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Pediatric Obesity: Issues Facing the
Center for Devices and Radiological Health
Ron Yustein, M.D.Clinical Deputy Director
Office of Device EvaluationCenter for Devices and Radiological Health
November 16, 2005This presentation may contain images which may be copyrighted
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OutlineGoals for This Meeting
The “Epidemic”
Role of CDRH and ODE
Background of Approved Devices
Typical Features of Adult Trials
Questions to be Addressed by Panel
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CDRH’s Meeting GoalsProvide an open forum for discussion between FDA, the clinical community, and the public on a vital public health issue.
Discuss the epidemiology of obesity in the U.S. pediatric population.
Discuss current treatment options for obesity in the pediatric population.
Discuss issues related to designing and performing trials for devices to treat obesity in the pediatric population and provide recommendations for such to FDA.
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CDRH’s Meeting Goals
Although prevention of obesity is certainly a key issue when addressing this “epidemic”, CDRH would like this meeting to focus on the treatment of the condition after it presents.
Keep the differences between drugs and devices as well as the differences in regulations of the two in mind and recognize that devices pose their own unique issues.
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The “Epidemic”
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Current Treatment Options
DietExercise
Diet/exercise and pharmacological therapy are less invasive than surgery, but are also probably generally less effective.
Less Invasive
More Invasive
Meds Surgery
RYGB
Less Effective??
More Effective??
? ? ? ? ? ?
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Filling the Void with Devices?
Diet
Exercise
Endoscopically or surgically implanted devices may fill a niche and offer treatment options which are intermediate in effectiveness and risk.
Less Invasive
More Invasive
Meds Surgery
RYGBDEVICES ???
Less Effective??
More Effective??
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Role of CDRH and ODECDRH/ODE: Promote & Protect the Public Health by Ensuring the Safety and Effectiveness of Medical Devices. Assess pre-clinical & clinical data.
Regulation/oversight of investigative trials.
Approve devices for marketing which are
reasonably safe and effective.
Keep or remove unsafe or ineffective devices
from the market.
Monitor devices after marketing.
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Device EvidenceValid Scientific Evidence per Device Regulations:
Well-Controlled Studies
Partially Controlled Studies
Objective Trials without Matched Controls
Case Histories
Significant Human Experience
Some Background:
Devices and Obesity
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Adults
BMI
Children
BMI-for-Age
Normal 18.5-24.9 5th- 84th Percentile
At Risk for Overweight 85th - 95th Percentile
Overweight 25-29.9 >95th Percentile
Obese 30-34.9
Obese – Severe 35-39.9
Obese – Extreme 40-49.9
Obese – Super 50-59.9
Obese – Super, Super > 60
BMI > 40 may also be referred to as “Morbid Obesity”
Definitions I
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Definitions II
% Excess Weight Loss (%EWL) Amount of weight lost as a fraction (%) of the
amount by which the person was over “ideal” weight (for height and frame) at baseline.
% EWL = [Wt Lost] / [Baseline Wt – Ideal Wt]
Example:Baseline Weight = 300 #
Ideal Weight for Height and Frame = 180#
Excess Weight = 120#
Patient Loses 40# at 12 months
% EWL = 40/120 = 33%
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Background
Only 2 devices have ever been approved by FDA specifically for the treatment of obesity – both for adults. Garren-Edwards Bubble
Inamed Lap-BAND
However, these may only be the tip of the
iceberg.
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Garren-Edwards Gastric Bubble
PMA Approved September 17, 1985
Indications for Use: Temporary aid to diet
and behavior modification in people who are at least 20% over their ideal weight.
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Garren-Edwards Bubble – Part II
Supporting Data (78 adult subjects at 3 sites)
Effectiveness data Mean implant time 7.5 monthsAt 4 months (n=50) Mean 34 lb. lossAt 6 months (n=41) Mean 40 lb. lossAt 10 months (n=4) Mean 76 lb. loss
Safety dataDeflation w/pyloric obstruction 1Deflation w/SBO 1Gastric ulcer 1
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Garren-Edwards Bubble – Part III
Post-marketing experience >100 MDRs in first 2 years 79 surgeries to remove deflated balloon
from small bowel.
1988Marketing Discontinued
1992PMA Voluntarily Withdrawn
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Inamed’s Lap-BAND Adjustable Gastric Band
Approved June, 2001
Indications for Use: For weight reduction for
severely obese patients 18 and over with BMI > 40 or BMI > 35 with > 1 severe comorbid condition, or those who are > 100 lbs over estimated ideal weight.
