Local clinical studies are an essential stage of drug development and state registration. But not only that.
Already after drug registration, you may need to introduce changes to the "medical" sections of the Drug Label. Or you may need to elaborate the efficacy, safety, pharmacokinetics or pharmacodymanics of the drug, to get evidence-based marketing material for promotion purposes.
As you well know, registration and post-marketing clinical studies are conducted in all of these cases.
Clinical trial is a prospective study to determine the efficacy, safety, tolerability and/or efficiency of medical intervention referred to therapy, prevention and diagnostics of a specific disease state of an individual.
They can be conducted with the participation of patients and healthy volunteers.
Clinical trial of a drug is a study of diagnostic, health-promoting, preventive, pharmacological properties of drug during its use by an individual, including absorption, distribution, alteration and depletion processes by applying scientific estimation to receive evidence of the safety, quality and efficiency of a drug, data on adverse drug reactions of the human body, and interaction effect with other drugs and/or food stuff (from the Federal Law of Russia No. 61, 2010 "On Drugs Circulation").