A clinical trial is an investigation in human volunteers, who receive investigational treatments under supervised conditions by medically qualified personnel. The investigational treatments are developed by pharmaceutical and biotechnology companies, called the sponsor companies, the sponsor companies identify qualified investigators (doctors) to conduct the trials under conditions regulated by Regulatory Authorities and Ethics Committees in each country, with the objectives to determine the benefits of the investigational drugs. And to ensure the safety of the participants in the trial.
Clinical trials are usually conducted in four phases (I, II, III, IV). Phases I to III are the pre-registration phases during which only a small number of people participate in phase I trials while the later phases involve a larger number of volunteers. Phase IV trials are called post registration trials during which pharmaceutical companies may continue to conduct studies that compare the new drug—in terms of its safety, effectiveness, and cost—to other drugs already on the market or assess a drug’s long-term effectiveness and its impact on the quality of a person’s life.