Sanofi and Regeneron's Dupixent approved in the United States as the first and only drug for allergic fungal rhinosinusitis

Wednesday, February 25, 2026

The U.S. Food and Drug Administration (FDA) has approved Dupixent (dupilumab) for the treatment of adult and pediatric patients 6 years of age and older with allergic fungal rhinosinusitis ( AFRS ) who have a history of sinonasal surgery. The FDA evaluated Dupixent under a Priority Review for the treatment of AFRS. This review is reserved for drugs that represent significant improvements in the treatment, diagnosis, or prevention of serious conditions. This approval expands our approved indications in sinonasal diseases to now include AFRS as well as chronic rhinosinusitis with nasal polyps.

“Allergic fungal rhinosinusitis (AFRS) is a condition that can cause inflammation of the nasal passages, nasal polyps, and thick mucus in children and adults, leading to persistent nasal congestion. Some patients may also experience more serious complications such as bone deterioration around the sinuses and facial deformities,” said Kenneth Mendez , president and CEO of the Asthma and Allergy Foundation of America (AAFA). “As the first treatment specifically approved for AFRS, Dupixent offers potential relief for adults and children six years of age and older who suffer from potentially debilitating symptoms.”

AFRS is a type 2 chronic inflammatory disease. It is a specific subtype of chronic rhinosinusitis caused distinctly by a severe allergic hypersensitivity to fungi. It primarily affects people living in warm, humid climates where fungal spores are more prevalent in the environment. It can lead to nasal polyps, nasal congestion, loss of smell, thick mucus discharge, and poor health-related quality of life. Some patients may also experience bone loss around the sinus cavities and facial deformities. AFRS can be a severe and difficult-to-treat form of chronic rhinosinusitis because it does not respond well to available treatment options. Current recommended treatments include surgery and prolonged systemic steroids; however, relapses of the disease are not uncommon.

“Before Dupixent, people living with allergic fungal rhinosinusitis had to rely on treatments that could leave them vulnerable to recurrence of nasal polyps and thick mucus that could rob them of their sense of smell,” said Dr.  Alyssa Johnsen , PhD, Global Therapeutic Area Director, Immunology Development at Sanofi . “As the first medicine approved specifically for AFRS, Dupixent has demonstrated efficacy in alleviating many signs and symptoms of the disease, helping to break the cycle of recurrence, and reducing the risk of further surgery and corticosteroid use by 92%. We look forward to working with regulatory agencies in other countries to bring this innovative option to more patients who need it.”

The FDA approval is supported by the Phase 3 LIBERTY-AFRS-AIMS study (clinical study ID: NCT04684524 ), in which 62 adults and children aged 6 years and older with AFRS were randomized to receive a dose of Dupixent (200 mg or 300 mg) based on age and weight every two or four weeks (n = 33) or a placebo (n = 29). The differences between Dupixent and placebo were as follows:

Primary objective: Sinus opacification scores (a measure of the extent of sinus involvement by disease assessed by computed tomography [CT]) improved by 50% versus 10% at week 52 (placebo-corrected reduction of 7.36 points; p < 0.0001); a significant reduction in sinus opacification scores was also observed at week 24 (p < 0.0001).

Secondary objectives:

• Specific nasal signs and symptoms
• Patient-reported nasal congestion/obstruction improved from 67% to 25% at week 24 (placebo-corrected reduction of 0.87 points; p < 0.0001), with continued improvement at week 52 to 81% from 11% (placebo-corrected reduction of 1.40 points; p < 0.0001).
• Nasal polyp size (assessed by endoscopy) decreased by 61% versus 15% at week 24 (placebo-corrected reduction of 2.36 points; p < 0.0001), with a continued reduction of 63% versus 4% through week 52 (placebo-corrected reduction of 2.77 points; p < 0.0001).
• Sensation of smell
• Patient-reported loss of smell decreased by 67% compared to 19% at week 24 (placebo-corrected reduction of 0.89 points; p < 0.0001)
• Treatment burden
• A 92% reduction in the risk of systemic corticosteroid use and/or the need for surgery (29% fewer patients; p = 0.0010) over 52 weeks. 3% or 0% of patients receiving Dupixent received systemic corticosteroids or underwent surgery, respectively, compared to 31% or 7% of patients receiving placebo.

The safety results of the LIBERTY-AFRS-AIMS study were similar to the known safety profile of Dupixent in PCRsPN. In pooled data from two pivotal studies of adult PCRsPN, the most common adverse reactions (≥1%) listed in the US PACKAGE LEAFLET and observed more frequently in patients treated with Dupixent compared to placebo were injection site reactions, conjunctivitis, arthralgia, gastritis, insomnia, eosinophilia, and toothache.

