Utilization of Ocrelizumab within Different Treatment Strategies for Multiple Sclerosis: A 5-Year Population-Based Study

Background: We aim to provide up-to-date real-world evidence on the persistence, adherence, healthcare resource utilization, and costs of multiple sclerosis (MS) by comparing ocrelizumab to other disease-modifying treatments (DMTs) and within different DMT sequences. Methods: We included 3371 people with MS who first received or switched DMT prescriptions from January 2018 to December 2022; they were identified through hospital discharge records, drug prescriptions, and exemption codes from the Campania Region (South Italy). We calculated persistence (time from the first prescription to discontinuation or switching to another DMT), adherence (proportion of days covered (PDC)), DMT costs, and MS hospital admissions and related costs. Results: The most frequently prescribed DMT was dimethyl fumarate (n = 815; age 38.90 ± 11.91 years; 69.5% females), followed by ocrelizumab (n = 682; age 46.46 ± 11.29 years; 56.3%); 28.8% of the patients treated with ocrelizumab were naïve to DMTs. Using ocrelizumab as a statistical reference, the risk of discontinuation was higher for other highly active (HR = 6.32; 95%CI = 3.16, 12.63; p < 0.01) and low-/medium-efficacy DMTs (HR = 10.10; 95%CI = 5.10, 19.77; p < 0.01); adherence was lower for other highly active DMTs (Coeff = -0.07; 95%CI = -0.10, -0.04; p < 0.01) and low-/medium-efficacy DMTs (Coeff = -0.16; 95%CI = -0.19, -0.14; p < 0.01). monthly DMT costs were higher for other highly active DMTs (Coeff = 77.45; 95%CI = 29.36, 125.53; p < 0.01) but lower for low-/medium-efficacy DMTs (Coeff = -772.31; 95%CI = -816.95, -727.66; p < 0.01). The hospital admissions and related costs of MS were similar between ocrelizumab, other highly active DMTs, and other low-/medium-efficacy DMTs, and with ocrelizumab as the first-line DMT after other highly active DMTs and after low-/medium-efficacy DMTs, which was possibly due to the low number of observations. Conclusions: From 2018 to 2022, ocrelizumab was among the most frequently prescribed DMTs, with 28.8% prescriptions to incident MS patients, confirming its relevance in clinical practice. Ocrelizumab was associated with the highest persistence and adherence, pointing towards its favorable benefit-risk profile. The costs of ocrelizumab were lower than those of other highly active DMTs.