Weight Loss Study: Genetics and Response to Naltrexone/Bupropion

March 31, 2024 updated by: Judith Korner, Columbia University

Association of Genetic Variations and Weight Loss Response to Naltrexone/Bupropion

The goal of this clinical trial is to understand if genetic variations are associated with the amount of weight loss with diet and while taking an FDA-approved medication for weight loss. The main question[s] it aims to answer are:

  • In Aim One, the investigators propose to rigorously test the hypothesis that presence of the Taq1A A1+ polymorphism is associated with greater weight loss with NB compared with the A1- genotype.
  • In Aim Two, the investigators will explore other genetic polymorphisms that might influence the efficacy of NB such as the fat mass and obesity-associated (FTO) gene which modulates DRD2 signaling, as carriers of risk alleles in both the FTO and ANKK1 gene demonstrate altered responses to reward-learning tasks associated with negative outcomes.

Participants will be in the study for 40 weeks, which consists of two phases:

  1. From baseline to week 12, participants will receive individual nutritional counseling on a calorie restricted diet. This phase includes in-person visits, blood tests, an EKG, vital signs, questionnaires, body weight, and nutritional visits.
  2. From week 12 to week 40, participants will continue to receive dietary counseling and will receive treatment with naltrexone/bupropion for 28 weeks. This phase includes in-person and phone visits, blood tests, vital signs, questionnaires, body weight, and nutritional visits.

Study Overview

Status

Recruiting

Conditions

Detailed Description

Weight loss can improve or prevent many obesity-related co-morbidities, yet time and again the cornerstone of obesity therapy - diet, physical activity and behavioral modification - fails to produce sufficient long-term weight loss in most individuals. In such cases, clinical guidelines recommend the addition of anti-obesity medication (AOM) when conservative methods are less than optimal. Yet even with the use of AOM, there is a wide range of inter-individual weight loss suggesting that there are "responders" and "non-responders." The variability in response to AOMs underscores the heterogeneity of obesity and the need for more personalized treatment that accounts for individual differences in etiologic factors. Given the strong heritability of obesity, it is possible that genetic factors play a role in an individual's response to a given pharmacotherapy.

This proposal focuses on the FDA-approved AOM, Contrave, which is a combination of two medications, naltrexone 32 mg and bupropion 360 mg (NB). Naltrexone is a µ-opioid receptor (MOPR) antagonist and bupropion inhibits the reuptake of dopamine and norepinephrine. Clinical trials of NB demonstrate a mean weight loss of 6.1% after 56 weeks of treatment; however, only 48% of patients achieved a clinically significant reduction in body weight of at least 5%. Knowledge of the likely mechanisms of action of NB makes it possible to address what might underlie the variability in response. The bupropion component of NB activates the proopiomelanocortin (POMC) neuron, a key regulator in decreasing food intake and stimulating energy expenditure, through stimulation of dopamine D2 receptors (DRD2). Naltrexone also activates POMC neurons by binding MOPR.

The investigators postulated that some of the variability in response to NB may be due to the Taq1A genetic variant (rs1800497) located in the ankyrin repeat and kinase domain-containing protein 1 (ANKK1) gene, adjacent to the DRD2 gene. Individuals carrying at least one minor allele of the rs1800497 polymorphism (termed Taq1A A1+) represent about 45% of the population and have 30-40% fewer brain DRD2. Carriers of the minor allele likely have a relative deficiency in dopaminergic activation of POMC neurons and, therefore, might receive the greatest benefit from a drug that activates POMC neurons. With this hypothesis in mind, the investigators conducted a retrospective proof-of-concept pilot study reviewing charts of patients treated with NB and found that individuals with the Taq1A A1+ genotype had a greater response compared with non-carriers, suggesting that this genotype could be used to predict successful weight loss.

In Aim One, the investigators propose to rigorously test the hypothesis that presence of the Taq1A A1+ polymorphism is associated with greater weight loss with NB compared with the A1- genotype. In Aim Two, the investigators will explore other genetic polymorphisms that might influence the efficacy of NB such as the fat mass and obesity-associated (FTO) gene which modulates DRD2 signaling, as carriers of risk alleles in both the FTO and ANKK1 gene demonstrate altered responses to reward-learning tasks associated with negative outcomes. Functional polymorphisms within genes that influence the metabolism of bupropion and naltrexone will also be examined in relation to weight loss outcomes. The ultimate goal is to incorporate pharmacogenetics into obesity medicine in order to maximize positive results and limit unnecessary cost and exposure to side effects of medications that provide minimal benefit to the individual patient.

