Safety of reslizumab in uncontrolled asthma with eosinophilia: a pooled analysis from six trials

Abstract Background Intravenous reslizumab, a monoclonal interleukin-5 antibody, is approved for treating severe asthma with eosinophilia. Limited structured information is available on the safety of reslizumab in larger populations. Objective The aim of this study was to investigate the safety profile of intravenous reslizumab 3.0 mg/kg by analyzing data from six asthma clinical trials: five placebo-controlled (duration ≤52 weeks) and one open-label extension (up to 2 years of treatment). Methods Patients were aged 12–75 years with inadequately controlled asthma with eosinophilia. In the placebo-controlled trials, 730 patients received placebo and 1028 reslizumab 3.0 mg/kg. Results Adverse events (AEs) and serious AEs occurred in higher percentages of patients in the placebo group (81% and 9%) than with reslizumab (67% and 6%). Asthma, nasopharyngitis and upper respiratory tract infection were the most common AEs with placebo and reslizumab. Three cases of anaphylaxis, related to reslizumab, were successfully managed with standard therapies. No significant difference in the incidence of malignancies was seen when compared with placebo or the general population. Among 756 patients with >12 months of reslizumab exposure, the AE rate was lower than in the placebo-controlled trials (367.3 vs 433.9 events/100 patient-years). The incidence of AEs in patients on treatment for >12 months was no higher than in patients with shorter treatment durations. Conclusions This analysis confirms that treatment with intravenous reslizumab for >12 months is well tolerated in patients with asthma, with no evidence of rare safety events that were not detected in individual trials.