- In the LEAP2MONO phase 3 study, venglustat, dosed orally once daily, demonstrated clinically meaningful efficacy in patients with type 3 Gaucher disease (GD3), a rare lysosomal storage disorder
- Venglustat demonstrated superiority versus enzyme replacement therapy in addressing neurological symptoms in GD3, for which there are no approved treatments
- Sanofi will pursue global regulatory submissions for GD3
- In the PERIDOT phase 3 study in Fabry disease, venglustat did not show superiority on the patient-reported primary endpoint and an additional phase 3 CARAT study is ongoing
Paris, February 2, 2026. Positive results from the LEAP2MONO phase 3 study (clinical study identifier: NCT05222906) demonstrated that venglustat met the primary and three out of four key secondary endpoints in adults and pediatric patients (12 years and older) with neurological manifestations of type 3 Gaucher disease (GD3), a rare lysosomal storage disorder.
Venglustat, which works by reducing the abnormal accumulation of sugar-and-fat molecules in cells and organs, is an investigational glucosylceramide synthase inhibitor (GCSi) that crosses the blood-brain barrier with the goal of targeting some of the neurological aspects of GD3 that currently have no approved therapies. Sanofi has supported the Gaucher disease community for decades as part of an over 40-year commitment to improving care for rare diseases.
The results will be shared this week at the 22nd annual WORLDSymposium™ as late-breaking research.
"These findings underscore Sanofi's commitment to rare disease research and the promise we aim to deliver for people living with these conditions," said Houman Ashrafian, Executive Vice President and Head of Research and Development at Sanofi. "What excites us most is the potential to address critical unmet medical needs. A daily pill could make a serious difference for Gaucher patients facing neurological challenges. Most importantly, none of this would be possible without the courage of the patients and families who participate in our studies, and for that we owe them a debt of gratitude.”
In the LEAP2MONO study, GD3 patients receiving venglustat demonstrated statistically significant improvements in neurological symptoms measured by a global test score for two assessments, the Scale for Assessment and Rating of Ataxia (SARA) modified total score and the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS), at week 52 compared with those receiving enzyme replacement therapy (ERT) (p=0.007). Venglustat performed as well as ERT on non-neurological outcomes, including changes in spleen volume, liver volume, and hemoglobin levels, three key secondary endpoints of the study.
Venglustat is also being studied for the treatment of Fabry disease, another rare lysosomal storage disorder. Data from the phase 3 PERIDOT study (clinical study identifier: NCT05206773) show that reduction in neuropathic and abdominal pain was observed in both study arms and the primary endpoint was not met. Additional analyses of the data are ongoing with more information to be shared at a future medical meeting. A second phase 3 study, CARAT (clinical study identifier: NCT05280548), evaluating the effect of venglustat on left cardiac ventricular mass index in men and women with Fabry disease, is ongoing.
Venglustat was well tolerated overall with no new safety signals compared with previous studies. In LEAP2MONO, the most commonly reported adverse events during treatment among patients receiving venglustat (21 individuals) compared with those receiving ERT (22 individuals) 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).
Sanofi will pursue global regulatory filings for venglustat in GD3. Venglustat is investigational, and its safety and efficacy have not been evaluated by any regulatory authority.
Sanofi currently markets Fabrazyme, an ERT for Fabry disease, and Cerezyme and Cerdelga for Gaucher disease, an ERT and oral therapy, respectively, in markets around the world. In January 2026, the US approved an expanded label for Cerezyme to include non-central nervous system (CNS) manifestations of GD3, building on its long-standing approval in the US for GD1. This US supplemental label expansion was based exclusively on real-world evidence and leveraged data from the International Collaborative Gaucher Group Gaucher Registry. With the US label expansion, Cerezyme can now be prescribed globally to patients with either GD1 or GD3.
U.S. Indication
Cerezyme® (imiglucerase) for injection is indicated for the treatment of non-central nervous system (CNS) manifestations of Type 1 or Type 3 Gaucher disease in adult and pediatric patients.
Important Safety Information
WARNING: SEVERE ALLERGIC REACTIONS
Allergic reactions, including severe reactions that may be serious or life-threatening (known as anaphylaxis), have occurred during the early course and after repeated treatment with CEREZYME.
Your healthcare professional should initiate CEREZYME in a healthcare setting with appropriate medical monitoring and support measures. If a severe allergic or anaphylactic reaction occurs, your healthcare professional will immediately stop the infusion and provide appropriate medical treatment.
Seek immediate medical care should symptoms occur.
