which, as well, may just have a change in their level of disease activity as one ages, and the question is: “Is there an ongoing benefit of using the medication and does that benefit outweigh potential risk?”

So if the benefit is potentially going down as you age and if the risk is potentially going up as you age, those lines may cross where you don't really see that the benefits outweigh the risks, in which case - especially with extremely expensive medications as such as in our world [of MS] - it would at least be the impetus to us to say, “We should do a study to try and figure this out,” and that's what we're now at DISCO-MS.