WHO Performance Status Classification

Performance status is frequently used to quantify cancer patients’ well-being and often used to indicate whether or not a patient can tolerate certain treatment such as chemotherapy. Other uses include dose reduction, use in trial and quality of life.

Grade Explanation of activity

Criteria of chemotherapy response (WHO)

Clinical Trials and Drug Development

Clinical trials are divided into different stages, called phases. The earliest phase trials may look at drug safety or side-effect profile and tolerability. A later phase trial aims to test whether a new treatment is better than existing treatments.

There are three main phases of clinical trials – phases I to III. But some trials have an earlier stage called phase 0, and there are some phase IV trials done after a drug has been licensed.

Phase 0 Trials

Phase 0 trials are aimed to find out whether the behaviour of the drug in vivo is as expected from laboratory studies.

Phase I

Aim is to establish human toxicity of new drug; to establish the safe dose at which to start further trials and to measure the pharmacokinetics of the drug.

Phase II

Aim is to establish the anti-tumour activity of the drug against a particular tumour in patients where no curative therapy is possible; further information on toxicity is obtained. Phase II studies are usually non-randomised.

Phase III

Aim is to compare the new drug with the conventional best therapy. Trials are prospective, randomised and controlled. Large number of patients required to show effect.