DECT Study in Allopurinol-Treated Gout Patients

Study Overview
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Brief Summary
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The purpose of this study is to determine presence and volume of monosodium urate (MSU) crystal deposits as determined by dual-energy computed tomography (DECT) imaging in gout subjects treated with allopurinol with and without visible tophi.

Detailed Description
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DECT is a technique that enables visualization of MSU crystal deposits by analysis of the chemical composition of the scanned materials. This study will determine the extent of MSU crystal volume in the hands/wrists, feet/ankles, and knees as determined by DECT of subjects with gout taking a dose of at least 300 mg allopurinol daily for the past 12 weeks. Patients with gout on allopurinol with and without tophi to be assessed using DECT imaging for crystal deposition with assessments, which include patient and provider assessments of disease severity and pain, prior to and after the scan.

Official Title
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A Study to Determine the Presence and Volume of Monosodium Urate Crystals as Assessed by Dual-Energy Computed Tomography in Gout Patients Treated With Allopurinol

Conditions
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Gout

Intervention / Treatment
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* Procedure: DECT scan


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Subject is able to understand the study procedures, the risks involved and willing to provide written informed consent before the first study related activity. Subject is willing to adhere to the visit/protocol schedules. Subject meets the diagnosis of gout as per the American Rheumatism Association Criteria for the Classification of Acute Arthritis of Primary Gout. Subject has been taking allopurinol at a dose of at least 300 mg daily for at least 12 weeks prior to Day 1, as the sole uratelowering therapy. Exclusion Criteria: Subject who is pregnant or breastfeeding. Subject with any other medical or psychological condition, which in the opinion of the Investigator and/or Medical Monitor, might create undue risk to the subject or interfere with the subject's ability to comply with the protocol requirements (including dual energy computed tomography imaging), or to complete the study. Subject who has received an investigational therapy or has participated in any clinical trial or research study within 30 days of Day 1. Subject who has taken pegloticase (KRYSTEXXA®) or is expected to take pegloticase during the study.

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 85 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Gout subjects on stable dose of allopurinol (at least 300mg)<br> | Procedure: DECT scan<br> <br> |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Presence and volume of MSU crystal deposits as determined by DECT imaging |  | 8 weeks | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Joint erosion as visualized on DECT images |  | 8 weeks |