Study Type

Interventional

Enrollment (Estimated)

120

Phase

  • Phase 4

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact Backup

Study Locations

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • Men and women ages 18-65 years
  • BMI 30-50 kg/m2 or
  • BMI 27-29.99 kg/m2 with at least one weight-related comorbidity including controlled hypertension, dyslipidemia, obstructive sleep apnea, or osteoarthritis of a weight-bearing joint.

Exclusion Criteria:

  • Obesity of known endocrine or hypothalamic origin
  • HbA1c > 6.5%
  • Cerebrovascular, cardiovascular, hepatic or renal disease
  • History of seizures, serious psychiatric illness or suicide attempts, drug or alcohol misuse within prior 24 months
  • Glaucoma
  • Current tobacco use on a regular basis
  • Use of dopamine agonists, opioid analgesics, antipsychotics, antidepressants, neuroleptics, naltrexone, diabetes medications
  • Use of Monoamine oxidase (MAO) inhibitors < 14 days prior to screening
  • Concomitant use of CYP2B6 inhibitors
  • History of anorexia nervosa or bulimia
  • Previous surgery for obesity
  • Weight loss device intervention within prior 2 years
  • Currently pregnant or lactating, planning pregnancy or refusal to use birth control when appropriate (Women of childbearing potential will be required to use effective contraception.)
  • Blood pressure > 145/95 (use of anti-hypertensives will be allowed with the exception of verapamil, which can cause hyperprolactinemia)
  • Clinically significant thyroid disease
  • Triglycerides > 499 mg/dl
  • Current use or use of weight loss medication within prior six months
  • Any lifetime weight change deemed significant by Principal Investigator
  • An affirmative answer to any question in the Columbia-Suicide Severity Rating Scale

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Other
  • Allocation: N/A
  • Interventional Model: Single Group Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: All participants
Calorie restricted diet and treatment with Naltrexone/Bupropion
Participants receive 28 weeks of naltrexone-bupropion weight loss medication during phase two of this study.
Other Names:
  • Contrave

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Percent Weight Loss (40 Weeks)
Time Frame: Baseline and 40 Weeks
Percent weight loss from baseline to 40 weeks.
Baseline and 40 Weeks

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Percent Excess Weight Loss
Time Frame: Baseline and 40 Weeks
Percent excess weight loss defined as [(initial weight - weight lost at week 40)/(initial weight - weight at a BMI 25kg/m2)] x 100
Baseline and 40 Weeks
Percent Excess Weight Loss
Time Frame: 12 Weeks and 40 Weeks
Percent excess weight loss defined as [(Week 12 weight - weight lost at week 40)/(initial weight - weight at a BMI 25kg/m2)] x 100
12 Weeks and 40 Weeks
Percent of Participants Achieving ≥ 5% Weight Loss
Time Frame: Baseline and 40 Weeks
Percent of participants achieving ≥ 5% weight loss at week 40
Baseline and 40 Weeks
Percent of Participants Achieving ≥ 10% Weight Loss
Time Frame: Baseline and 40 Weeks
Percent of participants achieving ≥ 10% weight loss at week 40
Baseline and 40 Weeks
Percent Weight Loss
Time Frame: 12 weeks and 40 weeks
Percent weight loss from 12 weeks to 40 weeks.
12 weeks and 40 weeks

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Investigators

  • Principal Investigator: Judith Korner, MD,PhD, Columbia University

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

June 8, 2023

Primary Completion (Estimated)

June 30, 2027

Study Completion (Estimated)

June 30, 2027

Study Registration Dates

First Submitted

June 16, 2023

First Submitted That Met QC Criteria

June 16, 2023

First Posted (Actual)

June 26, 2023

Study Record Updates

Last Update Posted (Actual)

April 2, 2024

Last Update Submitted That Met QC Criteria

March 31, 2024

Last Verified

March 1, 2024

More Information

Terms related to this study

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

Yes

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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