Biologic Use Varies Between Races in Patients With Asthma

Pam Harrison

September 08, 2022

In comparison with White patients, Black patients are prescribed more anti-IgE biologics for the treatment of asthma, whereas Hispanic patients are prescribed fewer anti-IL-5 biologics, a retrospective cohort study suggests.

"Our data did not reveal broad racial or ethnic disparities in the prescription of asthma biologics by US physicians," senior author Taha Al-Shaikhly, MBChB, Penn State College of Medicine, Hershey, Pennsylvania, and colleagues observe.

"But to our knowledge, this is the first matched-cohort study that utilized real-world claims data to examine racial and ethnic disparities in biologic utilization among US adults with asthma, and herein, we noted higher biologic use among Black patients with asthma — specifically higher use of omalizumab (Xolair) — [which] was unexpected as Black patients have been shown to be under-prescribed controller therapies for asthma and generally have less access to biologic therapies as seen with other diseases," they comment.

The study was published online in the Journal of Allergy and Clinical Immunology: In Practice.

Moderate to Severe Asthma

Some 95,363 White patients, 15,435 Black patients, 12,645 Hispanic patients, and 1673 Asian patients with moderate to severe asthma were invovled in the study. The study included publicly and commercially insured patients, and cohorts were balanced for baseline comorbidities and medication utilization. After accounting for confounders, 15,432 patients remained in each of the Black and White cohorts.

Compared to White patients, "a higher proportion of Black patients were started on an asthma biologic," the authors note. Proportionately fewer Hispanic patients received anti-IL-5 therapies compared to White patients. In contrast, an equal proportion of Asian and White patients were prescribed any biologic, the investigators note.

The higher use of asthma biologics by Black patients may be explained by the fact that morbidity and mortality from asthma is higher among Black patients than White patients, according to the authors. "Black individuals [also] have a higher prevalence of allergic asthma [which] possibly [explains] the higher utilization of omalizumab," they observe.

Asthma rates among Hispanic patients are comparable to rates among White patients, although Hispanic patients are more likely to seek emergency treatment for asthma. "Therefore, the relatively lower prescription of anti-IL-5 therapy and the equivalent biologic prescription overall among White and Hispanic patients noted in our study should be cautiously interpreted, especially as more Hispanic individuals are uninsured or publicly insured, a factor we could not account for in our study," the authors caution.

Editorial Comment

Asked by Medscape Medical News to comment on the study, Juan Carlos Cardet, MD, MPH, assistant professor of medicine, University of South Florida, Gainesville, Florida, said the study shows that among patients prescribed medium- to high-dose inhaled corticosteroids (ICS) and long-acting beta-agonists (LABA) to control asthma, non-Hispanic Black patients were more likely than White patients to be prescribed biologic therapies for asthma, and of those therapies, non-Hispanic Black patients were more likely to be prescribed omalizumab (Xolair).

"In contrast, the proportion of Hispanic and White patients prescribed biologics was similar, but fewer Hispanic patients received anti-IL5 biologics," he added in an email. While it is cautiously encouraging that Black and Hispanic patients may have access to efficacious biologic therapies, Cardet felt the study design has a few important limitations ― which the authors acknowledge ― and that readers should be cautioned against such an interpretation just yet.

"One [factor] is that the higher rates of Black patients receiving biologics relative to White patients might be because Black patients are more likely to experience greater rates of asthma exacerbations, morbidity, and mortality relative to White patients; eligibility for biologics does not only require a prescription for medium-high ICS and LABA (which was one of the study's entry criteria) but also a history of asthma exacerbations, with a threshold number of asthma exacerbations per year that varies by insurance company," Cardet pointed out.

A second factor, and perhaps most importantly, the study does not capture patients who were not prescribed medium-high dose ICS/LABA, which is relevant to the question regarding access to care. "Black patients may still be more likely to have uncontrolled, exacerbation-prone asthma, likely benefit from biologics, but not have been factored in by the study authors, as they were not prescribed medium-high dose ICS/LABA, perhaps precisely because of lack of access to care that would get them medium-high- dose ICS/LABA," Cardet suggested.

The choice of biologic for both Black and Hispanic patients (eg, omalizumab, anti-IL5 biologics) may also be informed by insurance company preferences, not necessarily clinical characteristics. Finally, the data are from 2017–2018, so these results describe recent prescription practice in the country, and the study does not inform clinicians as to whether patients with asthma should be managed differently on the basis of racial and ethnic group.

The study was supported by the National Center for Advancing Translational Sciences, National Institutes of Health. Taha Al-Shaikhly has patents pending for microRNA as predictors of response to anti-ige therapies as well as for microRNAs in methods of treatment using omalizumab and ligelizumab. Cardet has received honoraria for work on advisory boards or for giving educational lectures on asthma pathobiology and management from Genentech, AstraZeneca, GSK, and Sanofi.

J Allergy Clin Immunol Pract. Published online August 19, 2022. Abstract

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