Abstract Rationale Severe asthma remains a major cause of morbidity in urban populations with high environmental exposure and socioeconomic barriers to care. Biological therapy is indicated for severe asthma, uncontrolled on inhaler therapy. Omalizumab (Xolair) is indicated for patients with elevated IgE and an environmental allergen. Dosing is based on weight and IgE level, and was initially approved up to 300mg. Data on IgE pharmacokinetics indicate potential benefit of higher doses (600 mg) for persistent symptoms or refractory disease, including in patients with comorbid sinusitis. Evidence on real-world outcomes in underserved, high-burden populations is limited. We hypothesized that initiation of high-dose Xolair (600 mg) would improve asthma control and reduce exacerbations among patients able to maintain treatment adherence. Methods We conducted a retrospective cohort study of adult asthma patients treated with Xolair 600 mg at a large urban NYC safety-net hospital since January 2023. Data collected included demographics, total IgE, prior biologic therapy (including escalation from Xolair 300 mg), Asthma Control Test (ACT) scores, dosing adherence as a proportion of scheduled doses received, asthma exacerbations, and emergency department visits. Full adherence was assumed for patients receiving home administration based on prior institutional experience. Results Twenty-two (22) patients were included after excluding five (5) lost to follow-up. Average adherence over six months was 73.86%. Eleven patients demonstrated high adherence (75%), while four patients showed low adherence (50%). Six patients received home injections with assumed full adherence, while clinic-administered dosing showed more variability. Minimal improvement in ACT scores was observed overall (average of 15, SD 3.34). Higher adherence was associated with fewer ED visits compared with pre-treatment, while low-adherence patients had little change. Among the four patients escalated from 300 mg to 600 mg, ED visits remained low, but no consistent improvement in symptoms was observed. Conclusion In this real-world cohort, high-dose Xolair (600 mg) was associated with reduced ED utilization among patients with high adherence, particularly those receiving home-administered doses. However, variable adherence limited broader clinical benefit, and symptom improvement was minimal over six months. Given the small sample, findings likely reflect a trend rather than statistical significance. The study limitations, including a small sample size and inconsistent adherence, limit our understanding of the impact of high-dose Xolair. Future research could benefit from exploring the relationship between allergen reactivity and treatment response, particularly in high-burden urban populations. This abstract is funded by: None
Pichardo et al. (Fri,) studied this question.