Anti-CD20 Cell Therapies in Multiple Sclerosis—A Fixed Dosing Schedule for Ocrelizumab is Overkill

Authors

  • Jagannadha Avasarala Department of Medicine, Division of Neurology, USC School of Medicine Greenville, Greenville, SC, USA. Department of Internal Medicine, Division of Neurology, USC School of Medicine and UMG-Neuroscience Associates, Greenville, SC, USA.

DOI:

https://doi.org/10.33393/dti.2017.1367

Keywords:

Ocrelizumab, Multiple Sclerosis, CD19/20 cells, anti-CD therapies, Rituxan, Dosing schedules, Ocrevus, Neuromyelitis opticaspectrum disorder

Abstract

Anti-CD 20 therapies have found significant uses in multiple sclerosis (MS). Based singularly on the accumulated evidence with the use of rituximab (RTX; Rituxan, Genentech, and Biogen) in neuroimmunological diseases, ocrelizumab (OCR; Ocrevus, Genentech) was developed as a treatment option for MS and selectively targets CD20 B cells, a cell surface antigen found on pre-B cells, mature, and memory B cells, but not on lymphoid stem cells and plasma cells. On the basis of indirect evidence, elimination of the antigen-presenting capabilities and antigen nonspecific immune functions of B cells appear to be central to the therapeutic efficacy of anti-CD20 B-cell therapies. An important question is this—Why does the drug need to be dosed at fixed intervals and not based on a measurable endpoint, such as tracking peripheral CD20 cell counts? There is minimal scientific validity in infusing the drug every 6 months particularly if CD20 cell counts are negligible in the peripheral blood. In this analysis, a case is made for following CD19 cell populations as a surrogate for CD20 cells on a monthly basis to guide OCR redosing parameters and does not follow a scheduled dosing parameter.