Clinical trials on new and established therapies are an important part of improving the care and treatment offered of patients.
- What are clinical trials?
- Who performs clinical trials?
- How are clinical trials carried out?
- Which treatments & therapies are approved for use?
A clinical trial is a research study in human volunteers to evaluate the effectiveness and safety of medications or medical devices by monitoring their effects in human volunteers.
There are different kinds of clinical trials, including the study of:
- new diagnostic and screening techniques,
- new treatments or new methods of use of existing treatments,
- options for improving the quality of life for people who have serious medical conditions and
- disease prevention options.
These trials can only take place once satisfactory information has been gathered on the non-clinical safety of the product and Health Authority/Ethics Committee approval must be granted in the country where the trial is taking place.
Clinical research trials are conducted by government health agencies such as National Institute of Health (NIH), researchers affiliated with a hospital or university medical program, independent researchers, or private industry.
Clinical trials are conducted according to a plan called a protocol. The protocol specifies the length of study, schedules of prodecures and tests, type of drug, drug dosges, the nature of the results to be measured and what types of patients may enter the study. Each person participating in the study must provide consent that they agree to the rules set out by the protocol.
Participants are usually unpaid recruited volunteers, but sometimes research subjects may be paid. To test the effect of a treatment, a comparision is made between two or more groups of subjects, including a test group that receives the experimental treatment and a control group that receives a receives either a tried-and-true therapy or a placebo (inactive substance) instead of the experimental treatment.
Clinical trials are carried out in a series of steps, called phases, which are designed to answer separate questions:
- Phase I: Researchers test a new drug or treatment in a small group of people for the first time to evaluate its safety, determine a safe dosage range, and identify side effects.
- Phase II: The drug or treatment is given to a larger group of people to see if it is effective and to further evaluate its safety.
- Phase III: The drug or treatment is given to large groups of people to confirm its effectiveness, monitor side effects, compare it to commonly used treatments, and collect information that will allow the drug or treatment to be used safely.
- Phase IV: Studies are done after the drug or treatment has been marketed to gather information on the drug's effect in various populations and any side effects associated with long-term use.
Government agencies approve or disapprove new treatments based on the results of clinical trials. There are 4 possible outcomes of clinical trials:
- Positive trial: the new treatment has a large beneficial effect and is superior to standard treatment (strong evidence for granting approval).
- Non-inferiority trial: the new treatment is equivalent to standard treatment (may be granted approval).
- Inconclusive trial: the new treatment is not clearly superior or clearly inferior to standard treatment (no evidence to support approval).
- Negative trial: a new treatment is inferior to standard treatment (strong evidence against granting approval).