Mepolizumab Reduces Exacerbations in Biologic-Experienced Patients With Severe Asthma

Clinical summary

• NEST post hoc analysis: A 9-country observational cohort included 174 biologic-experienced patients with severe asthma; 94.8% previously received omalizumab. Outcomes were compared over 12 months before and after mepolizumab initiation.
• Exacerbations decreased 74% (incidence rate ratio, 0.26; 95% CI, 0.18-0.36). Among 170 patients, oral corticosteroid use declined from 60.0% to 23.5%; mean daily dose among users decreased from 20.8 to 6.7 mg.
• Mean Asthma Control Test scores increased from 14.0 to 19.5; 66.4% of 125 assessed patients improved ≥3 points. Authors emphasized patient-centered biologic treatment; findings reflect observational associations.

Mepolizumab treatment was associated with fewer clinically significant exacerbations (CSEs), reduced oral corticosteroid (OCS) use, and improved asthma control among biologic-experienced patients with severe asthma, according to a post hoc analysis of the Nucala Effectiveness Study (NEST).

Investigators evaluated real-world outcomes among biologic-experienced patients enrolled in NEST, a multicountry, bidirectional observational cohort study conducted across Chile, Colombia, India, Kuwait, Oman, Qatar, Saudi Arabia, Türkiye, and the United Arab Emirates. The primary outcome compared CSE incidence during the 12 months before and after mepolizumab initiation.

The analysis included 174 patients, 94.8% of whom had previously received omalizumab. Lack of treatment efficacy was the reason for discontinuation in 84.8%.

Following mepolizumab initiation, CSEs decreased by 74%, with an incidence rate ratio of 0.26 (95% CI, 0.18-0.36).

Among 170 patients, OCS use decreased from 60.0% (n=102) before mepolizumab initiation to 23.5% (n=40) afterward. Of the 102 patients initially receiving OCS, 39 (38.2%) continued treatment following mepolizumab initiation. Among OCS users, mean daily dose decreased from 20.8 mg to 6.7 mg.

Asthma control also improved. Mean Asthma Control Test (ACT) scores increased from 14.0 before treatment to 19.5 after mepolizumab initiation. Among 125 patients with available data, 66.4% achieved an ACT score improvement of at least 3 points.

“Mepolizumab treatment led to reduced CSEs and OCS use, and improved ACT scores in biologic-experienced patients with severe asthma,” the investigators concluded.

According to the authors, the findings “indicate the importance of a patient-centred approach regarding biologic treatment” for patients with severe asthma who have previously received biologic therapy.

References

Galeano Mesa A, Al-Lehebi RO, Bavbek S, et al. Effectiveness of mepolizumab in patients switching from prior biologic treatments for severe asthma: a post hoc analysis of the NUCALA Effectiveness Study (NEST). Journal of Asthma Published online September 17, 2026:1-18. doi:10.1080/02770903.2026.2730876