Tolerization Reduces Intolerance to Pegloticase and Prolongs the Urate Lowering Effect

Study Purpose

The purpose of this study is to evaluate the effect of a high zone tolerizing regimen of pegloticase on clinical outcome, as defined by an serum uric acid level <6 mg/dL, in patients with chronic, refractory gout.

Recruitment Criteria

Accepts Healthy Volunteers

Healthy volunteers are participants who do not have a disease or condition, or related conditions or symptoms

Study Type

An interventional clinical study is where participants are assigned to receive one or more interventions (or no intervention) so that researchers can evaluate the effects of the interventions on biomedical or health-related outcomes.

An observational clinical study is where participants identified as belonging to study groups are assessed for biomedical or health outcomes.

Searching Both is inclusive of interventional and observational studies.

Eligible Ages 18 Years and Over
Gender All
More Inclusion & Exclusion Criteria

Inclusion Criteria:

1. Adult (age ≥18 years) men and women of non-childbearing potential, with chronic gout refractory to conventional therapy, defined as patients who have failed to normalize SUA and whose signs and symptoms are inadequately controlled with xanthine oxidase inhibitors at the maximum medically appropriate dose, or for whom these drugs are contraindicated. 2. Hyperuricemic
  • - Screening visit SUA must be >6 mg/dL 3.
On gout flare prophylactic regimen for 7 days prior to the first dose. 4. Willing and able to give informed consent and adhere to visit/protocol schedules (informed consent must be given before the first study procedure is performed)

Exclusion Criteria:

1. Glucose-6-phosphate dehydrogenase (G6PD) deficiency (confirmed at Screening visit) 2. Non-compensated congestive heart failure, uncontrolled arrhythmia, treatment for acute coronary syndrome (ACS) (myocardial infarction or unstable angina) or hospitalization for congestive heart failure within 3 months of screening or uncontrolled blood pressure (>160/100 mm Hg) at baseline (Screening and pre-dose at Week 1 visit ) 3. Women of childbearing potential defined as:
  • - Pre- or perimenopausal (<24 months of natural [spontaneous] amenorrhea).
  • - <6 weeks after surgical bilateral oophorectomy with or without hysterectomy.
4. Prior treatment with pegloticase or another recombinant uricase 5. Prior treatment or concomitant therapy with a polyethylene glycol (PEG) conjugated drug 6. Known allergy to PEG products or history of anaphylactic reaction to a recombinant protein or porcine product 7. Concurrent treatment with urate lowering agents (ULAs), such as allopurinol and febuxostat. Patients treated with these medications must discontinue treatment 7 days prior to the first dose of study drug 8. Recipient of an investigational drug within 4 weeks prior to study drug administration or plans to take an investigational agent during the study 9. Current liver disease as determined by alanine transaminase (ALT) or aspartate transaminase (AST) levels >3 times upper limit of normal (ULN) 10. History of malignancy within 5 years other than basal cell skin cancer or carcinoma in situ of the cervix 11. Has any other medical or psychological condition which, in the opinion of the Investigator, might create undue risk to the patient or interfere with the patient's ability to comply with the protocol requirements, or to complete the study 12. Solid organ transplant recipients 13. Uncontrolled hyperglycemia with a plasma glucose value >240 mg/dL at screening 14. Currently on dialysis Additional Exclusion Criteria for Imaging Sub-study Only 15. Contraindication to receiving a gadolinium-based contrast agent (GBCA) or > 2 previous lifetime exposures to a GBCA 16. Implanted pacemaker, certain older intracranial aneurysm clips, cochlear implants, certain prosthetic devices, implanted drug infusion pumps, neurostimulators, bone-growth stimulators, certain intrauterine contraceptive devices, or any other type of iron-based metal implants. 17. Any internal metallic objects such as bullets or shrapnel, as well as most surgical clips, pins, plates, screws, metal sutures, or wire mesh. Additional Exclusion Criteria for FDG-PET-CT Sub-study Only 18. Contraindication to FDG Additional Exclusion Criteria for Pegloticase and AZA Therapy Arm Only 19. Any active serious bacterial infection (2 weeks prior to screening) requiring antibiotic treatment 20. Severe chronic or recurrent bacterial infections, such as recurrent pneumonia, chronic bronchiectasis 21. Current immunocompromised condition, including current or chronic treatment with systemic immunosuppressive agents (e.g., prednisone or equivalent dose >510 mg/day) 22. At risk for tuberculosis. Specifically, subjects with: a) current clinical, radiographic, or laboratory evidence of active or latent tuberculosis; b) a history of active tuberculosis within the last 31 years even if it was treated; c) a history of active tuberculosis >31 years ago unless there is documentation that the prior anti-tuberculosis treatment was appropriate in duration and type 23. Known history of hepatitis B surface antigen-positivity or hepatitis B DNA positivity 24. Known history of hepatitis C RNA-positivity 25. Known history of human immunodeficiency virus positivity 26. Severe chronic renal impairment (glomerular filtration rate <25 mL/min/1.73 m2) 27. AZA treatment is contraindicated or considered inappropriate 28. Subject has a homozygous or heterozygous thiopurine methyltransferase (TPMT) variant genotype 29. Diagnosis of osteomyelitis 30. Known hypoxanthine-guanine phosphoribosyl-transferase deficiency, such as Lesch-Nyhan and Kelley-Seegmiller syndrome 31. Concurrent use of a xanthine oxidase inhibitor

Trial Details

Trial ID:

This trial id was obtained from, a service of the U.S. National Institutes of Health, providing information on publicly and privately supported clinical studies of human participants with locations in all 50 States and in 196 countries.


