FDA Conditionally Approves Medtronic's SYMPLICITY HTN-3 Renal Denervation Trial

July 11, 2011—Medtronic, Inc. (Minneapolis, MN) announced that the US Food and Drug Administration has conditionally approved the protocol for the SYMPLICITY HTN-3 clinical trial.

SYMPLICITY HTN-3 is a single-blind, randomized controlled trial designed to evaluate the safety and effectiveness of renal denervation with the company's Symplicity catheter system in patients with resistant hypertension, defined as high blood pressure in the presence of three or more medications. George Bakris, MD, and Deepak L. Bhatt, MD, are Principal Investigators of the SYMPLICITY HTN-3 trial.

Medtronic stated that the study will enroll approximately 500 patients at 60 medical centers in the United States. The patients will be randomized to receive either renal denervation and treatment with antihypertensive medications or treatment with antihypertensive medications alone. The primary endpoints of the study are the change in blood pressure from baseline to 6 months after randomization and incidence of major adverse events at 1 month after randomization. Patient enrollment in the study is expected to start soon.

“The imminent start of this clinical trial marks a pivotal point in the study of hypertension treatments,” commented Dr. Bakris, who serves as President of the American Society of Hypertension. “SYMPLICITY HTN-3 will assess the efficacy and safety of renal denervation with the Symplicity catheter system—a treatment approach that represents a first in our field: a catheter-based intervention for patients with resistant hypertension who have been unable to achieve target blood pressure levels despite multiple medications.”

The Symplicity system consists of a generator and a flexible catheter. Using femoral artery access, the device is threaded up into the renal artery near each kidney. The tip of the catheter delivers low-power radiofrequency energy in accordance with a Medtronic algorithm to modulate the surrounding sympathetic nerves. The procedure does not involve a permanent implant, the company noted.

Medtronic advised that the Symplicity catheter system is not approved for commercial distribution in the United States. The Symplicity device has received CE Mark approval and a listing with Australia's Therapeutic Goods Administration. It is commercially available in Europe and Australia. Medtronic is providing more information about the SYMPLICITY HTN-3 trial online at www.symplifybptrial.com.

According to Medtronic, clinical research to date shows that renal denervation with the Symplicity catheter system may provide a significant and sustained reduction in blood pressure levels for many patients with uncontrolled blood pressure despite multiple medications. Results from SYMPLICITY HTN-2, a randomized controlled trial of 106 patients in Europe, Australia, and New Zealand, showed that patients with resistant hypertension randomized to renal denervation achieved a mean blood pressure reduction of 32/12 mm Hg at 6 months, whereas the patients in the control group randomized to antihypertensive medications alone had blood pressures that did not vary from baseline (1/0 mm Hg). The overall occurrence of adverse events did not differ between groups. These findings were published in December 2010, in The Lancet (2010;376:1903–1909). In January 2011, Medtronic acquired Ardian, Inc. (Mountain View, CA), which developed the Symplicity system and sponsored the SYMPLICITY HTN-2 trial.