Safety and effectiveness of mepolizumab in adult patients with severe asthma with an eosinophilic phenotype from India: a Phase IV, open-label, single-arm, 24-week study (PRISM).

Objective: Existing mepolizumab trials have excluded patients with severe asthma with an eosinophilic phenotype (SAEP) from India. This study (NCT04276233) investigated the safety and effectiveness of mepolizumab in Indian adults with SAEP.

Methods: Multi-center, open-label, single-arm, interventional study; patients received 100 mg mepolizumab subcutaneously every four weeks for 24 weeks. Primary endpoint: incidence of adverse events (AEs), serious AEs (SAEs), and AEs of special interest (AESIs). Secondary endpoints: clinically significant exacerbation (CSEs) frequency (including exacerbations requiring hospitalization); change from baseline to Week 24 in forced expiratory volume/second (FEV₁), peak expiratory flow (PEF), and Asthma Control Questionnaire (ACQ-5) scores.

Results: Overall, 100 patients received ≥1 mepolizumab dose. Baseline characteristics: female, 51.0%; mean (standard deviation [SD]) age, 44.8 (12.0) years; mean (SD) body mass index, 24.4 (4.7) kg/m². On-treatment AEs and SAEs were reported by 18.0% and 3.0% of patients, respectively; regarding AESIs, 5.0% reported infection and 2.0% reported systemic reaction. One fatal event occurred (unrelated to mepolizumab). CSEs were reported by 8.0% of patients; 2.0% had an exacerbation requiring hospitalization. Least squares (LS) mean change (95% confidence interval) in pre- and post-bronchodilator FEV₁ and PEF by Week 24 was 0.081 L (-0.05, 0.21; p = 0.231), 0.055 L (-0.06, 0.17; p = 0.325), and 13.67 L/min (3.08, 24.25; p = 0.012), respectively. By Week 24, ACQ-5 scores had significantly improved (LS mean change [standard error]: -0.69 [0.121]; p < 0.001).

Conclusions: Mepolizumab was well tolerated in Indian adults with SAEP and improved asthma control and health-related quality of life.