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EMPOWER Clinical Trial: Vagal Blocking for Obesity Control (EMPOWER)

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details. Identifier: NCT00521079
Recruitment Status : Completed
First Posted : August 27, 2007
Results First Posted : February 20, 2017
Last Update Posted : August 24, 2018
Information provided by (Responsible Party):
ReShape Lifesciences

Brief Summary:
This is a randomized multi-center study being done to measure the ability of a new medical device, Maestro System, to safely reduce body weight over five years in people who are considered obese.

Condition or disease Intervention/treatment Phase
Obesity Device: Therapy ON Device: Therapy OFF Not Applicable

Detailed Description:

The Maestro System is a neuromodulation system that consists of implantable and external components.

Implantable components: two leads (one electrode each for the anterior and posterior intra-abdominal vagal nerve trunks) that are connected to an implantable neuroregulator.

External components: one programmable, battery-powered, ambulatory external controller connected via a small, flexible cable to a cutaneous transmit coil that is positioned externally over the neuroregulator. A clinician programmer that transmits information to the controller and uploads data from the controller.

All non-diabetic subjects will be randomized in a 2:1 allocation to therapy ON or therapy OFF groups. All type 2 diabetes mellitus subjects will be randomized in a 1:1 allocation to therapy ON or therapy OFF groups.

All subjects will receive blinded therapy through the 12-month follow-up visit. All subjects will participate in a medical weight management program.

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Study Type : Interventional  (Clinical Trial)
Actual Enrollment : 294 participants
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Quadruple (Participant, Care Provider, Investigator, Outcomes Assessor)
Primary Purpose: Treatment
Official Title: EMPOWER Clinical Trial: Vagal Blocking for Obesity Control
Study Start Date : August 2007
Actual Primary Completion Date : October 2009
Actual Study Completion Date : May 2018

Resource links provided by the National Library of Medicine

Arm Intervention/treatment
Experimental: vBloc
Subjects implanted with a functional Maestro System device that delivers therapy (Therapy ON).
Device: Therapy ON
Intermittent, programmable, intra-abdominal vagal blocking device that delivers therapy (Therapy ON)
Other Name: Maestro System

Sham Comparator: Placebo
Subjects implanted with a functional Maestro System device that does NOT deliver therapy (Therapy OFF).
Device: Therapy OFF
Active intra-abdominal placebo device that delivers no therapy (Therapy OFF)
Other Name: Maestro System

Primary Outcome Measures :
  1. Percentage of Excess Weight Loss (EWL) With the Maestro System [ Time Frame: Baseline and 1 Year ]
    Observe at least a 10% greater percentage excess weight loss (%EWL) with vBloc therapy delivered by the Maestro System compared to sham 12 months following randomization using MetLife Method (ideal body weight is calculated based on Metropolitan Height and Weight Tables)

  2. Rate of System and Procedure-related Serious Adverse Events (SAEs). [ Time Frame: 1 Year ]
    To estimate the rate of serious, system- and procedure-related adverse events associated with the Maestro System.

Secondary Outcome Measures :
  1. Percentage of Participants Achieving 25% Excess Weight Loss (%EWL) [ Time Frame: Baseline and 1 Year ]
    To evaluate the percentage of participants achieving 25% excess weight loss from baseline (implant) to 12 months between treatment groups.

Information from the National Library of Medicine

Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the contacts provided below. For general information, Learn About Clinical Studies.

