Efficacy of Biologics in Patients With Severe Allergic Asthma

In this video, Jonathan A. Bernstein, MD, explains the results of a study that focused on efficacy of biologics in patients with severe allergic asthma, including omalizumab, belimumab, mepolizumab, dupilumab, and tezepelumab. 

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Jonathan A. Bernstein, MD, is a professor of clinical medicine at the University of Cincinnati College of Medicine in the Division of Rheumatology, Allergy and Immunology and Partner of Bernstein Allergy Group and Bernstein Clinical Research Center (Cincinnati, OH).

TRANSCRIPTION:

Dr Jonathan A. Bernstein: I'm Dr Jonathan Bernstein, Professor of Medicine at the University of Cincinnati and Partner of Bernstein Allergy Group and Clinical Research Center. This is an oral presentation of a study that was conducted and the purpose of this was to describe reductions in annualized asthma exacerbation rates from randomized control trials for patients with severe allergic asthma with no blood eosinophilic cell restriction and by baseline blood eosinophil cell category. And so this was a literature search. And so they looked at phase three placebo control, randomized controlled trials, FDA-approved biologics for severe uncontrolled asthma. Patients had to have severe asthma, confirmed allergy to perennial air allergens, and allergic asthma exacerbation rates reduction were required to be measured in the overall population and/or the reduction measured in high or low blood eosinophil count subgroups. And these are defined as greater than or equal to 300 cells per microliter and less than 300 cells per microliter, respectively.

They basically looked at the currently approved therapies for severe asthma, which included omalizumab, belimumab, mepolizumab, dupilumab, and tezepelumab. They looked at the different characteristics and they were able to do some forest plots that would show which therapy was favored treatment versus placebo when there was no blood eosinophillic restriction and all of the therapies that they could assess, including tezepelumab, dupilumab, and omalizumab showed favorable response to treatment when there was no blood eosinophilic restriction in patients who had blood eosinophils greater than 300 cells, or more. Tezepelumab, mepolizumab, dupilumab, benralizumab, and omalizumab, all favored were all favored over placebo in terms of responses to treatment. And interestingly, when you look at the blood eosinophils cells less than 300, there weren't that many studies. Basically, there was mepolizumab. And again, because the only mepolizumab data available for patients with severe allergic asthma and a blood eosinophillic count of less than 300 were those for with a history of blood eosinophils greater than quarter of 300. And they found that it was favorable, but they had subcategorized the patients for greater than or less than 300 eosinophils.

And then they looked at patients who had less than 300 cells. And the studies that actually looked at tezepelumab, benralizumab, and omalizumab, they were the ones that seemed to be favorable. But the greatest favor, the one that had the greatest favorable of treatment compared to placebo, was tezepelumab, compared to benralizumab and omalizumab, which actually had the least.

So I think that the purpose of this in terms of the conclusions and all the available data demonstrated efficacy and reducing allergic asthma exacerbation rates in patients with perennial allergy and baseline blood eosinophil counts greater than or equal to 300 cells. The smallest reduction was observed with omalizumab and among patients with severe allergic asthma tezepelumab was the only biologic that demonstrated meaningful reduction in those with a baseline eosinophil count less than 300 regardless of prior blood eosinophil counts.

And so the efficacy of biologics and reducing exacerbations and randomized control trials varies considerably overall and by blood eosinophil count, and these difference can help inform treatment provider decisions. And of course, caution in terms of direct comparison always has to be considered as these, were not head on head comparative trials. These are just comparing different studies so that's a limitation of this study.