Ocrelizumab and Rituximab Demonstrate Similar Safety, Efficacy in Treatment of Multiple Sclerosis

Author(s):

Treatment with either rituximab and ocrelizumab, 2 FDA-approved therapies that target CD20, resulted in similar odds of experiencing a clinical disease activity in both unadjusted and adjusted analyses.

Enrique Alvarez, MD, PhD

In a comparative study of middle-aged patients with multiple sclerosis (MS) on rituximab (Rituxan; Genentech) and ocrelizumab (Ocrevus; Genentech), findings showed similar safety and efficacy over a 2-year period.

Presented at the 2023 Americas Committee for Treatment and Research in Multiple Sclerosis (ACTRIMS) Forum, held February 23-25, in San Diego, California, the odds of experienced disease activity was similar between ocrelizumab and rituximab, before (P = .063) and after adjustments (P = .249). Over a 2-year period, 20.8% and 24.7% of patients on ocrelizumab and rituximab, respectively, discontinued treatment.

Senior investigator Enrique Alvarez, MD, PhD, associate professor of neurology, University of Colorado School of Medicine, and colleagues randomly selected patients treated with ocrelizumab (n = 245) and rituximab (n = 182), and observed outcomes such as lab data, relapse history, adverse events (AEs), MRI outcomes, disease history, and patient characteristics. Descriptive statistics and logistic regression adjusting for age disease duration, MS type, sex and enhancement on baseline MRI were used to describe and compare the sample groups.

Both rituximab and ocrelizumab have similar mechanisms of action that target CD20, resulting in B-cell depletion. Rituximab, first approved in 1997, is also indicated for patients with non-Hodgkin’s lymphoma, chronic leukemia, rheumatoid arthritis, granulomatosis with polyangiitis, microscopic polyangiitis, and pemphigus vulgaris. In 2017, Ocrelizumab was approved as a treatment for adults with relapsing or primary progressive forms of MS. It represented the first product approved for primary progressive MS.

At first infusion, the mean age of those on ocrelizumab and rituximab were 44.4 and 43.9 years, respectively, with mean MS disease durations of 9.6 and 12.7. Both groups featured predominately women (ocrelizumab: 73.9%; rituximab: 65.9%). For the ocrelizumab group, 4 (1.99%), 1 (0.50%), and 20 (9.95%) patients experienced a clinical relapse, enhancing lesion, and new T2 lesions, respectively. In comparison, 6 (3.30%), 1 (0.72%), and 23 (16.67%) patients on rituximab experienced similar outcomes.

In terms of safety, during the first and second ocrelizumab infusion, 16.9% and 10.0% of patients, respectively, experienced an infusion reaction that interrupted the infusion compared with 33.5% and 10.3% of those for respective rituximab infusions. Neither group had any patients that had treatment result in an emergency visit or life-threatening reaction. Infusion-related reactions that resulted in an emergency department visit occurred in 6.9% in the ocrelizumab group and 7.7% in the rituximab group. Infections that led to hospitalization were found in 1.6% of those on ocrelizumab and 5.5% of those on ritixumab.

In 2022, a real-world observational study compared the effectiveness of these 2 therapies in patients with primary progressive MS, with a minimum follow-up of 1 year. In total, 49 patients received rituximab and 46 were on ocrelizumab, with rituximab-treated patients showing significantly higher baseline Expanded Disability Status Scale scores, disease duration, and history of previous disease-modifying therapies than the rituximab group. After a mean follow-up of 18.3 months, 30.6% (n =15) and 23.9% (n = 11) of patients in the rituximab and ocrelizumab groups, respectively, experienced confirmed disability progression; however, survival analyses revealed no differences in time to CDW. Additionally, the 2 groups showed no differences in serum neurofilament light levels.²

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REFERENCES
1. Vollmer B, Nair K, Sillau S, Corboy JR, Alvarez E. Comparison of ocrelizumab and rituximab over 2 years of treatment for multiple sclerosis. Presented at: 2023 ACTRIMS Forum; February 23-25; San Diego, California. Abstract P159
2. Alcala C, Quintanilla-Bordas C, Gascon F, et al. Effectiveness of rituximab vs ocrelizumab for the treatment of primary progressive multiple sclerosis: a real-world observational study. Journal of Neurology. 2022;269:3676-3681. doi:10.1007/s00415-022-10989-0.