Cerezyme can cause serious side effects including:
Allergic Reactions (Including Anaphylaxis) and Infusion-Associated Reactions (IARs): Signs of an allergic reaction reported during or shortly after an infusion included itching, flushing, hives, swelling under the skin, chest discomfort, shortness of breath, coughing, a bluish discoloration of the skin due to diminished oxygen, rapid heart rate, and low blood pressure.
Signs of an infusion reaction included rash, chills, fatigue, infusion-site burning, infusion-site discomfort, or infusion-site swelling, fever, and high blood pressure. Tell your healthcare professional right away if you experience any reactions. Your healthcare professional may slow or stop the infusion or may lower the next dose. Your healthcare professional may decide to give you antihistamine, anti-fever, and/or steroid medications before your infusions and monitor you for new signs and symptoms of a reaction.
Common Side Effects:
- Common side effects reported in adults and children include back pain, chills, dizziness, fatigue, headache, allergic reactions, nausea, fever, and vomiting.
Please see accompanying full Prescribing Information, including Boxed WARNING.
U.S. Indication
CERDELGA is a prescription medicine used for the long-term treatment of Gaucher disease type 1 (GD1) in adults who are CYP2D6 extensive metabolizers (EMs), intermediate metabolizers (IMs), or poor metabolizers (PMs) as detected by an FDA-cleared test. Your doctor will perform a test to make sure that CERDELGA is right for you.
Limitations of Use:
- CYP2D6 ultra-rapid metabolizers may not achieve adequate concentrations of CERDELGA to achieve a therapeutic effect.
- A specific dose cannot be recommended for CYP2D6 indeterminate metabolizers.
Important Safety Information
Certain patients should not use CERDELGA based on their CYP2D6 metabolizer status due to an increased risk of side effects, including heart problems. Do not use CERDELGA if you are:
- An Extensive Metabolizer (EM) taking a medicine that is a strong or moderate CYP2D6 inhibitor along with another medicine that is a strong or moderate CYP3A inhibitor, an EM with moderate or severe liver problems, or an EM with mild liver problems and taking a medicine that is a strong or moderate CYP2D6 inhibitor.
- An Intermediate Metabolizer (IM) taking a medicine that is a strong or moderate CYP2D6 inhibitor along with another medicine that is a strong or moderate CYP3A inhibitor, an IM taking a medicine that is a strong CYP3A inhibitor, or an IM with any degree of liver problems.
- A Poor Metabolizer (PM) taking a medicine that is a strong CYP3A inhibitor, or a PM with any degree of liver problems.
Your doctor will perform a test to help determine if CERDELGA is right for you.
CERDELGA can affect the way other medicines work and other medicines can affect how CERDELGA works. Using CERDELGA with other medicines or herbal supplements may cause an increased risk of side effects, including changes in electrical activity of your heart (ECG changes) and irregular heart beat (arrhythmias). Especially tell your doctor if you take St. John’s Wort, or medicines for fungal infections, tuberculosis, seizures, heart conditions, high blood pressure, or depression or other mental health problems. Your doctor may need to prescribe a different medicine, change your dose of other medicines, or change your dose of CERDELGA. Tell your doctor about all of the medicines you take, including prescription and over-the-counter medicines, vitamins, and herbal supplements before you start taking them.
Before taking CERDELGA, tell your doctor about all of your medical conditions, including heart problems (including a condition called long QT syndrome), a history of heart attack, kidney or liver problems. If you are pregnant or plan to become pregnant or breastfeed, talk to your doctor. It is not known if CERDELGA will harm your unborn baby. Talk to your doctor if you are breastfeeding or planning to breastfeed. It is not known if CERDELGA passes into your breast milk. You and your doctor will decide if you should take CERDELGA or breastfeed. You should not do both.
CERDELGA, used with certain other medicines, may cause changes in the electrical activity of your heart (ECG changes) and irregular heart beat (arrhythmias). Tell your doctor if you have new symptoms such as palpitations, fainting, or dizziness.
The most common side effects (≥10%) of CERDELGA include: tiredness, headache, nausea, diarrhea, back pain, pain in extremities, and upper abdominal pain. Call your doctor for medical advice about adverse effects.
Tell your doctor if you have any side effect that bothers you or that does not go away. These are not all the possible side effects of CERDELGA. Call your doctor for medical advice about side effects.
It is not known if CERDELGA is safe and effective in children.
Please see the full Prescribing Information, including the Patient Medication Guide, for CERDELGA.
U.S. Indication
Fabrazyme® is used to treat adults and children 2 years of age and older with confirmed Fabry disease.
