Dupixent® (dupilumab) Approved in Japan for Children Aged 6 to 11 Years with Bronchial Asthma

Rhea-AI Summary

Regeneron (NASDAQ: REGN) and Sanofi announced that Japan's Ministry of Health, Labour and Welfare approved Dupixent (dupilumab) for children aged 6 to 11 years with severe or refractory bronchial asthma inadequately controlled by existing therapy, expanding prior approval for ages 12 and up.

Approval was supported by the global Phase 3 VOYAGE program and the EXCURSION extension, where Dupixent added to standard care reduced severe exacerbations 54%–65% and improved lung function 4.68%–5.32% versus placebo; a Japanese pediatric sub-study showed improved lung function at 12 weeks and low annual exacerbation rates.

Positive

• Japan MHLW approval for ages 6–11 with severe/refractory asthma
• Severe exacerbations reduced by 54%–65% in Phase 3 VOYAGE
• Lung function improved by 4.68%–5.32% versus placebo
• First biologic to show lung function benefit in randomized Phase 3 pediatric trial
• Dupixent now approved for this pediatric asthma indication in 50 countries

Negative

• Treatment-related adverse events: injection site reactions, fever, oral herpes, eosinophilia
• Approval limited to severe or refractory children inadequately controlled by current therapy

News Market Reaction – REGN

+0.75%

1 alert

+0.75% News Effect

On the day this news was published, REGN gained 0.75%, reflecting a mild positive market reaction.

Data tracked by StockTitan Argus on the day of publication.

Key Figures

Exacerbation reduction: 54% to 65% Lung function improvement: 4.68% to 5.32% P-value exacerbations: p<0.0001 +3 more

6 metrics

Exacerbation reduction 54% to 65% Severe asthma exacerbations vs placebo in VOYAGE Phase 3

Lung function improvement 4.68% to 5.32% Lung function gain vs placebo in VOYAGE Phase 3

P-value exacerbations p<0.0001 Statistical significance for reduced severe exacerbations in VOYAGE

P-values lung function p=0.0012, 0.0009, 0.0036 Statistical significance for lung function endpoints in VOYAGE

Pediatric age range 6 to 11 years Children with bronchial asthma in Japan approval

Global pediatric asthma approvals 50 countries Dupixent approved for asthma in children 6–11 years

Market Reality Check

Price: $764.93 Vol: Volume 811,169 is below t...

normal vol

$764.93 Last Close

Volume Volume 811,169 is below the 20-day average of 1,033,157, indicating no outsized pre-news positioning. normal

Technical Price 779.36 is trading above the 200-day MA of 601.27 and sits 1.47% below the 52-week high of 790.98.

Peers on Argus

REGN gained 1.48% while close peers showed mixed moves: VRTX up 1.31%, ALNY, ARG...

REGN gained 1.48% while close peers showed mixed moves: VRTX up 1.31%, ALNY, ARGX, ONC and INSM down modestly. This points to a more stock-specific setup rather than a broad biotech move.

Historical Context

5 past events · Latest: Dec 07 (Positive)

Pattern 5 events

Date	Event	Sentiment	Move	Catalyst
Dec 07	Clinical data update	Positive	-2.1%	Phase 1/2 Lynozyfic data in NDMM showed fast, deep responses without DLTs.
Dec 01	Collaboration deal	Positive	-3.9%	Global TSRA-196 gene-editing partnership for AATD with shared costs and profits.
Nov 25	Regulatory approval EU	Positive	+3.4%	EU approval of Dupixent for CSU based on LIBERTY-CUPID Phase 3 program.
Nov 19	Regulatory approval US	Positive	-3.1%	FDA approval of EYLEA HD 8 mg for RVO and monthly dosing across indications.
Nov 19	Regulatory approval EU	Positive	-3.1%	EU approval of Libtayo as first adjuvant immunotherapy for high‑risk CSCC.

Pattern Detected

Recent positive regulatory and clinical news has often seen mixed-to-negative next-day price reactions, with only one of five events aligning positively.

