A Humanized Anti-IL-4Rα Monoclonal Antibody Improves Aural Fullness

Background and Clinical Significance: Otitis media with effusion (OME) is characterized by persistent middle ear effusion without acute infection. Type 2 inflammation, mediated by IL-4 and IL-13 signaling via the IL-4Rα receptor, has been implicated in the pathogenesis of chronic rhinosinusitis with nasal polyps (CRSwNP), asthma, and possibly OME. Refractory OME in adults remains a therapeutic challenge, as conventional treatments often fail to achieve long-term resolution. Targeted biologic therapies that modulate type 2 inflammation may offer a novel treatment option. Case Presentation: We report the case of a 60-year-old man with a 15-year history of allergic rhinitis and CRSwNP, complicated by recurrent asthma exacerbations, who presented with bilateral aural fullness, hearing loss, and tinnitus. His symptoms persisted despite repeated tympanic punctures, Eustachian tube insufflation, and corticosteroid therapy. Otoscopy revealed dull tympanic membranes with effusion, and audiometry showed conductive hearing loss with a B-type tympanogram on the left. Laboratory findings demonstrated mild peripheral eosinophilia. The patient was diagnosed with OME, likely secondary to type 2 inflammation. After nine biweekly injections of Stapokibart (CM310)—a humanized monoclonal antibody targeting IL-4Rα—aural fullness completely resolved. Otoscopic findings and tympanograms normalized, and hearing thresholds improved significantly. Retrospective evaluation using Iino’s diagnostic framework suggested that the patient did not meet the full criteria for eosinophilic otitis media (EOM); nevertheless, marked symptomatic and functional improvement was achieved. No recurrence or adverse effects were observed during follow-up. Conclusions: This case suggests that IL-4Rα blockade with Stapokibart may be effective in treating refractory OME associated with type 2 inflammation, even in patients who do not fulfill the diagnostic criteria for EOM. These findings highlight the potential of anti-IL-4Rα biologics as a novel therapeutic option for middle ear diseases driven by type 2 inflammation.