An Investigator-Initiated Trial (IIT) is a clinical study designed and led by an investigator rather than initiated by a commercial sponsor.
IITs may be funded through grants, institutional support, or industry-provided funding or product, but the investigator typically assumes sponsor responsibilities for oversight. The study must follow the same ethical and regulatory expectations as other clinical trials, including IRB review, informed consent, and safety reporting. IITs often address clinically important questions not prioritized in sponsor-led programs, including new uses, dosing strategies, or comparative effectiveness. Clear governance is essential because sponsor obligations still apply even when the sponsor is an investigator.