Fridley, Minn.-based Medtronic said the three-year, 340-patient Spyral HTN-On Med sham-controlled study is designed to compare treatment with the Symplicity Spyral device and a sham procedure, randomized on a 2:1 basis, after treatment with up to three anti-hypertensive medications, including diuretics, calcium channel blockers, ACE/ARB inhibitors and beta blockers. The primary safety endpoints include major adverse events at one month and new renal artery stenosis at six months. The primary efficacy endpoint is 24-hour ambulatory blood pressure at six months.
The trial is based on a pilot investigational device exemption study that showed an average 9mm Hg drop in 24-hour mean systolic ambulatory blood pressure in the treatment arm at six months.
“Medtronic is committed to building a robust global renal denervation clinical program with results from several randomized, sham-controlled, prospectively-powered, blinded clinical studies, in both the absence and presence of prescribed medications,” coronary & renal denervation GM Dave Moeller said in prepared remarks. “Results from the On Med trial will add to the growing body of evidence supporting renal denervation and is intended to support clinicians in making treatment decisions for patients who might benefit from this procedure.”
“A broad range of patients suffer with hypertension today, many of whom remain uncontrolled despite being prescribed a variety of medications; the consequences of uncontrolled hypertension represent both a substantial impact to public health and a large unmet need in medicine for new approaches,” added principal investigator Dr. David Kandzari of Atlanta’s Piedmont Heart Institute. “This trial will add yet another critical piece to the RDN evidence basis and is designed to build on the success of our pilot study, which showed a benefit for RDN in an on-med patient population.”
Looking to clear up some confounding factors
Back in January 2014, Medtronic shocked medtech when it announced the failure of a highly anticipated trial examining ablation of the nerves around the renal arteries in treating hypertension.
The company suspended enrollment in other Symplicity studies and later took a $200 million write-down on its renal denervation assets. News of the trial’s failure reverberated throughout the medical device industry, prompting other companies to follow suit by either scaling back their RDN programs or spiking them altogether.
But the Symplicity HTN-3 study’s failure was due to some confounding factors – namely, issues around differing medication regimens and patient compliance. Hence the design of the Spyral HTN program, involving both on- and off-medication trials.
Last summer Medtronic said positive preliminary results from one of those studies, the 353-patient Spyral HTN-Off Med IDE study, prompted it to proceed with its plans to win regulatory approvals for the Symplicity Spyral ablation catheter in the U.S., Japan and elsewhere.