Glossary

The first phase of clinical trial testing for a new medicine. Phase I trials are normally conducted on a limited number of subjects. Subjects for Phase I trials are normally healthy volunteers rather than patients suffering from the relevant diseases when medicines are being tested.

The second phase of clinical trial testing for a new medicine conducted if Phase I trials have progressed satisfactorily. Usually the first trials to assess side effect potential and some measures of efficacy in patients, for mass market medicines.

The third stage of clinical trial testing, conducted to determine whether a new medicine can be granted regulatory approval for distribution and sale.

An initial clinical trial to evaluate the efficacy of a new drug in a small group of patients (see randomised double blind placebo controlled trial).

Gathering data to substantiate the feasibility of a key stage in a new drug development program.