Are there different types of clinical trials?
The answer is yes. Clinical trials are classified into different phases. In general, these phases are:
• Phase 1: the new drug is studied in a small group of patients, between 20 and 100 children, who take a very small dose of the drug so that it can be studied in case it is toxic. For example, if it damages their kidney or liver. In this case, the investigation of this drug will not be carried on.
• Phase 2: it usually involves a group of 100 to 300 patients, who are divided into different groups and given different amounts of the drug. This time of the investigation helps to obtain information on its positive and negative effects on the disease, and on its minimum safe and effective quantity according with the patient’s age.
• Phase 3: more patients collaborate, between 1,000 and 5,000, and this allows us to know if the drug is better than another drug or than a placebo (when no previous drug is authorized).