Published online: August 9, 2019
Patients with inadequately controlled asthma with elevated blood eosinophils (eosinophilia) are known to benefit from therapy that inhibits the cytokine interleukin-5 (IL-5). Reslizumab, a humanized monoclonal antibody targeting IL-5, is approved in several countries as an intravenous (IV) ‘add-on’ therapy for the treatment of adult patients with severe asthma with eosinophilia. In several individual studies lasting up to 52 weeks and in a 2-year open-label study, IV reslizumab showed benefits compared with placebo in terms of reducing acute exacerbations, and improving lung function, asthma control, and patient quality of life, and was well tolerated. However, limited information is currently available regarding rare adverse events or the long-term safety of IV reslizumab.
In a study recently published in The Journal of Allergy and Clinical Immunology: In Practice, Virchow and colleagues investigated the safety profile of IV reslizumab dosed at 3.0 mg/kg every 4 weeks, by combining five individual placebo-controlled trials (up to 52 weeks) and one open-label extension (up to 2 years, in which patients previously taking placebo were switched to receive reslizumab), to investigate risk of rare adverse events not seen in the individual trials. Thus, data were included for a larger number of patients over a longer duration than previously available. Patients aged 12–75 years with moderate-to-severe asthma with eosinophilia were included. In the placebo-controlled trials 730 patients received placebo and 1028 patients received reslizumab.
The authors found that the overall safety profile of IV reslizumab was similar to placebo. There were three cases of anaphylaxis related to reslizumab, however these were successfully managed with standard therapies. Patients who received reslizumab for longer than 12 months had no higher incidence of adverse events (AEs) than patients receiving a shorter treatment duration; AE rates were generally lower in patients who received reslizumab for longer than 12 months (367.3 patient-years) than in those treated for 52 weeks or less (433.9 events/100 patient-years). A 23% reduction in use of concomitant medications in patients receiving reslizumab compared with placebo suggested a reduced need for other therapies because of the therapeutic benefits of reslizumab.
Consistent with previous data indicating that IV reslizumab is well tolerated in patients with eosinophilic asthma, the authors’ findings revealed no evidence of rare adverse events or of new safety issues with reslizumab for treatment durations of more than 12 months.
The Journal of Allergy and Clinical Immunology: In Practice is an official journal of the AAAAI, focusing on practical information for the practicing clinician.