Recent Company History

Over the past two months, Regeneron has reported several major catalysts, including EU approval for Dupixent in CSU on Nov 25, FDA approval for EYLEA HD RVO and monthly dosing on Nov 19, and EU approval for Libtayo in high‑risk CSCC also on Nov 19. It also announced a gene‑editing collaboration for TSRA‑196 in AATD and encouraging early‑stage Lynozyfic data in NDMM. Despite generally positive fundamentals, four of these five events saw negative next‑day moves, suggesting a tendency for muted or contrarian trading around good news.

Market Pulse Summary

This announcement extends Dupixent’s reach in Japan to children aged 6–11 with severe or refractory ...

Analysis

This announcement extends Dupixent’s reach in Japan to children aged 6–11 with severe or refractory bronchial asthma, backed by the VOYAGE Phase 3 program showing 54–65% reductions in severe exacerbations and 4.68–5.32% lung function gains vs placebo. It follows a string of recent Regeneron approvals across Dupixent, EYLEA HD and Libtayo. Investors may focus on how pediatric uptake, safety in real‑world use and broader Dupixent franchise growth evolve from here.

Key Terms

phase 3 trial, type 2 inflammation, eosinophils, fractional exhaled nitric oxide, +4 more

8 terms

phase 3 trial medical

"a randomized Phase 3 trial, and inhibits IL-4 and IL-13"

A Phase 3 trial is a large, late-stage test of a new drug or medical treatment done on many people to make sure it really works and is safe. For investors, it matters because a successful Phase 3 usually means the company can ask regulators to sell the product and could earn lots of money, while failure can sharply reduce the company’s value.

type 2 inflammation medical

"two key and central drivers of type 2 inflammation TARRYTOWN"

An immune response driven by a specific set of cells and signaling molecules that causes allergic-type inflammation in tissues such as the lungs, skin and sinuses; think of it as the body’s alarm system stuck in the “allergy” mode. It matters to investors because drugs that reduce or block this pathway can treat common, chronic conditions (asthma, eczema, chronic sinusitis) and represent large, targeted markets with potential for premium-priced, specialty medicines.

eosinophils medical

"phenotype (defined by raised blood eosinophils and/or fractional"

Eosinophils are a type of white blood cell that help the body fight parasites and control allergic and inflammatory reactions; think of them as specialized firefighters that respond to certain immune threats. Investors watch eosinophil counts because changes can signal how a drug affects the immune system, predict safety or efficacy in clinical trials, and influence regulatory decisions or market perception of therapies for asthma, allergies, and related conditions.

fractional exhaled nitric oxide medical

"defined by raised blood eosinophils and/or fractional exhaled nitric oxide)"

Fractional exhaled nitric oxide is a simple breath test that measures the small amount of nitric oxide a person exhales, which rises when the airways are inflamed. For investors, it acts like a smoke alarm for airway inflammation: it helps doctors decide who needs or is responding to asthma treatments and influences demand, reimbursement and market size for related drugs, devices and diagnostic services.

open-label extension medical

"EXCURSION, an open-label extension of VOYAGE that included"

An open-label extension is a continuation of a clinical trial where all participants and researchers know which treatment is being given, often after an initial blinded phase. It allows further study of a drug's long-term safety and effectiveness. For investors, it can indicate ongoing interest and confidence in a product's potential, influencing perceptions of its future value.

placebo medical

"those with raised blood eosinophils, compared to placebo. In the"

A placebo is an inactive pill, injection or procedure that looks and feels like the real treatment but contains no therapeutic ingredient, often called a sugar pill. Investors care because comparing a drug to a placebo reveals whether observed benefits come from the medicine itself or from expectation; clear superiority over placebo reduces regulatory and commercial risk, much like a blind taste test proves a new recipe really tastes better.

systemic corticosteroids medical

"may require the use of multiple courses of systemic corticosteroids that"

Systemic corticosteroids are prescription medicines that mimic natural steroid hormones and are taken by mouth or given by injection to reduce inflammation and calm the immune system throughout the whole body. They matter to investors because they can drive large prescription sales and strongly influence clinical trial outcomes, safety warnings, regulatory approvals and insurance coverage; like a master switch that eases symptoms but can cause significant side effects that affect a drug’s market value.

biologic medicine medical

"Dupixent is the first and only biologic medicine to demonstrate improved"

Biologic medicine is a therapeutic product made from living cells or large biological molecules—like proteins, antibodies, or vaccines—rather than small chemically made drugs. It matters to investors because biologics are complex and expensive to develop and manufacture, often earning higher prices and longer market protection but also carrying greater regulatory, manufacturing and supply risks; think of them as custom-made machinery versus mass-produced gadgets.

