Sanofi's venglustat accepted for priority review in the US to treat type 3 Gaucher disease Paris

Sanofi's venglustat accepted for priority review in the US to treat type 3 Gaucher

Paris, May 28, 2026. The US Food and Drug Administration (FDA) has granted priority review to the

new drug application (NDA) for venglustat, a novel, investigational oral glucosylceramide synthase inhibitor (GCSi), for the treatment of type 3 Gaucher disease (GD3), a rare lysosomal storage disorder.

If approved, venglustat would become the first treatment available in the US to address the progressive neurological manifestations associated with

GD3 and expand Sanofi's portfolio of treatment options for patients living with lysosomal storage diseases. The target action date for the FDA decision is November 25, 2026.

Gaucher disease is marked by the abnormal buildup of sugar-and-fat

molecules called glycosphingolipids (GSL) in the spleen, liver, bone marrow, and lungs. In patients with GD3, these molecules also accumulate in the central nervous system (CNS) where they drive neuroinflammation, which can result in neurological

manifestations, including cognitive deficits and difficulty in coordination and balance (ataxia), in addition to the disease's systemic effects. There are currently no approved targeted treatments that specifically address the neurological

symptoms of GD3. By crossing the blood brain barrier, venglustat has the potential to treat neurological manifestations of GD3.

supported by positive data from the LEAP2MONO phase 3 study (clinical study identifier: NCT05222906), evaluating the efficacy and

safety of venglustat in adults and pediatric patients, with neurological manifestations of GD3, who previously achieved stabilization of systemic manifestations with enzyme replacement therapy (ERT). In results shared at the WORLDSymposiumTM earlier this year, venglustat met both of the

study's primary endpoints and three out of four key secondary endpoints. In the study, venglustat was well tolerated overall with no new safety signals compared with previous studies. The most commonly reported adverse events were headache

(14.3% in the venglustat arm versus 18.2% in the ERT arm), nausea (14.3% versus 4.5%), spleen enlargement (14.3% versus 0), and diarrhea (14.3% versus 0).

Venglustat previously earned breakthrough therapy designation and fast-track designation from the FDA for its potential in GD3, as well as orphan

designation for GD3 in the US, EU, and Japan. Venglustat is also currently under regulatory review for GD3 in the EU. Sanofi will pursue additional global regulatory filings for venglustat in GD3 in 2026.

The safety and efficacy of venglustat for GD3 have not been evaluated by any regulatory authority.

Priority review is given to regulatory applications seeking approval for therapies that have the potential to provide significant improvements in the

treatment, diagnosis, or prevention of serious conditions.

The LEAP2MONO phase 3 study was a double-blind, double-dummy, active-comparator, two-arm study that evaluated the efficacy and

safety of once daily oral venglustat versus intravenous ERT every two weeks in adults and pediatric patients aged 12 and older with GD3. Forty-three patients were randomized [1:1] to receive venglustat and placebo infusion or ERT and placebo tablet.

Patients must have been treated with ERT for at least three years and achieved therapeutic goals for systemic disease manifestations. The primary endpoints for the study were change in scale for assessment and rating of ataxia (SARA) modified total

score and change in repeatable battery for the assessment of neuropsychological status (RBANS) total scale index score for patients receiving venglustat versus those receiving ERT from baseline to week 52. Systemic key secondary endpoints include

percent change in spleen volume, liver volume and platelet count and change in hemoglobin levels. Biomarker key secondary endpoints include percent change in cerebrospinal fluid and plasma GL1 and lyso-GL1.

The LEAP2MONO study is ongoing and results from its open-label phase will be presented in the future when available.

Venglustat is a novel, investigational oral GCSi, designed to cross the blood brain barrier (i.e., brain-penetrant), that has the potential to slow the

progression of certain diseases by inhibiting abnormal GSL accumulation and its pathophysiology consequences. GSLs are cellular building blocks whose abnormal accumulation is implicated in several rare diseases leading to both cell dysfunction and

disease progression. Venglustat was previously granted orphan designation in the EU, the US, and Japan for its potential treatment of both GD3 and Fabry disease. It also received fast-track designation by the FDA for its potential use in GD3 and

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guided by one purpose: we chase the miracles of science to improve people's lives; this inspires us to drive progress and deliver positive impact for our people and the communities we serve, by addressing the most urgent healthcare,

environmental, and societal challenges of our time. Sanofi is listed on EURONEXT: SAN and NASDAQ: SNY

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