Sample size determination for a specific region in a multiregional trial

Area of Science:

• Clinical pharmacology
• Biostatistics
• Regulatory science

Background:

• Geotherapeutics are gaining attention, necessitating efficient global development strategies.
• Traditional bridging studies (ICH E5) cause delays and resource duplication.
• Global drug development aims to shorten approval times and improve patient access.

Purpose of the Study:

• To establish statistical criteria for evaluating regional consistency in multiregional clinical trials.
• To assess if a specific region's treatment effect aligns with overall or other regional results.
• To provide a framework for sample size evaluation in the region of interest.

Main Methods:

• Focus on a specific region within a multiregional trial framework.
• Development of four statistical criteria to assess treatment effect consistency.
• Criteria evaluate if the region's effect is as large as overall/other regions and consistent with them.

Main Results:

• Proposed statistical criteria can evaluate regional treatment effect consistency.
• The criteria allow for assessment of alignment between a specific region and global results.
• Sample size determination for the region of interest can be informed by these criteria.

Conclusions:

• Multiregional trials offer a framework for global drug development and approval.
• Statistical criteria are crucial for demonstrating regional consistency and applicability of results.
• This approach can optimize resource allocation and expedite drug availability to patients worldwide.