A Study to Evaluate the Safety, Tolerability, Pharmacokinetics, and Pharmacodynamics of MBX 4291 in Adult Participants With Obesity

A Randomized, Double-blind, Placebo-controlled First-in-human Study to Evaluate the Safety, Tolerability, Pharmacokinetics, and Pharmacodynamics of Single and Multiple Ascending Doses of MBX 4291 in Adult Participants With Obesity

Status

Recruiting

Phases

Phase 1

Study type

Interventional

Source

ClinicalTrials.gov

Registry ID

NCT07142707

Enrollment

124

Registered

2025-08-27

Start date

2025-09-03

Completion date

2026-10-30

Last updated

2026-06-09

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Obesity

Keywords

Body Weight, Body Mass Index, Overweight, Nutrition Disorders

Brief summary

The purpose of this study is to evaluate the safety and tolerability of single and multiple subcutaneous (SC) doses of MBX 4291 in adults with obesity.

Detailed description

This is a Phase 1, double-blind, placebo-controlled first-in-human study to evaluate the single ascending doses (SAD) and multiple ascending doses (MAD) of MBX 4291 in participants with obesity, who are otherwise generally healthy. Approximately 124 patients aged 18 to 65 years old will be enrolled.

Interventions

DRUGMBX 4291

MBX 4291 will be administered subcutaneously (SC)

DRUGPlacebo

Placebo: Placebo will be administered subcutaneously (SC)

Study design

Allocation

RANDOMIZED

Intervention model

PARALLEL

Primary purpose

TREATMENT

Masking

TRIPLE (Subject, Caregiver, Investigator)

Eligibility

Sex/Gender

ALL

Age

18 Years to 65 Years

Healthy volunteers

Inclusion criteria

* Age of \>18 to ≤65 years at the time of signing the informed consent. * Has a BMI of ≥30 to \<50 kg/m2 at screening and baseline. * Weight-stable, i.e., no more than ±5% change in body weight for at least 3 months prior to screening and between screening and baseline.

Exclusion criteria

* History of, or currently active, significant illness or medical disorders that in the opinion of the investigator may preclude participants from participating in the study. * History of currently active pancreatitis, type I and type II diabetes. * Secondary causes of obesity, including but not limited to hypothalamic, monogenic, syndromic, or endocrine causes. * A personal or family history of medullary thyroid carcinoma or multiple endocrine neoplasia syndrome type 2.

Design outcomes

Primary

Measure	Time frame
Number of participants with Treatment Emergent Adverse Events (TEAEs)	The total duration of study participation for each participant including screening, treatment period, follow-up, and end of study visit will be up to 91 days in Part A, up to 99 days in Part B, and up to 148 days in Part C.

Countries

United States

Contacts

CONTACTElisa Fabbrini, MD, PhD

MBX4291.Clinicaltrials@mbxbio.com844-877-4473

CONTACTStewart Hallett