Biologics comparably effective in controlling eosinophilic severe asthma symptoms

Key takeaways:

• There were no significant differences in the incidence of the first exacerbation event between the biologics.
• All three biologics improved FEV₁ and Asthma Control Test scores with no significant differences.

Mepolizumab, reslizumab and dupilumab were equally effective in controlling symptoms among patients with eosinophilic severe asthma, according to a study published in Annals of Allergy, Asthma & Immunology.

But reslizumab (Cinqair, Teva Pharmaceutical Industries Ltd.) may have an advantage over dupilumab (Dupixent; Sanofi, Regeneron) in reducing the number of future exacerbations, Duong Duc Pham, MD, PhD, department of allergy and clinical immunology, Asan Medical Center, University of Ulsan College of Medicine, and colleagues wrote.

The Precision Medicine Intervention in Severe Asthma or PRISM study involved 96 patients aged 18 to 80 years with eosinophilic severe asthma. These patients included:

• 39 receiving subcutaneous doses of 100 mg of mepolizumab (Nucala, GSK) every 4 weeks;
• 27 receiving intravenous doses of 3 mg/kg of reslizumab every 4 weeks; and
• 30 receiving subcutaneous doses of 300 mg of dupilumab every 2 weeks.

The researchers followed up with the patients on mepolizumab and reslizumab 12 months after baseline and with the patients on dupilumab 8 months after baseline.

The patients in the reslizumab group had a lower incidence of exacerbation than the other groups, but the researchers did not consider this difference to be statistically significant. A Cox regression model also found no significant difference in incidence of first exacerbation events between the three treatment groups.

Hazard ratios for incidence of first exacerbation included 2.99 (95% CI, 0.92-9.75) for the dupilumab group and 2.69 (95% CI, 0.87-8.29) for the mepolizumab group across the entire dataset.

Among patients with blood eosinophil counts (BECs) of 300 cells/µL or higher, hazard ratios included 3.49 (95% CI, 0.82-14.78) for the dupilumab group and 2.39 (95% CI, 0.7-8.09) for the mepolizumab group.

Using BEC instead of sputum eosinophils, similar analysis found a comparable trend, the researchers said. When follow-up steroid use was added to the model, the researchers continued, the relationship between exposure and outcomes was enhanced.

Proportions of patients who did not experience any asthma exacerbations during the follow-up period included 59% in the reslizumab group, 37% in the dupilumab group and 33% in the mepolizumab group. Negative binomial regression analysis indicated that the dupilumab group had a higher exacerbation rate than the reslizumab group.

Rate ratios included 3.97 (95% CI, 1.17-14.74) in the overall analysis and 2.27 (95% CI, 0.73-7.1) among patients with BEC of 300 cells/µL or higher.

When follow-up steroid usage was included, rate ratios increased to 6.21 (95% CI, 1.72-25.53) for the dupilumab group and to 2.94 (95% CI, 0.95-9.35) for the mepolizumab group.

However, the researchers said, there were no significant differences between the reslizumab and mepolizumab groups, nor were there any significant differences in exacerbation rates between all three groups when BEC was used instead of sputum eosinophils.

Lung function based on FEV₁ values and Asthma Control Test scores substantially improved in all three groups after 6 months as well, the researchers said, with no significant differences in baseline and slopes of changes between the groups.

Based on these findings, the researchers concluded that all three treatments have comparable performance in reducing the incidence of a first exacerbations event as well as in improving lung function and in achieving asthma control.

Further, the researchers said, sputum eosinophils may be a confounding factor that is worth considering in selecting a biologic for patients with severe asthma instead of basing treatment on BEC status.