Given that the size of the pharmaceutical industry at times overshadows the medical device market, it is no surprise that companies that are just getting started in device development sometimes need clarification about the regulatory implications and practical differences between pharma clinical trials and medical device clinical trials. We’ve put together a basic primer to help guide readers through the most important steps along the medical device regulatory pathway to market, and to explain the disparities between it and the clinical trial process for drug approval.
It’s important to first understand that medical device trials use different terminology than that used in the pharma world. Rather than referring to the phases of a particular trial by number, each step has a specific name that describes the activity it represents.
Initially, devices undergo an Investigational Device Exemption (IDE), which clears a product to become part of an FDA-sanctioned clinical study. This is roughly parallel to the Investigational New Drug application (IND). The IDE process can also include a pre-IDE component wherein new clinical sponsors participate in an early meeting with FDA representatives to discuss their specific study plans and requirements prior to the formal IDE submission and implementation of a clinical study.
Once an IDE has been approved, the goal is to collect sufficient and appropriate clinical data to support a 510(k) premarket notification or Premarket Approval (PMA) application, or in some cases a Biologics License Application (BLA) or a Humanitarian Device Exemption (HDE) application. It is here that medical device trials move sharply away from what would be considered the norm in a pharmaceutical investigation.
Device class is what determines whether a 510(k) or a PMA is appropriate. Class I and Class II medical devices are those which have been determined to pose low or moderate risk to the health of a patient, while Class III devices pose a significant risk.
The 510(k) clearance process is a nuanced one, depending on whether the device being introduced is new, whether it is a modification of an existing device, or whether it results from the repurposing of an existing product to treat a different health condition. It applies to some Class I (almost all are exempt from premarket notification requirements) and most Class II devices, and requires that manufacturers prove substantial equivalence to a previously-marketed product. This proof is most often gathered through pre-clinical testing, but in approximately 10% of 510(k) submissions a clinical trial is required. Class III devices are generally subject to a PMA application, which will require conduct of a clinical trial to provide stringent scientific evidence of a product’s safety and efficacy above and beyond substantial equivalence.
The concept of substantial equivalence is an important difference between pharmaceutical clinical trials and medical device clinical trials. Drug investigators do not have the luxury of comparing a new compound against an established treatment and gaining an exemption from certain aspects of Phase 1 safety trials. Rather than a shortcut, however, substantial equivalence is an acknowledgement by the FDA of the difficulty – or impossibility – of conducting traditional double blind randomized clinical trials with medical devices.
In part two of our primer examining the differences between drug and device trials we will take a more detailed look at some of the aspects of early stage investigations, as well as examine the next steps past 510(k) and PMA applications.