AI-generated analysis. Not financial advice.

Approval based on global Phase 3 program in children demonstrating Dupixent significantly reduced exacerbations (by 54% to 65%) and improved lung function (by 4.68% to 5.32%) compared to placebo

Dupixent is the first and only biologic medicine to demonstrate improved lung function in this young patient group in a randomized Phase 3 trial, and inhibits IL-4 and IL-13, two key and central drivers of type 2 inflammation

TARRYTOWN, N.Y. and PARIS, Dec. 23, 2025 (GLOBE NEWSWIRE) -- Regeneron Pharmaceuticals, Inc. (NASDAQ: REGN) and Sanofi today announced that the Ministry of Health, Labour and Welfare (MHLW) in Japan has granted marketing and manufacturing authorization for Dupixent^® (dupilumab) for the treatment of bronchial asthma in children aged 6 to 11 years with severe or refractory disease whose symptoms are inadequately controlled with existing therapy. This expands the previous approval in Japan in this indication for patients aged 12 years and older.

The approval in Japan is based on data from the overall population and those with a type 2 inflammation phenotype (defined by raised blood eosinophils and/or fractional exhaled nitric oxide) in VOYAGE, a global Phase 3 trial evaluating Dupixent in children aged 6 to 11 years with uncontrolled moderate-to-severe asthma. Additionally, data from EXCURSION, an open-label extension of VOYAGE that included a sub-study of exclusively Japanese pediatric patients supported the approval. In the VOYAGE trial, Dupixent added to standard-of-care asthma therapy significantly reduced severe exacerbations (by 54% to 65%, p<0.0001) and improved lung function (by 4.68% to 5.32%, p=0.0012, p=0.0009 and p=0.0036, respectively) in the overall population, those with type 2 inflammation, and those with raised blood eosinophils, compared to placebo. In the sub-study of Japanese pediatric patients, Dupixent improved lung function from baseline at 12 weeks and resulted in a low rate of severe asthma exacerbations over one year. The treatment-related adverse events most commonly reported with Dupixent were injection site reactions (erythema, edema and induration) in VOYAGE and fever, oral herpes, eosinophilia and injection site reactions (erythema and induration) in EXCURSION.

Asthma is one of the most common chronic diseases in children. Despite treatment with current standard-of-care inhaled corticosteroids and bronchodilators, children may continue to experience serious symptoms, such as coughing, wheezing and difficulty breathing. Additionally, impaired lung function in young children can have potentially long-lasting impacts, such as reduced lung growth and persistent airway obstruction, if not addressed early. Patients also may require the use of multiple courses of systemic corticosteroids that carry significant risks. Uncontrolled asthma can interfere with day-to-day activities, like sleeping, attending school and playing sports.

In addition to asthma, Dupixent is approved in Japan in certain patients with atopic dermatitis, chronic rhinosinusitis with nasal polyposis (CRSwNP), prurigo nodularis, chronic spontaneous urticaria (CSU) and chronic obstructive pulmonary disease (COPD). Dupixent has been approved in 50 countries around the world for the treatment of asthma in children aged 6 to 11 years.

About Dupixent
Dupixent is available in Japan as a 200 mg or 300 mg pre-filled syringe or pre-filled pen and is now available for children aged 6 to 11 years with asthma. Dupixent is intended for injection under the skin (subcutaneous injection) and is given every two or four weeks based on weight. It can be given in a clinic or at home by self-administration after training by a healthcare professional. In children younger than 12 years of age, Dupixent should be administered by a caregiver if given at home.