“With this approval, Dupixent is once again demonstrating its value in advancing the therapeutic landscape for a chronic type 2 inflammatory disease with a high unmet need,” commented Dr.  George D. Yancopoulos, PhD, Co-Chair of the Board, President, and Chief Scientific Officer at Regeneron . “Beyond reducing nasal signs and symptoms, Dupixent has decreased the need for surgery or systemic corticosteroids, with fewer patients experiencing bone erosion in the sinuses. These results underscore its potential to establish a new standard of care for people with allergic fungal rhinosinusitis (AFRS). This ninth FDA approval for Dupixent, the most widely used innovative branded antibody drug, reinforces the established efficacy and the growing body of evidence that IL-4 and IL-13 are major drivers of type 2 inflammation in many chronic diseases.”

Additional submissions are planned to other regulatory authorities worldwide.

About LIBERTY-AFRS-AIMS:

The Phase 3 LIBERTY-AFRS-AIMS study is a randomized, double-blind, placebo-controlled trial evaluating the safety and efficacy of Dupixent in adults and children aged 6 years and older with AFRS. The 52-week study included an age- and weight-based dose of Dupixent (300 mg every two weeks for adults and children weighing ≥ 60 kg, 200 mg every two weeks for children weighing ≥ 30 kg to < 60 kg, or 300 mg every four weeks for children weighing ≥ 15 kg to < 30 kg) or placebo. More than 80% of patients had a history of type 2 comorbidities.

The primary endpoint assessed the change from baseline in sinus opacification as evaluated by computed tomography using the Lund-Mackay score (LMK; scale: 0–24) at 52 weeks. Some secondary endpoints assessed at week 24 included:

• Variation from the patient-reported nasal congestion reference level (scale: 0-3)
• Variation from the reference level in nasal polyp score (scale: 0-8) measured by endoscopy
• Score LMK
• Patient-reported variation from the reference on the SNOT-22 scale (scale: 0-110)

Several secondary endpoints were also assessed at week 52, in addition to the proportion of patients requiring surgery or systemic corticosteroids during the treatment period. The proportion of patients with sinus bone erosion assessed by computed tomography was a tertiary endpoint assessed at week 52.

About Dupixent:

Dupixent (dupilumab) is an injection given under the skin (subcutaneous injection) at various injection sites. In adults with AFRS, Dupixent 300 mg is given every two weeks. In children with AFRS, Dupixent is given according to weight: 300 mg every two weeks for children ≥ 60 kg, 200 mg every two weeks for children ≥ 30 kg to < 60 kg, or 300 mg every four weeks for children ≥ 15 kg to < 30 kg. Dupixent is intended for use under the supervision of a healthcare professional and can be administered in a clinic or at home after training by a healthcare professional. In children aged 12 to 17 years, Dupixent must be given under adult supervision. In children under 12 years of age, Dupixent must be administered by a caregiver if given at home.

Dupixent is a fully human monoclonal antibody that inhibits interleukin-4 (IL-4) and interleukin-13 (IL-13) signaling pathways and is not an immunosuppressant. The Dupixent development program has demonstrated significant clinical benefit and a reduction in type 2 inflammation in phase 3 studies, establishing that IL-4 and IL-13 are two key and central drivers of type 2 inflammation, which plays a major role in multiple related and often comorbid diseases.

Sanofi and Regeneron are committed to helping U.S. patients prescribed Dupixent access their medication and receive the support they may need through the DUPIXENT MyWay® program. For more information, please call 1-844-DUPIXENT (1-844-387-4936) or visit  www.DUPIXENT.com .

Dupixent has received regulatory approvals in more than 60 countries for one or more indications, including in patients with atopic dermatitis, asthma, chronic rhinosinusitis with nasal polyps, eosinophilic esophagitis, prurigo nodularis, chronic spontaneous urticaria, chronic obstructive pulmonary disease, bullous pemphigoid, and AFRS in various age populations. More than 1.4 million patients worldwide are treated with Dupixent.

Dupilumab Development Program:

Dupilumab is being jointly developed by Sanofi and Regeneron under a global collaboration agreement. To date, dupilumab has been studied in more than 60 clinical trials involving over 12,000 patients with various chronic diseases, some of which are caused by type 2 inflammation.

In addition to its currently approved indications, Sanofi and Regeneron are investigating dupilumab in a broad range of diseases caused by type 2 inflammation or other allergic processes in phase 3 studies, including chronic pruritus of unknown origin and chronic lichen simplex. These potential uses of dupilumab are currently being studied clinically, and safety and efficacy in these conditions have not yet been fully evaluated by regulatory authorities.

About Regeneron

: Regeneron (NASDAQ: REGN) is a leading biotechnology company that invents, develops, and commercializes life-transforming medicines for people living 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 therapies and product candidates in development, most of which have been manufactured 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, hematological and infectious diseases, and rare diseases.

Regeneron is pushing the boundaries of scientific research and accelerating the drug development process with proprietary technologies, such as VelociSuite® , which produces fully human, optimized antibodies and novel classes of bispecific antibodies. Regeneron is shaping the new landscape of medicine with data from the Regeneron Genetics Center® and advanced genetic medicine platforms, enabling it to identify innovative targets and complementary approaches for the potential treatment or cure of diseases.

