Influence of physicians’ risk perception on switching treatments between high- efficacy and non–high-efficacy disease‑modifying therapies in multiple sclerosis

Background: The decision of initiating treatment for multiple sclerosis (MS) with a high-efficacy DMT (HE DMT) or non–high-efficacy DMT (non-HE DMT) is influenced by several factors, including risk perception of patients and physicians. Objective: Investigate the influence of physicians’ risk perception on decision-making when switching treatments for MS and the reasons for switching. Methods: Data were drawn from the Adelphi Real-World MS Disease-Specific Program (a retrospective survey) and analysis included people with RMS identified between 2017– 2021. Results: Of 4129 patients with reasons for switch available, 3538 switched from non-HE DMT and 591 from HE DMT. Overall, 4.7% of patients were switched treatment by their physicians due to the risk of malignancies and infections including PML risk. The proportion of switches that were made due to the risk of PML were 23.9% in the HE DMT and 0.5% in the non-HE DMT groups. The top reasons for switching were relapse frequency (non-HE DMT vs HE-DMT: 26.8% vs 15.2%), lack of efficacy (20.9 vs 11.7) and increased number of MRI lesions (20.3% vs 12.4%). Conclusions: Physicians’ risk perception of malignancies and infection excluding PML was not a leading factor when switching treatment. The risk of PML was a key factor, especially for switching patients from HE DMTs. In both groups, lack of efficacy was the key contributing factor for switching. Initiating the treatment with HE DMTs may potentially reduce the number of switches due to sub-optimal efficacy. These findings might help physicians to engage more in discussions with patients about the benefit/risk profile of DMTs.