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Lessons Learned From Hundreds of Thorough QT Studies
Joanne Zhang1, Huifang Chen1, Yi Tsong1
11 Division of Biometrics VI, Office of Biostatistics, Center of Drug Evaluation and Research, Food and Drug Administration, Silver Spring, MD, USA.
Analyzing the QTc-drug concentration relationship slope helps predict QT study outcomes. A positive slope strongly suggests positive QT study results, potentially avoiding unnecessary thorough QT (TQT) studies.
Area of Science:
- Pharmacology
- Clinical Pharmacology
- Drug Development
Background:
- Investigating the relationship between QTc interval and drug plasma concentration.
- Evaluating this relationship against International Council for Harmonisation (ICH) E14 findings using extensive QT study data.
Purpose of the Study:
- To determine the predictive value of the QTc-drug concentration relationship slope for QT study outcomes.
- To inform decisions on the necessity of thorough QT (TQT) studies during drug development.
Main Methods:
- Analysis of the slope representing the QTc-drug plasma concentration relationship.
- Correlation of slope findings with existing QT study reports and ICH E14 guidelines.
- Assessment of confidence intervals for QTc at fixed drug concentrations (e.g., Cmax).
Main Results:
- A non-positive slope correctly predicted negative QT studies in 86% of cases.
- A positive slope correctly predicted positive QT studies in 92% of cases.
- Confidence intervals at fixed concentrations can help stratify risk.
Conclusions:
- Relationship analysis between QTc and drug concentration, using single ascending dose (SAD) and multiple ascending dose (MAD) data, can guide TQT study decisions.
- If the relationship is undetectable and confidence intervals are below 10 ms, a TQT study may be avoidable.
- Established relationships with confidence intervals above 10 ms warrant further investigation, potentially including intensive safety monitoring or a TQT study.
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