Defining Clinically Relevant Target Populations Using Real-World Data to Guide the Design of Representative Antidiabetic Drug Trials

The US Food and Drug Administration is considering replacing cardiovascular outcome trials of antidiabetic drugs with trials that better represent patients with type 2 diabetes. However, designing such representative trials requires understanding the underlying target populations (i.e., populations intended to receive the drug in the real-world setting). Thus, we used the Liraglutide Effect and Action in Diabetes: Evaluation of Cardiovascular Outcome Results (LEADER) trial as a motivating example to illustrate how different target populations impact trial representativeness. Using the United Kingdom Clinical Practice Research Datalink, we identified three target populations: (i) all patients with type 2 diabetes; (ii) patients prescribed liraglutide; and (iii) patients who would have been eligible to receive liraglutide based on treatment stage (i.e., patients with poorly controlled diabetes eligible to receive a second-to-fifth line antidiabetic drug). We then examined the representativeness of the LEADER trial by applying its eligibility criteria to each target population. The target populations of patients with type 2 diabetes (n = 279,763), those prescribed liraglutide (n = 14,421), and those eligible to receive liraglutide based on the treatment stage (n = 85,610) differed substantially in terms of hemoglobin A1c, body mass index, prevalence of heart failure, and chronic kidney disease. Applying the LEADER trial eligibility criteria to these target populations resulted in the inclusion of 19.1%, 20.7%, and 34.8% patients, respectively. This study highlights how real-world data can be used to define different target populations. Explicitly defining these target populations can help in the design of future trials of antidiabetic drugs.