Tirzepatide (Spartina) in Obese Kidney Transplant Recipients

Safety and Efficacy of Tirzepatide (Spartina) in Obese Kidney Transplant Recipients: A Pilot Study on Weight Loss, Gastrointestinal Tolerability, and Graft Function

Post-transplant obesity is a common complication after kidney transplantation, largely attributed to recovery from uremia, increased appetite, sedentary lifestyle, and long-term corticosteroid exposure. Obesity in kidney transplant recipients increases the risk of cardiovascular disease, post-transplant diabetes mellitus (PTDM), and may contribute to graft injury through hyperfiltration-related mechanisms, potentially leading to reduced graft survival. Current approaches for weight management in transplant recipients, including lifestyle modification, are often insufficient, while bariatric surgery carries considerable risks and concerns regarding altered absorption of immunosuppressive medications.

Tirzepatide (Iranian brand name: Spartina), the first dual agonist of glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1) receptors, has demonstrated superior effects on weight reduction and glycemic control compared with earlier GLP-1 receptor agonists in the general population. However, its use in kidney transplant recipients requires careful evaluation due to potential gastrointestinal adverse effects, dehydration risk, and possible interaction with calcineurin inhibitor absorption caused by delayed gastric emptying.

This prospective single-arm pilot clinical trial aims to assess the preliminary safety and efficacy of tirzepatide in obese kidney transplant recipients with stable graft function. Outcomes include changes in anthropometric indices, percent weight change, gastrointestinal tolerability, immunosuppressive drug trough levels, and graft function over 24 weeks of treatment.

Study Overview

• Status: Recruiting
• Conditions: Tirzepatide
• Intervention / Treatment: Drug: Tirzepatide

Detailed Description

Obesity following kidney transplantation is a frequent metabolic complication, related to improved appetite after resolution of uremia, reduced physical activity, and corticosteroid therapy. Post-transplant obesity is associated with increased risk of cardiovascular disease, PTDM, and chronic graft dysfunction. In addition, obesity-related hyperfiltration may accelerate structural injury to the transplanted kidney, potentially contributing to glomerulopathy and reduced graft survival.

Pharmacologic management of obesity in kidney transplant recipients remains challenging. Lifestyle-based interventions often fail to produce sustained weight loss. Bariatric surgery may be effective but is associated with increased risks in transplant recipients, including adhesions, infection, and altered absorption of immunosuppressive agents.

Tirzepatide is a dual GIP and GLP-1 receptor agonist with robust effects on weight reduction and glycemic control. Nevertheless, its safety profile in kidney transplant recipients remains insufficiently studied, particularly regarding gastrointestinal adverse events, dehydration risk, and the potential impact on immunosuppressive drug exposure due to delayed gastric emptying.

This study is designed as a prospective single-arm pilot clinical trial. Eligible kidney transplant recipients with obesity and stable graft function will receive weekly subcutaneous tirzepatide for 24 weeks using a stepwise dose escalation regimen. Participants will be monitored for changes in body weight, BMI, waist circumference, graft function parameters (serum creatinine and eGFR), metabolic indices (fasting glucose, HbA1c, lipid profile), gastrointestinal adverse events, and calcineurin inhibitor trough levels (tacrolimus or cyclosporine).

This pilot trial will provide preliminary evidence regarding feasibility, safety, and potential efficacy of tirzepatide in this high-risk transplant population and may guide the design of larger randomized controlled trials.

