Sanofi's frexalimab promising in relapsing MS study

Sanofi's investigational monoclonal antibody, frexalimab, has demonstrated promising results in a mid-stage clinical study aimed at treating multiple sclerosis (MS). MS is a chronic neurological disease affecting around 2.9 million people globally. It is characterized by the immune system attacking the myelin sheath, which protects nerve cells, leading to disrupted communication between the brain and the rest of the body. Relapsing forms of MS, where patients experience episodes of worsened neurological function followed by periods of recovery, account for approximately 85% of initial diagnoses.

Sanofi has highlighted that frexalimab has the potential to tackle both acute and chronic neuroinflammation in MS without leading to lymphocyte depletion, which is often a concern with other treatments.

In the phase 2 trial, 129 patients were randomized to receive either a high dose or low dose of frexalimab or a placebo over a 12-week period. Following this initial phase, 97% of participants entered an open-label extension, and 87% remained in the study by the 48-week mark.

The study results indicated a significant reduction in plasma levels of neurofilament light chain (NfL), a biomarker associated with nerve cell damage in MS, after one year of treatment. Patients on the high-dose regimen of frexalimab saw a 41% reduction in plasma NfL levels from baseline at week 48. Those on the low-dose regimen experienced a 35% reduction in the same time frame.

Participants who initially received a placebo but switched to the high-dose frexalimab at week 12 showed a 24% reduction in plasma NfL levels from baseline to week 48 and a 39% decrease from week 12 to week 48. Similarly, those who transitioned from the placebo to the low-dose frexalimab experienced a 33% reduction from baseline to week 48 and a 39% reduction from week 12 to week 48.

Erik Wallström, Sanofi’s global head of neurology development, emphasized the importance of these findings. He stated that individuals with MS require new, highly effective treatment options that can address disability progression, which remains an unmet medical need. Wallström added that the results from this phase 2 study, along with previously reported efficacy and safety data, suggest that frexalimab’s unique mechanism of action could offer significant improvements for those living with MS.

In anticipation of further validation of these results, Sanofi has already commenced phase 3 clinical trials of frexalimab for both relapsing MS and non-relapsing secondary progressive MS. This progression to advanced trials underlines the company's commitment to developing new therapies aimed at improving the quality of life for individuals suffering from this debilitating condition.