Dupilumab Meets All Endpoints in Phase 3 Study for Allergic Fungal Rhinosinusitis; FDA Grants Priority Review

The monoclonal antibody dupilumab significantly improved signs and symptoms of allergic fungal rhinosinusitis (AFRS) in adults and children aged ≥6 years, according to results from the phase 3 LIBERTY-AFRS-AIMS study presented at the American College of Allergy, Asthma and Immunology (ACAAI) 2025 Annual Scientific Meeting. The investigational use of dupilumab met all primary and secondary endpoints, showing reductions in sinus opacification, nasal congestion, and nasal polyp size compared with placebo.

The US Food and Drug Administration (FDA) has accepted the supplemental biologics license application (sBLA) for dupilumab for priority review, with a target action date of February 28, 2026. If approved, dupilumab would become the first and only therapy specifically indicated for AFRS and its ninth FDA-approved indication.

AFRS is a chronic, type 2 inflammatory sinus disease characterized by hypersensitivity to fungi, most often Aspergillus. The condition typically affects individuals in warm, humid climates and is associated with nasal polyps, congestion, and potential complications such as bone erosion and facial deformities. Current treatment options include surgery and systemic corticosteroids, but recurrence rates remain high.

“People with allergic fungal rhinosinusitis live with persistent nasal obstruction, congestion, and polyps that can place a great strain on their day-to-day lives,” study lead investigator Amber U. Luong, MD, PhD, FACS, of the McGovern Medical School at the University of Texas Health Science Center at Houston. “The ability of dupilumab to alleviate hallmark signs and symptoms of AFRS, and to reduce the risk for surgery and corticosteroids by 92%, provide the strongest evidence to date that IL-4 and IL-13 are key drivers of the type 2 inflammation leading to this disease.”

In the 52-week study, 62 participants were randomized to dupilumab (n=33) or placebo (n=29). Key findings included:

• Primary endpoint: Sinus opacification improved by 50.0% with dupilumab vs 9.8% with placebo at week 52 (7.36-point placebo-corrected reduction; P < .0001).
• Nasal congestion: 80.6% improvement with dupilumab vs 11.1% with placebo at week 52 (P < .0001).
• Nasal polyp score: 62.5% reduction with dupilumab vs 3.6% with placebo at week 52 (P < .0001).
• Systemic corticosteroid use/surgery: 92% lower risk with dupilumab vs placebo (P = .0010).

The safety profile was consistent with prior dupilumab indications. Adverse events occurred in 70% of patients receiving dupilumab and 79% receiving placebo, with serious adverse events reported in 0% and 7%, respectively.

Dupilumab is a fully human monoclonal antibody that inhibits interleukin-4 and interleukin-13 signaling, key pathways in type 2 inflammation. The drug is currently approved in more than 60 countries for conditions including atopic dermatitis, asthma, chronic rhinosinusitis with nasal polyps, eosinophilic esophagitis, and chronic obstructive pulmonary disease.

Reference: ACAAI: Sanofi and Regeneron’s Dupixent pivotal study met all primary and secondary endpoints, reducing signs and symptoms of allergic fungal rhinosinusitis; sBLA accepted for FDA priority review. Sanofi. News release. November 7, 2025. Accessed November 7, 2025. https://www.news.sanofi.us/2025-11-07-ACAAI-Sanofi-and-Regenerons-Dupixent-pivotal-study-met-all-primary-and-secondary-endpoints,-reducing-signs-and-symptoms-of-allergic-fungal-rhinosinusitis-sBLA-accepted-for-FDA-priority-review