In patients with late-onset asthma who have elevated blood eosinophils, the anti-interleukin 5 (IL-5) antibody reslizumab can reduce exacerbations by 75% compared with placebo, according to a new analysis of data from two phase 3 trials originally published in February.

That is an unprecedented result, said Guy Brusselle, MD, PhD, professor of medicine at Ghent University Hospital, in Belgium, who presented the research here at the European Respiratory Society (ERS) International Conference 2015.

Reslizumab is an interleukin-5 inhibitor, in the same class as GlaxoSmithKline’s mepolizumab — which has just been recommended for approval in adults only by an FDA advisory committee — and AstraZeneca’s benralizumab, which is due to be filed in the US and Europe next year.

“No study has shown such a dramatic benefit of targeted add-on therapy with monoclonal antibodies,” Dr Brusselle told Medscape Medical News.

Late-onset asthma was defined as occurring in those who were diagnosed with asthma after the age of 40 years. The drug also reduced exacerbations in patients younger than 40 years, but to a much lesser extent (42%).