Clinical and Cost-Effectiveness of Omalizumab in Concomitant Asthma and Chronic Rhinosinusitis with Nasal Polyps: A Real-World Exploratory Study.

PURPOSE: Severe asthma and chronic rhinosinusitis with nasal polyps (CRSwNP) frequently coexist, representing the severe "United Airway Disease" (UAD) phenotype. Although omalizumab is approved for both conditions individually, real-world evaluations of its clinical and economic viability for this concomitant phenotype remain limited. We evaluated the cost-effectiveness of omalizumab add-on therapy in Chinese adults with UAD. METHODS: This 52-week exploratory study compared omalizumab add-on therapy (n=23) with standard care (n=17) in patients with concomitant asthma and CRSwNP. Clinical outcomes included acute exacerbations (AEs), endoscopic sinus surgery (ESS) requirements, asthma control test (ACT) scores, sinus CT Lund-Mackay (LM) scores, corticosteroid and antibiotic exposure. Cost-effectiveness was analyzed from a healthcare provider perspective using 2024 constant prices, with decision uncertainty assessed via 1000-iteration bootstrapping. Scenario analyses evaluated the economic impact of recently approved domestic biosimilars. RESULTS: At week 52, compared with standard care, the omalizumab add-on group achieved significant reductions in annual AEs (median 0 [IQR 1.00] vs 1.0 [IQR 2.00]; P = 0.037) and ESS rates (8.70% vs 41.18%; P = 0.016). Although cross-sectional ACT scores at week 52 were comparable, omalizumab demonstrated superior peak efficacy with higher best ACT scores (median 25.0 [IQR 1.00] vs 24.0 [IQR 3.00]; P = 0.029) and greater maximum improvement from baseline (mean 7.52 [SD 4.90] vs 4.47 [SD 2.83]; P = 0.018). Omalizumab also produced significantly lower LM scores (median 12.92 [IQR 2.50] vs 18.00 [IQR 0]; P < 0.001) and a profound antibiotic-sparing effect (median duration 0.0 [IQR 8.5] vs 23.0 [IQR 24.0] days; P < 0.001). Total direct medical costs were approximately 7-fold higher (¥44,681.09 [IQR 47,780.91] vs ¥6282.25 [IQR 16,179.90]; P < 0.0001), primarily driven by biologic acquisition costs. Baseline incremental cost-effectiveness ratios (ICERs) for the reference originator were ¥64,223.84 per AE avoided and ¥114,398.72 per ESS avoided, with 0% probability of cost-effectiveness at strict willingness-to-pay thresholds. Substituting the originator with the lowest-priced domestic biosimilar substantially reduced the ICERs to ¥42,943.60 and ¥76,493.28, respectively. CONCLUSION: Omalizumab provides superior multi-domain clinical control and profound antibiotic-sparing effects. While the reference originator is not cost-effective over a 52-week horizon at its baseline price in China, stepwise price reductions through centralized procurement and the emergence of affordable biosimilars provides a highly viable economic pathway. Future optimization requires dynamic value-based pricing and targeting high-burden UAD phenotypes.