Five Minutes with…Robin Blackstone, MD: Exploring a New Horizon–The EMPOWER Study

| July 18, 2008 | 0 Comments

Dr. Blackstone is Surgeon and Director, Scottsdale Bariatric Center, and Medical Director, Scottsdale Healthcare Bariatric Program. The Scottsdale Bariatric Center was named as an American Society for Metabolic and Bariatric Surgery Center of Excellence in 2005.

In your opinion, what is new and exciting in the field of obesity treatment?
A new pivotal study called EMPOWER is currently investigating the effectiveness of an implanted weight loss device for the treatment of obesity. VBLOC therapy is a new neuromodulation technique delivered by an implantable device intended to block signals carried on the vagus nerves between the brain and the digestive system. The vagus nerves are known to provide the main line of communication between the brain and the digestive system and control feelings of hunger and fullness. The idea for VBLOC was born after observing a loss of appetite and initial weight loss in vagotomy patients, a procedure that resects part of the vagus nerve.

The device itself uses laparoscopically implanted electrodes that deliver high-frequency, low-energy electrical impulses to block the signals conveyed through the vagus nerves. The hope is by reversibly controlling these signals, VBLOC may aid in weight loss. VBLOC includes both external and implanted components and may be turned off; it is designed to be reversible, programmable, and noninvasively adjustable.

One of the most powerful aspects of VBLOC is that we understand exactly how the technology works, making it a significant research tool.

What research has been conducted with VBLOC therapy? What research is in progress?
Initial studies have indicated that VBLOC may safely and effectively help patients reduce excess body weight. In a 33-patient feasibility study conducted outside the US, data showed an average excess weight loss of 29.5 percent for the nine patients who had been receiving VBLOC for nine months.

In addition to my practice, bariatric specialists across the country are enrolling patients in the EMPOWER study at clinics such as Tufts Medical Center, Virginia Commonwealth University, University of California at Irvine, and Mayo Clinic Rochester. Through the EMPOWER study, researchers aim to establish, for the first time, if vagal neuroblockade can offer hope for patients suffering from obesity.

Who is eligible to participate in the EMPOWER study?
Male and female patients between the ages of 18 and 65 who have a body mass index (BMI) between 35 and 45 are eligible for this study. Participants with a BMI of less than 40 must have at least one comorbid condition, such as hypertension, high cholesterol, obesity-related cardiomyopathy, or sleep apnea syndrome. Patients with type 2 diabetes mellitus (T2DM) are being enrolled at selected sites only. Scottsdale Bariatric Center, with its research focus on T2DM, is one of the sites that is enrolling diabetic patients.

What is the experience like for patients participating in the EMPOWER study?

Once patients have enrolled in the study and signed an informed consent, they will undergo surgery to have the device implanted, and are then randomized to either having the device turned ON or remain OFF. One third of the study participants will be randomly selected to have the device turned OFF for the first year. There is no way of influencing to which group patients are assigned. However, following 12 months of implantation, all participants will have their device turned ON.

The duration of the EMPOWER study is five years. Patients will have 43 planned visits over this time period, with 21 visits required during the first year of the study. In addition, there are regularly scheduled telephone and clinic visits throughout the study period.

What is the anticipated time line for when the product will be available commercially?
The study sponsor, EnteroMedics, currently anticipates that the study will be enrolled by August 2008. If that deadline and all other anticipated milestones for the study are met, we could see a commercial product within the next two years.

If you have patients that might be interested in participating in the EMPOWER study they can learn more by calling (866)-97-VBLOC (866) 978-2567 or by visiting

What do you believe is the potential impact of VBLOC on obesity therapy?
As a bariatric surgeon, I am looking for treatment options with a high degree of safety and a reasonable degree of efficacy in the group of patients who have a lower BMI (BMI range of 30–45). Less invasive therapies are extremely desirable in this group of patients who are not as sick. The risk-benefit ratio is different in this group of patients; they want a solution to their obesity that does not have the downside risk of a gastric bypass.

If the VBLOC results in this trial are consistent with the early data, then it will be one of the options for this particular group of patients.

Time’s up!

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