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Clinical Trials

»‘Raising the Bar’ through Clinical Trials
»A Large Patient Population
»Getting Started…
»Clinical Trial Phases
»Major Successes

Clinical Trial Phases

Clinical trials that involve new drugs generally involve four phases of testing before the drugs can be marketed and used outside of strict testing situations. A drug is usually approved for sale by the national regulatory authority after successful completion of Phase III.

Phase I trials are the first stage of testing a new drug in humans. It is a stage designed to assess the safety and tolerability of a new drug. Usually the drug is administered to a small sample of 20 to 50 people in groups of three to six at a time, with very careful monitoring by fully trained health care professionals. This is the phase when the appropriate dose (and frequency of use) is determined.

With the initial safety of a drug confirmed in Phase I, Phase II trials are performed on larger groups of patients with a focus on determining the effectiveness of the drug.

Phase III trials are typically randomized and involve multiple hospitals/facilities. ‘Randomized’ means that each patient in the trial is randomly assigned to receive either the test drug or the current ‘standard of care’ for their type of cancer. The latter group is called the ‘control group’. The size of each group is typically in the range of 300 to 3,000 people. These trials are expensive, time-consuming and challenging to set up, but if the results are positive, a Phase III trial is considered a definitive assessment of a drug’s effectiveness.

Below is a diagram that shows the approximate timeline involved in developing and testing a new drug.

Phase IV trials often have different objectives. They can be testing the long-term safety of the drug, testing the drug against different populations (e.g., people with specific health conditions) or testing the drug in combination with different drugs.

It is important to note that not all clinical trials result in moving a new treatment or drug forward. In fact, despite the best preparation and optimism for a potential new treatment, there are many that do not get past phase I. However, without many trials, there would not be the breakthroughs that are needed for cancer prevention and treatment.