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

Abstract

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.