Real-world evidence of ocrelizumab in Chilean patients with multiple sclerosis.

Background: Real-world studies are needed to expand our knowledge concerning populations underrepresented in clinical trials.

Objective: This study aimed to evaluate the safety and effectiveness of ocrelizumab in Hispanic/Latino people with multiple sclerosis (pwMS).

Methods: Prospective longitudinal observational study including pwMS who received at least one dose of ocrelizumab between June 2018 and October 2023.

Results: A total of 305 pwMS (223 relapsing-remitting MS (RRMS), 29 secondary progressive MS (SPMS), and 53 primary progressive MS (PPMS)), 67% female, mean age 38.7, mean disease duration 7 years, and median Expanded Disability Status Scale (EDSS) 2.0 (range 0-7). Median follow-up under ocrelizumab 29.5 (range 6-65) months. Only 1 patient had a relapse, 12-week-confirmed disability worsening was observed in 12.4% of the full cohort. Survival analysis showed higher risk of 12-week-confirmed disability worsening in SPMS compared with RRMS and PPMS (p = 0.0009). Magnetic resonance imaging (MRI) activity was significantly reduced from baseline across all disease phenotypes. Serious infections were observed in 4.6%, and two patients died during follow-up (one serious COVID-19 and one metastatic cancer). Notably, 22 pregnancies were reported, with 11 newborns and 6 pregnancies still on course.

Conclusion: This study supports the effectiveness of ocrelizumab in a real-world cohort of individuals from traditionally underrepresented groups, such as the Latin American population, with a consistent safety profile in patients receiving care at a specialized MS Unit.