DMT switches were evaluated on an annual basis over a 4 year period, from late 2015 to early 2019. Data was based on N=1,002 to N=1,035 MS patient chart reviews contributed online by Neurologists (N=194 to N=260). 2020 data will be included at presentation.

77% of recent DMT switches involve a first switch (up from 69% in 2015), 17% involve a second switch, and only 6% involve a third or higher switch. Overall, the most common 2019 switches have been from injectables, glatiramer acetate (GA; 38%) and interferon betas (IFNβs; 30%). Patients frequently switched to an oral DMT (35%) or a monoclonal antibody (mAb; 30%); few switched to an injectable (36%), either IFNβ (12%) or GA (24%). Over the past 4 years, switching from an IFNβ to an oral DMT is decreasing (22% in 2015 vs. 13% in 2019), while switching from GA to a mAb (5% vs. 10%), or from an oral DMT to a mAb (3% vs. 11%), is increasing. Over the same period, the most common first switch was consistently from an injectable to an oral DMT (35% vs. 32%); GA agents were a slightly larger source of first switches (41%) than IFNβ (35%) in 2019. The most common second switch in 2019 was from an oral DMT to a mAb (22%), or from GA to a mAb (13%).

MS DMT switch patterns are changing. There are fewer second or later switches perhaps related to earlier use of a higher efficacy DMT as a switch agent.