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RecruitingNCT07280156RELEASEUpdated Sep 29, 2026

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)

A Phase 2 interventional study of PRX-115 and Methotrexate (MTX) in Gout, sponsored by Protalix. Recruiting at 35 sites in 3 countries. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-09-29.

Sponsored by Protalix · Phase 2, Interventional, and Treatment

From the registry’s dates

  • Started Dec 2025; still recruiting 10 months later.
Updated Sep 29, 20268 sites addedGo to Updates ↓
Phase
Phase 2
Study type
Interventional
Enrollment
150
Allocation
Randomized
Ages
18 Years and older
Sex
All
01

Study summary

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.

Read the 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).

02

Conditions studied

  • Gout

Browse trials for

Keywords

  • gout
  • uricase
  • uric acid
  • hyperuricemia
  • PRX-115
03

In context

Gout

345 studies on the registry are indexed under Gout; 49 are open to participants now.

This study's planned enrollment of 150 is above the median of 83 across 286 interventional studies indexed under Gout.

Browse Gout studies →

Lead sponsor

Protalix is the lead sponsor of 16 studies on the registry; 1 is open to participants now.

Counted across the registry records on this site, refreshed daily.

04

Who can participate

Ages eligible
18 Years and older
Sexes eligible
All
Accepts healthy volunteers
No

Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.

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 to these drugs.
  4. Willing to discontinue any oral ULT
  5. Females who are sterile, , or non-pregnant and using methods.

Exclusion criteria

Exclusion Criteria:

  1. Any condition known to have arthritis as a clinical manifestation.
  2. Positive testing for ,, or .
  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 disorders within 5 years of Screening and/or patient is or treated with immunosuppressive medications.
  10. Non-compensated CHF or hospitalization for CHF (Stage 3-4 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 or AST levels above at Screening Visit.
  12. Chronic liver disease.
  13. \<11 g/dL, \<1500 /µl, or count \<100,000 /µl.
  14. Known severe pulmonary fibrosis, bronchiectasis or interstitial pneumonitis.
  15. ≤ 40 mL/min/1.73m2 tested at Screening Visit. Kidney transplant or requires dialysis.
  16. Known intolerance and/or known to MTX treatment or MTX treatment considered inappropriate
  17. Has uncontrolled type 2 diabetes at Screening with ≥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 in the last 5 years, excluding localized, nonmelanoma skin cancers (e.g. basal or squamous cell)
Terms in these criteria, in plain language(17)

Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.

Contraindication

A reason a treatment, test or procedure should not be given to a particular person, such as an allergy, another illness or a medicine they take.

Postmenopausal

Periods have stopped for good: usually no period for 12 months in a row without another medical reason, sometimes confirmed by a blood test (FSH).

Contraception

Ways of preventing pregnancy. “Highly effective” methods fail less than 1% of the time a year when used correctly — for example an IUD or an implant.

Criteria usually say which methods count and how long to keep using them after the last dose, sometimes for male participants too. Some studies accept a partner’s vasectomy if it was confirmed successful and that person is the participant’s only sexual partner.

Hepatitis B tests

Hepatitis B is a virus that infects the liver. These are separate tests: HBsAg positive usually means a current infection (a recent vaccination can briefly cause it too); total anti-HBc (HBcAb) positive means an infection now or in the past; HBV DNA measures how much virus is in the blood.

Some studies accept a past infection if HBV DNA is undetectable, sometimes with antiviral medicine during the study. Check what this study allows.

Hepatitis C tests

Hepatitis C is a virus that infects the liver. An HCV antibody test can stay positive after an infection has cleared (and is occasionally positive without one); an HCV RNA test shows whether the virus is there now.

After treatment, hepatitis C counts as cured when HCV RNA is still undetectable 12 weeks or more after the treatment ended. Studies often accept people cured this way.

HIV

The human immunodeficiency virus, which weakens the immune system.

Many studies now accept people whose HIV is controlled on treatment, judged by the viral load and the CD4 count. Check the limits this study sets.

Autoimmune disease

A condition in which the immune system attacks the body’s own tissues, such as rheumatoid arthritis, lupus, psoriasis, type 1 diabetes or inflammatory bowel disease.

Immunotherapy studies often leave out active autoimmune disease, and some name exceptions, such as thyroid disease on replacement hormone. Check the exceptions this study lists.

Immunosuppression

A weakened immune system. It can come from an illness, such as HIV or some blood cancers, or from medicines that turn the immune system down, for example after an organ transplant or for an autoimmune disease; steroids at higher doses count.

Read whether the line is about a condition or about medicines, and which medicines and doses it means.

NYHA class (heart failure)

The New York Heart Association’s four classes of how much heart failure limits physical activity.

I
No limits: ordinary activity causes no undue tiredness or breathlessness.
II
Slight limits: comfortable at rest, ordinary activity causes symptoms.
III
Marked limits: comfortable at rest, less than ordinary activity causes symptoms.
IV
Symptoms even at rest; any activity makes them worse.

Studies set their own limit — many outside heart failure leave out class III–IV, while heart failure studies may ask for a particular class. Check the class this study names.

