US FDA Asks Prostate Ablation Device-Sponsors For More Clinical Safety Data To Support Clearances

Almost four years after the agency first authorized a prostate ablation device, regulators have proposed a number of requirements for clinical studies that sponsors would have to meet to comply with special controls needed for the devices to be cleared for marketing.

Makers of devices used to carve out or destroy prostate tissue, such as certain ultrasound technology, could be required to provide additional safety and effectiveness data before regulators in the US clear them for marketing. The US Food and Drug Administration sets out the type of information and clinical trial protocols it’s looking for from sponsors before green-lighting certain ablation products.

On 25 June, the FDA published a proposed guidance titled, “Clinical Investigations for Prostate Tissue Ablation Devices,” that outlines the agency’s thinking.

“Our proposal highlights the use of clinical evidence under the 510(k) premarket notification program,” said Jeff Shuren, director of the FDA’s Center for Devices and Radiological Health. “This guidance also advances both safety and innovation by clarifying the clinical evidence that would support new and safe ways to destroy prostate tissue such as ultrasound or alternative technologies. By doing so, we can help give patients access to safer, more effective devices than they had even a few years ago.”

The guidance lists recommendations to sponsors on how clinical testing must be done on the devices that conform to special controls requirements for high-intensity ultrasound systems for prostate tissue ablation that are regulated under the FDA’s 510(k) premarket notification pathway. It also gives recommendations on clinical data collections for other new technologies that may use different forms of energy to cut out or destroy prostate tissue.

The bottom line is the FDA wants clinical testing data that showed these new products do not ablate or destroy tissue beyond the targeted area and that that they are as effective in doing the job as other similar devices with a similar safety profile.

The agency highlights the draft guidance is limited to clinical investigations for devices that are generally used to ablate prostate tissue and does not specifically address devices that are intended to treat specific prostate diseases such as prostate cancer or benign prostatic hyperplasia.

“Disease-specific studies use different endpoints and study designs to demonstrate safety and effectiveness compared to a study to demonstrate effective tissue ablation,” the FDA added.

Certain energy-based products such as high-intensity ultrasound systems can be used to create and heat a targeted region in the body to cut out certain prostate masses. Regardless of the type of energy used, the FDA us using the draft guidance to outline its thinking on such devices.

In 2015, the FDA gave a de novo authorization to SonaCare Medical LLC’s Sonablate 450 high intensity-focused ultrasound system for prostate tissue ablation which was quickly followed by a 510(k) clearance for EDAP TMS SA’s AblathermHIFU system for the same indication leading to a race to the top from both manufacturers. (Also see "HIFU Face-Off: US Competition Begins For Prostate High-Intensity Focused Ultrasound" - Medtech Insight, 11 Nov, 2015.)

However, clearance and authorization of the devices were no walk in the park. Initially, FDA advisory committees declined to recommend both devices for premarket authorization. (Also see "De Novo Cleared For Sonablate Device After Panel Rejects PMA" - Medtech Insight, 14 Oct, 2015.) (Also see "FDA Panel Votes Down Ablatherm HIFU Device For Prostate Cancer" - Medtech Insight, 30 Jul, 2014.)

Following up, the agency advised the device-makers to resubmit a more limited application. (Also see "FDA Recommends Narrowed Indication For EDAP’s Ablatherm-HIFU" - Medtech Insight, 6 Nov, 2014.)

Under the FDA’s special controls required through the de novo authorization and 510(k) clearance, the agency mandates that sponsors conduct clinical testing to document adverse events, provide evidence of prostatic ablation and demonstrate that the product meets the intended performance requirements based on the condition of use.

The FDA recommends in the draft guidance that sponsors of such ablation products comply with the clinical testing special controls for new high-intensity ultrasound systems for prostate tissue ablation or to support marketing submissions for other prostate tissue ablation devices.

“In some cases, ‘real-world data’ (RWD) may be used to support changes to the ablation energy output characteristics for a device for which 510(k) clearance has already been obtained,” said the FDA. “Whether the collection of RWD for a legally marketed device requires an IDE (investigational device exemption) depends on the particular facts of the situation. Specifically, if a cleared device is being used in the normal course of medical practice, an IDE would likely not be required.”

The draft guidance includes specific clinical study recommendations including the study objective, design, sample size, duration, follow-up schedule endpoint requirements and more.

The FDA recommends sponsors recruit at least 100 patients for the clinical study in order to have a clinically meaningful estimate of the product’s adverse event profile. The agency also recommends patient follow-up at least a year after the study is completed.

“This recommended minimum follow-up duration is based on the delayed onset or presentation of known probable adverse events (eg, urethral stricture, rectal fistul, and osteomyelitis pubis),” said the FDA. “The protocol should prospectively specify collection of adverse event information at regular intervals, with specific assessment of known probable device- and procedure-related adverse events.”

Stakeholders interested in responding to the draft guidance can do so by submitting comments to www.regulations.gov under docket no. FDA-2019-D-2223 until 25 August.