Treatment Gaps Identified: Respiratory Biologics Underused in Patients With Obesity and Asthma

A retrospective study of electronic health records from a major U.S. health system has revealed startlingly low prescription rates for respiratory biologics among eligible adults with asthma and elevated body mass index. Spanning from 2018 to 2023, the analysis focused on over 5,800 patients who suffered from moderate-to-severe asthma and met the FDA’s criteria for these advanced treatments. The findings, recently published in The Journal of Allergy and Clinical Immunology: In Practice, suggest that obesity itself may act as an unintended barrier to receiving modern asthma care.

Patients who struggle with both asthma and obesity face a dual burden. They generally experience a higher baseline risk for severe attacks, also known as exacerbations, and are more likely to suffer from the negative effects of the corticosteroids typically used to manage the condition. Biologics offer a targeted alternative that can reduce the need for these systemic steroids, yet the data shows that the vast majority of eligible candidates are not being offered this option. Specifically, while nearly 60% of the eligible cohort had obesity, only about one in ten were actually prescribed a biologic.

One of the most telling aspects of the study was the timeline for treatment. Adjusted analyses indicated that a higher BMI was directly associated with a longer wait time from becoming eligible to actually receiving a prescription. This delay persists even when patients meet the specific biological markers, such as high eosinophil counts, that should trigger a conversation about advanced therapy. The research suggests that clinicians may be prioritizing other aspects of care or potentially misinterpreting the severity of asthma symptoms when obesity is present.

The study underscored that the single most important factor in whether a patient received a biologic was access to subspecialist care. Those who were referred to allergists or pulmonologists were far more likely to be evaluated for advanced therapies than those managed solely by primary care physicians. This points toward a systemic need for better referral patterns and a more streamlined approach to identifying patients who could benefit from specialty management.

Interestingly, the effectiveness of these drugs was not diminished by a patient’s weight. For the small group of individuals with obesity who did receive T2-directed biologics, the rate of severe asthma attacks dropped significantly. This confirms that these treatments are highly effective even in populations that have traditionally been considered more difficult to treat. The study also looked at whether lowering the threshold for certain biomarkers would help identify more candidates for treatment, but found that expanding eligibility in this way did not necessarily lead to better clinical outcomes.

Moving forward, medical professionals are calling for two major shifts in practice. First, there is an urgent need to ensure equitable access to these life-changing therapies for those who already qualify under current guidelines. Second, further research is required to refine how biomarkers are interpreted in the context of obesity, ensuring that every patient receives the most appropriate level of care. By addressing these barriers, health systems can better support one of the most at-risk segments of the asthma community.