A new draft guidance issued by the US Food and Drug Administration (FDA), Molecular Diagnostic Instruments with Combined Functions, aims to clarify the standards by which federal regulators will assess a particular subset of medical diagnostic tests.
As FDA explains in its draft guidance document, molecular diagnostic instruments are "critical components of certain in vitro diagnostic devices (IVDs)."
"These types of instruments are not generally approved/cleared alone, i.e., without an accompanying assay, because their safety and effectiveness or substantial equivalence cannot be evaluated without reference to the assays they run and the assay's defined performance parameters," FDA continued. "The same instruments may also be used for additional purposes that do not require FDA approval or clearance, such as for basic scientific research-purposes this document refers to as functions for which approval/clearance is not required."
Such uses most notably include lab-developed tests (LDTs), which are not intended for use by consumers directly. The problem, FDA says, is that because some devices can have a multitude of claims and uses-some approved and some not-companies frequently solicit the agency for advice regarding "the permissibility of having functions for which approval/clearance is not required on an instrument intended to be used with approved/cleared in vitro diagnostic assays."
In other words, does a company need to separately market the devices' applications, or may a single device have the full information, including the approved and un-approved labeling?
New Guidance Calls for Clear Approach
It's complicated, says FDA, but hopefully less so now that a guidance document exists to establish a reliable framework.
Under the new guidelines, FDA said it has determined that such devices may be approved even if they have functions for which the sponsor does not need clearance or approval. That said, those functions need to be clearly separate and otherwise have measures in place to assure that un-approved/cleared functions do not interfere with or affect approved/cleared functions. The manufacturer will also need to show that the device will not cause confusion with the end user.
These controls and assurances can be done with the help of instrument and software design controls, the creation of validated procedures for users, a risk mitigation plan, clear labeling and result reports that distinguish between approved uses and unapproved uses.
These functions will be a critical part of FDA's review of the device, and the guidance states that regulators will use them to "determine if such measures described are sufficient to provide a reasonable assurance of safety and effectiveness or substantial equivalence for the approved/cleared functionalities."
"FDA may request additional information if we determine that it is necessary to assess safety and effectiveness or substantial equivalence of the device," FDA added.
Does this Constitute Approval for Some Unapproved/Un-Cleared Devices?
This will not constitute a review of the claims for which the device does not seek approval, FDA explained, and any review will only cover the extent to which the functions are clearly separable.
However, medical device reporting (MDR) will extend to the non-cleared/approved functions as well-a significant deviation from current practice-since problems with one aspect of the device are likely to affect the device as a whole.
"All instrument device functions, whether approved/cleared or not required to be approved/cleared can have a direct or indirect adverse impact on approved/cleared indications," FDA wrote.
FDA's guidance also gives a number of examples of potential controls. Software, for instance, might have a start-up screen that asks users to select either the approved functions or those unapproved. "The user would not be able to switch between functions without first going back to the start-up screen, "FDA postulated. "This approach may serve, for example, to effectively separate the software functions and prevent any confusion on the part of the user as to which function the instrument is performing and to provide a protective mechanism that prevents the user from altering any approved/cleared function parameters."
Regulators also advised industry not to combine approved and unapproved claims, such as, "You can use this instrument for detecting MRSA and for basic research," explaining that such a combination might be cause for confusion. All labeling and instructions should clearly be separate.