Inamed Website
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Lap-BAND – Part IISupporting Data (Pre-Market)299 adult patients (as own control) x 3 years
Effectiveness
% EWL Δ Wt Δ BMI
1 Year 34.5% 52# 8.5
2 Years 37.8% 59# 10.5
3 Years 36.2% 53# 9.0
SafetyN/V
51%
GERD34%
Abd. Pain 27%
Band Slippage 24%
Stoma Obstruction 14%
Esophageal Dil 10%
Dysphagia 9%
Erosion 1%
Revision Surgeries 9%
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Lap-BAND – Part IIIPost-marketing Experience Port/Tubing Leak
New Port + Advisory on Technique (2002)
U.S. Clinical ExperienceReplacing VBG as restrictive procedure?
Results approaching European experience 1 year: 40-50% EWL 2 year: 40-60% EWL Decreased adverse events
2020
Other Approaches per Literature
Gastric Space-Occupying Devices Newer Balloons
Stimulators Gastric electrical stimulation
The Study of Obesity Devices in Adults
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Typical Study Issues
Patient Eligibility Age 18 and over
BMI
> 40 or
> 35 with at least one co-morbidity
Lower-risk devices may be studied in patients with BMI > 30 with at least one co-morbidity
Minimum duration of disease (3-5 years).
Failure to respond to conservative treatments.
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Typical Study Issues
Patient Eligibility Exclusion of (poorly controlled) diabetics.
Exclusion of patients with bulimia, etc.
Certain baseline characteristics that may
identify subjects most likely to respond prior
to treatment.
Normal swallowing and GI motility.
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Typical Study IssuesPivotal Study Design FDA encourages randomized, sham-controlled
studies when possible: Surgically implanted devices with on/off modesEndoscopically implanted devices
Active Group Control Group* Active device Sham Procedure
Inactive Device
Diet/Behavior/Exercise Diet/Behavioral/Exercise
*Activated or offered device after pre-determined amount of time
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Typical Study Issues“Problem” with Sham Control Studies
Ethics of keeping patients Ethics of keeping patients without effective treatment without effective treatment for prolonged period of for prolonged period of time (1 year or more)time (1 year or more)
Fact that device may not Fact that device may not reach maximum or reach maximum or meaningful effectiveness meaningful effectiveness in shorter time period. in shorter time period.
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Typical Study Issues
Other Possible Designs: Control with approved product (Lap-BAND).
Superiority studyNon-inferiority study with pre-specified delta.
Control with surgery (RYGB).Non-inferiority study?
Control with Optimal Medical Care (OMC)DietBehaviorExercisePharmacological agents
Patient as own control
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Typical Study IssuesDuration/1° Endpoint Assessment > 1 year for permanent implant.
3 - 6 months for temporary implants depending on design and intended use.
Anticipate requesting continued evaluation postmarket for 2-5 years for long-term implants in adults.
Long-term safety
Maintenance of weight loss
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Typical Study IssuesEndpoints Effectiveness
Primary %EWL
Secondary Absolute Wt Δ Δ in BMI QoL Assessments Δ in Comorbidities Δ hip/waist circum
SafetyProcedure or surgery related adverse events
Device related adverse events
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Typical Study Issues
Concurrent Treatments Diet
Calorie restriction (-500 Cal/day) or ad-lib
Behavioral Modification and TherapyGroup or Individual Therapy
Exercise or Physical Activity
No weight loss medications or herbals.
Issues for Discussion:
What We Will Ask
You?
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Issues for Obesity Device Trials
Please keep in mind that, unlike most drugs, devices come in different forms:
Permanent unremovable (for-life) implant
Permanent but removable (long-term) implant
Temporary removable implant
External devices (non-implants)
Anatomy altering devices
Anatomy preserving devices
Please consider this when discussing each question as you may have different recommendations for different device types.
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Question # 1
What are appropriate patient populations to include in these trials? Age Weight/BMI Developmental Milestones Medical Co-morbidities Failure of prior conservative therapies Psychological assessments Specific exclusion criteria Assent/Consent issues
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Question # 2
What are appropriate endpoints for studying devices to treat obesity in the pediatric population?
Appropriate primary and secondary effectiveness endpoints.
Appropriate safety endpoints.
Appropriate duration for assessment of primary endpoints.
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Question # 3What are appropriate study designs for these trials? Role of RCT.
Role of Sham Controls.
Other appropriate study designs and controls.
Minimizing confounding factors.
Appropriate duration of pre-market study.
Role of DMC or DSMBs?
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Question # 4What long-term safety and effectiveness issues may be important and how should they best be addressed? Effect on future growth and development. Effect on future comorbidities. Maintenance of weight loss. Role of post-approval studies (PAS) to
collect this information. Registries.
Thank You