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Published on: September 16, 2012
Designing phase II clinical trials to target subgroup of interest in a heterogeneous population: A case study using
B Cabarrou1, P Sfumato2, E Leconte3
1Institut Claudius Regaud-IUCT-O. Biostatistics Unit, Toulouse, France.
Abstract:
Phase II trials that evaluate target therapies based on a biomarker must be well designed in order to assess anti-tumor activity as well as clinical utility of the biomarker. Classical phase II designs do not deal with this molecular heterogeneity and can lead to an erroneous conclusion in the whole population, whereas a subgroup of patients may well benefit from the new therapy. Moreover, the target population to be evaluated in a phase III trial may be incorrectly specified. Alternative approaches are proposed in the literature that make it possible to include two subgroups according to biomarker status (negative/positive) in the same study. Jones, Parashar and Tournoux et al. propose different stratified adaptive two-stage designs to identify a subgroup of interest in a heterogeneous population that could possibly benefit from the experimental treatment at the end of the first or second stage. Nevertheless, these designs are rarely used in oncology research. After introducing these stratified adaptive designs, we present an R package (ph2hetero) implementing these methods. A case study is provided to illustrate both the designs and the use of the R package. These stratified adaptive designs provide a useful alternative to classical two-stage designs and may also provide options in contexts other than biomarker studies.
Insights
Biomarker-guided Phase II trials need adaptive designs to identify patient subgroups benefiting from targeted therapies. This study introduces stratified adaptive designs and an R package (ph2hetero) to improve clinical trial efficiency and accuracy in heterogeneous populations.
Area of Science:
- Clinical trial design
- Biostatistics
- Oncology research
Background:
- Classical Phase II trial designs struggle with molecular heterogeneity in biomarker-targeted therapies.
- This can lead to erroneous conclusions about treatment efficacy in the overall population.
- Subgroups of patients may benefit, but current designs may fail to identify them, impacting Phase III trial targeting.
Purpose of the Study:
- To introduce and evaluate stratified adaptive two-stage designs for Phase II trials with biomarker-selected patient populations.
- To address the limitations of classical designs in identifying patient subgroups that benefit from targeted therapies.
- To present an R package (ph2hetero) for implementing these advanced trial designs.
Main Methods:
- Review of stratified adaptive two-stage designs proposed by Jones, Parashar, and Tournoux et al.
- Development and presentation of the R package 'ph2hetero' for implementing these designs.
- Illustration of designs and package utility through a case study.
Main Results:
- Stratified adaptive designs allow for the identification of patient subgroups (biomarker-positive/negative) within a single study.
- These designs can accurately assess anti-tumor activity and clinical utility of biomarkers.
- The 'ph2hetero' R package provides a practical tool for applying these methods in oncology research.
Conclusions:
- Stratified adaptive designs offer a valuable alternative to classical two-stage designs for Phase II biomarker studies.
- These methods enhance the ability to detect treatment benefits in specific patient subgroups.
- The presented R package facilitates the adoption of these advanced designs in clinical research beyond biomarker studies.
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