Ocrevus (ocrelizumab) eliminated the immunity, acquired through vaccination, to the varicella-zoster virus — the virus that causes chickenpox and shingles — in a man with relapsing-remitting multiple sclerosis (RRMS), a case study reported.
Its authors recommended that MS patients being treated with Ocrevus be retested for immunity against the varicella-zoster virus.
The study, “Varicella Zoster immunity loss in multiple sclerosis patient treated with ocrelizumab,” was published in the journal Clinical Immunology.
Ocrevus (developed by Genentech) is an antibody-based therapy approved for patients with relapsing MS and primary progressive MS (PPMS). It is designed to suppress immune system attacks on the myelin sheath, the coating that protects nerve fibers.
The treatment targets mature B-cells, a type of immune cell that produces a protein called CD20 on its surface. While depleting mature B-cells, Ocrevus has been shown to preserve the ability to generate new B-cells as well as maintain pre-existing immunity acquired from previous infections or vaccinations.
But evidence shows that some patients given vaccines to protect against the influenza virus or pneumococcal bacteria lose such immunity after Ocrevus treatment.
Current guidelines recommend assessing the vaccination status of MS patients before prescribing therapies that suppress or modulate the immune system. However, there are no specific recommendations about reassessing vaccine-based immunity after treatment with Ocrevus.
Researchers at the Magna Graecia University of Catanzaro in Italy described the case of a 48-year-old man with RRMS who lost vaccine-based immunity against varicella-zoster virus after the first Ocrevus treatment.