Newer Biological Agents in the Treatment of Severe Asthma: Real-World Results from a Tertiary Referral Center

Purpose: To determine the efficacy of IL-5 inhibitory therapy in severe, refractory asthma in a real-world clinical setting from a tertiary referral center. Methods: A retrospective chart review of patients with severe asthma treated with IL-5 biologic therapy for ≥ 6 months at Mayo Clinic in Rochester, Minnesota between January 1, 2013 and August 31, 2019. Results: Over the study period, we identified 63 patients with a mean age of 54 who received an IL-5 inhibitor for ≥ 6 months. A total of 55 patients received mepolizumab, 2 received benralizumab, and 9 patients received both. Patients were followed up for a mean of 25 months. The mean number of months of oral prednisone use prior to biologic initiation was 64. There was a significant reduction in the median dose of prednisone in the 24 months after drug initiation (15 mg vs. 0 mg; p = < 0.0001). Similarly; there was a significant decline in the median number of asthma exacerbations in the 24 months before and after drug initiation (7 vs. 2; p = < 0.0001). The mean number of emergency room (ER) visits and hospitalizations decreased from 5.1 and 2.0 to 1.6 and 0.4 in the 24 months before and after therapy initiation (p < 0.0001 and p = 0.007, respectively) Conclusions: IL-5 inhibitory therapy is associated with significant and long-term sustained reductions in asthma exacerbation frequency, ER visits, hospitalizations, as well as oral steroid usage in a patient population with refractory steroid-dependent asthma referred to a tertiary referral center.