Unmet needs include both improved myasthenia gravis treatments as well as a way to monitor progression of the disease, said James F. Howard, Jr, MD, professor of neurology at the University of North Carolina at Chapel Hill.
Current therapies for myasthenia gravis are not targeted and better therapeutics are needed, said James F. Howard, Jr, MD, professor of neurology at the University of North Carolina at Chapel Hill, former chief of the Neuromuscular Disorders Division, and former James F. Howard Distinguished Professor of Neuromuscular Disease.
What are some of the unmet needs in myasthenia gravis?
We need better therapeutics. Currently, we use broad spectrum immune suppression. And with that, while it works very well for many of our patients, the quality of life of that individual often is not met. We have adverse event profiles to deal with, which impact on employment, impacts on social interactions, impacts on family interactions. There's been a shift in the paradigm that rather than be thankful I’m doing something for you and making you stronger, to now, yes, I want to be stronger, but I want good quality of life.
And so new classes of drugs—targeted therapies, if you will—are coming out in which side effect profiles are much narrower, much more acceptable, we see good efficacy, and more importantly, they work very quickly. In the MuSK population, for instance, we need drugs that will have much less way of potential adverse events. Most commonly, we use a drug called rituximab, which depletes the body, the system, of B cells, those cells in our immune system that make antibodies. And with that comes potential adverse events.
Some of these individuals, they have a profound reduction, such that they're at risk for infections, for instance. There's a subset of patients that don't respond to these drugs. We're limited in what we can use in that subgroup. And we need newer and targeted therapies, and there's some in the pipeline—they're absolutely fascinating—that will meet this need, for instance. And I selectively remove that MuSK antibody and leave everything else alone. That would be fantastic. There are individuals who are working on that as we speak.
The other problem we have is that with our standard therapies, when I place somebody on a drug, it takes months to start working, and more than a year, year-and-a-half, sometimes 3 years, before I see the full benefit of drug. And so if I'm cycling through drug A, it’s not working; let's try drug B, it's not working. And I have to give them a reasonable shot to see if it's working. I'm now consuming years of their life, which again impacts quality of life. And so, we're searching for therapeutics that work very quickly, that we can then establish, is this beneficial or not? If not, move on to something else.
What we lack in myasthenia is a biomarker, a tool that will tell us what could be the disease course? Is this individual going to respond to drug A, B, not C or D, but maybe E, that we could then use advanced precision medicine, if you will. And we don't have that.
Contrast that to the multiple sclerosis world with the use of a MRI scanner, where they can now see lesion burden. They can quickly determine is this drug beneficial? Am I reducing this burden of disease? And we know from work that has been done by folks like Gavin Giovannoni in London, that the earlier adaptation of these disease-modifying therapies leads to much less in terms of morbidity, disability, and better quality of life outcomes, etc. And we'd like to apply that to the MG space. But we don't have the tools to monitor yet.