OPTI-OAGB

Not yet recruiting

Preoperative Optimization With Tirzepatide, Ketogenic Diet, or Standard Care Before One Anastomosis Gastric Bypass Surgery

Efficacy of Preoperative Tirzepatide, Ketogenic Diet, and Standard Care on 1-Year Weight Loss After One Anastomosis Gastric Bypass (OAGB)

Lead sponsor

Mario Musella MD

Asset

Tirzepatide

Subcutaneous · GLP-1 / GIP dual

Listed sites

Recruiting sites

—

Enrollment

estimated

Study population

Bariatric Surgery Candidate, Obesity / overweight

Key I/E criteria

•BMI 40-55•HbA1c ≥6.5%

Primary endpoint

•Percentage of Total Weight Loss

Footprint

Where this trial recruits

Site locations as reported to ClinicalTrials.gov. Site count is not enrollment count; per-site enrollment is not available from source.

Identifiers

Registered as

NCT IDNCT07622992

Org study IDOPTI-OAGB Trial

Timeline

Milestones

Study first posted2026-06-03actual

Last update posted2026-06-03actual

Study start2026-07-01estimated

Primary completion2029-07-01estimated

Study completion2029-12-01estimated

Assets

Investigational agents

Tirzepatide

Study populations

Who this study enrolls

Bariatric Surgery CandidateObesity / overweight

Eligibility

Who can enroll

Minimum age18 Years

Maximum age65 Years

SexAll

Healthy volunteersNot accepted

Sampling methodNon probability sample

Study population text

Patients between 18 to 65 years, with Body Mass Index (BMI) between 40 and 55 kg/m² at screening visit. The patients must be eligible for bariatric surgery according to current international guidelines (IFSO 2022) with documented failure of conservative weight loss attempts. Patients enrolled need to have at least one obesity-related comorbidity and the ability to understand study procedures and provide written consent.

Inclusion criteria

•Age 18 to 65 years at enrollment

•Body Mass Index (BMI) between 40 and 55 kg/m² at screening visit

•Appropriate candidates for bariatric surgery according to current international guidelines (IFSO 2022) with documented failure of conservative weight loss attempts

•Presence of at least one obesity-related comorbidity: Type 2 Diabetes Mellitus (HbA1c at least 6.5%, fasting plasma glucose at least 126 mg/dL, 2-hour OGTT glucose at least 200 mg/dL, or use of antidiabetic medications); Hypertension (systolic BP at least 140 mmHg or diastolic BP at least 90 mmHg, or use of antihypertensive medications); Dyslipidemia (total cholesterol at least 200 mg/dL, LDL-C at least 130 mg/dL, HDL-C less than 40 mg/dL for men or less than 50 mg/dL for women, triglycerides at least 150 mg/dL, or use of lipid-lowering medications); Obstructive Sleep Apnea Syndrome (AHI at least 15 events/hour or AHI 5-14 with symptoms requiring treatment)

•Ability to understand study procedures and provide written informed consent

•Demonstrated ability and willingness to adhere to study protocol requirements including preoperative interventions and postoperative follow-up visits

•No use of GLP-1 receptor agonists or dual GIP/GLP-1 receptor agonists within 12 months prior to enrollment

Exclusion criteria

•History of any prior bariatric procedure or major upper gastrointestinal surgery that could confound outcomes or increase surgical risk

•Severe uncontrolled psychiatric disorders including active psychosis, severe depression with suicidal ideation, active substance abuse, or eating disorders (other than binge eating disorder) that could impair protocol adherence or informed consent capacity

•Current pregnancy, lactation, or planning pregnancy within 18 months of enrollment (women of childbearing potential must use effective contraception throughout study period)

•Contraindications to tirzepatide for patients potentially randomized to Arm A: personal or family history of medullary thyroid carcinoma; Multiple Endocrine Neoplasia syndrome type 2 (MEN 2); history of pancreatitis; severe gastrointestinal disease (inflammatory bowel disease, gastroparesis); known hypersensitivity to tirzepatide or excipients

•Contraindications to ketogenic diet for patients potentially randomized to Arm B: chronic kidney disease (eGFR less than 30 mL/min/1.73m²); severe hepatic insufficiency (Child-Pugh C); active gallbladder disease; history of kidney stones; porphyria; carnitine deficiency or other metabolic disorders

•Current or recent malignancy (within 5 years) at any stage

•Severe cardiopulmonary disease including recent myocardial infarction (less than 6 months), unstable angina, heart failure (NYHA class III-IV), severe pulmonary hypertension, or other conditions representing absolute contraindications to general anesthesia

•Systemic infection requiring treatment at time of enrollment

•Inability or unwillingness to attend required follow-up visits, language barriers preventing adequate communication, or any condition that would compromise protocol compliance

Endpoints (3)

What's being measured

Protocol endpoints and posted registry outcome measures, grouped into outcome categories. Composite endpoints show their component event types. Standard codes (LOINC, SNOMED CT) are shown where available.

Weight & body composition

3 endpoints

Primary/protocol endpoint

Percentage of Total Weight Loss at 1 Year Post-Surgery

Time frame:1 year

descriptive

Secondary/protocol endpoint

Percentage of Excess Weight Loss at 1 Year

Time frame:1 year

descriptive

Secondary/protocol endpoint

Absolute Weight Loss at 1 Year

Time frame:1 year

descriptive

Provenance

Sources

Trial identity, design, statusClinicalTrials.gov API v2

Snapshot dateJuly 1, 2026

Endpoint classificationDelfa endpoint taxonomy v2 (May 13, 2026)

Results tableno registry results posted yet

Trial facts come from public ClinicalTrials.gov records. Endpoint categories are Delfa's classification of those records, not a ClinicalTrials.gov field. All figures reflect the July 1, 2026 snapshot.