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CompletedNCT00521079EMPOWERUpdated Aug 24, 2018Results posted

EMPOWER Clinical Trial: Vagal Blocking for Obesity Control

An interventional study of Therapy ON and Therapy OFF in Obesity, sponsored by ReShape Lifesciences. Completed at 15 sites in 2 countries. Open to participants aged 18 Years to 65 Years. Per ClinicalTrials.gov, last updated 2018-08-24.

Sponsored by ReShape Lifesciences · Not applicable, Interventional, and Treatment

Phase
Not applicable
Study type
Interventional
Enrollment
294
Allocation
Randomized
Ages
18 Years to 65 Years
Sex
All
01

Study 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.

Read the 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.

02

Conditions studied

  • Obesity

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Keywords

  • Obesity
  • Bariatric surgery
  • Excess weight loss
  • Vagus nerve
  • Vagal blocking
  • vBloc(TM) therapy
03

In context

Obesity

6,583 studies on the registry are indexed under Obesity; 1,718 are open to participants now.

This study's enrollment of 294 is above the median of 77 across 5,091 interventional studies indexed under Obesity.

Browse Obesity studies →

Lead sponsor

ReShape Lifesciences is the lead sponsor of 10 studies on the registry; none are open to participants now.

Counted across the registry records on this site, refreshed daily.

04

Who can participate

Ages eligible
18 Years to 65 Years
Sexes eligible
All
Accepts healthy volunteers
No

Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.

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

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).
05

Study design

Phase
Not applicable
Primary purpose
Treatment
Allocation
Randomized
Intervention model
Parallel assignment
Masking
Quadruple (Participant, Care provider, Investigator, Outcomes assessor)
Enrollment
294 participants (actual)

Study arms

  • Experimental
    vBloc

    Subjects implanted with a functional Maestro System device that delivers therapy (Therapy ON).

    Device: Therapy ON

  • Sham comparator
    Placebo

    Subjects implanted with a functional Maestro System device that does NOT deliver therapy (Therapy OFF).

    Device: Therapy OFF

Interventions

  • DeviceTherapy ON

    Intermittent, programmable, intra-abdominal vagal blocking device that delivers therapy (Therapy ON)

    Also known as: Maestro System

  • DeviceTherapy OFF

    Active intra-abdominal placebo device that delivers no therapy (Therapy OFF)

    Also known as: Maestro System

06

What researchers measure

Primary outcomes

  1. Percentage of Excess Weight Loss (EWL) With the Maestro System

    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)

    Time frame: Baseline and 1 Year

  2. Rate of System and Procedure-related Serious Adverse Events (SAEs).

    To estimate the rate of serious, system- and procedure-related adverse events associated with the Maestro System.

    Time frame: 1 Year

Secondary outcomes

  1. Percentage of Participants Achieving 25% Excess Weight Loss (%EWL)

    To evaluate the percentage of participants achieving 25% excess weight loss from baseline (implant) to 12 months between treatment groups.

    Time frame: Baseline and 1 Year

07

Results

Posted Feb 20, 2017
Limitations and caveats
Two confounding efficacy factors: Variable hours of therapy in both arms due to inconsistent external power source use and altered vagal excitability in the control arm due to small electrical inputs delivered to vagal nerves for safety checks.

Participant flow

Participant flow — Overall Study
MilestonevBlocPlacebo
Started192102
Surgical roll-in95
Completed17897
Not completed145
Withdrew: Adverse event71
Withdrew: Lost to follow-up21
Withdrew: Withdrawal by subject53

Outcome measures

PrimaryPercentage of Excess Weight Loss (EWL) With the Maestro System

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)

Time frame:
Baseline and 1 Year
Reported as:
Mean · Percentage of excess weight loss
Percentage of Excess Weight Loss (EWL) With the Maestro System
Percentage of excess weight lossvBlocPlacebo
Percentage of Excess Weight Loss (EWL) With the Maestro System17 ± 216 ± 2
PrimaryRate of System and Procedure-related Serious Adverse Events (SAEs).

To estimate the rate of serious, system- and procedure-related adverse events associated with the Maestro System.

Time frame:
1 Year
Reported as:
Number · Events
Rate of System and Procedure-related Serious Adverse Events (SAEs).
EventsvBlocPlacebo
Rate of System and Procedure-related Serious Adverse Events (SAEs).63
SecondaryPercentage of Participants Achieving 25% Excess Weight Loss (%EWL)

To evaluate the percentage of participants achieving 25% excess weight loss from baseline (implant) to 12 months between treatment groups.

Time frame:
Baseline and 1 Year
Reported as:
Number · Percentage of subjects
Percentage of Participants Achieving 25% Excess Weight Loss (%EWL)
Percentage of subjectsvBlocPlacebo
Percentage of Participants Achieving 25% Excess Weight Loss (%EWL)2225

Adverse events

Non-serious events are listed at a 5% frequency threshold.

