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Evaluating the efficiency of targeted designs for randomized clinical trials

Richard Simon¹, Aboubakar Maitournam

¹Biometric Research Branch, National Cancer Institute, Bethesda, Maryland 20892-7634, USA. rsimon@nih.gov

Clinical Cancer Research : an Official Journal of the American Association for Cancer Research

|October 27, 2004

Abstract

Purpose:

Genomic technologies make it increasingly possible to identify patients most likely to benefit from a molecularly targeted drug. This creates the opportunity to conduct targeted clinical trials with eligibility restricted to patients predicted to be responsive to the drug.

Experimental Design:

We evaluated the relative efficiency of a targeted clinical trial design to an untargeted design for a randomized clinical trial comparing a new treatment to a control. Efficiency was evaluated with regard to number of patients required for randomization and number required for screening.

Results:

The effectiveness of this design, relative to the more traditional design with broader eligibility, depends on multiple factors, including the proportion of responsive patients, the accuracy of the assay for predicting responsiveness, and the degree to which the mechanism of action of the drug is understood. Explicit formulas were derived for computing the relative efficiency of targeted versus untargeted designs.

Conclusions:

Targeted clinical trials can dramatically reduce the number of patients required for study in cases where the mechanism of action of the drug is understood and an accurate assay for responsiveness is available.

Insights

Targeted clinical trials can significantly reduce patient numbers by selecting individuals likely to respond to a drug. This approach enhances efficiency when the drug

Area of Science:

Biomedical research
Clinical trial design
Genomic medicine

Background:

Genomic technologies enable precise identification of patients likely to benefit from targeted therapies.
This facilitates the development of targeted clinical trials with restricted eligibility criteria.

Purpose of the Study:

To evaluate the efficiency of targeted clinical trial designs compared to traditional untargeted designs.
To assess the impact of patient selection on trial resource requirements.

Main Methods:

Comparative analysis of targeted versus untargeted randomized clinical trial designs.
Evaluation of efficiency based on patient numbers for randomization and screening.

Main Results:

The relative efficiency of targeted designs is influenced by the proportion of responsive patients, assay accuracy, and understanding of the drug's mechanism of action.
Formulas were developed to quantify the efficiency gains of targeted over untargeted designs.

Conclusions:

Targeted clinical trials offer substantial reductions in required patient numbers.
This efficiency is maximized when the drug's mechanism of action is understood and a reliable responsiveness assay is available.

Read full analysis

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