Definition of Primary Mode of Action of a Combination Product

The Food and Drug Administration (FDA) is amending its combination product regulations to define "mode of action" (MOA) and "primary mode of action" (PMOA). Along with these definitions, the final rule sets forth an algorithm the agency will use to assign combination products to an agency component for regulatory oversight when the agency cannot determine with reasonable certainty which mode of action provides the most important therapeutic action of the combination product. Finally, the final rule will require a sponsor to base its recommendation of the agency component with primary jurisdiction for regulatory oversight of its combination product by using the PMOA definition and, if appropriate, the assignment algorithm. The final rule is intended to promote the public health by codifying the agency's criteria for the assignment of combination products in transparent, consistent, and predictable terms.