Comparison of Modified Lund–Kennedy Endoscopic Score and Nasal Polyp Score in the Follow-Up of Patients with Severe Uncontrolled CRSwNP During Biological Therapy

Chronic rhinosinusitis with nasal polyps (CRSwNP) is a persistent inflammatory disorder of the upper airways, severely impacting quality of life. Dupilumab, targeting type 2 inflammatory pathways, is effective in managing severe, uncontrolled CRSwNP. However, the comparative accuracy of endoscopic scoring systems in monitoring therapeutic response to dupilumab remains unclear. This study compared the accuracy of the nasal polyp score (NPS) and the modified Lund–Kennedy endoscopic score (M-LKS) in assessing dupilumab response. Methods: A retrospective cohort analysis included 66 severe CRSwNP patients treated with dupilumab at Padua University. Endoscopic scores (NPS and M-LKS), patient-reported outcome mesures (PROMs), and clinician-reported outcome measures (CROMs), including peak nasal inspiratory flow (PNIF) and the Sniffin’ Sticks test, were evaluated at baseline and over 24 months. Results: Both NPS and M-LKS showed significant reductions over time (p < 0.001), significantly correlating with PNIF (p < 0.001). Given time and patient, PNIF emerged to be the only covariate related to endoscopic scores. No significant differences were observed between NPS and M-LKS regarding clinical outcome associations, suggesting equivalent accuracy. PNIF was identified as a critical predictor of endoscopic improvement, highlighting its clinical utility. These findings reinforce the role of standardized endoscopic metrics in assessing the efficacy of biologic therapies for CRSwNP.