Weight Regain Post Bariatric SurgeryRelayNCT06881485
Naltrexone/Bupropion With or Without Very Low Calorie Ketogenic Diet for Weight Regain After Bariatric Surgery
A study testing Very Low Calorie Diet in people with Weight Regain Post Bariatric Surgery and Obesity (Disorder), run by Universitaire Ziekenhuizen KU Leuven at 2 sites in Belgium.
Trial summary
The goal of this clinical trial is to evaluate the superiority of combined VLCKD, intensive lifestyle intervention and naltrexone/bupropion (N/B) versus standard of care with naltrexone/bupropion on weight loss for people with weight regain after bariatric surgery. Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Weight Regain Post Bariatric Surgery, Obesity (Disorder)
- What is being tested?
- Very Low Calorie Diet
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 62 participants
- Where
- 2 sitesBelgium
- Study dates
- 20 Jan 2025to 1 Jan 2027
- Phase
- Interventional
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 years and older
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Participants eligible for inclusion in this Trial must meet all of the following criteria:
- Voluntary written informed consent of the participant or their legally authorized representative has been obtained prior to any screening procedures
- Use of highly effective methods of birth control; defined as those that, alone or in combination, result in low failure rate (i.e., less than 1% per year) when used consistently and correctly; such as implants, injectables, combined oral contraceptives, some IUDs, true sexual abstinence (i.e. refraining from heterosexual intercourse during the entire period of risk associated with the Trial treatment(s)) or commitment to a vasectomised partner.
- Miminum 18 years of age at the time of Informed Consent signature
- Underwent bariatric surgery (RYGB or SG) with weight regain ≥10% of nadir weight
- People without Type 2 diabetes (T2D) • No history, no drugs, HbA1c < 6,5% and FPG <126 mg/dl) All participants that are considered for Trial participation, per the above criteria will be documented on the Screening Log, including Screen Failures.
Who cannot join
- Participants eligible for this Trial must not meet any of the following criteria:
- Participant has a history of type 2 diabetes mellitus (also drugs, HbA1c > 6,5% and FPG >126 mg/dl)
- IFemale who is pregnant, breast-feeding or intends to become pregnant or is of child-bearing potential and not using an adequate, highly effective contraceptive
- Participation in an interventional Trial with an investigational medicinal product (IMP) or device
- Not willing to sign informed consent
- Younger than 18 years of age at the time of Informed Consent signature
Show all 12Show fewer
- Other types of bariatric surgery other than RYGB or SG (including LAGB, BPD)
- Underwent bariatric surgery (RYGB or SG) with weight regain <10% of nadir weight
- Contraindication for VLCKD, including CKD stage 4-5, liver cirrhosis, type 1 diabetes mellitus, active gout
- Contraindication for NB including the use of opioids, history of CNS tumor or seizures, severe psychiatric disorder or > 2 psychotropic medications, uncontrolled hypertension
- Use of other drugs for weight management (e.g. GLP1Ra) in the last 3 months prior to trial intervention
- Any disorder, which in the Investigator's opinion might jeopardise the participant's safety or compliance with the protocol Participants who meet one or more of the above exclusion criteria must not proceed to be enrolled/randomized in the Trial and will be identified on the Screening Log as Screen Failure.
Trial locations and contacts
2 sites in 1 country. Contact the study team or a site near you to ask about taking part.
Belgium2 sites, 2 recruiting
- Not yet recruiting
AZ Sint-Jan Brugge
Bruges, West-Vlaanderen, 8000
Dr. B. Dillemans, +3250452553, obesitascentrum@azsintjan.be
- Recruiting
UZ Leuven
Leuven, Vlaams-Brabant, 3000
Prof. Dr. R. Vangoitsenhoven, +3216344775, relaytrial@uzleuven.be
About this study
The goal of this clinical trial is to evaluate the superiority of combined VLCKD, intensive lifestyle intervention and naltrexone/bupropion (N/B) versus standard of care with naltrexone/bupropion on weight loss for people with weight regain after bariatric surgery.
The main questions it aims to answer are:
Read more
Primary endpoint:
- The percentage of weight loss at 26 weeks
Secondary endpoints:
- A weight loss percentage at 10 weeks, 16 weeks and at end of trial (= 52 weeks from start)
- A proportion of patients with a weight loss percentage of 5% or more at 10, 16, 26 and 52 weeks
- A proportion of patients with a weight loss percentage of 10% or more at 10, 16, 26 and 52 weeks
- The time to reach a weight loss percentage of 5% and 10%
- The dose of naltrexone/bupropion used at 10, 16, 26 and 52 weeks and at the end of the trial
- The tolerability of VLCKD and NB
- The adherence to VLCKD and NB
- The Patient-Reported Outcome Measures (PROMs) of hunger and cravings at 0, 4, 10, 16, 26 and 52 weeks
- The change in fasting glucose, lipids and blood pressure at 10, 16, 26 and 52 weeks
Researchers will compare an experimental arm (N/B + Lifestyle + VLCKD) with comparator arm (NB + lifestyle) to see if combined VLCKD, intensive lifestyle and N/B is superior.