Important Safety Information
WARNING: SEVERE ALLERGIC REACTIONS
Patients treated with enzyme replacement therapies have experienced allergic reactions, including severe or life-threatening reactions (known as anaphylaxis). Anaphylaxis has occurred during the early course and after repeated treatment with enzyme replacement therapy.
Your healthcare professional should initiate Fabrazyme in a healthcare setting with appropriate medical monitoring and support measures. If a severe allergic or anaphylactic reaction occurs, your healthcare professional will immediately stop the infusion and provide appropriate medical treatment. Seek immediate medical care should symptoms occur.
Fabrazyme can cause serious side effects, including:
Severe Allergic Reactions Including Anaphylaxis
Approximately 1% of patients who received Fabrazyme experienced a severe allergic or anaphylactic reaction during their infusion. Some of these reactions were life-threatening, and included:
- Swelling of the face, mouth and throat, narrowing of breathing airways, low blood pressure, hives, difficulty swallowing, rash, trouble breathing, flushing, chest discomfort, itching and nasal congestion.
- Tell your healthcare professional if you experience any of these symptoms.
- Your healthcare professional may give you medicines before you receive Fabrazyme to help manage these reactions.
In clinical studies, some patients developed IgE antibodies or a reaction to an allergy skin test specific to Fabrazyme. IgE antibodies can sometimes be produced by the body’s immune system during an allergic reaction. Your healthcare professional may test you for IgE antibodies if you experience a suspected allergic reaction to help assess the risks and benefits of continuing treatment.
Infusion-Associated Reactions
In clinical studies, 59% of patients experienced infusion-associated reactions (IARs) during Fabrazyme administration, some of which were severe. IARs are defined as those occurring on the same day as your infusion. IARs occurred more frequently in patients who were positive for anti-Fabrazyme antibodies than those who did not have anti-Fabrazyme antibodies.
- You may receive medicines to help prevent IARs. IARs have happened in some patients even after taking these medications before their infusions.
- If an IAR occurs, tell your healthcare professional, who may slow the infusion rate, stop the infusion, and/or provide appropriate medical treatment as needed.
- People with advanced Fabry disease may have heart problems, which could put them at a higher risk for severe complications from IARs. Tell the healthcare professional for your infusions if you have known heart problems.
Common Side Effects
Side effects reported in 20% or more of Fabrazyme treated patients in clinical studies compared to placebo were upper respiratory tract infection, chills, fever, headache, cough, burning and/or tingling sensation, fatigue, swelling in the legs, dizziness, and rash.
Please see full Prescribing Information, including Boxed WARNING
About Gaucher disease
Gaucher disease (GD) is a rare inherited lysosomal storage disease that results from a deficiency of an enzyme called glucocerebrosidase (also known as acid β-glucosidase), leading to the accumulation of molecules called glycosphingolipids (GSLs), particularly in macrophages of the spleen, liver, bone marrow, and lungs. There are three major forms within the clinical spectrum of Gaucher disease: GD1, which is characterized by the lack of (or late) central nervous system (CNS) involvement; GD2, which is the acute neuronopathic form; and GD3, which is the chronic neuronopathic form. In people with GD3, accumulation of GSLs in the CNS can result in neurological manifestations, including ataxia and cognitive deficits, in addition to the systemic manifestations seen in GD1, such as liver and spleen enlargement, anemia, thrombocytopenia, or bone disease. Systemic manifestations of GD3 are treated with ERT, but there are no approved treatments for neurologic manifestations of GD3.
About Fabry disease
Fabry disease is an inherited rare lysosomal storage disease that results from a deficiency of functional alpha-galactosidase A (α-Gal A), leading to a build-up of GSLs, causing progressive cellular accumulation and organ damage in the kidney, cardiovascular and cerebrovascular systems. Neuropathic pain, abdominal pain and other gastrointestinal symptoms are among the first clinical manifestations of Fabry disease and can substantially impact activities of daily living. Clinically, there are two major subtypes: the more severe classic phenotype that presents in childhood with little or no functional α-Gal A enzymatic activity and the non-classic phenotype that presents later in life, typically in adulthood. Non-classic patients have residual α-Gal A activity but progressively accumulate GSLs.
About venglustat
Venglustat is a novel, investigational oral glucosylceramide synthase inhibitor (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 physio-pathologic 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 USA and Japan for its potential treatment of both GD3 and Fabry disease. It also received fast-track designation in the US Food & Drug Administration (FDA) for its potential use in GD3 and Fabry disease.
About the LEAP2MONO study
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 was change in SARA modified total score and change in 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.
