The International Council for Harmonisation (ICH) Good Clinical Practice (GCP) E6(R2) guideline explicitly requires that an investigator be qualified by education, training, and experience. To demonstrate these qualifications, the investigator must provide evidence to the sponsor, the Institutional Review Board/Independent Ethics Committee (IRB/IEC), and regulatory authorities. The primary document specified for this purpose is an up-to-date curriculum vitae (CV). The CV serves as a comprehensive summary of the investigator's professional background, credentials, and relevant experience, allowing stakeholders to assess their capability to properly conduct the clinical trial and ensure the safety of human subjects.

A. Proof of citizenship: This is not a standard requirement under ICH GCP for demonstrating an investigator's qualifications to conduct a clinical trial.

B. A letter of recommendation from a fellow physician: While potentially supportive, a letter of recommendation is not a formally mandated document for investigator qualification per ICH GCP guidelines.

D. A copy of medical license: A medical license is essential for a physician investigator, but the CV is the broader, explicitly required document that encompasses all qualifications, including licensure.

1. International Council for Harmonisation (ICH). (2016). Integrated Addendum to ICH E6(R1): Guideline for Good Clinical Practice E6(R2).

Section 4.1.1: "The investigator(s) should be qualified by education, training, and experience...and should provide evidence of such qualifications through an up-to-date curriculum vitae and/or other relevant documentation requested by the sponsor, the IRB/IEC, and/or the regulatory authority(ies)."

Section 8.2.10: Lists "Curriculum vitae and/or other relevant documents" as an essential document required before the trial's clinical phase to "document qualifications and eligibility to conduct trial."

2. U.S. Food and Drug Administration (FDA). (2023). Code of Federal Regulations Title 21, Part 312, Subpart D - Responsibilities of Sponsors and Investigators.

21 CFR 312.53(c)(1): "Selecting investigators. A sponsor shall select only investigators qualified by training and experience as appropriate experts to investigate the drug." The regulation requires the sponsor to obtain a completed investigator statement (Form FDA 1572), which requires the investigator to attach a curriculum vitae or other statement of qualifications.

3. Johns Hopkins University. (n.d.). Investigator Responsibilities - FAQs. Johns Hopkins Medicine.

In the section discussing investigator qualifications, it is stated that "The PI must be qualified by education, training and experience to conduct the clinical trial. The PI must provide the sponsor with a current copy of his/her curriculum vitae (CV)." This aligns with the requirements outlined in ICH GCP.