Understanding the 'Durable Effect' Concept of B-cell Modulating Therapies

This prospective, observational clinical study aims to longitudinally assess peripheral immune cell profiles of patients with relapsing-remitting multiple sclerosis (RRMS) receiving anti-CD20 therapy with ofatumumab (OFA), ocrelizumab (OCR), ublituximab (UBX), and rituximab (RTX). Throughout the study, clinical data - including relapse events, patient scores, and neuropsychological parameters - will be collected, along with results from imaging techniques such as Optical Coherence Tomography (OCT) and Magnetic Resonance Imaging (MRI). This clinical data will be combined with immunological analyses, including multidimensional flow cytometry (mFC), bulk RNA sequencing (bulk-Seq), T and B cell receptor sequencing (TCR/BCR-Seq), proteomics, and immunoglobulin analysis. This approach aims to enable a detailed characterization of changes in the immune cell repertoire and their impact on the clinical disease course.

B cell targeted therapies have become a key element in the treatment of multiple sclerosis due to their effectiveness in rapid and long-lasting depletion of B cells in peripheral blood (PB), significantly reducing relapse rates and disability progression. The monoclonal antibodies OFA, OCR, UBX, and RTX target the B cell surface protein CD20, however it is unclear how B cell depletion and subsequent repopulation allows for immune system reconstitution and how other immune cell populations are affected by these therapies. Furthermore, the relevance of immune cell changes - beyond B cell depletion - for clinical disease stability remains insufficiently understood. By collecting comprehensive and structured prospective clinical data alongside immunological analyses, this study aims for a better understanding of immunological changes in RRMS patients receiving anti-CD20 therapies and the implications of those alterations in immune cell profiles on the clinical disease course. REBELLION-MS plans for two patient cohorts: cohort 1 (C1; basic cohort) and cohort 2 (C2; in-depth cohort). Participants in C1 will be seen every 6 months up until month 24, then every 12 months. The following parameters will be collected: demographic data, disease characteristics incl. Expanded Disability Status Scale (EDSS) and magnetic resonance imaging (MRI) data, serum samples, and Peripheral Blood Mononuclear Cells (PBMCs). Furthermore, Short Form-36 (SF-36) and Fatigue Scale for Motor and Cognitive Functions (FSMC) are documented. Participants of C2 will receive additional evaluations: clinical evaluation incl. EDSS and sampling of serum and PBMCs at months 1 and 3, Multiple sclerosis functional composite (MFSC) every 6 months, and optical coherence tomography (OCT) as well as neuropsychological assessment (NPT) every 12 months. Serum samples and PBMCs will be analyzed by mFC, bulk-Seq, TCR/BCR-Seq, and proteomics, among other methods.