Sanofi’s CD40L monoclonal antibody, frexalimab, has demonstrated promising results in reducing a key biomarker associated with nerve cell damage in patients with relapsing multiple sclerosis (MS), suggesting potential benefits in delaying disability progression. Phase 2 findings presented at the 10th Congress of the European Academy of Neurology indicate a significant decrease in plasma levels of neurofilament light chain (NfL) after one year of treatment. Elevated NfL levels are typically observed in MS, reflecting nerve cell damage.
Dr. Patrick Vermersch of the University of Lille highlighted the evolving understanding of MS and the role of NfL as a critical biomarker, indicating both acute inflammatory damage and chronic neuronal loss leading to disability. The study showed that inhibition of CD40L with frexalimab may reduce nerve cell damage, potentially slowing disease progression.
Erik Wallström, MD, PhD, Global Head of Neurology Development at Sanofi, emphasized the need for effective treatments targeting disability progression in MS, underscoring frexalimab’s unique mechanism of action and its potential to offer meaningful improvements.
During the open-label extension of the phase 2 study, which included participants receiving high-dose and low-dose frexalimab regimens, as well as placebo-matched groups switching to frexalimab, plasma NfL levels were monitored over 48 weeks. Results showed significant reductions across all treatment groups by week 48, with the greatest reduction observed in the high-dose frexalimab group (41%). Participants who switched from placebo to frexalimab also experienced substantial decreases in NfL levels.
These findings build on earlier efficacy and safety data from the phase 2 study, published in The New England Journal of Medicine and presented at the American Academy of Neurology conference. Sanofi has initiated phase 3 trials investigating frexalimab’s potential in relapsing MS and non-relapsing secondary progressive MS.
Frexalimab, known as SAR441344, operates by blocking the CD40/CD40L pathway without depleting lymphocytes, thereby targeting both acute and chronic neuroinflammation. Beyond MS, frexalimab is being studied in systemic lupus erythematosus and Type 1 diabetes. Regulatory review of its safety and efficacy is ongoing.
For more information on frexalimab clinical studies and its development under Sanofi’s exclusive license from ImmuNext Inc.