Phase 1: Studies that emphasize safety and how the drug is metabolized and excreted in humans.

Phase 2: Studies that gather preliminary data on effectiveness (whether the drug works in people who have a certain disease or condition) and additional safety data.

Phase 3: Studies that gather more information about safety and effectiveness by studying different populations and different dosages and by using the drug in combination with other drugs.

Phase 4: Studies occurring after FDA has approved a drug for marketing, efficacy, or optimal use.

Phase 2
Lead Sponsor

The sponsor is the organization or person who oversees the clinical study and is responsible for analyzing the study data.

Ampel BioSolutions, LLC
Principal Investigator

The person who is responsible for the scientific and technical direction of the entire clinical study.

Principal Investigator Affiliation N/A
Agency Class

Category of organization(s) involved as sponsor (and collaborator) supporting the trial.

Overall Status Recruiting
Countries United States

The disease, disorder, syndrome, illness, or injury that is being studied.

Additional Details

This is an exploratory open-label, multicenter study to evaluate the effectiveness of a 16-week high zone tolerance regimen of pegloticase on response to therapy (serum uric acid <6 mg/dL) with this drug in adult hyperuricemic patients with gout refractory to conventional therapy. Eligible subjects will receive 1 of 3 different loading doses (8, 12, and 16 mg) on Study Day 1, and then receive 8 mg on Week 2 and 3, followed by 8 mg every 2 weeks through Week 17 for a total of 10 doses. Subjects will be monitored for efficacy and safety endpoints through Week 17. Subjects will also have blood drawn for pegloticase levels prior to each dose on Weeks 2, 3, 5, 7, 9, 11, 13,15, and 17. Following Study Week 17, subjects will have an option to continue dosing for an additional 8 weeks. A subset of subjects will participate in additional pharmacokinetic (PK) assessments. The study duration, per enrolled patient, will be approximately 26 weeks including a 2-week screening period, a 16-week treatment period (end of treatment [EOT] visit Week 17), and an optional 8-week dosing extension.

Arms & Interventions


Experimental: Pegloticase regimen <120 kg - Main Study

Subjects weighing <120 kg will receive a tolerizing dose of pegloticase 8 mg IV weekly for the first 3 weeks of dosing followed by an 8 mg IV dose every 2 weeks for a total of 10 doses.

Experimental: Pegloticase regimen ≥120kg

Subjects weighing ≥ 120 kg will be sequentially assigned to 1 of 3 different loading doses (8, 12, and 16 mg) on Study Day 1, and then receive 8 mg on Week 2 and 3, followed by 8 mg every 2 weeks through Week 17 for a total of 10 doses.

Experimental: Pegloticase PK Sub-Study

Subjects weighing <120 kg and ≥120 kg will be assigned to 1 of 2 different loading doses (12 and 16 mg) on Study Day 1, and then receive 8 mg on Week 2 and 3, followed by 8 mg every 2 weeks through Week 17 for a total of 10 doses. Subjects will have multiple blood sampled for PK levels over the 17 week dosing period.

Experimental: Pegloticase Imaging Sub-Study

A subset of subjects participating in the Main Study and weighing <120 kg will have dual-energy computed tomography (DECT) and dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) performed at Screen and at Week 17.

Experimental: Pegloticase FDG-PET-CT Sub-Study

A subset of subjects participating in the Main Study and weighing <120 kg will have fluorodeoxyglucose-positron emission tomography (FDG-PET-CT) to evaluate carotid and aortic (chest) atherosclerosis at Screen and at Week 17.

Experimental: Pegloticase and Azathioprine

Subjects weighing <120 kg will receive azathioprine (AZA) daily for a 2-week run-in period, followed by daily AZA plus pegloticase 8 mg IV every 2 weeks through Week 25 for a total of 13 doses.


Biological: - Pegloticase

Pegloticase, IV

Drug: - Azathioprine

Azathioprine (1.25 mg/kg, followed by 2.5 mg/kg) oral, daily

Contact a Trial Team

If you are interested in learning more about this trial, find the trial site nearest to your location and contact the site coordinator via email or phone. We also strongly recommend that you consult with your healthcare provider about the trials that may interest you and refer to our terms of service below.

University of Alabama at Birminingham, Birmingham, Alabama




University of Alabama at Birminingham

Birmingham, Alabama, 35294

Rheumatology Associates of North Alabama, Huntsville, Alabama




Rheumatology Associates of North Alabama

Huntsville, Alabama, 35801

Pacific Arthritis Center Medical Group, Santa Maria, California




Pacific Arthritis Center Medical Group

Santa Maria, California, 93454

Wheaton, Maryland




The Center for Rheumatology and Bone Research

Wheaton, Maryland, 20902

Clinical Pharmacology Study Group, Worcester, Massachusetts




Clinical Pharmacology Study Group

Worcester, Massachusetts, 01609

Henry Ford Health System, Detroit, Michigan




Henry Ford Health System

Detroit, Michigan, 48202

Saint Paul Rheumatology, Eagan, Minnesota




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Eagan, Minnesota, 55121

Montefiore Medical Center, Bronx, New York




Montefiore Medical Center

Bronx, New York, 10467

Buffalo Rheumatology and Medicine, Orchard Park, New York




Buffalo Rheumatology and Medicine

Orchard Park, New York, 14127

Cleveland Clinic, Cleveland, Ohio




Cleveland Clinic

Cleveland, Ohio, 44195

Altoona Center for Clinical Research, Duncansville, Pennsylvania




Altoona Center for Clinical Research

Duncansville, Pennsylvania, 16635

ACME Research, LLC, Orangeburg, South Carolina




ACME Research, LLC

Orangeburg, South Carolina, 29118