Sanofi’s Phase 3 Study on Frexalimab: A Potential Game-Changer for Multiple Sclerosis Treatment

Sanofi SA ((SNY)), Sanofi ((DE:SNW)), Sanofi ((SNYNF)) announced an update on their ongoing clinical study.

Sanofi is currently conducting a clinical study titled ‘Master Protocol of Two Independent, Randomized, Double-blind, Phase 3 Studies Comparing Efficacy and Safety of Frexalimab (SAR441344) to Teriflunomide in Adult Participants With Relapsing Forms of Multiple Sclerosis.’ The study aims to evaluate the annualized relapse rate of frexalimab compared to teriflunomide in adults aged 18 to 55 with relapsing forms of multiple sclerosis, highlighting its potential significance in advancing treatment options for this condition.

The study tests two interventions: Frexalimab, an experimental drug administered via infusion, and Teriflunomide, an active comparator given as an oral tablet. Both are designed to manage relapsing forms of multiple sclerosis, with frexalimab being the new investigational treatment.

This interventional study employs a randomized, parallel assignment model with quadruple masking, ensuring that participants, care providers, investigators, and outcomes assessors are blinded to the treatment allocations. The primary purpose is treatment, focusing on the efficacy and safety of the interventions.

The study began on December 13, 2023, with an estimated completion timeline of approximately 40 months for the first participant and 20 months for the last. The last update was submitted on August 12, 2025, indicating ongoing recruitment and progress.

The outcome of this study could significantly influence Sanofi’s stock performance and investor sentiment, particularly if frexalimab demonstrates superior efficacy and safety over existing treatments like teriflunomide. This development is crucial as it positions Sanofi competitively within the multiple sclerosis treatment market.

The study is currently ongoing, with further details available on the ClinicalTrials portal.