ALT and AST (liver enzymes)

Two enzymes measured in a routine blood test of the liver. Higher levels can mean the liver is under strain or damaged. SGPT and SGOT are older names for ALT and AST.

Criteria usually give a limit as a multiple of the upper limit of normal (ULN), often higher when cancer has spread to the liver.

ULN (upper limit of normal)

The top of the normal range for a blood test, as set by the laboratory that runs it. Each lab prints its own range next to your result.

“≤ 2.5 × ULN” means the result can be up to two and a half times that top value.

Hemoglobin (Hb)

The protein in red blood cells that carries oxygen. A low level is anaemia, which can cause tiredness and breathlessness. Measured in g/dL or g/L (9 g/dL is 90 g/L).

Absolute neutrophil count (ANC)

The number of neutrophils, white blood cells that help fight infection, in a given amount of blood. Too few raises the risk of infection.

It is a count, not a percentage of the white cells. Limits are written in units that mean the same: ≥ 1.5 × 10⁹/L is ≥ 1,500 per mm³ (µL). Each lab has its own reference range.

Platelets

Blood cells that help blood clot. Too few raises the risk of bleeding and bruising. A usual adult range is about 150–400 × 10⁹/L (150,000–400,000 per µL); each lab has its own reference range.

GFR and eGFR (kidney filtering)

GFR (glomerular filtration rate) is how much blood the kidneys filter each minute. It is usually estimated from a blood test — eGFR, by formulas such as CKD-EPI or MDRD — and some studies ask for it to be measured directly instead. Usually given in mL/min/1.73 m².

Check the method, the units and the minimum the study states. A value of 90 or above is in the normal-or-high range, but kidney damage can show in other tests too.

HbA1c

A blood test of average blood sugar over the past two to three months, given as a percentage or in mmol/mol. 6.5% (48 mmol/mol) or more is the usual threshold for diabetes, normally confirmed by a second test.

Cancer (malignancy)

Malignancy means cancer. Criteria about another or earlier malignancy ask whether you have had a different cancer, usually within a set number of years.

Some are commonly allowed, such as treated skin cancers other than melanoma and early cancers removed completely — check the exceptions this study lists.

05

Study design

Phase
Phase 2
Primary purpose
Treatment
Allocation
Randomized
Intervention model
Parallel assignment
Masking
Quadruple (Participant, Care provider, Investigator, Outcomes assessor)
Enrollment
150 participants (estimated)

Study arms

  • 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 · Other: Placebo-Methotrexate

  • Experimental
    E4W with MTX

    IV infusion of PRX-115 every 4 weeks (E4W) for a total of 6 doses with MTX

    Biological: PRX-115 · Drug: Methotrexate (MTX)

  • Experimental
    E6W with MTX

    IV infusion of PRX-115 every 6 weeks (E6W) for a total of 4 doses with MTX

    Biological: PRX-115 · Drug: Methotrexate (MTX)

  • Experimental
    E8W with MTX

    IV infusion of PRX-115 every 8 weeks (E8W) for a total of 3 doses with MTX

    Biological: PRX-115 · Drug: Methotrexate (MTX)

  • Placebo comparator
    placebo E4W

    infusion of PRX-115 placebo every 4 weeks (E4W) for a total of 6 doses with placebo-MTX

    Other: PRX-115 placebo · Other: Placebo-Methotrexate

  • Placebo comparator
    placebo E6W

    IV infusion of PRX-115 placebo every 6 weeks (E6W) for a total of 4 doses with placebo-MTX

    Other: PRX-115 placebo · Other: Placebo-Methotrexate

Interventions

  • BiologicalPRX-115

    intravenous (IV) infusion

  • Oral MTX 15 mg weekly

  • OtherPRX-115 placebo

    intravenous (IV) infusion

  • OtherPlacebo-Methotrexate

    Oral Placebo-MTX weekly

06

What researchers measure

Primary outcomes

  1. Percentage of Serum Uric Acid (sUA) Responders (sUA < 6 mg/dL) During Month 6

    Proportion of patients who achieve a reduction in sUA to \<6.0 mg/dL for at least 80% of the time during Month 6

    Time frame: 6 months of treatment

Secondary outcomes

  1. Percentage of Serum Uric Acid (sUA) Responders (sUA < 6 mg/dL) at different time points

    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.

