Which of the following is one of the responsibilities of an investigator who is NOT a sponsor?

An investigator's responsibilities, as distinct from a sponsor's, are focused on the conduct of the trial at their specific site. According to both U.S. Food and Drug Administration (FDA) regulations and International Council for Harmonisation (ICH) Good Clinical Practice (GCP) guidelines, the investigator is directly responsible for maintaining control over the investigational product. This includes ensuring proper storage, dispensing only to eligible subjects according to the protocol, and maintaining accurate accountability records for the product received, used, and returned. The other options listed are responsibilities of the study sponsor.

A. Reporting serious adverse events to the applicable regulatory agency is a sponsor's responsibility. The investigator reports SAEs to the sponsor and the Institutional Review Board (IRB).

B. Ensuring proper monitoring of an investigation at all investigational sites is a core function of the sponsor, who must select monitors and ensure trial oversight across all locations.

C. Ensuring that all participating investigators are promptly informed of significant new adverse events is the sponsor's duty, as they aggregate safety data from all sites.

1. U.S. Food and Drug Administration, Code of Federal Regulations Title 21, Part 312.61, "Control of the investigational drug." This regulation explicitly states, "An investigator is required to administer the drug only to subjects under the investigator's personal supervision or under the supervision of a subinvestigator responsible to the investigator. The investigator shall not supply the investigational drug to any person not authorized under this part to receive it."

2. International Council for Harmonisation (ICH) Harmonised Tripartite Guideline, "Guideline for Good Clinical Practice E6(R2)," Section 4.6, "Investigational Product(s)." This section details the investigator's responsibility for investigational product accountability at the trial site, including records of delivery, inventory, use, and disposition.

3. U.S. Food and Drug Administration, Code of Federal Regulations Title 21, Part 312.50, "General responsibilities of sponsors." This section outlines the sponsor's role in selecting qualified investigators, ensuring proper monitoring (312.56), and ensuring FDA and all participating investigators are informed of significant new adverse events (312.55(b)).

4. U.S. Food and Drug Administration, Code of Federal Regulations Title 21, Part 312.32, "IND safety reporting." This regulation specifies that the sponsor must notify the FDA and all participating investigators in an IND safety report of potential serious risks. The investigator's duty is to report adverse events to the sponsor.

5. Johns Hopkins University, "Investigator Responsibilities - FAQs." The university's guidance for researchers clarifies roles, stating, "The PI [Principal Investigator] is responsible for ensuring that the storage, dispensing, and use of the investigational agent is controlled and that accurate accountability records are maintained." It distinguishes this from sponsor duties like multi-site monitoring and regulatory reporting. (Available on the Johns Hopkins Medicine institutional website under research compliance).