To whom must an investigator report all adverse events during a clinical trial?

An investigator is required to report all adverse events during a clinical trial to the sponsor. This reporting is crucial because the sponsor is responsible for the overall conduct of the study, including monitoring safety and ensuring compliance with regulatory requirements. The sponsor uses the information about adverse events to assess the safety profile of the investigational product, make informed decisions about the continuation of the trial, and communicate relevant findings to regulatory authorities, including the FDA, if necessary.

The sponsor is typically responsible for reporting serious adverse events to the regulatory authorities, while the investigator keeps the sponsor informed about any adverse events that occur. This flow of information is essential for maintaining participant safety and upholding the integrity of the clinical trial.

Other options focus on different entities involved in the clinical trial process. While investigators do need to ensure that appropriate information reaches the Institutional Review Board (IRB) and, in certain cases, inform study participants about safety issues that affect them, the primary obligation for reporting all adverse events directly lies with the sponsor. Thus, the investigator's communication with the sponsor is a crucial aspect of responsible clinical trial management.