Plonmarlimab treatment for acute gouty arthritis

A Multicenter, Randomized, Double-Blind, Double-Dummy, Active-Controlled Phase II Clinical Study to Evaluate the Efficacy, Safety, Tolerability, Pharmacokinetics, and Immunogenicity of Punarlimab in Subjects With Acute Gouty Arthritis

This trial will test whether plonmarlimab can reduce pain and other symptoms in adults having acute gout attacks who cannot use or did not respond to colchicine or NSAIDs.

Quick facts

• Phase: PHASE2
• Study type: Interventional
• Enrollment: 170 (estimated)
• Ages: 18 Years and up
• Sex: All
• Sponsor: TJ Biopharma Co., Ltd. (industry)
• Drugs / interventions: chemotherapy, plonmarlimab
• Locations: 1 site (Shanghai, Shanghai Municipality)
• Trial ID: NCT07453004 on ClinicalTrials.gov

What this trial studies

This phase 2, randomized, double-blind, double-dummy, active-controlled trial plans to enroll about 120–170 adults with acute gouty arthritis. Participants will be randomized to one or more doses of plonmarlimab or to an active comparator (compound betamethasone) with matching placebos. An interim analysis after the first 60 subjects complete the 72-hour pain VAS assessment will guide selection of one or two plonmarlimab groups to continue enrollment, and pharmacokinetics and immunogenicity will be measured. The trial will track pain reduction, safety, tolerability, and antibody responses during acute flares.

Who should consider this trial

Good fit: Adults aged 18 or older who meet ACR/EULAR gout criteria, have had an acute flare within 5 days, have a history of at least three flares in the past year, and who are contraindicated, intolerant, or inadequately responsive to colchicine and/or NSAIDs.

Not a fit: Patients who respond well to standard treatments or whose gout is well-controlled between flares are unlikely to benefit, and those with contraindications to biological therapies or certain comorbidities may also be excluded or derive no benefit.

Why it matters

Potential benefit: If successful, plonmarlimab could offer faster pain relief and an alternative treatment for patients with acute gout who are intolerant of or unresponsive to standard therapies.

How similar studies have performed: Other biologic and anti-inflammatory agents, particularly IL-1 inhibitors, have shown efficacy in treating acute gout flares, so this approach builds on prior positive results though plonmarlimab itself remains investigational.

Eligibility criteria

Inclusion Criteria:

* Subjects aged ≥18 years, regardless of gender.
* Subjects are willing to participate in this study and voluntarily sign the informed consent form.
* Meet the 2015 American College of Rheumatology (ACR)/European League Against Rheumatism (EULAR) gout classification criteria.
* Experienced ≥3 episodes of acute gout flare within the 12 months prior to baseline (determination of an acute gout flare based on patient history, referral records, etc., will be made by the investigator).
* Subjects have experienced an acute gout flare within 5 days prior to administration of the investigational product (determination of an acute gout flare based on patient history, referral records, etc., will be made by the investigator).
* Contraindicated, intolerant, or inadequately responsive to colchicine and/or non-steroidal anti-inflammatory drugs (NSAIDs) (determination based on patient history, referral records, etc., will be made by the investigator).
* Baseline pain intensity assessment in the most severely affected joint by the subject using a 0-100 mm Visual Analogue Scale (VAS) is ≥50 mm.
* Subjects may or may not be receiving urate-lowering therapy. If planning to continue urate-lowering therapy during the study, it must have been at a stable dose for ≥2 weeks prior to baseline.
* Subjects (including their partners) have no pregnancy plans from the screening period until 90 days after dosing and voluntarily agree to use effective contraception.