Dupixent, which was invented using Regeneron’s proprietary VelocImmune^® technology, is a fully human monoclonal antibody that inhibits the signaling of the interleukin-4 (IL-4) and interleukin-13 (IL-13) pathways and is not an immunosuppressant. The Dupixent development program has shown significant clinical benefit and a decrease in type 2 inflammation in Phase 3 trials, establishing that IL-4 and IL-13 are two of the key and central drivers of the type 2 inflammation that plays a major role in multiple related and often co-morbid diseases.

Dupixent has received regulatory approvals in more than 60 countries in one or more indications including certain patients with atopic dermatitis, asthma, CRSwNP, eosinophilic esophagitis (EoE), prurigo nodularis, CSU, COPD and bullous pemphigoid (BP) in different age populations. More than 1,300,000 patients are being treated with Dupixent globally.¹

About Regeneron’s VelocImmune Technology 
Regeneron's VelocImmune technology utilizes a proprietary genetically engineered mouse platform endowed with a genetically humanized immune system to produce optimized fully human antibodies. When Regeneron's co-Founder, President and Chief Scientific Officer George D. Yancopoulos was a graduate student with his mentor Frederick W. Alt in 1985, they were the first to envision making such a genetically humanized mouse, and Regeneron has spent decades inventing and developing VelocImmune and related VelociSuite^® technologies. Dr. Yancopoulos and his team have used VelocImmune technology to create a substantial proportion of all original, FDA-approved fully human monoclonal antibodies. This includes Dupixent^® (dupilumab), Libtayo^® (cemiplimab-rwlc), Praluent^® (alirocumab), Kevzara^® (sarilumab), Evkeeza^® (evinacumab-dgnb), Inmazeb^® (atoltivimab, maftivimab and odesivimab-ebgn) and Veopoz^® (pozelimab-bbfg). In addition, REGEN-COV^® (casirivimab and imdevimab) had been authorized by the FDA during the COVID-19 pandemic until 2024.

Dupilumab Development Program 
Dupilumab is being jointly developed by Regeneron and Sanofi under a global collaboration agreement. To date, dupilumab has been studied across more than 60 clinical trials involving more than 10,000 patients with various chronic diseases driven in part by type 2 inflammation. 

In addition to the currently approved indications, Regeneron and Sanofi are studying dupilumab in a broad range of diseases driven by type 2 inflammation or other allergic processes in Phase 3 trials, including chronic pruritus of unknown origin, lichen simplex chronicus and allergic fungal rhinosinusitis. These potential uses of dupilumab are currently under clinical investigation, and the safety and efficacy in these conditions have not been fully evaluated by any regulatory authority. 

U.S. INDICATIONS 
DUPIXENT is a prescription medicine used:

• to treat adults and children 6 months of age and older with moderate-to-severe eczema (atopic dermatitis or AD) that is not well controlled with prescription therapies used on the skin (topical), or who cannot use topical therapies. DUPIXENT can be used with or without topical corticosteroids. It is not known if DUPIXENT is safe and effective in children with AD under 6 months of age.
• with other asthma medicines for the maintenance treatment of moderate-to-severe eosinophilic or oral steroid dependent asthma in adults and children 6 years of age and older whose asthma is not controlled with their current asthma medicines. DUPIXENT helps prevent severe asthma attacks (exacerbations) and can improve your breathing. DUPIXENT may also help reduce the amount of oral corticosteroids you need while preventing severe asthma attacks and improving your breathing. It is not known if DUPIXENT is safe and effective in children with asthma under 6 years of age.
• with other medicines for the maintenance treatment of chronic rhinosinusitis with nasal polyps (CRSwNP) in adults and children 12 years of age and older whose disease is not controlled. It is not known if DUPIXENT is safe and effective in children with CRSwNP under 12 years of age.
• to treat adults and children 1 year of age and older with eosinophilic esophagitis (EoE), who weigh at least 33 pounds (15 kg). It is not known if DUPIXENT is safe and effective in children with EoE under 1 year of age, or who weigh less than 33 pounds (15 kg).
• to treat adults with prurigo nodularis (PN). It is not known if DUPIXENT is safe and effective in children with PN under 18 years of age.
• with other medicines for the maintenance treatment of adults with inadequately controlled chronic obstructive pulmonary disease (COPD) and a high number of blood eosinophils (a type of white blood cell that may contribute to your COPD). DUPIXENT is used to reduce the number of flare-ups (the worsening of your COPD symptoms for several days) and can improve your breathing. It is not known if DUPIXENT is safe and effective in children with COPD under 18 years of age.
• to treat adults and children 12 years of age and older with chronic spontaneous urticaria (CSU) who continue to have hives that are not controlled with H1 antihistamine treatment. It is not known if DUPIXENT is safe and effective in children with CSU under 12 years of age, or who weigh less than 66 pounds (30 kg).
• to treat adults with bullous pemphigoid (BP). It is not known if DUPIXENT is safe and effective in children with BP under 18 years of age.
  
