The Effect of GLP1 Agonists on Weight Loss in BBS Cohort in the UK

GLP1 Agonists Once Weekly for the Treatment of Obesity in Patients With Bardet-Biedl Syndrome (BBS)

The goal of this observational study is to learn about the long-term effects of GLP1 agonists (weight loss jab, including Mounjaro) in patients with Bardet-Biedl Syndrome (BBS) who take GLP1 agonists to treat high body weight. The main question:

Do GLP1 agonists effectively and safely lower body weight in patients with BBS when taken long-term, compared to patients not on these medications? The investigators look at the change (%) in weight during the observational periods.

Study Overview

• Status: Completed
• Conditions: Bardet-Biedl Syndrome

Detailed Description

Demographics on time zero: Age, gender, Race, Body Weight (BW), Body Mass Index (BMI), Blood Pressure (clinic, DM meds), Pulse, Lipid profiles (Chol, HDL, LDL, TG), eGFR, HBA1c, (if feasible) genetic diagnosis

Primary outcome at the end of study date : Body weight change (%)

Secondary outcome at the end of study date: change in lipid (Chol, HDL, LDL, TG), Blood Pressure, DM status

Quality assurance plan: data validation will be secured due to the electronic record. The registry process was undertaken in our closed national BBS centres quality assured by multi-disciplinary team (MDT) looked after by senior specialty nurses, who followed all the patients with GLP1 agonists monthly over the telephone.

Data checks to compare data entered into the registry against predefined rules for range or consistency with other data fields in the registry.

Source data verification to assess the accuracy, completeness, or representativeness of registry data by comparing the data to external data sources.

Plan for missing data to address situations where variables are reported as missing, unavailable, non-reported, uninterpretable, or considered missing because of data inconsistency or out-of-range results: The investigators followed all the missing data by contacting patients' family doctors (GP) and their records.

Statistical analysis plan describing the analytical principles and statistical techniques to be employed in order to address the primary and secondary objectives, as specified in the study protocol or plan.

• Study Type: Observational
• Enrollment (Actual): 300

Contacts and Locations

Study Locations

• United Kingdom
  • West Midlands
    • Birmingham, West Midlands, United Kingdom, B15 2GW
      • Queen Elizabeth Hospital Birmingham

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

• Sampling Method: Non-Probability Sample

Study Population

All the patients with a genetic diagnosis of BBS living in the UK under the UK National BBS Centres (Birmingham and London).

Description

Inclusion Criteria:

• All the adult patients with a genetic diagnosis of BBS under the national BBS centres (London and Birmingham in the UK).

Exclusion Criteria:

• Adult patients with a genetic diagnosis of BBS under the national BBS centres (London and Birmingham in the UK) who lost follow ups or significant missing data, or BMI<30 in patients without GLP1 agonists.

Study Plan

How is the study designed?

Number of groups / cohorts

1

Cohorts and Interventions

Group / Cohort
Adult patients with diagnosis of BBS in national centre in the UK (London and Birmingham); Intervention arm (BMI>30): patients with BBS treated with GLP1 agonists Control arm (BMI>30): patients with BBS without GLP1 agonists

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Weight loss change (%) at the end of study date, compared to one at the time zero	Change (%) of Body weight (kg) from BW at the start date of this study and BW at the end of study date	From enrolment to the end of treatment at the end of study date up to 18 months

Collaborators and Investigators

• Sponsor: The Queen Elizabeth Hospital
• Investigators: Principal Investigator: Jeremy Tomlinson, Professor, University Hospital Birmingham NHS Foundation Trust

Publications and helpful links

General Publications

• Yuki Heath, Jeremy Tomlinson, Lukas Foggensteiner

Study record dates

Study Major Dates

• Study Start (Actual): January 1, 2023
• Primary Completion (Actual): April 1, 2026
• Study Completion (Actual): April 22, 2026

Study Registration Dates

• First Submitted: May 15, 2026
• First Submitted That Met QC Criteria: May 15, 2026
• First Posted (Actual): May 22, 2026

Study Record Updates

• Last Update Posted (Actual): May 27, 2026
• Last Update Submitted That Met QC Criteria: May 21, 2026
• Last Verified: May 1, 2026

More Information

Terms related to this study

• Keywords: Obesity; Weight Loss; GLP1 agonist
• Additional Relevant MeSH Terms: Ciliopathies; Brain Diseases; Central Nervous System Diseases; Nervous System Diseases; Nutrition Disorders; Genetic Diseases, Inborn; Overnutrition; Body Weight; Body Weight Changes; Eye Diseases; Eye Diseases, Hereditary; Congenital Abnormalities; Abnormalities, Multiple; Overweight; Hypothalamic Diseases; Retinitis Pigmentosa; Congenital, Hereditary, and Neonatal Diseases and Abnormalities; Pathological Conditions, Signs and Symptoms; Nutritional and Metabolic Diseases; Signs and Symptoms; Obesity; Weight Loss; Bardet-Biedl Syndrome
• Other Study ID Numbers: BBSGLP1

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: YES
• IPD Plan Description: The study protocol, Age, gender, Race, BW, BMI, BP and pulse (clinic), diabetic medications, Lipid (Chol, HDL, LDL, TG), eGFR, HBA1c, genetic diagnosis
• IPD Sharing Time Frame: Beginning right after publication with no end date
• IPD Sharing Access Criteria: a data sharing agreement must be signed, and those documents can be submitted via emails.
• IPD Sharing Supporting Information Type: STUDY_PROTOCOL; SAP

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No