Abstract
BACKGROUND: Prolongation of overall survival (OS) is commonly evaluated as a primary endpoint in confirmative oncology clinical trials; however, it is potentially affected by subsequent treatments carried out in practice. To design and implement multi-regional clinical trials properly, we compared survival outcomes between Organisation for Economic Co-operation and Development (OECD) and non-OECD countries. MATERIALS AND METHODS: Individual patient data from industry-sponsored multi-regional phase III oncology trials were obtained from the Project Data Sphere. Patients of each arm were divided into several subgroups based on race and country where patients were enrolled. We defined the member countries of the OECD. Cox regression analysis was conducted to estimate the hazard ratio (HR) for progression-free survival (PFS) and OS between the different subgroups in each trial, followed by a meta-analysis to estimate the summary HR and its confidence interval with a random-effect model. RESULTS: Eleven arms from 10 clinical trials were eligible for the analysis. No statistically significant difference was observed in PFS and OS between Caucasian and Asian. A prolongation of OS was observed in patients enrolled in the OECD group compared with non-OECD group, while no statistically significant difference was observed in PFS. CONCLUSION: The economic status and healthcare environment of countries where patients reside have an impact on the outcome of OS. Clinical trial sponsors are recommended to consider carefully how to properly design oncology clinical trials including the selection of countries and data management of subsequent treatments.