FDA is considering the use of evaluation matrices to help it assess whether benefits of weight-loss medical devices offset their risks
Since 1985, the agency has approved nine weight-loss devices, although only six of them are still available.
In a discussion paper released Thursday, FDA proposed ways to classify the benefits and risks of the devices, plus the use of evaluation matrices to support its assessments. The agency is seeking feedback to inform guidance that it says will help device developers provide patients with a wider variety of weight-loss tools.
Most of the available weight-loss medical devices, including BAROnova’s recently approved intragastric implant, have gained regulatory authorization since 2015. Despite those approvals, FDA said the complexity of the disease and presence of comorbidities illustrates there are still unmet medical needs.
To help industry fill those gaps, FDA has set out how it wants to evaluate whether it should approve a device. As in all areas, the evaluation involves a trade-off between safety and efficacy. The difference lies in how FDA plans to weigh those factors against each other.
FDA is proposing to divide devices into four categories based on their efficacy. If a device achieves between 2% and up to 5% more total body weight loss (TBWL) than a control intervention in 50% of patients over a minimum of six months and up to 12 months, FDA may approve it in the indication "Short-Term Limited Weight Loss." At the other end of the spectrum, a device that triggered 5% or greater TBWL for 12 months or more could get the "Weight Loss" indication.
The categories are intended to help FDA assess whether the benefits of a device outweigh the risks. FDA has created similar categories to assess the risks. The plan is to use a modified version of the Clavien-Dindo Classification, which provides the Grade I to V adverse event rankings commonly used in clinical trials, to determine the severity of a negative health outcome associated with a device.
FDA is proposing to bring these safety and efficacy ratings together in evaluation matrices. The matrices chart the rate and severity of the adverse events associated with a device. That information is then reviewed in light of the efficacy category to show whether the level of risk is acceptable. The acceptable level of risk is higher for devices in the "Weight Loss" indication than for products that only achieved "Short-Term Limited Weight Loss."
The discussion paper poses questions about FDA’s planned approaches to efficacy, safety and the evaluation matrices. FDA is accepting responses to these questions and other feedback for 90 days. Beyond that, FDA plans to review the submissions and develop draft guidance that aids "in assessing tolerability of risk in light of varying degrees of effectiveness for devices intended for weight loss."