An Open-label Study to Evaluate the Pharmacokinetics and Safety of Bimekizumab in Pediatric Study Participants With Active Juvenile Idiopathic Arthritis Subtypes Enthesitis-related Arthritis (Including Juvenile-onset Ankylosing Spondylitis) and Juvenile Psoriatic Arthritis

Open-Label, Single-Arm Trial to Evaluate the Pharmacokinetics and Safety of Bimekizumab in Pediatric Study Participants From 2 to Less Than 18 Years of Age With Active Juvenile Idiopathic Arthritis Subtypes Enthesitis-Related Arthritis (Including Juvenile-Onset Ankylosing Spondylitis) and Juvenile Psoriatic Arthritis

The purpose of this study is to assess plasma bimekizumab concentrations following subcutaneous (sc) bimekizumab administration.

Study Overview

• Status: Recruiting
• Conditions: Juvenile Psoriatic Arthritis; Enthesitis-related Arthritis
• Intervention / Treatment: Drug: Bimekizumab

• Study Type: Interventional
• Enrollment (Estimated): 40
• Phase: Phase 3

Contacts and Locations

• Study Contact: Name: UCB Cares; Phone Number: 001 844 599 2273
• Study Contact Backup: Name: UCB Cares; Phone Number: +18445992273; Email: ucbcares@ucb.com

Study Locations

• Canada
  • Calgary, Canada
    • Recruiting
    • Ja0005 50646
  • Montreal, Canada
    • Recruiting
    • Ja0005 50644
  • Saskatoon, Canada
    • Recruiting
    • Ja0005 50645
• France
  • Indre-et-Loire, France
    • Recruiting
    • Ja0005 40777
  • Le Kremlin-Bicêtre, France
    • Recruiting
    • Ja0005 40510
  • Paris, France
    • Recruiting
    • Ja0005 40778
  • Poitiers, France
    • Recruiting
    • Ja0005 40776
• Germany
  • Berlin, Germany
    • Recruiting
    • Ja0005 40369
  • Dresden, Germany
    • Recruiting
    • Ja0005 40356
  • Freiburg im Breisgau, Germany
    • Recruiting
    • Ja0005 40072
  • Hamburg, Germany
    • Recruiting
    • Ja0005 40852
  • Sankt Augustin, Germany
    • Recruiting
    • Ja0005 40787
  • Sendenhorst, Germany
    • Recruiting
    • Ja0005 40779
  • Tübingen, Germany
    • Recruiting
    • Ja0005 40427
• Poland
  • Krakow, Poland
    • Recruiting
    • Ja0005 40720
  • Sosnowiec, Poland
    • Recruiting
    • Ja0005 40780
• Spain
  • Esplugues de Llobregat, Spain
    • Recruiting
    • Ja0005 40781
  • Madrid, Spain
    • Recruiting
    • Ja0005 40100
  • Valencia, Spain
    • Recruiting
    • Ja0005 40782
• United Kingdom
  • Bristol, United Kingdom
    • Recruiting
    • Ja0005 40786
  • Manchester, United Kingdom
    • Recruiting
    • Ja0005 40783
  • Nottingham, United Kingdom
    • Recruiting
    • Ja0005 40785
  • Stroke-on-trent, United Kingdom
    • Active, not recruiting
    • Ja0005 40784

