Seamless phase II/III design: a useful strategy to reduce the sample size for dose optimization

Area of Science:

• Oncology
• Clinical Trial Design
• Pharmacology

Background:

• The conventional "more-is-better" dose selection paradigm, established for cytotoxic chemotherapeutics, presents challenges for novel molecularly targeted agents.
• The US Food and Drug Administration's Project Optimus aims to reform dose optimization in oncology drug development, prioritizing benefit-risk assessments.

Purpose of the Study:

• To identify and evaluate different Phase II/III dose-optimization designs for oncology drug development.
• To assess the statistical and operational considerations for effective dose optimization using these designs.

Main Methods:

• Classification of Phase II/III dose-optimization designs based on trial objectives and endpoint types.
• Computer simulations to examine the operating characteristics of various dose-optimization designs.
• Analysis of statistical power, type I error rates, and sample size requirements.

Main Results:

• Phase II/III dose-optimization designs effectively control family-wise type I error rates and achieve adequate statistical power.
• These designs offer substantial sample size reductions (16.6%–27.3%, mean 22.1%) compared to conventional methods.
• A reduction in patient toxicity is observed with the implementation of these optimized designs.

Conclusions:

• Phase II/III dose-optimization designs provide an efficient approach to reduce sample sizes and expedite the development of targeted oncology agents.
• Interim dose selection in these designs introduces logistical and operational complexities.
• Careful planning and implementation are crucial for maintaining trial integrity with Phase II/III dose-optimization designs.