Thorough QT/QTc (TQT/QTc) studies are used to assess the cardiovascular effects of a non-antiarrhythmic drug. They can be expensive, costing a great deal to perform, interpret and report a TQT study. The results can include detailed descriptions of the pharmacokinetics and pharmacodynamic results of a drug. Some studies also include positive and negative controls.
A thorough QT/QTc study aims to evaluate the effect of a new molecular entity on the cardiac repolarization interval. This is a critical step for the evaluation of drugs that may cause ventricular arrhythmias. Normally, these studies are conducted in healthy volunteers. It is a key component of all clinical development programmes. For more information on Thorough QT Studies, visit www.richmondpharmacology.com/specialist-services/tqt
TQT studies are generally run in the early stages of drug clinical development. It can take months to complete a TQT study, depending on the size of the sample. It is important to ensure that the study is conducted under stringent conditions. In particular, the study should have a positive control group and a blinded placebo group. The resulting data can be used to assess the predictive capabilities of preclinical biomarkers. The results can then be used to determine the probability of drug approval.
Almost all new drugs must be tested in a thorough TQT/QTc study. This is because there is a high risk of arrhythmia from some drugs. If there is no clear evidence of an adverse cardiovascular effect, the drug can continue in development. But a positive result in a TQT study can lead to expanded safety analysis during the whole course of drug development.
It is essential to conduct a thorough QT/QTc study on all investigational compounds. This is a standard part of any clinical development programme and has been developed into a standardized guideline. The regulatory bodies and the pharmaceutical industry have worked together to set these standards.
A thorough QT/QTc study is normally performed on healthy volunteers. During the trial, blood samples are obtained and analyzed at fixed time intervals. These studies are used to assess the cardiovascular effects of the drug. They may also be used in later-stage clinical trials.
Although the study design can be very dependent on the half-life of the drug, a sample size of 32 to 48 subjects is often enough to provide sufficient statistical power. The results from these studies will be useful in guiding the drug’s use.
