Asthma Biologics: Comparing Trial Designs, Patient Cohorts and Study Results

Objective: Five biologic therapies have FDA-approved indications for difficult-to-control asthma. The clinical trials that proved the efficacy and safety of these biologics were often similar in their inclusion criteria, study designs, and endpoints. Many of these trials have been reanalyzed post hoc to identify subsets of subjects considered to be enhanced responders. As a result, keeping up with the literature and deciding on the most appropriate biologic for our patients has become increasingly difficult. This review summarizes and compares trial designs, patient cohorts, and study results of the major trials involving these therapies.

Data Sources: Included are basic science articles, online Food and Drug Administration (FDA) applications, and all the published reports of phase II and phase III clinical trials for FDA-approved asthma biologics.

Study Selections: Included are the major phase II and phase III clinical trials of 5 asthma biologics.

Results: Because of variations in inclusion criteria and natural variations in enrolled cohorts, the baseline clinical traits and severity of study populations in asthma biologic trials differed significantly, which is important because baseline annualized exacerbation rates and blood eosinophilia are both strong predictors of a biologic's success. Notwithstanding, the trial results, when considered together, can help guide care providers in choosing the most appropriate biologic for our patients.

Conclusion: Understanding the details and differences in asthma biologic trial designs, patient cohorts, and in study results will help care providers make more informed decisions when choosing a biologic. We are hopeful this review will serve as a reference to care providers for this purpose.