Participants will:
- get NB and lifestyle changes for 26 weeks
- follow a VLCKD in the first 10 weeks on top of it, if they belong to the experimental arm
- follow NB combined with lifestyle the remaining 16 weeks
- be followed-up for an extension of 26 weeks
- come to the hospital at week 1, 10, 16, 26, 52
- Being tested
- Very Low Calorie Diet
- Medical subject headings
- Obesity
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Very Low Calorie DietOther
This is a parallel multicentric longitudinal randomized controlled trial in which prospective data will be collected from the electronic health record. The inclusion and exclusion criteria will be checked and afterwards patients will be randomized to (unblinded) medication only or combination with VLCKD. Both arms include NB and lifestyle changes for 26 weeks but the patients belonging to the experimental arm must follow a VLCKD in the first 10 weeks on top of it. Like the other arm, the remaining 16 weeks will consist of NB combined with lifestyle interventions. Afterwards there is a follow-up extension of 26 weeks.
| Study group | Role | What they receive |
|---|---|---|
| Naltrexon/Bupropion + Lifestyle + VLCKD | Experimental | Naltrexon/Bupropion + Lifestyle + VLCKD Receives: Other: Very Low Calorie Diet |
| Naltrexon/Bupropion + Lifestyle | No intervention | Naltrexon/Bupropion + Lifestyle |
What is being measured
The primary outcome is the main question the study is designed to answer.
To evaluate the superiority of combined VLCKD, intensive lifestyle intervention and naltrexone/bupropion versus standard of care with naltrexone/bupropion on weight loss.
The percentage of weight loss at 26 weeks
Measured: 26 weeks
Secondary outcomes (12)
• A weight loss percentage at 10 weeks, 16 weeks and at end of trial (= 52 weeks from start)
in %
Measured: 10,16 and 52 weeks
• A proportion of patients with a weight loss percentage of 5% or more at 10, 16, 26 and 52 weeks
in %
Measured: 10, 16, 26 and 52 weeks
• A proportion of patients with a weight loss percentage of 10% or more at 10, 16, 26 and 52 weeks
in %
Measured: 10, 16, 26 and 52 weeks
• The time to reach a weight loss percentage of 5% and 10%
in weeks
Measured: 52 weeks
• The dose of naltrexone/bupropion used at 10, 16, 26 and 52 weeks and at the end of the trial
the dose is in mg
Measured: 10, 16, 26 and 52 weeks
• The tolerability of VLCKD
The amount of reported adverse effects, in relation to the achieved VLCKD.
Measured: 52 weeks
• The tolerability of NB
The amount of reported adverse effects, in relation to the achieved dose level.
Measured: 52 weeks
• The adherence to VLCKD
The amount meals eaten per day, in accordance to the dietary advice.
Measured: 52 weeks
• The adherence to NB
The amount of tablets taken per day, in accordance with the medicinal advice.
Measured: 52 weeks
• The change in fasting glucose at 10, 16, 26 and 52 weeks
fasting glucose in mg/dl
Measured: at 10, 16, 26 and 52 weeks
• The change in lipids at 10, 16, 26 and 52
lipids in mg/dl
Measured: at 10, 16, 26 and 52 weeks
• The change in blood pressure at 10, 16, 26 and 52
blood pressure in mmHg
Measured: at 10, 16, 26 and 52 weeks
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted18 Mar 2025
- Study start20 Jan 2025
- Primary completion1 Jan 2027 (estimated)
- Study completion1 Jan 2027 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Weight Regain Post Bariatric SurgeryStudies of the same condition, open and under way.
- More trials run by Universitaire Ziekenhuizen KU LeuvenThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Other
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Enrolment
- 62 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Universitaire Ziekenhuizen KU Leuven
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06881485
- Sponsor's protocol ID
- S68952
- Acronym
- Relay
- Status last verified
- Mar 2025
- First submitted
- 27 Feb 2025
- Last updated
- 21 Mar 2025
- Results posted
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
Study at a glance
From the registry record, last updated by the sponsor on 21 Mar 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Naltrexone/Bupropion With or Without Very Low Calorie Ketogenic Diet for Weight Regain After Bariatric Surgery
- ClinicalTrials.gov ID
- NCT06881485
- Acronym / sponsor ID
- Relay / S68952
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 62 participants (estimated)
- Lead sponsor
- Universitaire Ziekenhuizen KU LeuvenUniversity, hospital or other
- Study start
- 20 Jan 2025 (actual)
- Primary completion
- 1 Jan 2027 (estimated)
- Study completion
- 1 Jan 2027 (estimated)
- First posted
- 18 Mar 2025 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
The goal of this clinical trial is to evaluate the superiority of combined VLCKD, intensive lifestyle intervention and naltrexone/bupropion (N/B) versus standard of care with naltrexone/bupropion on weight loss for people with weight regain after bariatric surgery.
