FDA Grants Sanofi’s GD3 Drug Priority Review

Rare Daily Staff

The U.S. Food and Drug Administration has granted priority review to Sanofi’s experimental therapy venglustat for the treatment of type 3 Gaucher disease, a rare and progressive lysosomal storage disorder with no approved therapies targeting neurological symptoms.

The agency set a target action date of Nov. 25, 2026, to act on the application.

If approved, venglustat would become the first therapy in the United States designed to address the neurological manifestations of Gaucher disease type 3 (GD3).

GD3 is caused by the accumulation of glycosphingolipids in organs such as the liver, spleen, and bone marrow. In this form of the disease, these lipids also build up in the brain, driving neuroinflammation and disease progression. Despite advances in treating systemic symptoms, no therapies currently approved in the United States specifically target neurological involvement.

Patients with GD3 can experience cognitive impairment, ataxia, and other neurological complications in addition to systemic disease.

Venglustat is an oral glucosylceramide synthase inhibitor designed to cross the blood-brain barrier, addressing a key limitation of existing enzyme replacement therapies, which primarily treat systemic symptoms but not neurological involvement.

The priority review designation shortens the FDA’s review timeline to six months and is typically granted to therapies that may offer significant improvements in treating serious conditions. The decision builds on earlier regulatory support for venglustat, including Breakthrough Therapy, Fast Track, and Orphan Drug designations.

The application is supported by data from the Phase 3 LEAP2MONO study, which evaluated venglustat in adults and pediatric patients aged 12 and older with GD3 who had previously stabilized systemic symptoms on enzyme replacement therapy. In results presented earlier this year, the study met both primary endpoints, showing statistically significant improvements in neurological measures compared with standard of care.

Patients treated with venglustat demonstrated improvements in assessments of ataxia and cognitive function over 52 weeks. The therapy also met three of four key secondary endpoints. Safety findings were consistent with prior studies, with the most commonly reported adverse events including headache, nausea, spleen enlargement, and diarrhea.

The trial enrolled 43 patients in a randomized, double-blind design comparing once-daily oral venglustat with biweekly intravenous enzyme replacement therapy. The study remains ongoing, with additional data expected from its open-label extension.

Venglustat is also under regulatory review in the European Union, and Sanofi said it plans additional global filings in 2026. The drug has also received orphan designation for both GD3 and Fabry disease across multiple regions.