  

DUPIXENT is not used to relieve sudden breathing problems and will not replace an inhaled rescue medicine or to treat any other forms of hives (urticaria).

IMPORTANT SAFETY INFORMATION

Do not use if you are allergic to dupilumab or to any of the ingredients in DUPIXENT^®.

Before using DUPIXENT, tell your healthcare provider about all your medical conditions, including if you:

• have eye problems.
• have a parasitic (helminth) infection.
• are scheduled to receive any vaccinations. You should not receive a “live vaccine” right before and during treatment with DUPIXENT.
• are pregnant or plan to become pregnant. It is not known whether DUPIXENT will harm your unborn baby.
  • A pregnancy registry for women who take DUPIXENT during pregnancy collects information about the health of you and your baby. To enroll or get more information call 1-877-311-8972 or go to https://mothertobaby.org/ongoing-study/dupixent/.
• are breastfeeding or plan to breastfeed. It is not known whether DUPIXENT passes into your breast milk.
  
  

Tell your healthcare provider about all the medicines you take, including prescription and over-the-counter medicines, vitamins, and herbal supplements.

Especially tell your healthcare provider if you are taking oral, topical, or inhaled corticosteroid medicines; have asthma and use an asthma medicine; or have AD, CRSwNP, EoE, PN, COPD, CSU, or BP and also have asthma. Do not change or stop your other medicines, including corticosteroid medicine or other asthma medicine, without talking to your healthcare provider. This may cause other symptoms that were controlled by those medicines to come back.

DUPIXENT can cause serious side effects, including:

• Allergic reactions. DUPIXENT can cause allergic reactions, including skin reactions, that can sometimes be severe. Stop using DUPIXENT and tell your healthcare provider or get emergency help right away if you get any of the following signs or symptoms: breathing problems or wheezing, swelling of the face, lips, mouth, tongue or throat, fainting, dizziness, feeling lightheaded, fast pulse, fever, hives, skin rash, including rash that looks like a bullseye, painful red or blue bumps under the skin, or red pus-filled spots on the skin, general ill feeling, itching, swollen lymph nodes, nausea or vomiting, joint pain, or cramps in your stomach area.
• Eye problems. Tell your healthcare provider if you have any new or worsening eye problems, including eye pain or changes in vision, such as blurred vision. Your healthcare provider may send you to an ophthalmologist for an exam if needed.
• Inflammation of your blood vessels. Rarely, this can happen in people with asthma who receive DUPIXENT. This may happen in people who also take a steroid medicine by mouth that is being stopped or the dose is being lowered. Tell your healthcare provider right away if you get: rash, chest pain, worsening shortness of breath, brown or dark colored urine, persistent fever, or a feeling of pins and needles or numbness of your arms or legs.
• Psoriasis. This can happen in people with atopic dermatitis and asthma who receive DUPIXENT. Tell your healthcare provider about any new skin symptoms. Your healthcare provider may send you to a dermatologist for an examination if needed.
• Joint aches and pain. Some people who use DUPIXENT have had trouble walking or moving due to their joint symptoms, and in some cases needed to be hospitalized. Tell your healthcare provider about any new or worsening joint symptoms. Your healthcare provider may stop DUPIXENT if you develop joint symptoms.
  
