Phentermine/Topiramate for Uric Acid Stones

NCT04621929 | Completed Phase 3 Results DMC FDA Drug

• 2 other identifiers: IRB202001895-A-N1R21DK122317-01A1
• Study Type: interventional
• Target: 19
• Locations: 1 country
• Sites: 1

Brief Summary

The investigator proposes an 18 month, feasibility pilot study, randomizing obese and diabetic individuals with pure uric acid nephrolithiasis (UAN) or mixed calcium oxalate (CO) UAN to either phentermine/topiramate or a pragmatic control group who will remain on their standard medication regimen (citrate salts, allopurinol, diet, etc.).

Conditions

Obesity; Uric Acid Stones; Type 2 Diabetes Mellitus in Obese; Pre-Diabetes

Outcome Measures

Primary Outcomes (1)

• Kidney Stone Size (mm^3) Determined by Non-contrast CAT Scan

  Stone perimeter within each cut of CT image was outlined using semiautomated volume tool (region of interest pen tool, CT software "Visage Imaging") and tallied to calculate stone volume (mm\^3) for each individual stone and recorded from right and left kidney from all study participants at baseline CT and at end of study CT (18 months)

  Baseline, 18 months

Secondary Outcomes (6)

• Weight (kg)

  Baseline, 18 months

• Urinary pH Parameters

  Baseline, 18 months

• %Hemoglobin A1c

  Baseline, 18 months

• Urinary Citrate Parameters

  Baseline, 18 months

• Urinary Calcium Parameters

  Baseline, 18 months

Study Arms (2)

Allocated to intervention/treatment

EXPERIMENTAL

Daily phentermine/topiramate x 18 months

Drug: Phentermine / Topiramate Oral Product

Allocated to pragmatic control

ACTIVE COMPARATOR

Remain on their current regimen

Combination Product: Citrate Salts, Allopurinol, Diet

Interventions

Phentermine / Topiramate Oral Product DRUG

All participants in the experimental group will receive oral generic tablet phentermine (18.75 or 37.5 mg dose) and topiramate (daily 100 mg or 150 mg dose)

Also known as: Duromine, Adipex-P, Lomaira, Suprenza, Trokendi XR, Topamax, Qudexy XR, Eprontia, Qsymia

Allocated to intervention/treatment

Citrate Salts, Allopurinol, Diet COMBINATION_PRODUCT

Control participants will complete initial visit requirements and study enrollment and will be maintained on their current therapy.

Allocated to pragmatic control

Eligibility Criteria

• Age: 18 Years - 75 Years
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• have recurrent pure uric acid nephrolithiasis (UAN) or mixed calcium oxalate (CO)/UAN. Recurrent stone disease is defined as at least two spontaneous kidney stone passages, two previous kidney stone procedures, or one previous stone passage and one previous procedure. Pure UAN is defined as at least one previous stone analysis demonstrating 100% uric acid mineral content. Mixed COUAN will be defined as at least one previous stone analysis with any mix of uric acid ≥80% and ≤20% calcium oxalate. If participant has more than one stone analysis, the most recent will be considered the current stone type.
• have obesity, defined as BMI \> 30 kg/m2.
• have type 2 diabetes mellitus or pre-diabetes, defined as previously diagnosed by laboratory testing (hemoglobin A1c, fasting plasma glucose, or oral glucose tolerance test) or as demonstrated by use of anti-hyperglycemic medications or insulin.
• have at least one 24-hour urine study off medications demonstrating urine pH \< 5.8 or a study 24-hr urine demonstrating urine pH \< 5.8

You may not qualify if:

• contraindications to topiramate, including: recurrent major depression, current substantial depressive symptoms, uncontrolled depression by PHQ 9 score \>= 10, history of suicidal ideation or behavior with intent to act (versus exclude those with depression); current pregnancy or attempting to conceive; pre-existing chronic kidney disease with eGFR \< 60 at time of enrollment; active cancer or active treatment for cancer (chemotherapy, radiation); and non-ambulatory.
• contraindications to phentermine, including: unstable cardiovascular disease defined as decompensated heart failure, unstable angina, atrial fibrillation, uncontrolled blood pressure (\>160 systolic), hyperthyroidism; monoamine oxidase inhibitor use; current history of drug or alcohol abuse.

Sponsors & Collaborators

• University of Florida: lead
• National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK): collaborator

Study Sites (1)

University of Florida

Gainesville, Florida, 32610, United States

Location

MeSH Terms

Conditions

Obesity; Glucose Intolerance

Interventions

Phentermine; Topiramate; Qsymia; Allopurinol; Diet

Condition Hierarchy (Ancestors)

Overweight; Overnutrition; Nutrition Disorders; Nutritional and Metabolic Diseases; Body Weight; Signs and Symptoms; Pathological Conditions, Signs and Symptoms; Hyperglycemia; Glucose Metabolism Disorders; Metabolic Diseases

Intervention Hierarchy (Ancestors)

Amphetamines; Phenethylamines; Ethylamines; Amines; Organic Chemicals; Fructose; Hexoses; Monosaccharides; Sugars; Carbohydrates; Ketoses; Purines; Heterocyclic Compounds, 2-Ring; Heterocyclic Compounds, Fused-Ring; Heterocyclic Compounds; Nutritional Physiological Phenomena; Diet, Food, and Nutrition; Physiological Phenomena

Results Point of Contact

• Title: Principal Investigator
• Organization: University of Florida

benjamin.canales@urology.ufl.edu

352273-6815

Study Officials

• Benjamin Canales, MD

  University of Florida

  PRINCIPAL INVESTIGATOR

Publication Agreements

• PI is Sponsor Employee: No
• Restrictive Agreement: No

Study Design

• Study Type: interventional
• Phase: phase 3
• Allocation: RANDOMIZED
• Masking: NONE
• Purpose: TREATMENT
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Model Details: 2:1 ratio block site of 6

Study Record Dates

• First Submitted: November 3, 2020
• First Posted: November 9, 2020
• Study Start: March 31, 2021
• Primary Completion: November 14, 2024
• Study Completion: November 14, 2024
• Last Updated: January 30, 2026
• Results First Posted: January 30, 2026

Record last verified: 2024-11

Data Sharing

• IPD Sharing: Will not share

Locations

US (1)