The following is a summary of “Is the assessment of asthma treatment efficacy sufficiently comprehensive?,” published in the March 2024 issue of Allergy & Immunology by Stempel, et al.

Asthma guideline therapy aims to achieve disease control by minimizing impairment and decreasing the risk of exacerbations and adverse effects of the disease and its treatment. The primary objective of most clinical trials of biologics for severe asthma is a reduction in exacerbation rate. Recently, studies with patients at the lower guideline steps have also selected exacerbation reduction as a primary objective.

These trials in patients with milder disease frequently demonstrated statistically significantly fewer exacerbations, but their power calculations reflect larger sample sizes and smaller effect sizes. Exacerbations have a precise consensus definition, although a minimal clinically significant difference has yet to be established. Reduction of exacerbations in severe asthma is commonly 10-fold greater than in mild disease. Further, reduction in exacerbations is not always associated with reduced impairment. If superior control is the objective, both domains should demonstrate consistent and parallel improvement. The disconnect may reflect the need for alternative tools for measuring impairment or, possibly, different therapeutic mechanisms of action.

Determining response to biologics or discussing disease remission requires assessing symptoms that may occur daily rather than focusing on exacerbations that occur once or twice a year for patients at the highest steps of care, according to the guidelines.

The discrepancy observed may underscore the necessity for alternative measurement tools for assessing impairment or, potentially, different therapeutic mechanisms of action. Evaluating response to biologics or discussing disease remission necessitates evaluating daily symptoms rather than solely focusing on exacerbations, which occur infrequently for patients at the highest steps of care according to the guidelines.

Reference: sciencedirect.com/science/article/abs/pii/S0091674923024582