A Study to Investigate the Clinical Effect and the Safety of PRX-115 Infused Intravenously at Different Dosing Regimens, With and Without Methotrexate, Versus Placebo in Adults Gout Patients (RELEASE) (RELEASE)

February 23, 2026 updated by: Protalix

A Multicenter, Randomized, Double-Blind, Placebo-Controlled, Phase 2 Study Assessing the Efficacy, Safety, and Dosing Regimen Selection of Multiple Intravenous Infusions of PRX-115 With and Without Methotrexate Versus Placebo in Adult Patients With Gout (RELEASE)

This is a multicenter, randomized, double-blind, placebo-controlled phase II study assessing the efficacy, safety, and dosing regimen selection of multiple IV infusions of PRX-115 over 24 weeks, with or without MTX, versus the respective placebos in adult patients with gout.

Study Overview

Status

Recruiting

Conditions

Intervention / Treatment

Detailed Description

This study will evaluate the efficacy, safety, tolerability, immunogenicity, pharmacokinetics (PK), and pharmacodynamics (PD) of PRX-115 (a recombinant pegylated Uricase) in adult patients with gout. Participants will receive PRX-115 by intravenous (IV) infusions according to different treatment schedules, with and without the immunomodulator methotrexate (MTX).

Study Type

Interventional

Enrollment (Estimated)

150

Phase

  • Phase 2

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

  • Name: Head of Clinical Development
  • Phone Number: +972-4-902-8100
  • Email: info@protalix.com

Study Locations

  • United States
    • Florida
      • Miami, Florida, United States, 33155
        • Recruiting
        • Bioclinical Research Alliance, Inc
        • Contact:

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  1. Males or females ≥18 years of age.
  2. Weight within the range of 50.0 - 150.0 kg.
  3. Gout patients who failed to normalize sUA (<7 mg/dL) with or without xanthine oxidase inhibitors or uricosuric agent or have contraindications to these drugs.
  4. Willing to discontinue any oral ULT
  5. Females who are sterile, postmenopausal, or non-pregnant and using birth control methods.

Exclusion Criteria:

  1. Any condition known to have arthritis as a clinical manifestation.
  2. Positive testing for HBV,HCV, or HIV.
  3. The patient is a pregnant or lactating female or plans to become pregnant during the study period.
  4. Known allergy or sensitivity to the injected proteins, including pegylated products.
  5. Prior exposure to any experimental or marketed uricase.
  6. Patient treated with a medication known to have an influence on urate metabolism or clearance such as ULTs.
  7. History of anaphylaxis, severe allergic reactions, or severe atopy.
  8. G6PD deficiency or known catalase deficiency.
  9. History of significant hematologic or autoimmune disorders within 5 years of Screening and/or patient is immunocompromised or treated with immunosuppressive medications.
  10. Non-compensated CHF or hospitalization for CHF (Stage 3-4 NYHA Functional Class) within 3 months of the Screening Visit, uncontrolled arrhythmia, treatment for acute coronary syndrome (myocardial infarction or unstable angina), or uncontrolled BP (>160/100 mmHg) at screening and prior to randomization at Week -4 (Visit 1).
  11. Current liver disease, as determined by ALT or AST levels above upper limit of normal at Screening Visit.
  12. Chronic liver disease.
  13. Hemoglobin <11 g/dL, neutrophil count <1500 /µl, or platelet count <100,000 /µl.
  14. Known severe pulmonary fibrosis, bronchiectasis or interstitial pneumonitis.
  15. eGFR ≤ 40 mL/min/1.73m2 tested at Screening Visit. Kidney transplant or requires dialysis.
  16. Known intolerance and/or known contraindication to MTX treatment or MTX treatment considered inappropriate
  17. Has uncontrolled type 2 diabetes at Screening with HbA1c ≥8.5%. Patients with type 1 diabetes will be excluded.
  18. Has known latent autoimmune diabetes of adult.
  19. Immunocompromised state, regardless of etiology.
  20. History or treatment of malignancy in the last 5 years, excluding localized, nonmelanoma skin cancers (e.g. basal or squamous cell)

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Quadruple

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: E4W with placebo-MTX
IV infusion of PRX-115 every 4 weeks (E4W) for a total of 6 doses with placebo-MTX
Biological: PRX-115
intravenous (IV) infusion
Other: Placebo-Methotrexate
Oral Placebo-MTX weekly
Experimental: E4W with MTX
IV infusion of PRX-115 every 4 weeks (E4W) for a total of 6 doses with MTX
Biological: PRX-115
intravenous (IV) infusion
Drug: Methotrexate (MTX)
Oral MTX 15 mg weekly
Experimental: E6W with MTX
IV infusion of PRX-115 every 6 weeks (E6W) for a total of 4 doses with MTX
Biological: PRX-115
intravenous (IV) infusion
Drug: Methotrexate (MTX)
Oral MTX 15 mg weekly
Placebo Comparator: placebo E4W
infusion of PRX-115 placebo every 4 weeks (E4W) for a total of 6 doses with placebo-MTX
Other: Placebo-Methotrexate
Oral Placebo-MTX weekly
Other: PRX-115 placebo
intravenous (IV) infusion
Placebo Comparator: placebo E6W
IV infusion of PRX-115 placebo every 6 weeks (E6W) for a total of 4 doses with placebo-MTX
Other: Placebo-Methotrexate
Oral Placebo-MTX weekly
Other: PRX-115 placebo
intravenous (IV) infusion
Experimental: E8W with MTX
IV infusion of PRX-115 every 8 weeks (E8W) for a total of 3 doses with MTX
Biological: PRX-115
intravenous (IV) infusion
Drug: Methotrexate (MTX)
Oral MTX 15 mg weekly

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Percentage of Serum Uric Acid (sUA) Responders (sUA < 6 mg/dL) During Month 6
Time Frame: 6 months of treatment
Proportion of patients who achieve a reduction in sUA to <6.0 mg/dL for at least 80% of the time during Month 6
6 months of treatment

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Percentage of Serum Uric Acid (sUA) Responders (sUA < 6 mg/dL) at different time points
Time Frame: 3 to 6 months of treatment
Proportion of patients that achieve a reduction in sUA to <6.0 mg/dL for at least 80% of the time during Month 3 or 4, 5 and 6.
3 to 6 months of treatment
Treatment-emergent adverse events (TEAEs)
Time Frame: From enrollment to 8 months of study
Occurrence and severity of treatment-emergent adverse events (TEAEs)
From enrollment to 8 months of study

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Protalix

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

December 22, 2025

Primary Completion (Estimated)

December 1, 2027

Study Completion (Estimated)

June 1, 2028

Study Registration Dates

First Submitted

December 3, 2025

First Submitted That Met QC Criteria

December 3, 2025

First Posted (Actual)

December 12, 2025

Study Record Updates

Last Update Posted (Actual)

February 25, 2026

Last Update Submitted That Met QC Criteria

February 23, 2026

Last Verified

January 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • PB115-GT-201

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

Yes

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

Clinical Trials on Gout

Clinical Trials on PRX-115

Search Similar Trials

Sponsors and Collaborators

Medical Conditions

Drug Interventions

CROs by country

CROs in Burkina Faso

Conditions

Rare Diseases

Drug Interventions

Dietary Supplements

Sponsor/Collaborators

Locations

Subscribe