  

The most common side effects include:

• Eczema: injection site reactions, eye problems, including eye and eyelid inflammation, redness, swelling, itching, eye infection, dry eye, and blurred vision, cold sores in your mouth or on your lips, and high count of a certain white blood cell (eosinophilia).
• Asthma: injection site reactions, high count of a certain white blood cell (eosinophilia), pain in the throat (oropharyngeal pain), and parasitic (helminth) infections.
• Chronic Rhinosinusitis with Nasal Polyps: injection site reactions, eye problems, including eye and eyelid inflammation, redness, swelling, itching, eye infection, and blurred vision, high count of a certain white blood cell (eosinophilia), stomach problems (gastritis), joint pain (arthralgia), trouble sleeping (insomnia), and toothache.
• Eosinophilic Esophagitis: injection site reactions, upper respiratory tract infections, cold sores in your mouth or on your lips, and joint pain (arthralgia).
• Prurigo Nodularis: eye problems, including eye and eyelid inflammation, redness, swelling, itching, and blurred vision, herpes virus infections, common cold symptoms (nasopharyngitis), dizziness, muscle pain, and diarrhea.
• Chronic Obstructive Pulmonary Disease: injection site reactions, common cold symptoms (nasopharyngitis), high count of a certain white blood cell (eosinophilia), viral infection, back pain, inflammation inside the nose (rhinitis), diarrhea, stomach problems (gastritis), joint pain (arthralgia), toothache, headache, and urinary tract infection.
• Chronic Spontaneous Urticaria: injection site reactions.
• Bullous Pemphigoid: joint pain (arthralgia), eye problems, including eye and eyelid inflammation, redness, swelling, itching, and blurred vision, and herpes virus infections.
  
  

Tell your healthcare provider if you have any side effect that bothers you or that does not go away. These are not all the possible side effects of DUPIXENT. Call your doctor for medical advice about side effects. You are encouraged to report negative side effects of prescription drugs to the FDA. Visit www.fda.gov/medwatch, or call 1-800-FDA-1088.

Use DUPIXENT exactly as prescribed by your healthcare provider. It’s an injection given under the skin (subcutaneous injection). Your healthcare provider will decide if you or your caregiver can inject DUPIXENT. Do not try to prepare and inject DUPIXENT until you or your caregiver have been trained by your healthcare provider. In children 12 years of age and older, it’s recommended DUPIXENT be administered by or under supervision of an adult. In children 6 months to less than 12 years of age, DUPIXENT should be given by a caregiver.

Please see accompanying full Prescribing Information including Patient Information.

About Regeneron
Regeneron (NASDAQ: REGN) is a leading biotechnology company that invents, develops and commercializes life-transforming medicines for people with serious diseases. Founded and led by physician-scientists, our unique ability to repeatedly and consistently translate science into medicine has led to numerous approved treatments and product candidates in development, most of which were homegrown in our laboratories. Our medicines and pipeline are designed to help patients with eye diseases, allergic and inflammatory diseases, cancer, cardiovascular and metabolic diseases, neurological diseases, hematologic conditions, infectious diseases, and rare diseases.

Regeneron pushes the boundaries of scientific discovery and accelerates drug development using our proprietary technologies, such as VelociSuite, which produces optimized fully human antibodies and new classes of bispecific antibodies. We are shaping the next frontier of medicine with data-powered insights from the Regeneron Genetics Center^® and pioneering genetic medicine platforms, enabling us to identify innovative targets and complementary approaches to potentially treat or cure diseases.

For more information, please visit www.Regeneron.com or follow Regeneron on LinkedIn, Instagram, Facebook or X.

