Phase 4
N=147
Use of Medication to Improve Weight Loss in Suboptimal Early Responders to Behavioral Treatment
Obesity
Bottom Line
View on ClinicalTrials.gov: NCT03779048 ↗Enrolled (actual)
147
Serious AEs
0.0%
Results posted
Mar 2025
Primary outcome: Primary: Phase 1: Percent Weight Loss — 1.7; 0.9; 0.3 % change in weight
Study Design & Population
- Study type
- Interventional
- Phase
- Phase 4
- Interventions
- Behavioral Treatment (Behavioral); Placebo (Drug); Phentermine 15 MG (Drug)
- Age
- Adult, Older Adult · 21+ yrs
- Sex
- All
- Sponsor
- University of Pennsylvania
- Primary completion
- May 2022
Outcome Measures
| Outcome | Result | p-value |
|---|---|---|
| PRIMARY Phase 1: Percent Weight Loss |
1.7; 0.9; 0.3 | — |
| PRIMARY Phase 1: Number of Participants Who Are Categorized as Early Non-responders at Randomization (Week 0), Based on Percent Weight Loss |
76 | — |
| PRIMARY Phase 1: Baseline Satiety, as Measured by Visual Analogue Scales (Range 0-100 mm) During a Test Meal; Satiety Quotient = [(Post-preload Rating - Fasting Rating Before Preload)] / (Energy Content of Preload in kcal) x 100. |
787.3 | .24 |
| PRIMARY Phase 1: Baseline Postprandial Change in GLP-1 During a Test Meal |
0.52 | .34 |
| PRIMARY Phase 1: Baseline Gastric Emptying During a Test Meal (Acetaminophen Test) |
5.22 | .78 |
| PRIMARY Phase 2: Percent Weight Loss |
2.8; 5.9 | .003 sig |
| SECONDARY Phase 1: Baseline Hunger, as Measured by Visual Analogue Scales (Range 0-100 mm, Higher = More Hunger) During a Test Meal |
-770.97 | .23 |
| SECONDARY Phase 1: Baseline Relative Reinforcing Value of Food (Computer Task), Number of Food Reinforcer Points Earned |
1.85 | .23 |
| SECONDARY Phase 1: Baseline Delay Discounting (Computer Task), Area Under the Curve Representing the Ratio of Immediate Reward Size to Time Delay |
0.34 | .033 sig |
| SECONDARY Phase 1: Baseline Implicit Wanting, Reaction Time on Leeds Food Preference Questionnaire |
7.0; -12.2; -13.5; 18.7 | .04 sig |
| SECONDARY Phase 1: Baseline Fasting Ghrelin |
75.65 | .73 |
| SECONDARY Phase 1: Baseline Fasting Leptin |
46980.6 | .25 |
| SECONDARY Phase 1: Baseline Postprandial Change in Insulin During a Test Meal |
20.96 | .72 |
| SECONDARY Phase 1: Baseline Postprandial Change in Peptide YY During a Test Meal |
7.44 | .82 |
| SECONDARY Phase 2: Weight Loss (kg) |
2.6; 5.7 | .002 sig |
| SECONDARY Phase 2: Number of Participants With a Weight Loss of 5% or Greater of Randomization Body Weight at Week 24 |
8; 20 | — |
| SECONDARY Phase 2: Number of Participants With a Weight Loss of 10% or Greater of Randomization Body Weight at Week 24 |
2; 6 | — |
| SECONDARY Phase 2: Change in Appetite Suppression, as Measured by Visual Analogue Scales (Range 0-100 mm) During a Test Meal |
1167.7; 1357.5; 862.8; 1245.3 | — |
| SECONDARY Phase 2: Change in Hunger, as Measured by Visual Analogue Scales (Range 0-100 mm, Higher=More Hunger) During a Test Meal |
-1062.5; -1113.2; -579.5; -935.2 | — |
| SECONDARY Phase 2: Change in Delay Discounting (Computer Task), Area Under the Curve Representing the Ratio of Immediate Reward Size to Time Delay |
0.41; 0.38; 0.42; 0.38 | .68 |
Summary
This is a two-phase study. Phase 1 will evaluate obesity-related behavioral and biological characteristics as potential predictors of response to behavioral treatment (BT) for weight loss. Phase 2 is a double-blind, placebo-controlled, RCT to test whether adding weight loss medication to BT improves 24-week weight loss, as compared to BT with placebo, in subjects identified as having suboptimal early weight loss after 4 weeks of individual behavioral weight control. All participants, regardless of their early weight loss, will receive the same BT program of diet, physical activity, and behavior therapy for weight loss for an additional 24 weeks (28 total weeks of treatment).
