Phase I & II Trials

Picture of a GP taking medical notesPhase I clinical trials are the first trials in human subjects. These are usually healthy volunteers, but some medicines, such as treatments for cancer, are tested on patients.

A Trial Manager will coordinate the work of the team from beginning to end, with administrative help from Trials Assistants.

At the start of a study, A Principal Investigator (a research scientist who may also be a doctor) writes a protocol to describe how the medicine will be tested and to make sure that the study will provide useful results. The protocol then must be approved by an Ethics Committee to make sure that the study is ethical and does not pose unnecessary risks.

A Drug Supply Manager will oversee the formulation of the medicines, and a Qualified Person will check each batch of medicine to make sure that it has been manufactured correctly. A Clinical Database Manager will design a computer system to store data from the trial. Medical Statisticians and a Data Manager will oversee and analyse the data gathered during the trial, and Clinical Research Associates will coordinate the data collection and recording. Research Nurses will work with the patients. This whole process will be overseen by a Quality Assurance Manager, who makes sure the clinical side of the research team follows the protocol.

Phase I trials may identify side effects in humans which were not seen or predicted from tests in animals, and many potential medicines are ruled out at this stage.

Where Phase I trials are used to screen out medicines with unpleasant side effects, Phase II trials are used to determine whether a medicine has the expected activity and the optimum effective dose. This is the point where the balance of activity (how well the medicine works) and toxicity (any damage the medicine causes the patient) is most acceptable.