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 

Regeneron Forward-Looking Statements and Use of Digital Media 
This press release includes forward-looking statements that involve risks and uncertainties relating to future events and the future performance of Regeneron Pharmaceuticals, Inc. (“Regeneron” or the “Company”), and actual events or results may differ materially from these forward-looking statements. Words such as “anticipate,” “expect,” “intend,” “plan,” “believe,” “seek,” “estimate,” variations of such words, and similar expressions are intended to identify such forward-looking statements, although not all forward-looking statements contain these identifying words. These statements concern, and these risks and uncertainties include, among others, the nature, timing, and possible success and therapeutic applications of products marketed or otherwise commercialized by Regeneron and/or its collaborators or licensees (collectively, “Regeneron’s Products”) and product candidates being developed by Regeneron and/or its collaborators or licensees (collectively, “Regeneron’s Product Candidates”) and research and clinical programs now underway or planned, including without limitation Dupixent® (dupilumab) for the treatment of bronchial asthma in children aged 6 to 11 years pursuant to the approval by Japan’s Ministry of Health, Labour and Welfare (MHLW) discussed in this press release; the likelihood, timing, and scope of possible regulatory approval and commercial launch of Regeneron’s Product Candidates and new indications for Regeneron’s Products, including Dupixent for the treatment of chronic pruritus of unknown origin, lichen simplex chronicus, allergic fungal rhinosinusitis, and other potential indications; uncertainty of the utilization, market acceptance, and commercial success of Regeneron’s Products (such as Dupixent) and Regeneron’s Product Candidates and the impact of studies (whether conducted by Regeneron or others and whether mandated or voluntary), including the studies discussed or referenced in this press release, on any of the foregoing; the ability of Regeneron’s collaborators, licensees, suppliers, or other third parties (as applicable) to perform manufacturing, filling, finishing, packaging, labeling, distribution, and other steps related to Regeneron’s Products and Regeneron’s Product Candidates; the ability of Regeneron to manage supply chains for multiple products and product candidates and risks associated with tariffs and other trade restrictions; safety issues resulting from the administration of Regeneron’s Products (such as Dupixent) and Regeneron’s Product Candidates in patients, including serious complications or side effects in connection with the use of Regeneron’s Products and Regeneron’s Product Candidates in clinical trials; determinations by regulatory and administrative governmental authorities which may delay or restrict Regeneron’s ability to continue to develop or commercialize Regeneron’s Products and Regeneron’s Product Candidates; ongoing regulatory obligations and oversight impacting Regeneron’s Products, research and clinical programs, and business, including those relating to patient privacy; the availability and extent of reimbursement or copay assistance for Regeneron’s Products from third-party payors and other third parties, including private payor healthcare and insurance programs, health maintenance organizations, pharmacy benefit management companies, and government programs such as Medicare and Medicaid; coverage and reimbursement determinations by such payors and other third parties and new policies and procedures adopted by such payors and other third parties; changes to drug pricing regulations and requirements and Regeneron’s pricing strategy; other changes in laws, regulations, and policies affecting the healthcare industry; competing drugs and product candidates that may be superior to, or more cost effective than, Regeneron’s Products and Regeneron’s Product Candidates (including biosimilar versions of Regeneron’s Products); the extent to which the results from the research and development programs conducted by Regeneron and/or its collaborators or licensees may be replicated in other studies and/or lead to advancement of product candidates to clinical trials, therapeutic applications, or regulatory approval; unanticipated expenses; the costs of developing, producing, and selling products; the ability of Regeneron to meet any of its financial projections or guidance and changes to the assumptions underlying those projections or guidance; the potential for any license, collaboration, or supply agreement, including Regeneron’s agreements with Sanofi and Bayer (or their respective affiliated companies, as applicable), to be cancelled or terminated; the impact of public health outbreaks, epidemics, or pandemics on Regeneron's business; and risks associated with litigation and other proceedings and government investigations relating to the Company and/or its operations (including the pending civil proceedings initiated or joined by the U.S. Department of Justice and the U.S. Attorney's Office for the District of Massachusetts), risks associated with intellectual property of other parties and pending or future litigation relating thereto (including without limitation the patent litigation and other related proceedings relating to EYLEA® (aflibercept) Injection), the ultimate outcome of any such proceedings and investigations, and the impact any of the foregoing may have on Regeneron’s business, prospects, operating results, and financial condition. A more complete description of these and other material risks can be found in Regeneron’s filings with the U.S. Securities and Exchange Commission, including its Form 10-K for the year ended December 31, 2024 and its Form 10-Q for the quarterly period ended September 30, 2025. Any forward-looking statements are made based on management’s current beliefs and judgment, and the reader is cautioned not to rely on any forward-looking statements made by Regeneron. Regeneron does not undertake any obligation to update (publicly or otherwise) any forward-looking statement, including without limitation any financial projection or guidance, whether as a result of new information, future events, or otherwise.

