A predicate device is an existing medical product that has already been legally put on the market in the United States. This device serves as the primary benchmark for comparison when a manufacturer seeks to introduce a new, similar product. It provides a reference point for the Food and Drug Administration (FDA) to evaluate the safety and effectiveness of the new device relative to one already in use.
The Role in Medical Device Review
The concept of the predicate device is central to the Premarket Notification process, commonly known as the 510(k) pathway. This regulatory mechanism is intended for devices that carry a low to moderate risk, primarily Class I or Class II products. The pathway allows a new device to enter the market without undergoing the lengthy Premarket Approval (PMA) process, which is reserved for high-risk Class III products requiring extensive clinical trials.
Manufacturers must submit a 510(k) application to show that the new device is “substantially equivalent” to an already legally marketed predicate device. By establishing this equivalence, the FDA assumes the new product is as safe and effective as the existing one. This streamlined approach expedites the availability of new medical tools while maintaining regulatory oversight.
Determining Similarity
The determination that a new device is “substantially equivalent” (SE) to a predicate device is the most important step of the 510(k) process. This finding requires the FDA to conclude that the new device is at least as safe and effective as the legally marketed predicate. The comparison focuses on a specific set of criteria that address both the purpose and the design of the device.
Intended Use
The first and most critical criterion is the intended use of the device, which must be the same as the predicate’s. Intended use refers to the overall medical purpose, such as diagnosis, cure, mitigation, treatment, or prevention of disease. Differences in the specific indications for use, patient population, or user profile do not necessarily disqualify the device, but the fundamental purpose must align.
Technological Characteristics
The second criterion relates to the device’s technological characteristics, which must be either the same or acceptably different from the predicate. Technological characteristics include factors like design, materials used, chemical composition, and energy source. If the technological characteristics are identical, the new device is typically found to be substantially equivalent.
If the technological characteristics are different, the manufacturer must provide sufficient data to demonstrate two key points. The first is that the differences do not raise any new questions of safety or effectiveness compared to the predicate device. The second is that the new device is still as safe and effective as the legally marketed device. This evidence often includes performance data, which may be scientific, bench testing, or clinical data, depending on the nature of the difference.
Practical Considerations for Selection
The process of choosing the most appropriate predicate device is an important strategic step for any manufacturer. While a single predicate device is generally preferred, a manufacturer may use multiple predicates if the new device combines features from several existing, legally marketed products. In cases where multiple devices are cited, each one must have the same intended use as the new product.
A legally marketed device that can serve as a predicate falls into one of several categories, including those cleared through a previous 510(k). Another category includes “pre-amendment devices,” which were legally marketed in the United States before the Medical Device Amendments of 1976. These older devices were essentially grandfathered in and did not require initial 510(k) clearance.
Manufacturers are now encouraged to select a predicate that aligns with modern safety and performance expectations. Current best practices suggest avoiding predicates that have been subject to a design-related recall or have unmitigated safety issues. This focus helps ensure that the new device is compared against a contemporary standard that promotes the evolution of safer and more effective products over time.