Sanofi has received a significant regulatory boost after the U.S. Food and Drug Administration (FDA) granted priority review to the new drug application (NDA) for venglustat, an investigational oral therapy for type 3 Gaucher disease (GD3), a rare and progressive lysosomal storage disorder. If approved, the therapy could become the first treatment available in the United States to specifically address the neurological complications associated with the disease, an area of major unmet medical need.
The FDA has assigned a target action date of November 25, 2026, for its review of the application. Priority review status is reserved for therapies that may offer significant improvements in the treatment, prevention or diagnosis of serious diseases, potentially accelerating the agency’s assessment timeline.
Gaucher disease is a rare inherited condition caused by an inability to properly break down fatty substances known as glycosphingolipids (GSLs), resulting in their accumulation in organs such as the liver, spleen, lungs and bone marrow. Type 3 Gaucher disease, a rarer and more severe form, also affects the central nervous system, leading to progressive neurological symptoms that can include impaired coordination and balance, cognitive deficits and neuroinflammation.
Currently available therapies, including enzyme replacement treatments, mainly target the systemic manifestations of Gaucher disease but have limited ability to address neurological complications because they cannot effectively cross the blood-brain barrier. Venglustat, an oral glucosylceramide synthase inhibitor, has been designed to penetrate the central nervous system, potentially allowing it to slow or treat neurological progression in patients with GD3.
The NDA submission is supported by positive findings from the Phase 3 LEAP2MONO clinical study, which evaluated the safety and efficacy of venglustat in both adult and pediatric patients whose systemic symptoms had previously stabilized with enzyme replacement therapy. According to results presented earlier this year at the WORLDSymposium, the drug met both of the study’s primary endpoints and achieved three of four key secondary endpoints, suggesting meaningful therapeutic benefit in neurological disease progression.
Sanofi reported that venglustat was generally well tolerated during the study and no new safety concerns emerged compared with prior clinical trials. Commonly reported adverse events included headache, nausea, spleen enlargement and diarrhea, with rates varying between treatment groups.
The investigational therapy has already received breakthrough therapy, fast-track and orphan drug designations from the FDA for GD3, highlighting the urgency of developing treatment options for the rare disorder. Venglustat is also under regulatory review in Europe, and Sanofi plans to pursue additional global filings during 2026.
If approved, venglustat could represent a major milestone for patients living with type 3 Gaucher disease, offering a targeted treatment option for neurological symptoms that currently remain largely unaddressed.