out to 2 years, according findings of the BORA trial, an extension study of the phase 3 and trials. The study follows up and reinforces previously reported 1-year data and was reported by William W. Busse, MD, of University of Wisconsin, Madison, and his colleagues in the .
Benralizumab is a monoclonal antibody that targets interleukin-5 receptor alpha. It causes rapid deletion of eosinophils through cell-mediated cytotoxicity. A 30-mg dose of benralizumab every 8 weeks is approved for severe asthma treatment in Canada, Europe, Japan, the United States, and other countries.
In the second year of treatment, there were no new adverse events associated with depleted eosinophils, and the frequency of opportunistic infections was similar to that observed in the first year.
Eosinophilic inflammation occurs in about half of asthma cases and is associated with greater severity.
The 48-week SIROCCO trial, the 56-week CALIMA trial, and the 28-week ZONDA trial tested the effect of benralizumab 30 mg given every 4 weeks or 8 weeks, combined with high-dosage inhaled steroids and long-acting beta2-agonists. The 8-week dose of the drug reduced annual exacerbations by 51%, compared with placebo in the SIROCCO trial and by 28% in the CALIMA trial. In the ZONDA trial, benralizumab reduced oral glucocorticoid use by 75%, compared with placebo, and by 25% from baseline.
Theincluded participants in the previous three trials. In the current report, researchers presented results from the analysis from BORA participants recruited from the SIROCCO and CALIMA trials. Data from participants from all three trials will be reported in the future.
The analysis included 1,576 patients who continued to receive benralizumab after being assigned to the treatment arm in SIROCCO or CALIMA, or who had received placebo were randomized to benralizumab on the 4-week (n = 783; 265 from placebo) or 8-week dose (n = 793; 281 from placebo) schedule.
A total of 166 patients, or about 10% in each group, discontinued treatment. The frequency of any serious adverse event (SAE) ranged between 10% and 11% in all groups. SAEs associated with infections ranged from 1% to 3%, indicating that there were no significant differences in SAE frequencies between those who were originally assigned to placebo and those who originally received benralizumab. That suggests no safety differences between receiving the drug for 1 year or 2 years.
A total of 1,046 subjects had blood eosinophil counts of 300 cells per mcL or greater at baseline; 72% of these patients had no asthma exacerbations during the BORA study. This was true for 74% of patients in the 8-week treatment arm.
The crude asthma exacerbation rate for patients who received benralizumab in SIROCCO or CALIMA was 0.48 in the 4-week arm, compared with placebo (95% confidence interval, 0.42-0.56) and 0.46 in the 8-week arm (95% CI, 0.39-0.53). For patients who started out on placebo, the crude exacerbation rate during BORA was 0.53 in the 4-week group (95% CI, 0.43-0.65) and 0.57 in the 8-week group (95% CI, 0.47-0.68).
Patients who started on benralizumab had similar exacerbation frequencies during year 1 and year 2.
AstraZeneca and Kyowa Hakko Kirin funded the studies. The authors have received fees from AstraZeneca and other pharmaceutical companies, and some are employees of AstraZeneca.