A Diagnostics & Imaging Week

Bone sonometers are hardly the most exciting device reviewed by FDA these days, but makers of these devices might think the latest news about them from FDA is exciting.

The agency released a July 17 guidance for the reclassification of bone sonometers from class III devices to class II devices that gives sponsors some idea of what to expect in any 510(k) applications. Class II devices require "special controls," but these controls are a lot less work than a PMA. And while clinical data may be needed in a few instances, most sponsors should be able to get to market without clinical trials.

FDA recommends that anyone filing a 510(k) for such a device "include performance specifications," but also describe "how this special controls guidance document was used during device development and testing."

Among the health risks FDA wants to see data for are electrical hazards, electromagnetic interference, tissue damage (due to acoustic intensity) and patient mismanagement.

The guidance states that in many cases, "clinical studies will not be needed," but exceptions include instances in which a device's labeled indications are "dissimilar from legally marketed devices of the same type," but also when a design is "dissimilar from legally marketed designs." Any novel technology embedded in a sonometer may also trigger a clinical data requirement.

A sponsor will have to obtain an investigational device exemption for any such study, but the study may qualify as a non-significant risk study, in which case the institutional review board that oversees the study acts as a proxy for FDA. The guidance also refers to "major differences in the record keeping and reporting requirements," but goes into no detail.

Should a sponsor have to undertake clinical studies, FDA recommends that the exclusion criteria should include anyone taking a number of drugs within a time period specified by the sponsor. This list includes bisphosphonates (such as alendronate, aka, Fosamax), calcitonin and therapeutic doses of vitamin D. Also, any patients who have been diagnosed with hyperparathyroidism or hypoparathyroidism in the previous five years should be excluded.