Real-World Outcomes of Biologic Therapy for Severe Asthma in a High-Burden Urban Population

Background Asthma prevalence and mortality are disproportionately higher in underserved areas such as the Bronx compared to other regions of New York City. Biologic therapy is recommended for severe asthma but may present challenges in access and adherence among patients in low-resource settings. This study evaluates the real-world effectiveness and feasibility of biologic therapy in an inner-city cohort. Methods We conducted a retrospective cohort study of adult patients with severe asthma treated at an urban outpatient pulmonary and allergy clinic. Patients who received biologic therapy for at least six months between January 2020 and August 2023 were included. Outcome measures included Asthma Control Test (ACT) scores, asthma exacerbation rates, oral corticosteroid (OCS) use, lung function (forced expiratory volume in one second (FEV₁) and forced vital capacity (FVC)), and emergency department (ED) visits. Adherence was assessed using the proportion of days covered (PDC). Results Out of the 110 patients receiving biologics in our clinic, 44 met the inclusion criteria. The mean age was 63 years; 93% of patients self-reported Hispanic or African American race, and 86% were insured through Medicaid. Benralizumab was the most commonly prescribed biologic, as most of our patients had severe eosinophilic asthma. Following biologic therapy, ACT scores improved significantly (from 15 ± 4.48 to 20 ± 3.8, p < 0.001), ED visits declined (from 54 to 23, p = 0.004), and median daily systemic steroid dosage decreased (from 11.25 mg to 7.5 mg, p < 0.001). Mean FEV₁ increased from 73.64% to 78% predicted (p = 0.059). Among patients on biologics for over one year, the average PDC was 78%. Conclusions Biologic therapy appears to be both feasible and effective for treating severe asthma in underserved urban populations. Through a structured multidisciplinary care model, patients in real-world inner-city settings can achieve improved asthma control, reduced healthcare utilization, and strong treatment adherence as evidenced by a PDC of 78%. These findings highlight the importance of equitable access to advanced therapies in populations historically underrepresented in clinical trials.