After the drug is registered and marketing authorization is obtained, CTs may be performed 4 phases – post-marketing trials (post-registration).

Purpose of research

The purpose of such studies is to collect as much additional information as possible regarding the drug in terms of its effectiveness and safety.. This is done to possibly expand the indications for use of the drug., dosage regimen optimization, searching for new ways to enter the international pharmaceutical market, etc.. Information about the side effects of the drug is subject to the most careful analysis., its impact on patient survival and quality of remission. Studies usually include very large numbers of patients (tens of thousands) and have been carried out for many years.

Research focus

According to their focus, they can be:

• prospective - CTs are planned before recruiting patients and are carried out according to the protocol in specially selected hospitals;
• retrospective - carried out on the basis of past experience with the use of drugs according to patient medical records.