Principal Investigators in Clinical Research

Principal Investigator: The Master of a Clinical Trial Site

The principal investigator of a clinical trial is the primary person who is responsible for the preparation as well as conduct and administration of the clinical trial at a clinical trial site after the clinical trial has been granted by the sponsor. The leadership provided by the principal investigator is very important as its the foundation for a successful clinical trial. Thus the sponsor or the contract research organization which works on behalf of the sponsor must be critical in selection of the right sponsors for the trial. The sponsor and the principal investigator signs a contract as part of a corporative agreement to abide by conducting the clinical trial lawfully and within applicable laws and regulations with compliance to GCP and FDA requirements. 

The principal investigator is usually a physician holding a specialization in the field of therapeutic area in which the clinical trial is being conducted. However, a principal investigator need not always be a physician. In places where a principal investigator is not from a medical background then, he or she must delegate a qualified sub-investigator who is a physician who can assist with the clinical trial duties and assume responsibility for trial related medical decisions. 

As a clinical trial has a long list of duties to be executed and as all these activities cannot be done solely by a principal investigator, the PI thus, delegates the duties to subordinates who could be more clinicians serving as sub-investigators to conduct subject evaluations as well as clinical research coordinators helping with the conduct of the trial. It is the principal investigator and not the contract research organization which is accountable and responsible for the clinical trial running at site. The PI is responsible in ensuring that the delegated staff are qualified by education as well as training and education to perform the delegated task. However, if something goes wrong the FDA holds the principal investigator responsible. Thus, it is the principal investigator who is responsible for the breach of any protocol as well as any discrepancies which can occur in the preparation of source notes though done by a delegated staff. The concept of complete responsibility being vested in the PI is according to the ICH international guidelines. Although the day-to-day management of the trial may be delegated, the principal investigator is responsible in ensuring that the clinical trial is conducted compliantly and that recordkeeping is appropriate and up to date. 

The principal investigator has many important roles to play and this includes:

Subject safety: Ensure that the clinical trial participants from the site are protected as well as ensure that the investigational product is well stored. The IRB approvals must be up-to-date and source data must be maintained properly.

Delegated staff trained: The PI must ensure that the delegated staff are well trained and if there are amendments to the protocol or investigator brochure, the delegated staff must be trained on. 

Reports: The PI is responsible for the reporting of serious adverse events on time as well as do financial disclosures. The PI must also sign the 1572 Form committing to conducting the clinical trial strictly according to the protocol. 

FDA inspections: The PI must ensure that the site’s clinical trial records are complete and accessible by FDA if needed. If violations have been found, then written responses must be submitted within 15 business days.

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