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Child; Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Study participant must be 2 to <18 years of age inclusive, at the Baseline Visit.
• Study participants who have confirmed diagnosis of enthesitis-related arthritis (ERA; including juvenile-onset ankylosing spondylitis (JAS)) and/or juvenile psoriatic arthritis (JPsA) according to the juvenile-International League of Associations for Rheumatology (JIA-ILAR) classification criteria of at least 3 months duration prior to the Screening Visit.
• Study participants who have active disease (ERA [including JAS] and/or JPsA) defined as having at least 3 active joints, each of which needs to be included in the joints assessed in the JADAS27, and for ERA at least 1 site of enthesitis at Baseline or documented by history.
• Study participants with inadequate response (at least 1 month) or intolerance to at least 1 nonsteroidal anti-inflammatory drug (NSAID).
• Study participants taking concomitant methotrexate or sulfasalazine are allowed to continue the medication if it has been used for the past 12 weeks with a stable dose for the 4 weeks prior to Baseline, with no change in dose for the first 16 weeks of treatment foreseen. (Note: prior or concomitant use of methotrexate or sulfasalazine is NOT required for study participation.)
• Study participants with no concomitant use of second line agents such as disease-modifying and/or immunosuppressive drugs with the exception of methotrexate or sulfasalazine.
• Body weight of ≥10kg.
• Male and female.

• A female study participant will be eligible to participate if she is not pregnant, not breastfeeding, and at least 1 of the following conditions applies:

  1. Not a woman of childbearing potential (WOCBP) OR
  2. A WOCBP who agrees to follow the contraceptive guidance during the Initial Treatment Period, the Open-label Extension (OLE) Period, and for at least 20 weeks after the final dose of investigational medicinal product (IMP; ie, the Safety Follow-up (SFU) Period)
• Capable of giving/having parent(s) or legal representative provide signed informed consent/assent (where appropriate), which includes compliance with the requirements and restrictions listed in the Informed Consent Form (ICF) and assent and in this protocol.

Exclusion Criteria:

• Study participants fulfilling any International League of Associations for Rheumatology (ILAR) diagnostic juvenile idiopathic arthritis (JIA) category other than enthesitis-related arthritis (ERA; including juvenile-onset ankylosing spondylitis (JAS)) and/or juvenile psoriatic arthritis (JPsA).
• Study participant has history of inflammatory bowel disease (IBD) or signs/symptoms suggestive of IBD.
• Study participant has active uncontrolled uveitis.
• Study participant has history of active tuberculosis (TB) unless successfully treated, latent TB unless prophylactically treated.
• Study participant has had major surgery (including joint surgery) within the 3 months prior to the Baseline Visit or has planned major surgery within 6 months after entering the study.
• Study participant has laboratory abnormalities at Screening defined in the Protocol.
• Study participant has an active infection or history of infections (such as serious infection, chronic infections, opportunistic infections, unusually severe infections).
• Study participant has received drugs listed in the protocol outside the specified timeframes relative to the Baseline Visit or receives prohibited concomitant treatments.
• Study participant had previous therapy with bimekizumab or prior treatment with other IL-17 biologic response modifier.
• Study participant had prior treatment with more than one biologic response modifier (other than an IL-17).
• Presence of active suicidal ideation, or positive suicide behavior.
• Study participant has been diagnosed with severe depression in the past 6 months.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: N/A
• Interventional Model: Single Group Assignment
• Masking: None (Open Label)

Number of Arms

1

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Bimekizumab; Study participants will receive a bimekizumab dose which is dependent on their weight.	Drug: Bimekizumab; Bimekizumab will be administered at pre-specified timepoints.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Plasma bimekizumab concentrations over the Initial Treatment Period	Plasma samples will be collected at pre-specified timepoints for measurement of plasma bimekizumab concentrations over the Initial Treatment Period.	Up to Week 16