Regeneron uses its media and investor relations website and social media outlets to publish important information about the Company, including information that may be deemed material to investors. Financial and other information about Regeneron is routinely posted and is accessible on Regeneron's media and investor relations website (https://investor.regeneron.com) and its LinkedIn page (https://www.linkedin.com/company/regeneron-pharmaceuticals)

Sanofi Disclaimers or 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 regarding the marketing and other potential of the product, or regarding potential future revenues from the product. 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, unexpected regulatory actions or delays, or government regulation generally, that could affect the availability or commercial potential of the product, the fact that product may not be commercially successful, the uncertainties inherent in research and development, including future clinical data and analysis of existing clinical data relating to the product, including post marketing, unexpected safety, quality or manufacturing issues, competition in general, risks associated with intellectual property and any related future litigation and the ultimate outcome of such litigation, and volatile economic and market conditions, 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, 2024. 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 except for VelociSuite and Regeneron Genetics Center.

Regeneron Contacts: Media Relations Sharon Chen Tel: +1 914-847-1546 Sharon.Chen@regeneron.com	Investor Relations Mark Hudson Tel: +1 914-847-3482 Mark.Hudson@regeneron.com
Sanofi Contacts: Media Relations Sandrine Guendoul Tel: +33 6 25 09 14 25 Sandrine.Guendoul@sanofi.com	Investor Relations Thomas Kudsk Larsen Tel: +44 7545 513 693 Thomas.Larsen@sanofi.com
Evan Berland Tel: +1 215-432-0234 Evan.Berland@sanofi.com Léo Le Bourhis Tel: + 33 6 75 06 43 81 leo.lebourhis@sanofi.com Victor Rouault Tel: +33 6 70 93 71 40 Victor.Rouault@sanofi.com Timothy Gilbert Tel: +1 516-521-2929 Timothy.Gilbert@sanofi.com Léa Ubaldi Tel: + 33 6 30 19 66 46 lea.ubaldi@sanofi.com	Alizé Kaisserian Tel: +33 6 47 04 12 11 Alize.Kaisserian@sanofi.com Keita Browne Tel: +1 781-249-1766 Keita.Browne@sanofi.com Nathalie Pham Tel: +33 7 85 93 30 17 Nathalie.Pham@sanofi.com Thibaud Châtelet Tel: +33 6 80 80 89 90 Thibaud.Chatelet@sanofi.com Yun Li Tel: +33 6 84 00 90 72 Yun.Li3@sanofi.com

____________________
¹ Data on File

FAQ

What did Regeneron (REGN) announce about Dupixent on December 23, 2025?

Japan's MHLW approved Dupixent for children 6–11 years with severe or refractory bronchial asthma on December 23, 2025.

How effective was Dupixent in reducing exacerbations in the VOYAGE Phase 3 trial?

In VOYAGE, Dupixent added to standard care reduced severe exacerbations by 54%–65% versus placebo.

What lung function improvements did Dupixent show in pediatric trials for REGN?

Dupixent improved lung function by 4.68%–5.32% compared to placebo in the VOYAGE analyses.

Are there safety concerns for children using Dupixent (REGN) for asthma?

Common treatment-related events included injection site reactions; EXCURSION also reported fever, oral herpes and eosinophilia.

Does the Japan approval cover all pediatric asthma patients for Dupixent (REGN)?

No; the approval covers children 6–11 with severe or refractory asthma whose symptoms are inadequately controlled with existing therapy.