A randomized group sequential enrichment design for immunotherapy and targeted therapy.

Area of Science:

• Biostatistics
• Clinical Trial Design
• Pharmacology

Background:

• Many patients benefit from targeted therapy or immunotherapy, but only a specific subpopulation is sensitive.
• Pre-clinical data often incorrectly identifies the sensitive subpopulation, leading to challenges in clinical trials.
• Existing methods struggle to accurately identify responsive patient groups in real-time during trials.

Purpose of the Study:

• To propose a novel randomized, group sequential enrichment (GSE) design for clinical trials.
• To simultaneously determine experimental treatment efficacy and identify the sensitive patient subpopulation.
• To improve upon conventional and existing two-stage enrichment designs.

Main Methods:

• The GSE design enrolls patients broadly initially, then adapts eligibility criteria using short-term and long-term survival endpoints.
• It employs a group sequential approach for adaptive enrichment based on accumulating trial data.
• Short-term endpoints facilitate enrichment with limited survival events, while survival data confirms efficacy.

Main Results:

• Simulation studies demonstrate that the GSE design effectively controls the type I error rate.
• The proposed design shows substantially higher statistical power compared to conventional group sequential designs.
• It outperforms existing two-stage enrichment designs in identifying sensitive subpopulations.

Conclusions:

• The GSE design is a robust adaptive strategy for precision medicine in clinical trials.
• It successfully balances the goals of confirming treatment efficacy and identifying the target patient population.
• This approach offers a more powerful and accurate method for evaluating experimental treatments in sensitive subpopulations.