Clinical Development Phases
A new drug is administered, for the first time, to humans with the aim to evaluate how the drug should be given, how often, and what blood levels are to be expected at which times post administration. Usually only a small number of patients or healthy volunteers are enrolled into Phase I trials.
The safety of the drug continues to be tested, and evaluations begin on how well the new drug works in treating an illness or medical condition and what dosage scheme is appropriate. Information about the drug's safety, side effects, and potential risks is also collected.
The new drug is tested in comparison to the current standard. A participant will usually be assigned to the standard group or the new group at random. Phase III trials often enroll large numbers of people. Additional information about the effectiveness and safety of the new drug is gathered and provides the primary basis for the risk-benefit assessment and much of the core information that will be described in the labeling of the medicine.
Non-interventional studies are conducted after the regulatory approval of a medicine. Through such trials, researchers collect additional information about long-term risks, benefits, and optimal use during routine clinical treatment. These trials often involve hundreds of subjects and may continue for many years.