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Points to Consider in Defining Region for a Multiregional Clinical Trial: Defining Region Work Stream in PhRMA MRCT Key Issue Team

Title
Points to Consider in Defining Region for a Multiregional Clinical Trial: Defining Region Work Stream in PhRMA MRCT Key Issue Team

Abstract
This article describes the work of the PhRMA MRCT work stream in examining the points to consider when defining “region” and recommends a more systematic approach in defining region in MRCTs. This approach goes beyond drawing lines on a map. By a standardized approach, the key is the need for the sponsor to think through carefully, prespecify, and justify any regional definition as well as to obtain regulatory concurrence prior to study conduct. The article proposes that adequate justification of the definition would take into consideration intrinsic and extrinsic factors such as race or ethnicity, disease epidemiology, medical practice, and geographic proximity, among others. The article also provides a review of regional definition and analysis of 60 recent FDA advisory committee reviews to provide context. Predefining region, accounting for any factors within or across regions that may affect the size of the treatment effect, and documenting this definition as early in the trial conduct as possible (eg, a protocol or statistical analysis plan) will have benefits at the design, analysis, and regulatory review stages.