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Ages Eligible for Study:   18 Years to 65 Years   (Adult, Older Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No

Inclusion criteria

  1. Informed consent.
  2. Body mass index (BMI) ≥ 40 kg/m2 to 45 kg/m2 or BMI ≥ 35 kg/m2 to 39.9 kg/m2 with one or more obesity related co-morbid condition. Co-morbid conditions may include one or more of the following:

    • Type 2 diabetes mellitus (note: type 2 diabetics are allowed at selected centers only, see Inclusion criterion #5)
    • Hypertension as defined by systolic pressure ≥140 mmHg and/or diastolic pressure ≥90 mmHg a) treated or untreated with systolic ≥140 mmHg or diastolic ≥90 mmHg or b) treated with systolic <140 mmHg and diastolic <90 mmHg
    • Dyslipidemia as defined by total cholesterol ≥200 or LDL ≥130 a) treated or untreated with total cholesterol ≥200 or LDL ≥130 or b) treated with total cholesterol <200 or LDL <130
    • Sleep apnea syndrome (confirmed by overnight p02 studies)
    • Obesity related cardiomyopathy
  3. Females or males Note: females of child-bearing potential must have a negative urine pregnancy test at Screen and also within 14 days of implant procedure followed by physician-approved contraceptive regimen for the duration of the study period.
  4. 18-65 years of age inclusive.
  5. Type 2 diabetes mellitus subjects (at selected centers, limited to approximately 34 subjects) with:

    • Glycosylated hemoglobin (Hb A1c) 6.5 - 9 % inclusive at screening visit.
    • Onset: 10 years or less since initial diagnosis.
    • Stable treatment regimen: no change in oral hypoglycemic treatment regimen within past 3 months.
    • Currently not using insulin therapy, GLP-1 receptor agonists (e.g., exenatide), or DPP-4 inhibitors (e.g., sitagliptin) for diabetes treatment and have not been on these treatments in the past 6 months.
    • Creatinine within normal reference range.
    • No history of proliferative retinopathy.
    • No history of peripheral neuropathy.
    • No history of autonomic neuropathy.
    • No history of coronary artery disease, with or without angina pectoris.
    • No history of peripheral vascular disease.
  6. Failure to respond to supervised diet/exercise program(s) in which the subject was engaged for at least 6 months within the last five years.
  7. Ability to complete all study visits and procedures.

Exclusion criteria

  1. Concurrent chronic pancreatic disease.
  2. History of Crohn's disease and/or ulcerative colitis.
  3. History of bariatric surgery, fundoplication, gastric resection or major upper-abdominal surgery (acceptable surgeries include cholecystectomy, hysterectomy).
  4. History of pulmonary embolism or blood coagulation disorders.
  5. Clinically significant hiatal hernias known from subject's medical record as or determined by upper endoscopy prior to implant if they have not had one done during the previous 6 months that specifically reported on the presence or absence of hiatal hernia making reference to the Z-line and/or diaphragmatic notch, in order to rule out subjects with hiatal hernia that may require surgical repair (to support exclusion criterion #7).
  6. Current portal hypertension and/or esophageal varices.
  7. Intra-operative exclusion: hiatal hernia requiring surgical repair or extensive dissection at esophagogastric junction at time of surgery.
  8. Treatment with weight-loss prescription drug therapy within the prior three months and the use of prescription drug therapy or the use over-the-counter weight loss preparations for the duration of the trial.
  9. Smoking cessation within the prior six months.
  10. Known genetic cause of obesity (e.g., Prader-Willi Syndrome).
  11. Overall sustained reduction of more than 10% of body weight in the previous 12 months.
  12. Physician-prescribed pre-operative diet with intent to lose weight prior to surgery (note: a) study subject may continue any personal diet they were on prior to study enrollment [see exclusion criterion #24] b) standardized EMPOWER weight management program to be initiated in all subjects at time of activation, approximately two weeks after implant)
  13. Current type 1 diabetes mellitus (DM).
  14. Current or recent history (within 12 months) of ongoing bulimia.
  15. Current alterations in treatment for thyroid disorders (stable treatment regimen for prior three months acceptable).
  16. Current alterations in treatment for epilepsy (stable treatment regimen for prior six months acceptable).
  17. Current treatment for peptic ulcer disease (previous history acceptable).
  18. Chronic (more than 4 weeks of daily use) treatment with narcotic analgesic drug regimens (treatment with non-steroidal anti-inflammatory drugs acceptable).
  19. Current alterations in treatment regimens of anti-cholinergic drugs, including tricyclic antidepressants (stable treatment regimen for prior six months acceptable).
  20. Current medical condition that, in the opinion of the investigator, would make subject unfit for surgery under general anesthesia or that would be exacerbated by intentional weight loss. Some examples include diagnosis of cancer, recent heart attack, recent stroke or recent serious trauma.
  21. Presence of permanently implanted electrical powered medical device or implanted gastrointestinal device or prosthesis (e.g., pacemakers, implanted defibrillators, neurostimulators etc.).
  22. Planned or contemplated use of Magnetic Resonance Imaging (MRI) or oncological radiation during the course of the trial.
  23. Significant psychiatric disorders that, in the opinion of the investigator, may interfere with subject's ability to follow study procedures and/or instructions.
  24. Current, active member of an organized weight loss program (e.g., Weight Watchers, TOPS).
  25. Current participant in another weight loss study or other clinical trials.
  26. Have a friend or family member who is currently participating or is planning to participate in this clinical trial.
  27. Patient reported:

    • inability to walk for about 10 minutes without stopping,
    • feeling of pain in chest when doing physical activity,
    • feeling of pain in chest when not doing physical activity. Note: unless pain in chest in known to be related to upper gastrointestinal disorders such as gastroesophageal reflux disease or heartburn.
  28. Clinically significant cardiac rhythm disorder that requires either medical and/or surgical intervention (e.g., paroxysmal or chronic atrial fibrillation).

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its identifier (NCT number): NCT00521079

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United States, Arizona
HonorHealth (formerly Scottsdale Bariatric Center)
Scottsdale, Arizona, United States, 85258
United States, California
Scripps Clinic
La Jolla, California, United States, 92037
University of California, Irvine Medical Center
Orange, California, United States, 92868
Stanford University Medical Center
Stanford, California, United States, 94305
United States, Florida
Cleveland Clinic - Florida
Weston, Florida, United States, 33331
United States, Maryland
Johns Hopkins
Baltimore, Maryland, United States, 21224
United States, Massachusetts
Tufts New England Medical Center
Boston, Massachusetts, United States, 02111
United States, Minnesota
University of Minnesota
Minneapolis, Minnesota, United States, 55455
Mayo Clinic
Rochester, Minnesota, United States, 55905
United States, Missouri
Washington University School of Medicine
Saint Louis, Missouri, United States, 63110
United States, Ohio
Cleveland Clinic - Ohio
Cleveland, Ohio, United States, 44195
United States, Oregon
Oregon Health & Science University
Portland, Oregon, United States, 97239-3098
United States, Virginia
Virginia Commonwealth University
Richmond, Virginia, United States, 23298
Australia, New South Wales
Institute of Weight Control
Sydney, New South Wales, Australia, 2153
Australia, South Australia
Adelaide Bariatric Center - Flinders Private Hospital
Bedford Park, South Australia, Australia, 5042
Sponsors and Collaborators
ReShape Lifesciences
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Principal Investigator: Charles J Billington, MD VA Medical Center, Minneapolis, MN / University of Minnesota
Principal Investigator: Michael Sarr, MD Mayo Clinic

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Responsible Party: ReShape Lifesciences Identifier: NCT00521079     History of Changes
Other Study ID Numbers: D00343-000
First Posted: August 27, 2007    Key Record Dates
Results First Posted: February 20, 2017
Last Update Posted: August 24, 2018
Last Verified: May 2018
Individual Participant Data (IPD) Sharing Statement:
Plan to Share IPD: No
Keywords provided by ReShape Lifesciences:
Bariatric surgery
Excess weight loss
Vagus nerve
Vagal blocking
vBloc(TM) therapy
Additional relevant MeSH terms:
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Nutrition Disorders
Body Weight
Signs and Symptoms