• Study Type: Interventional
• Enrollment (Estimated): 30
• Phase: Phase 4

Contacts and Locations

• Study Contact: Name: Nooshin Dalili, MD; Phone Number: 00989122404331; Email: dr.nooshindalili@gmail.com

Study Locations

• Iran
  • Tehran, Iran
    • Recruiting
    • Nooshin Dalili
    • Contact: SBMU; Phone Number: 00989122404331

Participation Criteria

Eligibility Criteria

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

Description

Inclusion Criteria:

• Age ≥ 18 years
• Kidney transplant recipient with ≥12 months since transplantation
• BMI ≥ 27 kg/m²
• Stable graft function in the last 3 months (serum creatinine variation < 20%)
• Stable immunosuppressive regimen
• Ability to provide written informed consent

Exclusion Criteria:

• History of pancreatitis
• Severe gastroparesis
• History of medullary thyroid carcinoma (MTC) or MEN2 syndrome
• eGFR < 30 mL/min/1.73m²
• Acute rejection episode within the past 6 months
• Any condition judged by the investigator to interfere with study participation or safety

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: N/A
• Interventional Model: Single Group Assignment
• Masking: None (Open Label)

Number of Arms

1

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Tirzepatide(Spartina); Route: Subcutaneous injection (SC); Frequency: Once weekly; Duration: 24 weeks; Dose escalation:; Weeks 1-4: 2.5 mg weekly; Weeks 5-8: 5 mg weekly (if tolerated); Weeks 9-24: Continue 5 mg weekly or increase to 7.5 mg weekly based on tolerability and physician judgment	Drug: Tirzepatide; Route: Subcutaneous injection (SC); Frequency: Once weekly; Duration: 24 weeks; Dose escalation:; Weeks 1-4: 2.5 mg weekly; Weeks 5-8: 5 mg weekly (if tolerated); Weeks 9-24: Continue 5 mg weekly or increase to 7.5 mg weekly based on tolerability and physician judgment; Other Names: Spartina

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Percent Change in Body Weight From Baseline at Week 24	Percent change in body weight compared to baseline	Baseline to Week 24
Incidence of Gastrointestinal Adverse Events	Number of participants with gastrointestinal adverse events ( nausea, vomiting, diarrhea, constipation, abdominal pain) graded according to Common Terminology Criteria for Adverse Events (CTCAE) version 5.0	Baseline to Week 24 (monthly assessment)
Change in Serum Creatinine	Change from baseline in serum creatinine (mg/dl).	Baseline to Week 24

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in Body Mass Index (BMI)	changes in BMI	Baseline to Week 24
Change in Waist Circumference	changes in centimeters	Baseline to Week 24
Proportion of Participants Achieving Clinically Meaningful Weight Loss • Definition	≥5% and ≥10% weight loss from baseline	week 24
change in tacrolimus trough Level	Change from baseline in tacrolimus trough level (ng/ml)	Monthly monitoring through Week 24
Change in Fasting blood glucose	change from baseline in fasting blood glucose (mg/dl).	Baseline to Week 24
Change in systolic blood pressure	changes from baseline in systolic blood pressure(mmHg).	Baseline to Week 24
Change in Proteinuria	Urine protein-to-creatinine ratio (UPCR) or 24-hour urine protein	Baseline to Week 24
Change in diastolic blood pressure	Change from baseline in diastolic blood pressure (mmHg).	Baseline to week 24

Collaborators and Investigators

• Sponsor: Shahid Beheshti University of Medical Sciences
• Investigators: Principal Investigator: Nooshin Dalili, SBMU

Study record dates

Study Major Dates

• Study Start (Actual): January 1, 2026
• Primary Completion (Estimated): July 1, 2026
• Study Completion (Estimated): September 1, 2026

Study Registration Dates

• First Submitted: February 8, 2026
• First Submitted That Met QC Criteria: February 13, 2026
• First Posted (Actual): February 20, 2026

Study Record Updates

• Last Update Posted (Actual): February 20, 2026
• Last Update Submitted That Met QC Criteria: February 13, 2026
• Last Verified: February 1, 2026

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Amino Acids, Peptides, and Proteins; Proteins; Glucagon-Like Peptide-1 Receptor; Glucagon-Like Peptide Receptors; Receptors, G-Protein-Coupled; Receptors, Cell Surface; Membrane Proteins; Receptors, Gastrointestinal Hormone; Receptors, Peptide; Tirzepatide
• Other Study ID Numbers: SBMU-12-1404

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