FDA grants clearance to Exablate MR-guided focused ultrasound for prostate cancer

The FDA has granted the Exablate Prostate system 510K clearance for treating prostate tissue with high-intensity magnetic resonance (MR)–guided focused ultrasound (MRgFUS).¹

Behfar Ehdaie, MD

"Exablate ultrasound has been shown to provide effective control of locally-confined prostate cancer in select patients based on 2-year biopsy outcomes," Behfar Ehdaie, MD, MS, a urologic surgeon at Memorial Sloan Kettering Cancer Center, and Exablate trial PI, stated in a press release. "Precision ablation together with MR imaging and thermal feedback may enable men to consider a tissue preserving approach and defer or avoid radical therapy."

The FDA’s 510(k) clearance designation allows a company to market a medical device in the United States if the company can prove that its device is “substantially equivalent” to a device already being legally marketed.²

Clinical support

Ehdaie shared data at the 2021 AUA Annual Meeting from a phase 2b study (NCT01657942) of Exablate MRgFUS in men with intermediate-risk prostate cancer.³ Overall, the study included 101 men who were treated at 7 academic centers and 1 private practice.

The average patient age was 63 years and 86% of the cohort was White. The median PSA was 5.7 ng/mL. Eighty-four patients had at least clinical stage T1c disease. Seventy-eight percent of patients were in grade group 2 and 22% were in grade group 3.

At 24 months, 88% of men had no evidence of grade group 2 or 3 prostate cancer in the treatment area according to targeted prostate biopsy. Additionally, 60% of men had no evidence of grade group 2 or 3 disease anywhere in the prostate gland, including outside of the treatment area. Serum PSA levels decreased by almost 50% after treatment and stabilized after 6 months.

Erectile function scores were slightly worse at 24 months compared with baseline (HR, -3.5; 95% CI, -5.4 to -1.6). Ten (13%) reported no sexual activity and 81% of patients achieved erections adequate for intercourse. Lower urinary tract symptoms were similar at baseline and 24 months (mean score difference, 1.1; 95% CI, 0.33-1.8).

“Overall, approximately 75% of men were able to achieve functional reactions after treatment at 24 months without starting a new erectile function medication,” Ehdaie said at the time of the AUA presentation. “No patients reported urinary incontinence and the estimated probability of urinary continence over time was excellent.”

In his concluding remarks at the time, Ehdaie said, “Exablate MR-guided focal therapy using real-time MR thermometry preserves urinary incontinence and sexual function and it’s effective for grade group 2 and 3 prostate cancer cancers based on 2-year biopsy outcomes. Exablate MR-guided focused ultrasound may enable men to consider a tissue preserving approach and defer or avoid radical therapy.”

References

1. Insightec Announces FDA Clearance For Exablate Prostate To Treat Prostate Tissue. Published online December 1, 2021. Accessed December 6, 2021. https://prn.to/31yk3iv.

2. 510(k) Clearances. US Food and Drug Administration. Accessed August 27, 2021. https://www.fda.gov/medical-devices/device-approvals-denials-and-clearances/510k-clearances

3. Ehdaie B, Tempany C, Holland F, et al. MRI-guided focused ultrasound (MRgFUS) focal therapy for intermediate-risk prostate cancer: final results of a phase IIb multicenter study. Presented at: 2021 American Urological Association Annual Meeting; September 10-13, 2021; virtual. Abstract LBA02-12.