Categorizing by eosinophilic/noneosinophilic subtype enables better targeted treatment, noted Anne Reihman, MD, third-year pulmonary and critical care fellow, University of Colorado, Division of Pulmonary Sciences and Critical Care Medicine.
Categorizing patients into eosinophilic and noneosinophilic subtypes enables better targeted treatment, emphasized Anne Reihman, MD, third-year pulmonary and critical care fellow, University of Colorado, Division of Pulmonary Sciences and Critical Care Medicine.
What differentiates eosinophilic asthma from nonallergic asthma?
We categorize into 2 big buckets. So there's eosinophilic, or T2, asthma and then there's noneosinophilic, or non-T2, asthma. And the eosinophilic asthmatics, or T2 asthmatics, are the patients we classically think of as having asthma. There are those patients who tend to have a lot of seasonal allergies, they may have other features of SOB [shortness of breath] like eczema, chronic sinusitis, things like that. And that's in comparison to the non-T2 asthmatics who don't demonstrate this allergic phenotype. Instead, it's thought to be more of a neutrophilic-driven process, and they actually probably tend to be harder to control because we don't have great drugs for them at this point in time. But the patients who we target with the anti–IL [interleukin]-5 therapies that I mentioned tend to be these eosinophilic asthmatics, and so actually categorizing patients into one of these 2 big categories is really important because it affects what drugs that are candidates for.
What targets do anti–IL-5 therapies address that other treatments do not?
So the anti–IL-5 therapies, as I've mentioned, have been really life-changing for some patients with eosinophilic asthma. From the studies on them, we know that they can decrease asthma exacerbation rates, they decrease systemic steroid use, they can improve lung function and improve asthma symptoms. And so these therapies specifically try and target inflammatory pathways involved in eosinophilic asthma, like I mentioned—the IL-5 inflammatory pathway—which goes on to lead to eosinophil production and activation.
There's other therapies, like omalizumab, which targets IgE [immunoglobulin E], which again is also involved in the allergic response in asthma. And then there's the most recently approved medication, dupilumab, which is an anti–IL-4 and -13 inhibitor, which are also important cytokines for the T2-inflammatory, or eosinophilic, kind of allergic asthma phenotype that we're talking about.