Sample size and power estimation in "thorough" QT/QTc studies with parallel group design

Area of Science:

• Pharmacology
• Clinical Trial Design
• Biostatistics

Background:

• Thorough QT/QTc studies are essential for assessing cardiac safety of new drugs.
• Accurate power and sample size calculations are critical for efficient study design.

Purpose of the Study:

• To develop and validate analytical methods for power calculation in four-arm parallel QT/QTc studies.
• To assess the non-inferiority of supratherapeutic to therapeutic doses using established statistical tests.

Main Methods:

• Developed analytical results for power computation in a four-group parallel design (placebo, positive control, supratherapeutic, therapeutic doses).
• Employed linear mixed-effects models with baseline covariate for non-inferiority assessment using intersection-union tests.
• Compared analytical power estimates with simulation study results.

Main Results:

• Analytical results for power estimation were developed for the specified study design.
• The intersection-union test within a linear mixed-effects model framework was used for non-inferiority assessment.
• Power estimates from analytical methods closely matched those from simulation studies.

Conclusions:

• The developed analytical results provide a reliable method for computing power and sample size in thorough QT/QTc studies.
• These analytical methods can be effectively utilized during the planning phase of clinical trials.
• The findings support the use of these methods for efficient and accurate study design in drug development.