The regulations governing the conduct of clinical trials by clinical investigators are intended to assure adequate protection of the rights, safety, and welfare of subjects involved in those trials, as well as the quality and integrity of the resulting data, while at the same time providing sufficient flexibility for clinical research. A brief description of the specific responsibilities of investigators follows.

Clinical investigators are responsible for protecting the rights, safety and welfare of human subjects in the studies they conduct. Among other things, investigators must assure that an Institutional Review Board (IRB) that complies with FDA regulations conducts initial and continuing ethical review of the study. An investigator must notify the IRB of changes in the research activity or unanticipated problems involving risks to human subjects or others, and must not make any changes in the protocol without IRB and sponsor approval, unless necessary to eliminate apparent immediate hazards to human subjects. An investigator must also obtain informed consent from each subject who participates in the study.

Clinical investigators are responsible for following the signed investigator statement (Form FDA 1572). The investigator's signed statement includes a commitment to:

• follow the study protocol, and to make changes only after notifying the sponsor, unless necessary to protect the rights, safety or welfare of the subjects;
• personally conduct or supervise the research; and
• inform subinvestigators and others assisting in the conduct of the investigation of their obligations in meeting these commitments.

Clinical investigators are also responsible for following the investigational plan.

Clinical investigators must ensure that the investigational drug is administered only to study subjects under the supervision of the investigator or a subinvestigator responsible to the investigator. Finally, clinical investigators must keep required records of the study and make required reports to the sponsor of the investigation. An investigator must prepare and maintain adequate case histories, including documentation of informed consent, and keep records of disposition of the drug. These records must be maintained for 2 years from the date FDA approves a marketing application for the drug under study or if FDA does not approve the drug or no application is filed for the drug, from the date the study is discontinued and FDA is informed. The investigator must make several types of reports to the sponsor, including progress reports, safety reports (prompt reports of adverse events, and immediate reports of alarming effects), and a final report. The investigator must also report his or her financial interests to the sponsor to permit assessment of conflicts of interest.

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