    Time frame: 3 to 6 months of treatment

  2. Treatment-emergent adverse events (TEAEs)

    Occurrence and severity of treatment-emergent adverse events (TEAEs)

    Time frame: From enrollment to 8 months of study

07

Study locations

35 of 35 sites recruiting
  • Rezen Clinical Trials
    Glendale, Arizona 85306, United States
    Recruiting
  • Applied Research Center of Arkansas
    Little Rock, Arkansas 72205, United States
    Recruiting
  • Advanced Research Center, Inc
    Anaheim, California 92805, United States
    Recruiting
  • Triwest Research Associates Llc
    El Cajon, California 91910, United States
    Recruiting
  • Imax Clinical Trials, LLC
    La Palma, California 90623, United States
    Recruiting
  • Kinetic Clinical Research
    Long Beach, California 90806, United States
    Recruiting
  • Clinical Research of West Florida, Inc.
    Clearwater, Florida 33765, United States
    Recruiting
  • Accel Research Sites - Deland Clinical Research Unit
    DeLand, Florida 32720, United States
    Recruiting
  • ICR Sites East
    Doral, Florida 33125, United States
    Recruiting
  • Qway Research
    Hialeah, Florida 33010, United States
    Recruiting
  • Bioclinical Research Alliance, Inc
    Miami, Florida 33155, United States
    Recruiting
  • D&H National Research Centers (North Miami)
    Miami, Florida 33169, United States
    Recruiting
  • Well Pharma Medical Research Group
    Miami, Florida 33173, United States
    Recruiting
  • Conquest Research - Lake Nona
    Orlando, Florida 32832, United States
    Recruiting
  • Combined Research Orlando Phase I-IV
    Orlando, Florida 32897, United States
    Recruiting
  • New Horizons Research
    Palmetto Bay, Florida 33176, United States
    Recruiting
  • Clinical Research of West Florida, Inc.
    Tampa, Florida 33606, United States
    Recruiting
  • Centricity Research - Columbus Georgia Multispecialty
    Columbus, Georgia 31904, United States
    Recruiting
  • Revival Research Institute, LLC
    Dearborn, Michigan 48126, United States
    Recruiting
  • Quest Research Institute
    Farmington Hills, Michigan 48334, United States
    Recruiting
  • Revive Research Institute, Inc
    Sterling Heights, Michigan 48313, United States
    Recruiting
  • Altoona Center for Clinical Research
    Duncansville, Pennsylvania 16635, United States
    Recruiting
  • Pioneer Research Solutions Inc
    Houston, Texas 77099, United States
    Recruiting
  • Mt. Olympus Medical Research, LLC - Sugar Land
    Sugar Land, Texas 77479, United States
    Recruiting
  • Velocity Clinical Research
    Waco, Texas 76710, United States
    Recruiting
  • Velocity Clinical Research
    Suffolk, Virginia 23435, United States
    Recruiting
  • Aleksandre Aladashvili Clinic LLC, Georgia
    Tbilisi, 0102, Georgia
    Recruiting
  • Tbilisi Heart and Vascular Clinic Ltd , Georgia
    Tbilisi, 0159, Georgia
    Recruiting
  • Mediclub Georgia
    Tbilisi, 0160, Georgia
    Recruiting
  • Tbilisi Institute of Medicine, Georgia
    Tbilisi, 0160, Georgia
    Recruiting
  • Georgian-Dutch Hospital, Georgia
    Tbilisi, 0172, Georgia
    Recruiting
  • LTD First Medical Center, Georgia
    Tbilisi, 0180, Georgia
    Recruiting
  • HaEmek MC, Israel
    Afula, 1834111, Israel
    Recruiting
  • Barzilai MC, Israel
    Ashkelon, 7830604, Israel
    Recruiting
  • Meir MC, Israel
    Kfar Saba, 4438164, Israel
    Recruiting
08

Updates

1 registry update since Sep 25, 2026
Sites
8 sites added
Show 8 added (8 United States)
  • Rezen Clinical Trials · Glendale, United States
  • Advanced Research Center, Inc · Anaheim, United States
  • Imax Clinical Trials, LLC · La Palma, United States
  • Kinetic Clinical Research · Long Beach, United States
  • Revival Research Institute, LLC · Dearborn, United States
  • Revive Research Institute, Inc · Sterling Heights, United States
  • Velocity Clinical Research · Waco, United States
  • Velocity Clinical Research · Suffolk, United States
Sep 29, 2026
Show all 1 update
  1. Sep 29, 2026
    8 sites added
    Show 8 added (8 United States)
    • Rezen Clinical Trials · Glendale, United States
    • Advanced Research Center, Inc · Anaheim, United States
    • Imax Clinical Trials, LLC · La Palma, United States
    • Kinetic Clinical Research · Long Beach, United States
    • Revival Research Institute, LLC · Dearborn, United States
    • Revive Research Institute, Inc · Sterling Heights, United States
    • Velocity Clinical Research · Waco, United States
    • Velocity Clinical Research · Suffolk, United States
    + 1 other change: verification date

From the registry record's own update history. This site started tracking changes on Sep 25, 2026; for anything earlier, see the record history on ClinicalTrials.gov ↗

09

Registry details

Key details

Study ID
NCT07280156
Lead sponsor
Protalix
Responsible party
Sponsor
First posted
Dec 12, 2025
Start date
Dec 22, 2025
Primary completion
Dec 2027 (estimated)
Completion
Jun 2028 (estimated)
Last update
Sep 29, 2026

Study contacts

Head of Clinical Development
Contact
info@protalix.com
+972-4-902-8100

Oversight

Data monitoring committee
Yes
FDA-regulated drug
Yes
FDA-regulated device
No
View the source record on ClinicalTrials.gov ↗

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