Clinical Trials

• Pharmaceutical companies must put their new medicines and vaccines through rigorous tests before they sell them as a final product.
• Vaccines and drugs are subjected to clinical trials to establish their safety and effectiveness before being licensed for use. Once tested and found to be safe the company is issued with a license for that product.
• 1. First of all the treatment undergoes extensive animal testing before a clinical trial begins.
  2. Approval is needed from the regulatory body for the next step. The protocol will be checked to make sure it meets agreed standards.
• 3. There are three phases to the clinical trials (I, II and III).

  • Phase I involves a very small number of healthy people who are given the treatment to check that it is safe.
  • Phase II involves a larger number of people who have the disease. The treatment is given to them to see if it is effective in combatting the disease and to determine the optimum safe dose.
  • Phase III of the clinical trial involves a very large number of people who have the illness. The clinical trial is set up using a randomised, placebo-controlled, double-blind protocol.
• 4. Finally, the results of the clinical trial are passed to the regulatory authority and if approved, a license is granted.
• In a double blind test both the patients and researchers do not know what treatment is being administered. This helps prevent any unconscious influence on the outcome of the trial.
• A placebo is an inactive substance which has been designed to look like the real medicine but contains no active ingredient. It is used so that neither the patient nor the researcher knows whether the person receiving the placebo or the actual medicine.
• Subjects in clinical trials are divided into groups in a randomised way to reduce bias in the distribution of characteristics such as age and gender.
• The placebo treatment contains all of the ingredients except the one being tested.
• Some patients given the placebo show an improvement in their condition. This can be due to the psychological effect of:

  - Thinking they were receiving the real treatment.

  - Receiving expert attention from doctors.

  - Expecting the treatment to be efficacious.
• A computer programme is used to ensure that patients are allocated to the placebo or real treatment randomly. Again this is done to eliminate bias as doctors may subconsciously put the most ill patients on the new treatment. This would affect the final results of the trial and

  may show the treatment to be more efficacious than it really is.
• A computer programme also ensures that the composition of the

  two groups is as similar as possible. It will take into account age,

  gender and weight when allocating a placebo or new treatment. This reduces experimental error which could invalidate the results.
• A large number of people in the sample will also reduce experimental error and establish statistical significance.
• Statistical analysis of the data obtained will allow a comparison between the placebo results and the new treatment results.
• At the end of the trial, results from the two groups, which must be of suitable size to reduce the magnitude of experimental error, are compared to determine whether there are any statistically significant differences between the groups.