Is Rituximab as Effective as Ocrelizumab in Relapsing MS?

Choosing between rituximab versus ocrelizumab remains a critical clinical decision for neurologists managing relapsing multiple sclerosis in India. Specifically, clinicians often face financial barriers when prescribing high-cost approved therapies like ocrelizumab. Consequently, they frequently turn to rituximab as a highly affordable off-label option. Therefore, this new clinical trial provides much-needed clarity for Indian doctors.

Designing the OVERLORD-MS Trial

Researchers in this phase 3 trial randomly assigned 218 adults with newly diagnosed relapsing multiple sclerosis. Specifically, they allocated participants in a 3:2 ratio to receive either rituximab or ocrelizumab. Furthermore, patients received their assigned drug intravenously every six months for a total of 24 months. The primary endpoint was the absence of new or enlarging brain lesions on MRI from month 6 to 24. Moreover, the noninferiority margin required a risk difference lower limit of at least -10 percentage points. Importantly, this trial evaluated safety, clinical relapse rates, and cognitive performance as secondary outcomes.

Comparing Rituximab Versus Ocrelizumab Efficacy

The results confirmed that rituximab is noninferior to ocrelizumab for treating newly diagnosed relapsing multiple sclerosis. In fact, 92.2% of patients receiving rituximab had no new or enlarging MRI lesions. Similarly, 94.8% of participants in the ocrelizumab group achieved the same lesion-free status. This resulted in a minor risk difference of only -2.6 percentage points. In addition, this difference comfortably met the prespecified noninferiority threshold. Importantly, relapse rates and disability outcomes remained highly similar between the two groups. Therefore, clinicians can confidently view both medications as highly effective therapeutic options.

Evaluating Safety Profiles and Adverse Events

While efficacy profiles matched closely, the safety analysis revealed some notable differences in infection rates. Specifically, infections occurred in 82% of patients receiving rituximab compared to 69% receiving ocrelizumab. However, the percentage of patients experiencing serious adverse events remained virtually identical between groups. Specifically, only 8% of the rituximab group and 7% of the ocrelizumab group had serious events. Consequently, the overall safety profile of both drugs remains highly acceptable for clinical use. Indian neurologists should therefore monitor patients carefully for infections during treatment.

Clinical Implications for Neurologists in India

For Indian doctors, these head-to-head results carry immense clinical and economic significance. As a result of high costs, many MS patients in India cannot afford proprietary ocrelizumab. Consequently, off-label rituximab has served as the practical standard of care for years. However, this landmark trial now provides robust, high-quality evidence supporting this common practice. Furthermore, the availability of rituximab biosimilars in India makes treatment even more accessible. Therefore, these findings will likely increase clinical confidence in using rituximab as a first-line therapy.

Frequently Asked Questions

Q1: Is rituximab as effective as ocrelizumab for newly diagnosed relapsing multiple sclerosis?

Yes, the phase 3 OVERLORD-MS trial demonstrated that rituximab is non-inferior to ocrelizumab. Specifically, both drugs suppressed new or enlarging MRI brain lesions with high and comparable efficacy over a 24-month period.

Q2: What are the safety differences between rituximab and ocrelizumab?

The trial showed that infections were more common in patients receiving rituximab than ocrelizumab. However, the rates of serious adverse events were nearly identical between the two treatment groups, indicating a similar overall safety profile.

Q3: Why is this trial significant for multiple sclerosis treatment in India?

Ocrelizumab is highly expensive, making it inaccessible for many Indian patients. Consequently, these findings validate the off-label use of more affordable rituximab, offering a highly effective and cost-saving alternative for local clinicians.

References

1. Torkildsen Ø et al. Rituximab versus Ocrelizumab in Newly Diagnosed Relapsing Multiple Sclerosis. N Engl J Med. 2026 Jul 02. doi: 10.1056/NEJMoa2600993. PMID: 42384870.
2. Schoof LG et al. Non-inferiority of Rituximab versus OCrelizumab in Multiple Sclerosis (ROC-MS)-an individual participant data meta-analysis. Mult Scler Relat Disord. 2026 Jan:105:106858. doi: 10.1016/j.msard.2025.106858.
3. ClinicalTrials.gov. Ocrelizumab VErsus Rituximab Off-Label at the Onset of Relapsing MS Disease (OVERLORD-MS). NCT04578639.