Exclusion Criteria:

* Secondary gout caused by various etiologies (e.g., gout induced by chemotherapy, judged by the investigator based on the subject's medical history, referral records, etc.).
* History of hypersensitivity to any component of the investigational product or to similar biological agents.
* Contraindication to compound betamethasone therapy.
* Presence of other rheumatic diseases besides gout that may interfere with interpretation of results, including but not limited to rheumatoid arthritis, infectious/suppurative arthritis, traumatic arthritis, etc.
* Pulmonary diseases including but not limited to asthma, chronic obstructive pulmonary disease, interstitial lung disease, pulmonary alveolar proteinosis, pulmonary granulomatosis, etc., or any underlying pulmonary disease that significantly impairs pulmonary function as assessed by the investigator, making the subject unsuitable for this clinical study.
* Cardiovascular diseases: history of acute myocardial infarction, unstable angina, severe arrhythmia (multifrequent premature ventricular contractions, ventricular tachycardia, ventricular fibrillation) within the past 6 months; New York Heart Association (NYHA) functional Class III-IV (see Appendix 4). Presence of long QT syndrome or QTc interval \> 450 msec (male) or \> 470 msec (female) during screening.
* History of malignancy within the past 5 years (regardless of treatment), except for successfully treated basal cell or squamous cell carcinoma of the skin.
* Other diseases: subjects with a past and/or current clinically significant, unstable, or uncontrolled acute or chronic disease unrelated to gout (e.g., acute pneumonia, pulmonary hypertension, diabetic ketoacidosis, acute pancreatitis, etc.), or scheduled medical/surgical procedures; or any condition that places the subject at undue risk or impairs the ability to participate voluntarily.
* Infections: presence of any known acute, chronic, or recurrent active infection during screening (e.g., tuberculosis, syphilis, HIV, HBV, HCV, Pneumocystis jirovecii, CMV, HSV, VZV, atypical mycobacteria, Histoplasma capsulatum, Salmonella infection, genital herpes, osteomyelitis, urinary tract infection, etc.).
* Abnormal hepatic and renal function: aspartate aminotransferase (AST), alanine aminotransferase (ALT), or gamma-glutamyl transferase (GGT) \> 2 × upper limit of normal (ULN); alkaline phosphatase (ALP) or total bilirubin (TBIL) \> 1.5 × ULN; creatinine (Cr) or blood urea nitrogen (BUN) \> 1.5 × ULN; or eGFR ≤ 60 mL/min/1.73 m² prior to screening (calculated using the MDRD formula, see Appendix 9).
* Hematological diseases or abnormal routine blood tests: subjects with a past or current hematological disease including but not limited to myelofibrosis, aplastic anemia, leukemia, lymphoma, etc.; hemoglobin \< 90 g/L, platelet count \< 80×10⁹/L, white blood cell or neutrophil count below the lower limit of normal with clinically significant abnormality judged by the investigator.
* Planned surgery or any other medical history (e.g., recent sepsis), laboratory abnormality, or other condition judged by the investigator to render the subject ineligible for this study.
* History of organ transplantation.
* Pregnant or lactating female subjects.
* Participation in any interventional clinical trial (including investigational vaccines) or use of an invasive investigational medical device within 3 months prior to enrollment, or current enrollment in another interventional study.
* Administration of live (attenuated) vaccine within 30 days prior to screening. Inability to receive intramuscular injection (e.g., subjects on anticoagulants, thrombocytopenia, known bleeding disorders such as idiopathic thrombocytopenic purpura).
* Drug abuse detected by urine drug screening, including morphine, ketamine, tetrahydrocannabinol, methamphetamine, MDMA, cocaine.
* Alcohol abuse within 3 months prior to screening, defined as alcohol consumption \> 14 units per week (1 unit = 17.5 mL or 14 g pure alcohol; 1 unit ≈ 35 mL of 50% spirits or 350 mL of 5% beer), or unwillingness to abstain from alcohol or alcohol-containing products during the trial.
* Any other condition deemed by the investigator to render the subject unsuitable for this clinical study, including any condition that may increase study-related risk, interfere with evaluation of the investigational product, or confound interpretation of study results.

Where this trial is running

Shanghai, Shanghai Municipality

• Renji Hospital, Shanghai Jiao Tong University School of Medicine — Shanghai, Shanghai Municipality, China (RECRUITING)

Study contacts

• Study coordinator: Lina Qin

Conditions: Acute Gouty Arthritis