FDA panel votes against EDAP’s ultrasound prostate cancer ablation

The FDA’s Gastroenterology & Urology Devices panel today voted against recommending approval of EDAP’s (NSDQ:EDAP) Ablatherm system for thermal ablation of the prostate gland to treat low-risk, localized prostate cancer.

The panel unanimously voted against Ablatherm’s effectiveness, in majority against the device’s safety (5 no votes, 3 yes votes and 1 abstention) and against its benefits outweighing its risks (8 no votes and 1 abstention).

Ablatherm is a computer-controlled high intensity focused ultrasound (HIFU) medical device that delivers treatment from an endorectal probe under ultrasound visualization and is intended to ablate the entire prostate gland, according to FDA background materials released ahead of the meeting.

While panelists admired the technology used by Ablatherm, they found fault with the study design and the primary endpoint used to demonstrate its effectiveness in the trial. EDAP compared 2-year biochemical survival rates for patients treated with Ablatherm to a performance goal derived from cryotherapy literature. The panel said that this was not adequate to show that the device is effective, saying that prostate cancer is often a slow-developing disease that can take up to 20 years to pose a mortality risk.

They also noted high rates of adverse events associated with Ablatherm, including erectile dysfunction and urinary incontinence, clinically significant rates of stricture, urethral injury and bowel injury.  

Prostate cancer is the second most common cause of cancer-related death in U.S. men and is now the leading cause of soft tissue malignancy in men, representing 1/3rd of incident cancer cases, the federal watchdog agency noted. Prostate cancer accounts for 3% of all male deaths.

Among patients diagnosed with the disease, 46% are reported as being at low risk, 30% at moderate risk, and 24% at high risk, according to the D’Amico classification. Due to the widespread use of PSA screening in clinical practice, more men are being diagnosed at earlier stages and thus have a lower risk of morbidity and mortality from the disease, the FDA pointed out.

There are currently no legally marketed HIFU devices to treat prostate cancer and men with localized prostate cancer are treated either aggressively with radical prostatectomy surgery or radiation or more conservatively with regular monitoring with delayed therapy when warranted. Cryotherapy and hormone therapy are also used on occasion to battle prostate cancer.

There is increasing evidence that therapeutic intervention delays disease progression and disease-specific mortality as compared to active surveillance (no treatment) but has little or no effect on overall survival regardless of risk strata, the FDA noted.

Despite this, the majority of patients with low-risk prostate cancer still undergo therapeutic intervention either initially or after a relatively short period of active surveillance. Though "no treatment" might be an acceptable option for low risk disease in patients with limited life expectancy, it is widely accepted that there is currently no definitive way to determine which men require treatment and who can be safely managed on active surveillance, the agency said.