Both Ocrevus (ocrelizumab) and Rituxan (rituximab) trigger a similar release of inflammatory mediators after a first infusion, with little difference seen in infusion reactions among a small group of multiple sclerosis (MS) patients treated with either therapy, said researchers from the Rocky Mountain MS Center at the University of Colorado in a presentation at the 7th Joint ECTRIMS-ACTRIMS Meeting held in Paris Oct. 25–28.
Ocrevus was approved to treat both relapsing and primary progressive forms of MS in the U.S. this year; rituximab — sold as Rituxan for indications like non-Hodgkin’s lymphoma, chronic lymphocytic leukemia, and rheumatoid arthritis — is used off-label to treat relapsing MS.
Both Ocrevus and Rituxan are based on antibodies that target B-cells with CD20 molecules on their surface — a type of cell thought to be involved in MS development. But the two treatments differ, for instance, in the targets they recognize on CD20. Both are administered through intravenous infusions, a method of drug delivery associated with infusion-related reactions.
It has been hypothesized that differences between these therapies result in different degrees of infusion-related reactions. So researchers looked for differing reactions by assessing cytokine levels after infusion.
Further analyses should provide a clearer picture of how the inflammatory mediators, or cytokines, are related to such reactions in patients given either therapy for the first time, said Enrique Alvarez, PhD, senior investigator on the study, which is not linked to their mutual developer, Genentech.
The poster presentation, “Characterizing the cytokine profile before and after antiCD20 infusions: comparison of rituximab versus ocrelizumab,” was the result of a small study at the University of Colorado, initially intended as a pilot study for a larger trial exploring the safety of switching from Rituxan to Ocrevus.
The study gathered patients having a first infusion of Ocrevus or Rituxan at the MS center to analyze cytokines released. Researchers believe these immune mediators are involved in the development of infusion-related side effects.