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Incidence of Treatment-emergent adverse events (TEAEs)	An AE is any untoward medical occurrence in a patient or clinical study participant, temporally associated with the use of IMP, whether or not considered related to the IMP.	From Baseline (Week 0) to End of Safety Follow-up (up to 141 weeks)
Incidence of Serious TEAEs	A SAE is defined as any untoward medical occurrence that, at any dose: Results in death; Is life-threatening; Requires inpatient hospitalization or prolongation of existing hospitalization; Results in persistent disability/incapacity; Is a congenital anomaly/birth defect; Important medical events	From Baseline (Week 0) to End of Safety Follow-up (up to 141 weeks)
Incidence of TEAEs leading to discontinuation of investigational medicinal product (IMP)	An AE is any untoward medical occurrence in a patient or clinical study participant, temporally associated with the use of IMP, whether or not considered related to the IMP.	From Baseline (Week 0) to End of Safety Follow-up (up to 141 weeks)
Incidence of TEAEs leading to withdrawal from the study	An AE is any untoward medical occurrence in a patient or clinical study participant, temporally associated with the use of IMP, whether or not considered related to the IMP.	From Baseline (Week 0) to End of Safety Follow-up (up to 141 weeks)
Incidence of selected safety events of interest (including infection [serious, opportunistic, fungal, and tuberculosis (TB)], inflammatory bowel disease [IBD], and injection site reactions)	Safety topics of interest are infections (serious, opportunistic, fungal, and tuberculosis), inflammatory bowel disease, and injection site reactions.	From Baseline (Week 0) to End of Safety Follow-up (up to 141 weeks)
Change from Baseline in vital signs (systolic and diastolic blood pressure) at Week 16	Blood pressure will be measured in millimeters of mercury (mmHg).	Baseline and Week 16
Change from Baseline in vital signs (heart rate) at Week 16	Heart rate will be measured in beats per minute (beats/min).	Baseline and Week 16
Change from Baseline in biochemistry parameters (alkaline phosphatase, alanine aminotransferase, aspartate aminotransferase, gamma-glutamyltransferase) at Week 16	Alkaline phosphatase, alanine aminotransferase, aspartate aminotransferase and gamma-glutamyltransferase will be measured in units per liter (U/L).	Baseline and Week 16
Change from Baseline in biochemistry parameters (glucose, potassium, sodium, calcium) at Week 16	Glucose, potassium, sodium and calcium will be measured in millimoles per liter (mmol/L).	Baseline and Week 16
Change from Baseline in biochemistry parameters (total bilirubin and direct bilirubin, total protein, blood urea nitrogen, and creatinine) at Week 16	Biochemistry parameters will be measured in micromols per liter (μmol/L).	Baseline and Week 16
Change from Baseline in hematology parameters (hemoglobin) at Week 16	Hemoglobin will be measured in grams per liter (g/L).	Baseline and Week 16
Change from Baseline in hematology parameters (hematocrit) at Week 16	Hematocrit will be measured in volume percentage (%) of red blood cells in blood.	Baseline and Week 16
Change from Baseline in hematology parameters (erythrocytes) at Week 16	Erythrocytes will be measured in number of red blood cells per liter (10^12/L).	Baseline and Week 16
Change from Baseline in hematology parameters (platelets, leukocytes neutrophils, lymphocytes, eosinophils, basophils, and monocytes) at Week 16	Platelets, leukocytes, neutrophils, lymphocytes, eosinophils, basophils, and monocytes will be measured in number of white blood cells per liter (10^9/L).	Baseline and Week 16
Change from Baseline in growth assessments (height) at Week 16	Growth assessment, as assessed by the change from Baseline in height will be measured in centimeters (cm).	Baseline and Week 16
Change from Baseline in growth assessments (weight) at Week 16	Growth assessment, as assessed by the change from Baseline in weight will be measured in kilograms (kg).	Baseline and Week 16
Acceptability assessments by injection site pain adverse events (AEs) during the Initial Treatment Period (Week 0 to Week 16)	Incidence rate of injection site pain AEs during the ITP will be reported.	Week 0 to Week 16
American College of Rheumatology pediatric (ACR Pedi) 30/50/70/90/100 response at Week 16	ACR assessments are based on a 30%, 50%, 70%, 90%, 100% or greater improvement (for ACR Pedi 30/50/70/90/100 respectively) in at least 3 of the 6 core set measures with no more than 1 of the remaining worsened by >30%. The 6 core set measures are: Number of joints with active arthritis (joints with swelling not due to deformity or inactive synovitis, or joints with limitation of motion with pain, tenderness, or both); Number of joints with limitation of range of motion; Physician's Global Assessment of Disease Activity; CHAQ total score (Disability Index) completed by parent or caregiver; Parent/caregiver global assessment of overall well being of study participant; Acute phase reactant (hs-CRP)	Week 16
Change from Baseline in Juvenile Arthritis Disease Activity Score (JADAS27) -high sensitivity C-reactive protein (hs-CRP) at Week 16	The JADAS27-hs-CRP is a composite disease activity score based on 4 core measures: Number of joints with active arthritis; Physician's Global Assessment of Disease Activity; Parent/caregiver global assessment of overall well being of study participant; Acute phase reactant (hs-CRP); inflammation biomarker. The JADAS27-hs-CRP is calculated as the sum of the scores of the 4 components with a total score range of 0 to 57.	Baseline and Week 16
Anti-bimekizumab antibody and neutralizing antibody detection prior to and following IMP administration during the Initial Treatment Period	Anti-bimekizumab antibody and neutralizing antibody detection prior to and following IMP administration during the Initial Treatment Period.	Up to Week 16

