A Study to Assess Efficacy and Safety of LB54640 in Patients With Hypothalamic Obesity

February 10, 2026 updated by: Rhythm Pharmaceuticals, Inc.

A Randomized, Placebo-controlled, Double-Blind Phase 2 Study to Assess Efficacy and Safety of LB54640 in Patients With Hypothalamic Obesity, With an Open-Label Extension

The goal of this study is to determine how well LB54640 works and how safe it is in patients with Hypothalamic Obesity (HO). The study will evaluate the effect of LB54640 on safety, weight reduction, hunger, and quality of life in patients 12 years of age and older with HO. Patients will take an oral daily dose of either LB54640 (low, middle, or high dose) or placebo through Week 14. Eligible patients who consent to continue in the study after Week 14 will take an oral daily dose of LB54640 through Week 56.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Completed

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Actual)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
28

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Phase 2

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

The name and contact information for the person who can answer enrollment questions for a clinical study. Each location where the study is being conducted may also have a specific contact, who may be better able to answer those questions.

Study Contact Backup

Study Locations

  • United Kingdom
      • Birmingham, United Kingdom, B15 2TG
        • Birmingham Women's and Children's NHS Foundation Trust
      • Cambridge, United Kingdom, CB2 1TN
        • University of Cambridge
      • London, United Kingdom, WC1N 3JH
        • Great Ormond Street Hospital for Children
  • United States
    • Colorado
      • Aurora, Colorado, United States, 80045
        • Children's Hospital Colorado
    • Iowa
      • Iowa City, Iowa, United States, 52242
        • University of Iowa Children's Hospital
    • Massachusetts
      • Boston, Massachusetts, United States, 02111
        • Tufts Medical Center
    • New York
      • New York, New York, United States, 10027
        • Columbia University
    • North Carolina
      • Chapel Hill, North Carolina, United States, 27514
        • The University of North Carolina at Chapel Hill
    • Oklahoma
      • Oklahoma City, Oklahoma, United States, 73112
        • Lynn Health Science Institute
    • Tennessee
      • Memphis, Tennessee, United States, 38105
        • St. Jude Children's Research Hospital

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

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

  • Child
  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

Key Inclusion Criteria:

  • Documented evidence of acquired hypothalamic obesity (HO)
  • Age 12 years and older
  • Weight gain associated with the hypothalamic injury and a BMI of ≥30 kg/m2 for patients ≥18 years of age or BMI ≥95th percentile for age and sex for patients <18 years of age
  • Male and female participants agree to follow study contraception requirements and use a highly effective form of contraception throughout the study and for 90 days after the study

Key Exclusion Criteria:

  • Weight loss >2% in the previous 3 months for patients ≥18 years of age or >2% reduction in BMI for patients <18 years of age
  • History of major surgical procedure within 30 days
  • HbA1c >10.9%
  • Fasting glucose level >270 mg/dL
  • Previous use of MC4R agonists
  • Diagnosis of Prader-Willi syndrome (PWS) or Rapid-onset obesity with hypoventilation, hypothalamic, autonomic dysregulation, neuroendocrine tumor syndrome (ROHHADNET).
  • Diagnosis of severe psychiatric disorders; any suicidal ideation, attempt or behavior
  • History or close family history of skin cancer or melanoma
  • Current clinically significant pulmonary, cardiac, or oncologic disease considered severe enough to interfere with the study and/or confound the results

Other protocol defined Inclusion/Exclusion criteria may apply.

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: Treatment
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Triple

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Experimental: LB54640 Low dose
Participants will be randomized to receive LB54640 low dose, middle dose, or high dose, or placebo by oral administration in a 1:1:1:1 ratio.
Drug: LB54640
Oral daily administration
Experimental: LB54640 Middle dose
Participants will be randomized to receive LB54640 low dose, middle dose, or high dose, or placebo by oral administration in a 1:1:1:1 ratio.
Drug: LB54640
Oral daily administration
Experimental: LB54640 High dose
Participants will be randomized to receive LB54640 low dose, middle dose, or high dose, or placebo by oral administration in a 1:1:1:1 ratio.
Drug: LB54640
Oral daily administration
Placebo Comparator: Placebo
Participants will be randomized to receive LB54640 low dose, middle dose, or high dose, or placebo by oral administration in a 1:1:1:1 ratio.
Drug: Placebo
Placebo matched to LB54640
Experimental: Open-label LB54640
Eligible participants who provide consent to continue into the open-label portion of the study will receive open-label LB54640.
Drug: LB54640
Oral daily administration

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Time Frame
Mean percentage change in BMI
Time Frame: From Baseline to Week 14
From Baseline to Week 14

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Frequency and severity of adverse events (AEs)
Time Frame: From Baseline to Week 52
From Baseline to Week 52
Mean change in BMI
Time Frame: Baseline to Weeks 6, 10, 14
Baseline to Weeks 6, 10, 14
Proportion of patients who achieve ≥5% reduction in body weight
Time Frame: Baseline to Week 14
Baseline to Week 14
Mean change in the weekly average of the daily most hunger score
Time Frame: Baseline to Week 14
Baseline to Week 14
Mean change and mean percentage change from baseline in body weight
Time Frame: From Baseline to Week 52
From Baseline to Week 52
Mean change and mean percentage change from baseline in waist circumference.
Time Frame: From Baseline to Week 52
From Baseline to Week 52
Mean change and mean percentage change from baseline in body composition assessed by dual energy x-ray absorptiometry
Time Frame: From Baseline to Week 52
Fat mass and lean mass will be measured through dual energy x-ray absorptiometry
From Baseline to Week 52

Collaborators and Investigators

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

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
Rhythm Pharmaceuticals, Inc.

Investigators

Investigators

A researcher involved in a clinical study. Related terms include site principal investigator, site sub-investigator, study chair, study director, and study principal investigator.
  • Study Chair: David Meeker, MD, Rhythm Pharmaceuticals, Inc.

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)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
July 11, 2024

Primary Completion (Actual)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
February 9, 2026

Study Completion (Actual)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
February 9, 2026

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
September 14, 2023

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
September 14, 2023

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
September 21, 2023

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
February 12, 2026

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
February 10, 2026

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
February 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • LG-MCCL005

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

product manufactured in and exported from the U.S.

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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