Drug Evaluation Committee 2007-20 Investigation into the effects of post-treatment after completion of investigational drug use

Is it acceptable to conduct a clinical trial to investigate the name, dosage, duration of use, efficacy, etc. of a post-treatment drug used after completion of administration of the investigational drug and before evaluation during the follow-up period?

Is it acceptable for a coordinating physician to attend case review meetings and review case report forms collected from Investigator Site?

As you know, GCP is a standard that defines the conditions of compliance for clinical trials and aims to ensure the scientific quality and reliability of the results of clinical trials while protecting the human rights, safety and welfare of the subjects. The standard does not specify the scope of validity data collection as part of the clinical trial design.
Therefore, if the investigational protocol, which specifies the purpose and items to be investigated regarding the drug used after administration, is approved by the investigational review committee and the clinical trial is conducted in accordance with the protocol, it will not be considered GCP noncompliance.

A coordinating physician is defined as a physician or dentist who is commissioned by the sponsor to "coordinate the interpretation of the protocol and other details of the clinical trial at the Investigator Site" during a multicenter clinical trial (GCP Article 2, Paragraph 20).
Article 18 Guidance 2 of the GCP stipulates that "coordinating tasks" include "tasks related to the coordination of Investigator Sites in a multicenter clinical trial, such as coordination among multicenter sites regarding the details of the study protocol and coordination of questions regarding the interpretation of the study protocol that arise during the trial. The scope of selection as a clinical trial coordinator includes "selection from among the investigators, but not necessarily limited to the investigators" (GCP Article 2 Guidance 9) and "it is possible for a collaborator to be a member of the Clinical Trial Coordinating Committee" (GCP Article 2 Guidance 10).
As described above, the Clinical Trial Coordinating Physician is on the Investigator Site side and is not in a position to perform the duties that the sponsor should perform, such as reviewing cases and deciding whether or not to accept a case. In your inquiry, the purpose of the coordinating physician attending the case review meeting and reviewing the case reports collected from Investigator Sites is not clear.