Persistence, Adherence, and Switching to Higher-Cost Therapy in Patients with Multiple Sclerosis Initiating Oral Disease-Modifying Therapies: A Retrospective Real-World Study

Introduction: Therapeutic efficacy of disease-modifying therapies (DMTs) for multiple sclerosis (MS) is often hindered by poor persistence and adherence, impacted by patient-perceived efficacy concerns, adverse effects, inconvenience, and forgetfulness. This study measured persistence, adherence, and time to switching to higher-cost therapy among patients with MS initiating teriflunomide, dimethyl fumarate, fingolimod, or diroximel fumarate treatment. Methods: This retrospective study used Symphony Health US claims data from patients with MS newly initiated on one of four oral DMTs between January and June 2020. Persistence was defined as the duration a patient continued their medication. Adherence was measured using medication possession ratio (MPR); patients with MPR >= 80% were considered adherent. Switching was measured by comparing proportions of patients switching and mean time to switch to one of three higher-cost therapies (ocrelizumab, natalizumab, or cladribine). Kaplan-Meier curves assessed persistence. Chi-square tests determined proportions of patients on therapy after 12 months. Results: A total of 6934 patients newly initiated on oral DMTs met study inclusion criteria (teriflunomide, n = 1968; dimethyl fumarate, n = 3409; diroximel fumarate, n = 616; fingolimod, n = 941). Patients newly initiated on teriflunomide and fingolimod had significantly higher persistence rates after 12 months (60% and 66%, respectively vs 44% dimethyl fumarate and 49% diroximel fumarate; p < 0.0001), and the highest proportion of adherent patients at 6 months (71% and 76%, vs 60% dimethyl fumarate and 58% diroximel fumarate) and 12 months (55% and 59%, vs 40% dimethyl fumarate and 44% diroximel fumarate). Mean time to switching to higher-cost therapies ranged from 247 days (diroximel fumarate to natalizumab) to 342 days (teriflunomide to ocrelizumab), with the highest rate of switching in patients on dimethyl fumarate (7%). Conclusion: Patients newly initiated on teriflunomide and fingolimod had better real-world persistence and adherence at 6 and 12 months, and longer time to switch to higher-cost therapies, than patients on dimethyl fumarate or diroximel fumarate. Plain Language Summary: People living with multiple sclerosis (MS for short) can find it difficult to maintain treatment plans. This can impact how well disease-modifying therapies (DMTs) work. This means treatments may not be as effective at controlling symptoms or stopping new symptoms (relapse). In this study, we looked at health records of 6934 previously diagnosed people living with MS in the USA. These people started DMTs for the first time between January and June 2020. Researchers studied how long people continued their treatment (known as persistence) and how often people took their treatment as recommended (adherence). We also studied how many people switched to a more expensive treatment (ocrelizumab, natalizumab, or cladribine). We measured persistence based on how many days people continued their treatment. We measured adherence through the number of people who took their treatment at least 80% of the time. After 1 year, more people who took teriflunomide and fingolimod continued treatment than people on dimethyl fumarate or diroximel fumarate. These people were also more likely to follow their treatment plan. People taking dimethyl fumarate were most likely to switch to a more expensive treatment. On average, people who changed to a more expensive treatment did so after around 8 months. In this study, we found that people with MS who started teriflunomide or fingolimod for the first time were more likely to continue treatment and take treatment as recommended than those on dimethyl fumarate or diroximel fumarate. They also took longer to switch to a more expensive treatment. [GRAPHICS] .