Precision Medicine for Multiple Sclerosis: Closer, But Not There Yet

Amit Bar-Or, MD, was selected to deliver the Whitaker Lecture at this year’s CMSC Annual Meeting in Orlando.ORLANDO, Fla. – Precision medicine, defined as optimized medical care for a particular patient or group based on that individual’s genetic or molecular profiling, is a long-awaited goal for the treatment of multiple sclerosis (MS). We’re not there yet, but the destination is well worth reaching, said Amit Bar-Or, MD, in his Whitaker Lecture at the Consortium of Multiple Sclerosis Centers (CMSC) Annual Meeting on Wednesday, October 27.

“To some extent, we already practice some degree of precision medicine for MS,” explained Dr. Bar-Or, Director of the Center for Neuroinflammation and Neurotherapeutics and Chief of the Multiple Sclerosis Division at Penn Medicine. “Our treatment choices are guided by patient demographics, clinical course, imaging, prior treatment history, safety signals, patient preferences, and other factors.” The transformed treatment landscape in MS has brought higher expectations of what our available therapies can do. “Now, on virtually every patient visit, the question arises about the optimal choice of what medication to start, when to switch, and when to stop,” Dr. Bar-Or said.

"We would love to be able to incorporate biological measures from clinical trials in a much more comprehensive and consistent way in practice, but there are a few challenges," he told the audience. One challenge relates to incomplete knowledge of all the subtleties of disease mechanisms involved in MS. “Another challenge is that our insights have been largely limited to one-size-fit- all clinical trials and looking at the average treatment response.” To practice true precision medicine, we need to be able to tailor therapies for the patient based on individual cellular profiles and biomarkers of disease expression, he added. “We have tended historically to shy away from what is important for biological heterogeneity. In my view, we need to truly capture this diversity in order to treat people with MS in a more precise fashion.”

In MS, disease heterogeneity is superimposed on a very substantial host heterogeneity with regard to immune responses. Dr. Bar-Or brought up the example of vaccines to illustrate this point. "When you vaccinate a healthy population looking for adequate responses, you can get a thousand-fold difference in antibody response across a healthy population with the same immune perturbation.”

Dr. Bar-Or summarized various lines of research applying newer advances in immunology, including the evolving understanding of cellular cross–talk that is helping to shed light on the different contributors to immune pathophysiology in MS.

Dr. Bar-Or’s lecture was named for noted neuroimmunology pioneer John R. Whitaker. “While I did not have the privilege of knowing Dr. Whitaker myself, I think what he represented has inspired mentorship by many who have emulated his principles. I am really honored to be following in the footsteps of those individuals.”