Final answer:
GCP mandates that signed protocols, amendments, and sample CRFs be stored in the Investigator's Site File at the research site, retained securely for regulatory purposes, and kept for specific durations after the conclusion of clinical research.
Step-by-step explanation:
According to Good Clinical Practice (GCP), essential documents like the signed protocol and any amendments, along with sample case report forms (CRFs), should be retained in the Investigator's Site File at the research site.
It is crucial for the integrity of clinical research that these documents are accessible for the purposes of monitoring, audits, and regulatory inspection.
The GCP guidelines stipulate that these documents be stored in a secure and confidential manner and be retained until at least 2 years after the last approval of a marketing application in an ICH (International Council for Harmonisation) region and until there are no pending or contemplated marketing applications in an ICH region or at least 2 years have elapsed since the formal discontinuation of clinical development of the investigational product.