Overview
External control arms (ECAs) use real-world or historical data to provide comparison groups for clinical trials when randomized controls are not feasible. While promising, building ECAs requires careful alignment between trial criteria and real-world data, which can be challenging.
In this study, nine groups across multiple organizations collaborated to test the feasibility of constructing an ECA for a metastatic pancreatic cancer trial as part of the Friends’ collaborative pilot. They developed a shared analysis plan and applied it across different datasets, examining patient selection, data completeness, and alignment with trial criteria. The study found that certain eligibility criteria—such as organ function requirements—led to substantial patient attrition, while data missingness varied across sources.
Why this matters
This work highlights both the potential and the challenges of using ECAs in oncology. It shows that while ECAs are feasible, success depends on high-quality data, consistent methodology, and careful planning—critical factors for supporting regulatory decision-making when traditional trials are not possible.