Effectiveness and Safety of Rituximab in Filipino Patients With Relapsing-Remitting Multiple Sclerosis: A Real-World Retrospective Cohort Study in a Resource-Limited Setting.

BACKGROUND

Multiple sclerosis (MS) is a chronic autoimmune disorder requiring prompt initiation of disease-modifying therapies to mitigate long-term disability. In resource-limited settings like the Philippines, the high cost of approved therapies makes evaluating accessible, off-label high-efficacy treatments like rituximab a clinical priority.

OBJECTIVE

To evaluate the real-world efficacy and safety of off-label rituximab in patients with relapsing-remitting MS (RRMS) in a tertiary center in the Philippines.

METHODS

This single-center retrospective cohort study involved 32 patients with RRMS treated with rituximab between 2017 and 2024. Primary outcomes included the proportion of patients free from clinical relapses, the annualized relapse rate (ARR), and disability progression (as measured by the Expanded Disability Status Scale (EDSS)). Achievement of No Evidence of Disease Activity (NEDA) was assessed, though limited by inconsistent MRI longitudinal data due to financial barriers. The study is further limited by its retrospective design, small sample size, and lack of a comparator arm.

RESULTS

The study included 32 patients (75% female) with a mean age of 25.7 + 8.5 years and a mean baseline EDSS of 1.5 +/- 1.3. Following rituximab initiation, the ARR was 0.55 +/- 0.75. At the two-year follow-up, 75% (n=24) of the cohort achieved NEDA; however, this assessment was based on available clinical and radiological data, as longitudinal MRI was incomplete for a subset of patients due to financial barriers. Disability levels remained stable, with no statistically significant change in mean EDSS from baseline. Rituximab was generally well-tolerated, with mild infusion-related reactions reported in 9.4% (n=3) of patients and no serious adverse events recorded.

CONCLUSION

In this small observational cohort, rituximab showed potential effectiveness and favorable tolerability, suggesting it may be a viable therapeutic alternative for achieving NEDA in settings where socioeconomic barriers limit access to approved anti-CD20 agents. However, given the lack of a comparator arm and modest sample size, these findings should be interpreted with caution and do not imply therapeutic equivalence to standardized high-efficacy therapies. Larger, prospective comparative studies are warranted.