Sanofi’s LEAP2MONO phase III trial of venglustat in type 3 Gaucher disease (GD3) enrolled 43 patients aged 12 and older, randomizing them to once-daily oral venglustat plus placebo infusion or biweekly enzyme replacement therapy (ERT) plus placebo tablet. The study met its primary endpoint of improving neurological function as assessed by oculomotor reflex velocity, and achieved three of four key secondary endpoints related to non-neurological measures: reduction in spleen volume, decrease in liver volume and stabilization of hemoglobin levels. Venglustat crossed the blood-brain barrier, addressing the unmet need for central nervous system manifestations of GD3, and was well tolerated with no new safety signals versus prior studies.

Following the positive LEAP2MONO readout, Sanofi plans to file global regulatory applications for venglustat in GD3. The company also reported phase III PERIDOT results in Fabry disease, where both the venglustat and control arms saw reductions in neuropathic and abdominal pain but failed to meet the primary endpoint. A second Fabry study, CARAT, is ongoing to evaluate left ventricular mass index. Sanofi markets ERTs Fabrazyme, Cerezyme and the oral Cerdelga for related lysosomal disorders, and in January 2026 the FDA granted an expanded label for Cerezyme to include non-CNS manifestations of GD3.

The Prescription Medicines Code of Practice Authority (PMCPA) in the United Kingdom ruled that Sanofi breached the UK Pharma Code by making unsubstantiated claims that its Beyfortus RSV prophylactic therapy outperformed Pfizer’s RSV vaccine. The ruling followed a competitor complaint and found that promotional materials lacked sufficient clinical data to support comparative efficacy statements. Sanofi must amend its promotional communications and undergo a compliance audit by the PMCPA within six months.