Medical Devices and in Vitro Diagnostics
Regulatory Pathway and Market Approval Process
In the United States, the FDA regulates around 190,000 cleared or approved medical devices and on average, clears 12 devices every business day. As of November 2018, the FDA had announced plans to “fundamentally modernize” the medical device and diagnostic review process. 43 However, this section will outline the current process used by the FDA.
Through the Federal Food, Drug, and Cosmetic Act, risk-based device classifications (I, II, or III) are assigned based on level of control necessary to ensure safety and effectiveness. As classification increases from I to III, the regulatory controls also increase 44,45 These devices and diagnostics are approved and monitored by the Center for Devices and Radiological Health (CDRH). See Figure 9 for a visual explanation of these device classification approval pathways.
Class I – Most Exempt From Premarket Submission
Class I devices and diagnostics pose the least amount of risk to consumers. These low-risk devices, such as oxygen masks or surgical tools, are subject to “general controls.” General controls ensure the safety and effectiveness of devices and diagnostics once they are manufactured. Around 47% of medical devices fall under this category. 46 In rare cases, Class I products will have to go through the 510(k) process outlined below.44,45
General controls include; good manufacturing practices, standards and reporting adverse events to FDA, registration, and general recordkeeping requirements.
Class II – Premarket Notification [510(k)]
Class II devices and diagnostics pose more risk to consumers than Class I devices. These devices are subject to special controls in addition to general controls.44, 45 About 43% of medical devices fall under this category.46
Special controls include labeling requirements, product-specific mandatory performance standards, and product-specific testing requirements.
Class II devices and diagnostics are registered through the 510(k) pathway with the FDA. This is a requirement of proof that the product is substantially equivalent (SE) to a legally marketed product that is not subject to a Premarket Approval (PMA). Applicants must compare their device to one or more similar legally marketed, so-called “predicate,” devices or diagnostics to support claims of SE. If the product is found to be SE, it is placed in the same class, if not, it is placed into Class III. Examples of 510(k) products include x-ray machines, dialysis machines, fetal monitors, lithotripsy machines, and muscle stimulators. Any device or diagnostic found to be not SE to a marketed Class I or II product must resubmit as a Class III product with a PMA. For Class II products that do not have an approved equivalent product, they may file a “de novo” 510(k) application (also called a “de novo request”), where review of safety and efficacy evidence is required. Class II devices that do not meet the requirements for a de novo 510(k) request may be required to proceed through a PMA pathway. 44,45,47,48
Class III – Premarket Approval [PMA]
Class III devices and diagnostics support or sustain life, are implanted in the body, or have the potential for unreasonable risk of illness or injury. Examples include pacemakers; breast implants; HIV diagnostic tests; companion diagnostics, which are tests providing information essential to the safe and effective use of their corresponding therapeutic products 49; and complementary diagnostics, which are tests that identify a biomarker-defined subset of patients that respond particularly well to a drug and aid risk/benefit assessments for individual patients, but that are not prerequisites for receiving the therapy. 50 Only around 10% of medical devices fall under this category.46 These products, due to risk, require premarket approval. The manufacturer must prove to the FDA that the device or diagnostic is safe and effective. 44,45
Class III devices known to be SE to a predicate with an already-established PMA can sometimes also proceed through a 510(k) pathway.48 Any Class III product without a predicate requires a PMA in order to be marketed in the United States. A PMA is similar to an NDA discussed in the pharmaceuticals section. This application must contain data from a registered clinical trial to ensure that the device or diagnostic is safe and effective. PMAs must be independent, meaning that data about a reference or companion product cannot be used to support another. During the approval process, the FDA will inspect manufacturing laboratories and facilities where the device or diagnostic will be made to monitor for good manufacturing practices. 44,45
Figure 9. The Device Approval Process by the US Food and Drug Administration