About the PERIDOT study
The PERIDOT phase 3 study was a double-blind, randomized, placebo-controlled study that evaluated the efficacy and safety of venglustat on neuropathic and abdominal pain in patients aged 16 years and older with Fabry disease. The study randomized 122 patients 1:1 to receive venglustat or placebo. Patients must have been treatment-naïve or untreated for at least six months. The primary endpoint was the percent change from baseline on patient-defined most bothersome symptoms (neuropathic pain in upper extremities, neuropathic pain in lower extremities or abdominal pain), as assessed by the FD-PRO instrument, in those treated with venglustat versus placebo. Secondary endpoints include percent change from baseline in plasma globotriaosylsphingosine (lyso-GL-3), frequency of rescue pain medication use, change from baseline in the percentage of days with diarrhea, percent change from baseline in tiredness component of FD-PRO, and proportion of responders on the patient-defined most bothersome symptoms.
About Sanofi
Sanofi is an R&D driven, AI-powered biopharma company committed to improving people’s lives and delivering compelling growth. We apply our deep understanding of the immune system to invent medicines and vaccines that treat and protect millions of people around the world, with an innovative pipeline that could benefit millions more. Our team is 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
Media Relations
Sandrine Guendoul | +33 6 25 09 14 25 | sandrine.guendoul@sanofi.com
Evan Berland | +1 215 432 0234 | evan.berland@sanofi.com
Léo Le Bourhis | +33 6 75 06 43 81 | leo.lebourhis@sanofi.com
Victor Rouault | +33 6 70 93 71 40 | victor.rouault@sanofi.com
Timothy Gilbert | +1 516 521 2929 | timothy.gilbert@sanofi.com
Léa Ubaldi | +33 6 30 19 66 46 | lea.ubaldi@sanofi.com
Ekaterina Pesheva | + 1 410 926 6780 | ekaterina.pesheva@sanofi.com
Investor Relations
Thomas Kudsk Larsen | + 44 7545 513 693 | thomas.larsen@sanofi.com
Alizé Kaisserian | + 33 6 47 04 12 11 | alize.kaisserian@sanofi.com
Keita Browne | + 1 781 249 1766 | keita.browne@sanofi.com
Nathalie Pham | + 33 7 85 93 30 17 | nathalie.pham@sanofi.com
Thibaud Châtelet | + 33 6 80 80 89 90 | thibaud.chatelet@sanofi.com
Nina Goworek | nina.goworek@sanofi.com
Yun Li | +33 6 84 00 90 72 | yun.li3@sanofi.com
Sanofi forward-looking statements
This press release contains forward-looking statements as defined in the Private Securities Litigation Reform Act of 1995, as amended. Forward-looking statements are statements that are not historical facts. These statements include projections and estimates and their underlying assumptions, statements regarding plans, objectives, intentions, and expectations with respect to future financial results, events, operations, services, product development and potential, and statements regarding future performance. Forward-looking statements are generally identified by the words “expects”, “anticipates”, “believes”, “intends”, “estimates”, “plans” and similar expressions. Although Sanofi’s management believes that the expectations reflected in such forward-looking statements are reasonable, investors are cautioned that forward-looking information and statements are subject to various risks and uncertainties, many of which are difficult to predict and generally beyond the control of Sanofi, that could cause actual results and developments to differ materially from those expressed in, or implied or projected by, the forward-looking information and statements. These risks and uncertainties include among other things, the uncertainties inherent in research and development, future clinical data and analysis, including post marketing, decisions by regulatory authorities, such as the FDA or the EMA, regarding whether and when to approve any drug, device or biological application that may be filed for any such product candidates as well as their decisions regarding labelling and other matters that could affect the availability or commercial potential of such product candidates, the fact that product candidates if approved may not be commercially successful, the future approval and commercial success of therapeutic alternatives, Sanofi’s ability to benefit from external growth opportunities, to complete related transactions and/or obtain regulatory clearances, risks associated with intellectual property and any related pending or future litigation and the ultimate outcome of such litigation, trends in exchange rates and prevailing interest rates, volatile economic and market conditions, cost containment initiatives and subsequent changes thereto, and the impact that global crises may have on us, our customers, suppliers, vendors, and other business partners, and the financial condition of any one of them, as well as on our employees and on the global economy as a whole. The risks and uncertainties also include the uncertainties discussed or identified in the public filings with the SEC and the AMF made by Sanofi, including those listed under “Risk Factors” and “Cautionary Statement Regarding Forward-Looking Statements” in Sanofi’s annual report on Form 20-F for the year ended December 31, 2025. Other than as required by applicable law, Sanofi does not undertake any obligation to update or revise any forward-looking information or statements.
All trademarks mentioned in this press release are the property of the Sanofi group.