Although the substance of the Common Rule (45 CFR §46) and FDA regulations (21 CFR §50 and §56) largely overlap, there are important differences. FDA regulations apply to “clinical investigations,” understood as studies involving FDA-regulated drugs, biologics, or devices. Of note, clinical investigations can include studies evaluating drugs or devices even when those drugs or devices are already FDA-approved products.

Importantly, FDA-regulated clinical investigations can require review by FDA before the study commences and the issuance by FDA of an Investigational New Drug application (IND) for a drug or biologics study, or an Investigational Device Exemption (IDE) for a device study. Another key difference between FDA-regulated and Common Rule studies is that FDA regulations require ongoing continuing review in all cases, whereas continuing review for low-risk Common Rule studies is typically not needed.

The IRB of record is responsible for assessing whether a proposed activity meets the definition of a clinical investigation and thus whether FDA regulations apply, as well as whether an IND application or IDE is needed, based on information provided to the IRB at the time of initial study intake. Investigators conducting studies of FDA-regulated therapies are encouraged to consult with their IRB early in study planning.