Xavier Montalban, MD, PhD, MBA, Vall d’Hebron University Hospital, Barcelona, Spain, describes research exploring the effects of disease modifying therapies (DMTs) in patients with active and inactive lesions in multiple sclerosis (MS). An statistically insignificant difference in efficacy was reported in patients with secondary progressive MS (SPMS) receiving siponimod who had active and inactive lesions. A similar effect was seen in patients with primary progressive MS (PPMS) receiving ocrelizumab. This interview was conducted during the 2022 World Congress on Controversies in Neurology (CONy) meeting.