While rituximab does not carry indications for the treatment of Multiple Sclerosis
) or aquaporin-4-positive (AQP4) neuromyelitis optica spectrum disorder (NMOSD), the CD20-depleting therapy and its biosimilars are commonly used off-label, as the therapy has been demonstrated to be effective in reducing relapses in MS
as well as in reducing the frequency and severity of attacks in NMOSD.
The availability of biosimilar rituximab—already a reality in Europe and soon to arrive in the United States—has the potential to increase patient access to anti-CD20 therapy, but despite the common use of the drug in neurology, there are few data that help guide individual patients’ treatment with rituximab. Important questions remain, such as how long a patient should ideally be treated with rituximab, on what schedule treatment should occur, or what therapies may be optimal after treatment with the product is discontinued.
During last week’s 35th Annual Congress of the European Committee for Treatment and Research in Multiple Sclerosis, which was held in Stockholm, Sweden, multiple teams presented findings on the use of rituximab in both of these challenging neurological disorders.
First, in a poster session, researchers from the Institute of Neuropathology and University Medical Center Göttingen, in Göttingen, Germany, presented findings on their study on the phenotype and function of B cells that reappear after treatment with rituximab.1
The researchers assessed peripheral blood mononuclear cells of 15 patients with relapsing MS prior to rituximab therapy and during B-cell repletion. They found that, while most B cells before rituximab treatment were mature memory B cells, the B cells that reappeared showed a naïve phenotype, and also manifested an accentuated activation profile and a more proinflammatory cytokine profile.
These findings suggest the need for further exploration of the phenotype of these repleting B cells to help guide therapeutic decisions, particularly with regard to maintenance therapies that may be initiated after treatment with anti-CD20 agents like rituximab.