Peak Nasal Inspiratory Flow and the Association with Nasal Obstruction in Patients with Severe CRSwNP from the SINUS-24/-52 Studies

Introduction: Nasal congestion/obstruction (NC) contributes to the high disease burden in patients with severe chronic rhinosinusitis with nasal polyps (CRSwNP). Patient perception of NC may not accurately reflect nasal patency, while peak nasal inspiratory flow (PNIF) is an objective method with established thresholds for normal nasal airflow. This analysis evaluated the association between NC and PNIF and the impact of baseline PNIF on dupilumab efficacy in patients with severe CRSwNP. Methods: This was a post hoc analysis of patients treated with placebo or dupilumab 300 mg every 2 weeks in the SINUS-24 (NCT02912468) and SINUS-52 (NCT02898454) phase III studies. Patients provided daily e-diary measures of PNIF (L/min) using PNIF meters, and NC by patient-reported evaluation of severity (scored 0–3). Other assessed outcomes were nasal polyp score (NPS), 22-item Sinonasal Outcome Test (SNOT-22), loss of smell (LoS), University of Pennsylvania Smell Identification Test (UPSIT), and Lund–Mackay computed tomography. Outcomes were assessed in two subgroups: baseline PNIF < 120 L/min and ≥ 120 L/min. Results: Of 724 patients, 552 (76%) had PNIF < 120 L/min and 172 (24%) had PNIF ≥ 120 L/min at baseline. The PNIF < 120 L/min subgroup had higher mean scores for NPS and SNOT-22 and more smell impairment (LoS and UPSIT). PNIF weakly correlated with NC at baseline (Spearman coefficient − 0.348 [95% CI − 0.410, − 0.282], P < 0.0001). Correlations between change from baseline in PNIF and NC at week 24 were weak in the dupilumab group (− 0.390 [− 0.468, − 0.305], P < 0.0001) and moderate in the placebo group (− 0.497 [− 0.582, − 0.399], P < 0.0001). Conclusion: These results confirm PNIF as a valuable method for assessing nasal obstruction in patients with severe CRSwNP. The degree of nasal flow impairment at baseline does not impact dupilumab’s efficacy. A