How to Determine a Combination Product’s Primary Mode of Action

Combination products raise distinct regulatory challenges because they comprise two or more regulated components. Depending on its constituent parts, your combination product may require a review by several agency centers at the U.S. Food and Drug Administration (FDA). The FDA will then designate one agency center as the lead agency center for your combination product. This center will oversee the pre-market review and regulation of your combination product as a whole.

Determining the Primary Mode of Action of Your Combination Product

Under Part 3 of Title 21 of the Food, Drug, and Cosmetic Act’s Code of Federal Regulations (21 CFR Part 3), the primary mode of action (PMOA) of a combination product determines the lead agency center. The Act defines the PMOA as “the single mode of action of a combination product that provides the most important therapeutic action of the combination product.” In other words, the component that contributes the most to your combination product’s intended therapeutic effects determines the lead agency center. For example, if the PMOA of a drug-biologic combination product is attributable to the drug, the agency center responsible for the pre-market review and regulation of that drug will have primary jurisdiction for the combination product.

Obtaining a Formal Classification for Your Combination Product

If the PMOA of your combination product is unclear, you may need to file a request for designation (RFD) as per 21 CFR Part 3. This step will enable you to establish the lead center for your combination product. You should submit your RFD once you have sufficient information for the FDA to make a classification determination, and before filing any investigational or marketing applications for your product.

After receiving your RFD, the FDA will assign your combination product to the agency center that regulates other similar combination products. If no similar combination products exist, the FDA will assign your combination product to the agency center with the most expertise to evaluate the safety and effectiveness issues presented by your combination product.

Determining the PMOA for your combination product can be a challenge, but it is critical for ensuring regulatory compliance. For help with PMOA decision making, contact us at Quality Solutions Now (QSN) today.