Adverse event summary by group
GroupDeathsSeriousOther
vBloc—23/192 (12%)146/192 (76%)
Placebo—12/102 (11.8%)70/102 (68.6%)
Most frequent serious events
Showing 10 of 16
Most frequent serious events
EventvBlocPlacebo
OtherGeneral disorders8/1926/102
Pain abdominalGastrointestinal disorders3/1920/102
Infection neuroregulator siteInfections and infestations2/1921/102
Lead impedance highSurgical and medical procedures0/1921/102
Pain neuroregulator siteSkin and subcutaneous tissue disorders1/1921/102
HypertensionCardiac disorders0/1921/102
Infection otherInfections and infestations1/1921/102
Large bowel dysfunctionGastrointestinal disorders0/1921/102
Incision pain incision siteSurgical and medical procedures1/1920/102
Neuroregulator malfunctionSurgical and medical procedures1/1920/102
Most frequent other events
Showing 10 of 26
Most frequent other events
EventvBlocPlacebo
Cold/flu/respiratory tract infectionRespiratory, thoracic and mediastinal disorders93/19246/102
Pain neuroregulator siteSkin and subcutaneous tissue disorders42/19228/102
Heartburn/DyspepsiaGastrointestinal disorders47/19215/102
Pain AbdominalGastrointestinal disorders32/19219/102
ConstipationGastrointestinal disorders32/19212/102
NauseaGastrointestinal disorders32/1929/102
DiarrheaGastrointestinal disorders23/19215/102
DepressionPsychiatric disorders24/1926/102
EructationGastrointestinal disorders20/19210/102
HeadacheGeneral disorders20/1926/102

Baseline characteristics

Age, Categorical
Age, Categorical(Participants)vBlocPlaceboTotal
<=18 years000
Between 18 and 65 years18397280
>=65 years000
Age, Continuous
Age, Continuous(years)vBlocPlaceboTotal
Mean45.7 ± 9.745.6 ± 10.645.7 ± 10
Sex: Female, Male
Sex: Female, Male(Participants)vBlocPlaceboTotal
Female16583248
Male181432
Region of Enrollment
Region of Enrollment(participants)vBlocPlaceboTotal
United States14277219
Australia412061
08

Study locations

15 sites
  • HonorHealth (formerly Scottsdale Bariatric Center)
    Scottsdale, Arizona 85258, United States
  • Scripps Clinic
    La Jolla, California 92037, United States
  • University of California, Irvine Medical Center
    Orange, California 92868, United States
  • Stanford University Medical Center
    Stanford, California 94305, United States
  • Cleveland Clinic - Florida
    Weston, Florida 33331, United States
  • Johns Hopkins
    Baltimore, Maryland 21224, United States
  • Tufts New England Medical Center
    Boston, Massachusetts 02111, United States
  • University of Minnesota
    Minneapolis, Minnesota 55455, United States
  • Mayo Clinic
    Rochester, Minnesota 55905, United States
  • Washington University School of Medicine
    St Louis, Missouri 63110, United States
  • Cleveland Clinic - Ohio
    Cleveland, Ohio 44195, United States
  • Oregon Health & Science University
    Portland, Oregon 97239-3098, United States
  • Virginia Commonwealth University
    Richmond, Virginia 23298, United States
  • Institute of Weight Control
    Sydney, New South Wales 2153, Australia
  • Adelaide Bariatric Center - Flinders Private Hospital
    Bedford Park, South Australia 5042, Australia
09

References and documents

Individual participant data

Plan to share: No

No publications or documents are linked to this record.

10

Timeline

Tracking since Sep 25, 2026
Not marked actual or estimatedDates not marked actual or estimated

The record gives a start of Aug 2007, a primary completion of Oct 2009 and a completion of May 2018. It does not say whether these dates are actual or estimated.

Results were first posted in Feb 2017, 7 years 4 months after primary completion.

How these figures are worked out, and which studies are left out of them.

Registered
Aug 23, 2007
First posted
Aug 27, 2007
Start
Aug 2007
Primary completionActual
Oct 2009
CompletionActual
May 2018
Results first posted
Feb 20, 2017
Last update
Aug 24, 2018
What these dates mean
Start.
When the first participant enrolled; while estimated, when the study expects to open to recruitment.
Primary completion.
When the last participant was examined or treated to collect data for the study's main question, its primary outcome. A study that stopped early gives the date its data collection stopped.
Completion.
When the last participant's last visit took place, for every outcome, secondary ones and side effects included: the end of the study. Often later than primary completion, sometimes the same day.
Actual and Est.
Actual means the registry says the date has happened. Est. (estimated) is a date the sponsor plans or expects. It can still move, and the sponsor is expected to change it to actual once it has passed.
No changes since tracking began. The registry record was last updated on Aug 24, 2018, before this site started recording changes on Sep 25, 2026. Its history is on ClinicalTrials.gov ↗
11

Registry details

Key details

Study ID
NCT00521079
Lead sponsor
ReShape Lifesciences
Responsible party
Sponsor
First posted
Aug 27, 2007
Start date
Aug 2007
Primary completion
Oct 2009
Completion
May 2018
Results posted
Feb 20, 2017
Last update
Aug 24, 2018

Study contacts

Charles J Billington, MD
principal investigator · VA Medical Center, Minneapolis, MN / University of Minnesota
Michael Sarr, MD
principal investigator · Mayo Clinic

Oversight

Data monitoring committee
Yes
View the source record on ClinicalTrials.gov ↗

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