Sanofi And Regeneron Win U.S. Approval For Dupixent As The First-Ever Treatment For Allergic Fungal Rhinosinusitis In The United States

The US Food and Drug Administration (FDA) has approved Dupixent (dupilumab) for adults and children aged six and older who have allergic fungal rhinosinusitis (AFRS) and a history of sino-nasal surgery. The FDA reviewed the treatment under priority review, a process reserved for medicines that can significantly improve how serious conditions are treated or managed. With this decision, Dupixent’s approved uses in sino-nasal diseases now extend beyond chronic rhinosinusitis with nasal polyps to include AFRS as well.

Kenneth Mendez, President and CEO of the Asthma and Allergy Foundation of America, explained that AFRS can cause intense and persistent inflammation of the nasal passages. Patients often experience nasal polyps, thick mucus, and constant congestion, which can severely impact daily life. In the most serious cases, AFRS can even lead to bone erosion around the sinuses and structural changes in the face. He noted that Dupixent is the first treatment specifically approved for AFRS, offering a new option for both children and adults who struggle with symptoms that can be physically and emotionally draining.

AFRS is a chronic type 2 inflammatory condition and is considered a distinct subtype of chronic rhinosinusitis. It develops due to a strong allergic reaction to fungi present in the environment. The condition is more common in warm and humid regions where fungal spores thrive. Symptoms typically include nasal blockage, loss of smell, thick mucus discharge, and nasal polyps. Many patients also report a reduced quality of life because of the constant discomfort and recurring flare-ups. In severe instances, the disease can cause bone loss around the sinus cavities and facial deformities. Treating AFRS is particularly challenging because many standard treatments, such as surgery and long-term systemic steroids, do not always prevent the disease from returning.

Alyssa Johnsen, MD, PhD, Global Therapeutic Area Head of Immunology Development at Sanofi, said that before this approval, patients had very few long-term options that truly controlled AFRS. Many relied heavily on steroids or repeated surgeries, both of which carried the risk of persistent regrowth of nasal polyps and mucus buildup. She emphasized that Dupixent has shown the ability to break this cycle. Clinical data demonstrated its effectiveness in reducing multiple signs and symptoms while lowering the need for repeat surgeries or systemic corticosteroids by 92 percent. She also mentioned that the company plans to work with regulators in other countries to make the treatment more widely accessible.

The FDA’s decision is based on evidence from the LIBERTY-AFRS-AIMS Phase 3 trial (NCT04684524). The trial included 62 patients aged six and older who were randomly assigned to receive either Dupixent or a placebo. Dupixent dosing was adjusted according to age and weight and administered every two or four weeks.

The primary measurement used in the study was improvement in sinus opacification, which reflects how much of the sinus area is affected by disease as seen on CT scans. At week 52, patients receiving Dupixent showed a 50 percent improvement in sinus opacification compared to only 10 percent in the placebo group. A significant improvement was already visible by week 24. The placebo-corrected reduction in the primary endpoint was 7.36 points, with strong statistical significance.

Secondary results also showed meaningful benefits. Nasal congestion improved by 67 percent in the Dupixent group by week 24 compared to 25 percent with placebo. By week 52, the improvement rose to 81 percent versus 11 percent. Nasal polyp size also decreased substantially, showing a 61 percent reduction by week 24 and a 63 percent reduction by week 52, while the placebo group showed only minimal improvement. Patients also reported better sense of smell, with a 67 percent reduction in loss of smell compared to 19 percent in the placebo group at week 24.

Another important outcome was the reduction in treatment burden. Over 52 weeks, Dupixent reduced the need for systemic corticosteroids or additional surgical procedures by 92 percent. Only a small percentage of patients on Dupixent required steroids, and none required surgery, compared to higher rates in the placebo group.

The safety profile observed in the AFRS trial was consistent with what is already known from Dupixent’s use in chronic rhinosinusitis with nasal polyps. In earlier clinical studies, the most common side effects seen more often with Dupixent than placebo included injection site reactions, conjunctivitis, joint pain, gastritis, insomnia, eosinophilia, and toothache.

George D. Yancopoulos, MD, PhD, Board co-Chair, President, and Chief Scientific Officer at Regeneron, said that this approval reinforces Dupixent’s important role in treating chronic type 2 inflammatory diseases that lack effective long-term options. He noted that in addition to easing nasal symptoms, Dupixent also reduced the likelihood of surgery and steroid use and was linked with fewer patients experiencing bone erosion in the sinuses. According to him, this advancement strengthens the growing body of evidence supporting Dupixent and highlights its ability to target IL-4 and IL-13 pathways across multiple chronic inflammatory conditions. This is now the ninth FDA approval for Dupixent, reflecting its broad potential and consistent clinical benefits.