The main questions it aims to answer are:
Primary endpoint:
- The percentage of weight loss at 26 weeks
Secondary endpoints:
- A weight loss percentage at 10 weeks, 16 weeks and at end of trial (= 52 weeks from start)
- A proportion of patients with a weight loss percentage of 5% or more at 10, 16, 26 and 52 weeks
- A proportion of patients with a weight loss percentage of 10% or more at 10, 16, 26 and 52 weeks
- The time to reach a weight loss percentage of 5% and 10%
- The dose of naltrexone/bupropion used at 10, 16, 26 and 52 weeks and at the end of the trial
- The tolerability of VLCKD and NB
- The adherence to VLCKD and NB
- The Patient-Reported Outcome Measures (PROMs) of hunger and cravings at 0, 4, 10, 16, 26 and 52 weeks
- The change in fasting glucose, lipids and blood pressure at 10, 16, 26 and 52 weeks
Researchers will compare an experimental arm (N/B + Lifestyle + VLCKD) with comparator arm (NB + lifestyle) to see if combined VLCKD, intensive lifestyle and N/B is superior.
Participants will:
- get NB and lifestyle changes for 26 weeks
- follow a VLCKD in the first 10 weeks on top of it, if they belong to the experimental arm
- follow NB combined with lifestyle the remaining 16 weeks
- be followed-up for an extension of 26 weeks
- come to the hospital at week 1, 10, 16, 26, 52
Study design
- Primary purpose
- Other
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Naltrexon/Bupropion + Lifestyle + VLCKD | Experimental | Other: Very Low Calorie DietNaltrexon/Bupropion + Lifestyle + VLCKD |
| Naltrexon/Bupropion + Lifestyle | No intervention | –Naltrexon/Bupropion + Lifestyle |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (6 listed)
- Participants eligible for inclusion in this Trial must meet all of the following criteria:
Key exclusion criteria (12 listed)
- Participants eligible for this Trial must not meet any of the following criteria:
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Very Low Calorie DietThis is a parallel multicentric longitudinal randomized controlled trial in which prospective data will be collected from the electronic health record. The inclusion and exclusion criteria will be checked and afterwards patients will be randomized to (unblinded) medication only or combination with VLCKD. Both arms include NB and lifestyle changes for 26 weeks but the patients belonging to the experimental arm must follow a VLCKD in the first 10 weeks on top of it. Like the other arm, the remaining 16 weeks will consist of NB combined with lifestyle interventions. Afterwards there is a follow-up extension of 26 weeks. | Other | Naltrexon/Bupropion + Lifestyle + VLCKD |
Primary outcome
To evaluate the superiority of combined VLCKD, intensive lifestyle intervention and naltrexone/bupropion versus standard of care with naltrexone/bupropion on weight loss.
Time frame: 26 weeks
The percentage of weight loss at 26 weeks
12 secondary outcomes
• A weight loss percentage at 10 weeks, 16 weeks and at end of trial (= 52 weeks from start)
Time frame: 10,16 and 52 weeks
• A proportion of patients with a weight loss percentage of 5% or more at 10, 16, 26 and 52 weeks
Time frame: 10, 16, 26 and 52 weeks
• A proportion of patients with a weight loss percentage of 10% or more at 10, 16, 26 and 52 weeks
Time frame: 10, 16, 26 and 52 weeks
• The time to reach a weight loss percentage of 5% and 10%
Time frame: 52 weeks
• The dose of naltrexone/bupropion used at 10, 16, 26 and 52 weeks and at the end of the trial
Time frame: 10, 16, 26 and 52 weeks
• The tolerability of VLCKD
Time frame: 52 weeks
• The tolerability of NB
Time frame: 52 weeks
• The adherence to VLCKD
Time frame: 52 weeks
• The adherence to NB
Time frame: 52 weeks
• The change in fasting glucose at 10, 16, 26 and 52 weeks
Time frame: at 10, 16, 26 and 52 weeks
• The change in lipids at 10, 16, 26 and 52
Time frame: at 10, 16, 26 and 52 weeks
• The change in blood pressure at 10, 16, 26 and 52
Time frame: at 10, 16, 26 and 52 weeks
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 21 Mar 2025.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
2 sites in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Very Low Calorie Diet in people with Weight Regain Post Bariatric Surgery and Obesity (Disorder), run by Universitaire Ziekenhuizen KU Leuven at 2 sites in Belgium.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 6 inclusion and 12 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: looking for participants now, as of the sponsor's last update on 21 Mar 2025. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 2 sites in Belgium. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Prof. Dr. R. Vangoitsenhoven (+3216344775, relaytrial@uzleuven.be), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
To evaluate the superiority of combined VLCKD, intensive lifestyle intervention and naltrexone/bupropion versus standard of care with naltrexone/bupropion on weight loss. (time frame: 26 weeks). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 21 Mar 2025.