Posted 19 January 2015
By Alexander Gaffney, RAC
The US Food and Drug Administration (FDA) has outlined a new framework for classifying and approving medical device accessories, making clear that device accessories can be brought to market more quickly than their parent devices in certain cases.
In the US, a medical device is defined as:
"an instrument, apparatus, implement, machine, contrivance, implant, in vitro reagent, or other similar or related article, including any component, part, or accessory, which is –
- recognized in the official National Formulary, or the United States Pharmacopeia, or any supplement to them;
- intended for use in the diagnosis of disease or other conditions, or in the cure, mitigation, treatment, or prevention of disease, in man or other animals, or
- intended to affect the structure or any function of the body of man or other animals, and which does not achieve its primary intended purposes through chemical action within or on the body of man or other animals and which is not dependent upon being metabolized for the achievement of its primary intended purposes."
Medical devices are brought to market, in general, in one of four ways:
- The Premarket Approval (PMA) – This process is intended to evaluate and approve high-risk devices or devices with no known predicate.
- The 510(k)/Premarket Notification – This process expedites the review and approval of devices that are highly similar to an already-marketed predicate device, or that are subject to certain controls on their manufacture.
- The De Novo Process – If a low-risk device is deemed ineligible for the 510(k) process because it lacks a predicate, a manufacturer may petition FDA to review it through the de novo process, which allows FDA to make a risk-based classification of the device.
- 510(k) Exempt -- Some low-risk devices, such as bandages, are explicitly exempted from FDA's premarket review process and can be brought to market almost immediately as long as they conform to established standards ("general controls").
Medical Device Accessories
That general framework, however, has proven a bit confusing for manufacturers of medical device accessories. Accessories function in tandem with another device, known as a "parent device," which is often (but not always) cleared or approved as a separate device.
As defined by FDA, a medical device "accessory" is a device "intended to support, supplement, and/or augment the performance of one or more parent devices," while a parent device is a device "whose performance is supported, supplemented, and/or augmented by one or more accessories."
At issue is how FDA should evaluate each device accessory. For example, if a parent device was deemed to be "high risk" but a subsequent accessory is inherently low-risk, should the accessory be judged on its own merits, or should it inherit its parent device's "high-risk" status?
A Nuanced Approach to Risk
FDA's guidance, Medical Device Accessories: Defining Accessories and Classification Pathway for New Accessory Types, is meant to clarify some of the ambiguity in this space.
As noted by FDA, a key consideration in the agency’s assessment of risk is the accessory's relationship with its parent device. Some accessories are critical to the proper function of a device, such as a rechargeable battery for an AED. Other accessories allow the parent device to perform new functions, but are not necessary to its core functions. Still other accessories allow a parent device to perform its functions better or more safely.
"FDA intends to determine the risk of accessories and the controls necessary to provide a reasonable assurance of their safety and effectiveness according to their intended use in the same manner that is used to determine such for devices that are not accessories," the regulator explains in its guidance.
FDA goes on to explain that it plans to access the risk of a device "when used, as intended, with the parent device." However, it does not plan to simply pass on a parent device's risk classification to its accessory. "The risk profile of an accessory can differ significantly from that of the parent device, warranting differences in regulatory classification," FDA wrote.
The regulator also recommended the use of the de novo classification pathway for many device accessories, which it said would help in allowing some manufacturers to get their products to market more quickly.
Medical Device Accessories: Defining Accessories and Classification Pathway for New Accessory Types (FR)