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

About Sanofi:

Sanofi is a biopharmaceutical company that innovates through R&D and leverages AI at scale to improve people's lives and achieve long-term growth. We apply our deep understanding of the immune system to invent medicines and vaccines that treat and protect millions of people worldwide, with an innovative pipeline that could benefit millions more. Our team is guided by a single purpose: we pursue the miracles of science to improve people's lives; this inspires us to drive progress and make a positive impact for our employees and the communities we serve, tackling the most pressing health, environmental, and societal challenges of our time.

Sanofi is listed on EURONEXT: SAN and NASDAQ: SNY.

Sanofi - 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

Sanofi - 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
Nina Goworek | +1 908 569 7086 | nina.goworek@sanofi.com
Thibaud Châtelet | +33 6 80 80 89 90 | thibaud.chatelet@sanofi.com
Yun Li | +33 6 84 00 90 72 | yun.li3@sanofi.com

Regeneron - Media Relations
Kailey Kilmartin | +1 914-652-0679 | kailey.kilmartin@regeneron.com

Regeneron - Investor Relations:
Mark Hudson | +1 914-847-3482 | mark.hudson@regeneron.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 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's Forward-Looking Statements and Use of Digital Media

This press release contains forward-looking statements that involve risks and uncertainties regarding the future performance and results of Regeneron Pharmaceuticals, Inc. (“Regeneron” or the “Company”). Actual events or results may differ materially from those described in these forward-looking statements. The words “expect,” “anticipate,” “intend,” “plan,” “believe,” “seek,” or “estimate,” variations of these words, or other similar expressions, are used to identify such forward-looking statements, although not all forward-looking statements explicitly contain these terms. These statements relate to, and these risks and uncertainties include, among other things, the nature, timing, potential success and therapeutic applications of products marketed or otherwise marketed by Regeneron and/or its collaborators or licensees (collectively, the “Regeneron Products”) and product candidates developed by Regeneron and/or its collaborators or licensees (collectively, the “Regeneron Product Candidates”) and research and clinical programs currently underway or planned, including, but not limited to, Dupixent® (dupilumab) for the treatment of adult and pediatric patients aged 6 years and older with allergic fungal rhinosinusitis; the likelihood, timing and scope of potential regulatory approval and commercial launch of Regeneron’s Product Candidates and new indications for Regeneron Products, including Dupixent for the treatment of chronic pruritus of unknown origin, chronic lichen simplex and other potential indications; Uncertainty regarding the use, market acceptance, and commercial success of Regeneron's products (such as Dupixent) and Regeneron's product candidates, and the impact of studies (conducted by Regeneron or others, mandatory or voluntary), including those mentioned or referred to in this press release, on the foregoing; the ability of Regeneron's employees, licensees, suppliers, or other third parties (as applicable) to perform manufacturing, filling, packaging, labeling, distribution, and other steps related to Regeneron's products and product candidates; Regeneron's ability to manage the supply chains for multiple products and product candidates, and the risks associated with customs duties and other trade restrictions; and safety issues arising from the administration of Regeneron's products (such as Dupixent) and Regeneron's product candidates to patients.including serious complications or side effects related to the use of Regeneron's products and product candidates in clinical trials; decisions by government regulatory and administrative authorities that may delay or restrict Regeneron's ability to continue developing or commercializing its products and drug candidates; ongoing regulatory obligations and oversight affecting Regeneron's products, research and clinical programs, and business, including those related to patient data privacy; the availability and extent of reimbursement or co-payment coverage for Regeneron products by third-party payers and other third parties, including private health insurance plans, health management organizations, pharmaceutical benefit management companies, and government programs such as Medicare and Medicaid; coverage and reimbursement decisions made by these payers and other third parties, and any new policies and procedures adopted by them; Changes to drug pricing regulations and requirements and to Regeneron's pricing strategy; other changes in laws, regulations, and policies affecting the healthcare industry; competing products and drug candidates (including biosimilars) that may be superior or more profitable than Regeneron's products and drug candidates; the extent to which the results of research and development programs conducted by Regeneron and/or its collaborators or licensees can be replicated in other studies and/or lead to the advancement of product candidates to clinical trials, therapeutic applications, or regulatory approval; unforeseen expenses; product development, production, and sales costs; Regeneron's ability to achieve its financial objectives and changes in the assumptions underlying those objectives; the possibility that any licensing, collaboration, or supply agreement, including Regeneron's agreements with Sanofi and Bayer (or their respective affiliates, as applicable), may be canceled or terminated; the impact of epidemics or pandemics on Regeneron's business; and the risks associated with litigation and other governmental proceedings and investigations concerning the Company and/or its business (including ongoing 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 third-party intellectual property and ongoing or future litigation related thereto (including, without limitation,Patent litigation and other related proceedings concerning the injection of EYLEA® (aflibercept), the final outcome of such proceedings and investigations, and the potential impact of the foregoing 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 fiscal year ended December 31, 2025. All forward-looking statements are based on management's current beliefs and judgment, and readers are cautioned not to place undue reliance on any forward-looking statements made by Regeneron. Regeneron undertakes no obligation to update (publicly or otherwise) any forward-looking statements, including, without limitation, any financial projections or advice, whether as a result of new information, future events, or otherwise.

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

Source: globenewswire.com