A Study to Investigate the Effect of Injection Site and Ethnicity on KAI-4729 Pharmacokinetics in Non-Asian and Asian Participants Living With Obesity or Overweight

A Phase 1, Randomized, Open-Label, Single-Dose Study to Investigate the Effect of Injection Site on Relative Bioavailability of KAI-4729 Subcutaneous Injection and Pharmacokinetics of KAI-4729 in Non-Asian and Asian Participants Living With Obesity or Overweight

The main objectives of this study are to assess the relative bioavailability of KAI-4729 subcutaneous (SC) injection in the upper arm and thigh compared with the abdomen and to measure the pharmacokinetics of KAI-4729 in plasma following a single SC dose in healthy non-Asian and Asian participants.

Study Overview

• Status: Not yet recruiting
• Conditions: Overweight or Obesity
• Intervention / Treatment: Drug: KAI-4729

• Study Type: Interventional
• Enrollment (Estimated): 60
• Phase: Phase 1

Contacts and Locations

• Study Contact: Name: Kailera Therapeutics, Inc.; Phone Number: 1-781-317-0291; Email: info-clinicalstudies@kailera.com

Study Locations

• United States
  • California
    • Anaheim, California, United States, 92801
      • Kailera Clinical Site

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 55 years (Adult)
• Accepts Healthy Volunteers: Yes
• Genders Eligible for Study: All

Description

Key Inclusion Criteria:

• Have a body mass index (BMI) ≥25 and ≤40 kilograms per square meter at screening (Days -28 to -2) and on Day -1 of the first Treatment Period
• Non-Asian Participants Only: Be of non-Asian descent and not identify as being of East Asian origin
• Asian Participants Only: Be of Asian descent, identify as being of East Asian origin, and have both parents and both sets of grandparents born in East Asia and of East Asian descent
• Medically healthy

Key Exclusion Criteria:

• Have estimated glomerular filtration rate <60 milliliters/minute/1.73 square meters at screening (Days -28 to -2) using the 2021 Chronic Kidney Disease Epidemiology Collaboration calculation.
• Have hemoglobin A1c test result ≥6.5% or blood glucose ≥126 milligrams/deciliter (≥7 millimoles/liter) at screening (Days -28 to -2).
• Have a history of, or positive test results at screening (Days -28 to -2) for, human immunodeficiency virus (HIV), hepatitis B surface antigen, or active hepatitis C virus infection.
• Have positive drugs of abuse or alcohol test results at screening (Days -28 to -2) or on Day -1 of each Treatment Period.
• Be pregnant or planning to be pregnant and/or breastfeeding or planning to breastfeed during the study and within 5 half-lives of the study drug (25 days) following the last study treatment dose.
• Have any history of malignant disease, including in situ cervical or prostate cancer, within the 5 years prior to informed consent (excludes basal or squamous cell carcinoma that was successfully treated).
• Have history or presence of clinically significant cardiovascular, pulmonary, hepatic, renal, hematological, gastrointestinal, endocrine, immunologic, dermatologic, psychiatric, or neurological disease/disorder, including any acute illness, within the 3 months prior to informed consent determined by the Investigator (or delegate) to be clinically relevant.
• Have known hypersensitivity to the study drug; glucagon-like peptide-1 (GLP-1), glucose-dependent insulinotropic polypeptide, and/or glucagon receptor agonist therapies; or any of the study drug ingredients.
• Have any other conditions or received prior therapy that, in the opinion of the Investigator (or delegate), would make the participant unsuitable for this study, including inability to cooperate fully with the requirements of the study protocol or likelihood of noncompliance with any study requirements.

Note: Additional inclusion/exclusion criteria may apply, per protocol.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Basic Science
• Allocation: Randomized
• Interventional Model: Crossover Assignment
• Masking: None (Open Label)

Number of Arms

4

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Upper Arm Injection Site; Participants will receive KAI-4729 as a single SC injection into the upper arm on Day 1 of either Treatment Period 1, 2, or 3.	Drug: KAI-4729; SC injection
Experimental: Abdomen Injection Site; Participants will receive KAI-4729 as a single SC injection into the abdomen on Day 1 of either Treatment Period 1, 2, or 3.	Drug: KAI-4729; SC injection
Experimental: Thigh Injection Site; Participants will receive KAI-4729 as a single SC injection into the thigh on Day 1 of either Treatment Period 1, 2, or 3.	Drug: KAI-4729; SC injection
Experimental: Abdomen Injection Site (Asian Participants); Asian participants will receive KAI-4729 as a single SC injection into the abdomen on Day 1 of Treatment Period 1.	Drug: KAI-4729; SC injection

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Time Frame
Maximum Observed Plasma Concentration (Cmax) of KAI-4729 in the Upper Arm and Thigh Compared to the Abdomen	Treatment Period 1, 2 and 3: Pre-dose and up to 29 days post-dose
Area Under the Concentration-time Curve From Time 0 to Time of Last Quantifiable Concentration (AUC0-t) of KAI-4729 in the Upper Arm and Thigh Compared to the Abdomen	Treatment Period 1, 2 and 3: Pre-dose and up to 29 days post-dose
Area Under the Concentration-time Curve From Time 0 to Infinity (AUC0-inf) of KAI-4729 in the Upper Arm and Thigh Compared to the Abdomen	Treatment Period 1, 2 and 3: Pre-dose and up to 29 days post-dose
Cmax of KAI-4729 in Healthy Non-Asian and Asian Participants	Treatment Period 1, 2 and 3: Pre-dose and up to 29 days post-dose; Treatment Period 1: Pre-dose and up to 29 days post-dose (Asian Participants)
AUC0-t of KAI-4729 in Healthy Non-Asian and Asian Participants	Treatment Period 1, 2 and 3: Pre-dose and up to 29 days post-dose; Treatment Period 1: Pre-dose and up to 29 days post-dose (Asian Participants)
AUC0-inf of KAI-4729 in Healthy Non-Asian and Asian Participants	Treatment Period 1, 2 and 3: Pre-dose and up to 29 days post-dose; Treatment Period 1: Pre-dose and up to 29 days post-dose (Asian Participants)

Secondary Outcome Measures

Outcome Measure	Time Frame
Number of Participants Who Experience a Treatment-emergent Adverse Event (TEAE)	Day 1 to Day 99
Number of Participants Who Experience a Serious Adverse Event (SAE)	Day 1 to Day 99
Number of Participants Who Experience Antidrug Antibodies (ADAs) to KAI-4729	Treatment Period 1, 2 and 3: Day 1, Day 8, Day 29 post-dose

Collaborators and Investigators

• Sponsor: Kailera
• Investigators: Study Director: Medical Director, Kailera Therapeutics, Inc.

Study record dates

Study Major Dates

• Study Start (Estimated): November 1, 2026
• Primary Completion (Estimated): April 1, 2027
• Study Completion (Estimated): April 1, 2027

Study Registration Dates

• First Submitted: November 3, 2026
• First Submitted That Met QC Criteria: November 3, 2026
• First Posted (Actual): November 9, 2026

Study Record Updates

• Last Update Posted (Actual): November 9, 2026
• Last Update Submitted That Met QC Criteria: November 3, 2026
• Last Verified: November 1, 2026

More Information

Terms related to this study

• Keywords: Obesity; Overweight; Pharmacokinetics; Bioavailability; KAI-4729
• Additional Relevant MeSH Terms: Nutrition Disorders; Overnutrition; Body Weight; Pathological Conditions, Signs and Symptoms; Nutritional and Metabolic Diseases; Signs and Symptoms; Overweight; Obesity
• Other Study ID Numbers: K4729-1115

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