Medtronic has received an investigational device exemption (IDE) from the US Food and Drug Administration (FDA) to initiate SYMPLICITY HTN-4, the first randomised trial to investigate renal denervation for the treatment of less severe uncontrolled hypertension in US patients.
The SYMPLICITY HTN-4 study builds upon SYMPLICITY HTN-3, which was a pivotal US clinical trial that evaluated patients with uncontrolled hypertension.
The new study will enrol up to 580 patients with systolic blood pressures ranging between 140mmHg and 160mmHg.
Enrolment will be conducted at approximately 100 sites and patient recruitment will be done in line with the Joint National Committee on the Prevention, Detection, Evaluation and Treatment of High Blood Pressure (JNC-7), the American Heart Association and the European Society of Hypertension's definition of uncontrolled hypertension.
Similar to SYMPLICITY HTN-3, the study will be blinded and include a sham control.
SUNY Downstate College of Medicine co-primary investigator of SYMPLICITY HTN-4 and professor of medicine Dr Michael Weber said: "This highly anticipated, robust study will serve a key role in evaluating renal denervation in these underserved patients with less severe hypertension so that we're able to understand what benefit this novel therapy may offer patients outside of the currently indicated patient population."
Efficacy of the study will be assessed based on the ability of patients to either meet the goal of achieving a systolic blood pressure below 140mmHg or to achieve a pre-specified reduction in one day ambulatory blood pressure.
Safety of the renal denervation system will be evaluated as it was in SYMPLICITY HTN-3, by assessing major adverse events at one-month and renal artery stenosis at six months.
Medtronic renal denervation vice-president, general manager Nina Goodheart said: "We're excited to initiate this study, even while patient follow-up continues in our pivotal US clinical trial for patients with uncontrolled hypertension who have systolic blood pressure at or above 160.
"The SYMPLICITY HTN-4 trial will allow us to potentially extend the benefits of renal denervation to patients with more moderate uncontrolled hypertension in the United States."
The SYMPLICITY renal denervation system consists of a proprietary generator and flexible catheter, which delivers a controlled, low-power radio-frequency (RF) energy through a proprietary algorithm, or pattern, to deactivate the surrounding renal nerves.
Medtronic anticipates that its global Symplicity clinical programme will involve more than 8,000 patients including the US, Europe, and Japan, with more than 1,200 of these patients participating in randomised clinical trials.
The SYMPLICITY renal denervation system is backed by more than five years of clinical experience in more than 5,000 patients with uncontrolled hypertension and is available in more than 80 countries. The system received CE mark approval in 2008 and is currently available for investigational use only in the US.
Image: The SYMPLICITY renal denervation system. Photo: courtesy of Medtronic Inc.