FDA Approves First HIFU Device for Prostate Tissue Ablation

Roxanne Nelson BSN, RN

October 22, 2015

The first ultrasound system for the ablation of prostate tissue in the United States has just been approved by the Food and Drug Administration (FDA).

The Sonablate 450, developed by SonaCare Medical, is a minimally invasive treatment approach that uses high-intensity focused ultrasound (HIFU) to ablate prostate tissue. This is the same device that was previously not recommended for approval for use in prostate cancer.

HIFU has already been approved for use in prostate tissue outside the US, and according to the manufacturer, more than 50,000 men globally have been treated with focused ultrasound for prostate cancer. It is the leading clinical application of the technology, with more than 50% of patients having undergone the procedure for this indication.

Focused ultrasound has already been available in the US to treat uterine fibroids and relieve pain from bone metastases. In addition, there are also a growing number of clinical applications in various stages of research and development around the world, including Parkinson's disease, essential tremor, breast cancer, pancreatic cancer, and brain tumors.

"For men with conditions like prostate cancer, the option of a non-invasive procedure that can selectively target and treat diseased tissue is very appealing," explained Neal Kassell, MD, chairman of the Focused Ultrasound Foundation, in a statement. "American men have been traveling overseas for focused ultrasound treatment for prostate diseases for years, and we are pleased that they will now have access to this innovative treatment at leading centers in the United States."

Nixed by Committee

The FDA approval appears to be somewhat of a surprise, as last year their advisory committee voted twice against recommending HIFU treatment for prostate cancer.

The first time was in July 2014, when members of the Gastroenterology-Urology Devices Panel of the FDA's Medical Devices Advisory Committee voted not to recommend approval for the Ablatherm Integrated Imaging High Intensity Focused Ultrasound (HIFU). The device is marketed in Europe by EDAP TMS, a French company operating in the US as EDAP Technology. The company says that this device has been used in other countries for 15 years, and has been used in more than 40,000 patients. The committee voiced a number of concerns, primarily about the lack of data available from the sponsor's research results that were presented as part of its US premarket approval application.

Then, in October 2014, the same panel voted against approval of the Sonablate 450, for the treatment of patients with recurrent prostate cancer. The indication proposed by SonaCare was to treat biopsy-proven recurrent cancer in patients, low-to-high risk, who have failed primary external beam radiation therapy and have prostate-specific antigen (PSA) readings lower than 10 ng/mL

SonaCare had based its request on an interim analysis of results from a nonrandomized, single-group clinical trial involving the first 100 of a planned 200 patients. At that time, the committee had encouraged SonaCare to continue to conduct research but to come back when the trial was completed and not halfway through.

Results that were reported at that committee meeting were based on both the 100 intention-to-treat (ITT) population and the 78 per-protocol (PP) population.

In the ITT group, 50 (50%) patients achieved local control, which was defined as a PSA nadir of 0.5 ng/mL or lower and having a negative prostate biopsy at 12 months, with the lower bound of a 97.06 confidence interval of 39% falling slightly below a targeted 40% performance goal.

However, the PP group of 78 patients achieved better than 40% success, and if only one more patient in the ITT group had done so, that group would have met its overall goal, according to the manufacturer.

SonaCare also felt that the overall success in the ITT group showed a clinically meaningful benefit in a trial in which endpoints are unique for the new technology and not comparable to other salvage treatments for recurrent prostate cancer. But the FDA committee felt that the study missed the success criteria in the ITT group, and the claim to success in the PP group "should be considered ancillary."

"The FDA felt that the study didn't meet its predefined endpoint," said Michael Koch, MD, Sonablate trial investigator and chairman of the department of urology at Indiana University, Indianapolis. "The bar was set pretty high."

A Change in Indication

But the approval application has been "tweaked," so to speak, and it is now not specifically for use in prostate cancer, Dr Koch told Medscape Medical News. The approval that has just been granted is "for prostate tissue ablation, which means it can be used to treat prostate cancer, although the approval is not specifically for that," he explained.

The technology has already been used to a wide variety of conditions, including benign prostatic hyperplasia, partial gland cancer, localized whole-gland prostate cancer, and recurrent prostate cancer.

There are a number of applications for this technology in prostate cancer, explained Dr Koch. "It can be used as an alternative to surgery or radiation, and it can also be used in surveillance patients whose disease is progressing."

"It is also more benign, with low rates of incontinence and post-treatment erectile dysfunction," he said.

Ablatherm on the Horizon Again

The Ablatherm HIFU may also receive FDA approval in the near future. Following in the footsteps of SonaCare, the company recently announced that they have withdrawn the De Novo application and submitted a 510(k) notice instead.

In a release, Marc Oczachowski, chief executive officer of EDAP TMS SA, commented that he believes that the "FDA's approval of HIFU technology for prostatic tissue ablation with a predicate device is a crucial milestone in the recognition and establishment of HIFU as a standard of care tool in prostate tissue ablation in the US and Worldwide."

"Our path to market in the U.S. is now clearer than ever, as we can now obtain clearance via a more straightforward 510(k) pathway by demonstrating that Ablatherm is substantially equivalent to the predicate device, without the need to pursue a de novo pathway," he noted.

Health Canada approved EDAP's Focal One HIFU device last January, which allows it to be marketed for the treatment of prostate cancer in Canada.


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