Eligibility Criteria
Inclusion Criteria
- BMI ≥ 31 kg/m² (or 28 kg/m2 with obesity-related comorbidity)
- Age ≥ 21 years and ≤ 70 years
- Eligible female patients will be:
- non-pregnant, evidenced by a negative urine pregnancy test
- non-lactating
- surgically sterile or postmenopausal, or they will agree to continue to use an accepted method of birth control during the study. Acceptable methods of birth control are: hormonal contraceptives; double barrier method (condom with spermicide or diaphragm with spermicide); intrauterine device; surgical sterility; abstinence; and/or postmenopausal status (defined as at least 2 years without menses).
- Subjects must:
- have a primary care provider (PCP) who is responsible for providing routine care
- understand and be willing to comply with all study-related procedures and agree to participate in the study by giving written informed consent
- plan to remain in the Philadelphia area for the next 9 months or more
Exclusion Criteria
- Pregnant or nursing, or plans to become pregnant in the next 9 months.
- Uncontrolled hypertension (systolic blood pressure ≥ 140 mm Hg or diastolic blood pressure ≥ 90 mm Hg)
- Type 1 diabetes
- Type 2 diabetes
- A fasting blood glucose > 126 mg/dL (on second assessment after first elevated value)
- History of cardiovascular disease (e.g., coronary artery disease, stroke, arrhythmias, congestive heart failure, or heart block greater than first degree
- Clinically significant hepatic or renal disease
- Hyperthyroidism
- Other thyroid disease, not controlled
- History of malignancy (except for non-melanoma skin cancer) in past 5 years
- Narrow angle glaucoma
- Presence or history of marked agitation
- Current severe major depressive episode (BDI-II score ≥ 29), current active suicidal ideation, or history of suicide attempts within the past 5 years.
- Any severity of thought or bipolar disorder, or bulimia nervosa.
- Psychiatric hospitalization within the past 6 months
- Self-reported alcohol or substance abuse within the past 6 months, including at-risk drinking (current consumption of ≥ 14 alcoholic drinks per week)
- Past year history of drug abuse
- Use in the past 2 weeks of monoamine oxidase inhibitors
- Current use of serotonin-norepinephrine reuptake inhibitors (SNRIs; e.g. venlafaxine, duloxetine, desvenlafaxine, milnacipran, levomilnacipran).
- Use in past 6 months of medications known to induce significant weight loss (i.e., prescription weight loss medications) or weight gain (e.g., chronic use of oral steroids, second generation antipsychotics)
- Loss of ≥ 5% of initial body weight within the past 6 months
- History of (or plans for) bariatric surgery (e.g., roux en y gastric bypass, sleeve gastrectomy, gastric banding), endoscopic intragastric balloon, or aspire assist.
- Inability to walk 5 blocks comfortably or engage in some other form of aerobic activity (e.g., swimming)
- Known or suspected allergy to sympathomimetic amines or related products
- The receipt of any investigational drug within 6 months prior to this trial
- Previous participation in this trial (e.g., randomized and failed to participate)
- Changes to any chronic medication (type or dosage) within the past 3 months.
- Any serious or unstable medical or psychological condition that, in the opinion of the investigator, would compromise the patient's safety or successful participation in the study
Other Therapy: Subjects will be expected to use medications (prescribed by their PCP) to control traditional cardiometabolic risk factors (e.g., hypertension, hypercholesterolemia, etc) and other co-morbid conditions, with the exception of medications listed above under "exclusions." In all cases, the subjects' PCP will be asked at the study's outset to keep medication does constant throughout the study, whenever possible. Subjects will be expected to have been on their medication regimen (including the dose) for 3 months prior to beginning the BT
Data sourced from ClinicalTrials.gov (NCT03779048). Outcome figures and adverse-event rates are extracted automatically from the registry's posted results and are provided for clinician reference, not as a substitute for the primary publication.