Dose-ranging study

A dose-ranging study is a clinical trial where different doses of an agent (e.g. a drug) are tested against each other to establish which dose works best and/or is least harmful.

Dose-ranging is usually a phase I or early phase II clinical trial. Typically a dose ranging study will include a placebo group of subjects, and a few groups that receive different doses of the test drug. For instance, a typical rose ranging study may include four groups: a placebo group, low-dose group, medium-dose group and a high-dose group. The maximum tolerable dose (MTD) information is necessary to be able to design such groups and therefore dose-ranging studies are usually designed after the availability of MTD information.

The main goal of a dose-ranging study is to estimate the response vs. dose given, so as to analyze the efficacy and safety of the drug. Although such a response will nevertheless be available from phase III or phase IV trials, it is important to carry out dose-ranging studies in the earlier phase I or phase II stages. The main reasons for this is to avoid trials in the later phases using doses that are significantly different from those that will subsequently be recommended for clinical use and also to avoid the need for modification of dosing schedules at later stages where a large amount of data has already been accumulated for a different dose range.