Collaborators and Investigators

• Sponsor: UCB Biopharma SRL
• Investigators: Study Director: UCB Cares, 001 844 599 2273

Study record dates

Study Major Dates

• Study Start (Actual): March 11, 2025
• Primary Completion (Estimated): April 12, 2028
• Study Completion (Estimated): July 31, 2030

Study Registration Dates

• First Submitted: October 30, 2024
• First Submitted That Met QC Criteria: October 30, 2024
• First Posted (Actual): October 31, 2024

Study Record Updates

• Last Update Posted (Actual): July 17, 2026
• Last Update Submitted That Met QC Criteria: July 16, 2026
• Last Verified: July 1, 2026

More Information

Terms related to this study

• Keywords: Arthritis; Bimekizumab
• Additional Relevant MeSH Terms: Musculoskeletal Diseases; Joint Diseases; Rheumatic Diseases; Connective Tissue Diseases; Autoimmune Diseases; Immune System Diseases; Skin and Connective Tissue Diseases; Arthritis; Arthritis, Juvenile; bimekizumab
• Other Study ID Numbers: JA0005; U1111-1305-2292 (Other Identifier: World Health Organization (WHO)); 2023-508845-41 (Registry Identifier: EU Clinical Trials)

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: YES
• IPD Plan Description: Data from this trial may be requested by qualified researchers six months after product approval in the US and/or Europe, or global development is discontinued, and 18 months after trial completion. Investigators may request access to anonymized individual patient-level data and redacted trial documents which may include: analysis-ready datasets, study protocol, annotated case report form, statistical analysis plan, dataset specifications, and clinical study report. Prior to use of the data, proposals need to be approved by an independent review panel at www.Vivli.org and a signed data sharing agreement will need to be executed. All documents are available in English only, for a prespecified time, typically 12 months, on a password protected portal. This plan may change if the risk of re-identifying trial participants is determined to be too high after the trial is completed; in this case and to protect participants, individual patient-level data would not be made available.
• IPD Sharing Time Frame: Data from this trial may be requested by qualified researchers six months after product approval in the US and/or Europe or global development is discontinued, and 18 months after trial completion.
• IPD Sharing Access Criteria: Qualified researchers may request access to anonymized IPD and redacted study documents which may include: raw datasets, analysis-ready datasets, study protocol, blank case report form, annotated case report form, statistical analysis plan, dataset specifications, and clinical study report. Prior to use of the data, proposals need to be approved by an independent review panel at www.Vivli.org and a signed data sharing agreement will need to be executed. All documents are available in English only, for a pre-specified time, typically 12 months, on a password protected portal.
• IPD Sharing Supporting Information Type: STUDY_PROTOCOL; SAP; CSR

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: Yes
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: Yes