Pediatric Lupus Trial of Belimumab Plus Background Standard Therapy (PLUTO)

A Multi-center, Randomized, Placebo-Controlled Trial to Evaluate the Safety, Efficacy, and Pharmacokinetics of Belimumab, a Human Monoclonal Anti-BLyS Antibody, Plus Standard Therapy in Pediatric Patients With Systemic Lupus Erythematosus

This is a multi-center study to evaluate the safety, pharmacokinetics, and efficacy of belimumab intravenous (IV) in pediatric patients 5 to 17 years of age with active systemic lupus erythematosus

Study Overview

• Status: Completed
• Conditions: Systemic Lupus Erythematosus
• Intervention / Treatment: Other: Placebo; Drug: Belimumab 10 mg/kg

Detailed Description

This is a multi-center study to evaluate the safety, pharmacokinetics, and efficacy of belimumab intravenous (IV) in pediatric patients 5 to 17 years of age with active systemic lupus erythematosus (SELENA SLEDAI score ≥ 6). The study will consist of three phases: a 52-week randomized, placebo-controlled, double-blind phase; a long term open label continuation phase; and a long term safety follow up phase. The long term open label continuation and safety follow up periods will continue for at least 5 years and possibly up to 10 years from a subject's initial treatment with belimumab. Enrolment will be staggered by age cohorts to allow safety and PK interim analyses. Subjects will be randomized to belimumab 10mg/kg or placebo IV monthly dosing while continuing to receive background standard therapy throughout the study. An independent data monitoring committee (IDMC) will monitor the study as it progresses.

• Study Type: Interventional
• Enrollment (Actual): 93
• Phase: Phase 2

Expanded Access

No longer available outside the clinical trial. See expanded access record.

Contacts and Locations

Study Locations

• Argentina
  • Buenos Aires, Argentina, C1270AAN
    • GSK Investigational Site
  • Rosario, Argentina, 2000
    • GSK Investigational Site
  • Santa Fe, Argentina, 5400
    • GSK Investigational Site
• Canada
  • Alberta
    • Calgary, Alberta, Canada, T3B 6A8
      • GSK Investigational Site
  • Ontario
    • Toronto, Ontario, Canada, M5G 1X8
      • GSK Investigational Site
• Japan
  • Aichi, Japan, 474-8710
    • GSK Investigational Site
  • Kagoshima, Japan, 890-8520
    • GSK Investigational Site
  • Miyagi, Japan, 989-3126
    • GSK Investigational Site
  • Tokyo, Japan, 113-8519
    • GSK Investigational Site
• Mexico
  • San Luis Potosí City, Mexico, 78240
    • GSK Investigational Site
• Peru
  • Lima, Peru, Lima 27
    • GSK Investigational Site
  • Lima, Peru, Lima 5
    • GSK Investigational Site
  • Surco, Peru, Lima 33
    • GSK Investigational Site
• Poland
  • Lodz, Poland, 91-738
    • GSK Investigational Site
  • Warsaw, Poland, 02-637
    • GSK Investigational Site
• Russia
  • Moscow, Russia, 119435
    • GSK Investigational Site
  • Saint Petersburg, Russia, 194100
    • GSK Investigational Site
  • Tolyatti, Russia, 445846
    • GSK Investigational Site
• Spain
  • Espluges de Llobregat, Spain, 08950
    • GSK Investigational Site
  • Madrid, Spain, 28034
    • GSK Investigational Site
  • Valencia, Spain, 46026
    • GSK Investigational Site
• United Kingdom
  • Bristol, United Kingdom, BS2 8BJ
    • GSK Investigational Site
  • Liverpool, United Kingdom, L12 2AP
    • GSK Investigational Site
  • London, United Kingdom, NW1 2PG
    • GSK Investigational Site
  • London, United Kingdom, WC1N 3JH
    • GSK Investigational Site
• United States
  • Arizona
    • Phoenix, Arizona, United States, 85016
      • GSK Investigational Site
  • District of Columbia
    • Washington D.C., District of Columbia, United States, 20010
      • GSK Investigational Site
  • Georgia
    • Augusta, Georgia, United States, 30912
      • GSK Investigational Site
  • Missouri
    • St Louis, Missouri, United States, 63104
      • GSK Investigational Site
  • New York
    • New York, New York, United States, 10032
      • GSK Investigational Site
    • The Bronx, New York, United States, 10467
      • GSK Investigational Site
  • Ohio
    • Cincinnati, Ohio, United States, 45229
      • GSK Investigational Site

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 5 years to 17 years (Child)
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• 5 years to 17 years of age at enrollment
• Have a clinical diagnosis of SLE according to the American College of Rheumatology (ACR) classification criteria.
• Have active SLE disease (SELENA SLEDAI score ≥ 6).
• Have positive anti-nuclear antibody (ANA) test results.
• Are on a stable SLE treatment regimen at a fixed dose for a period of at least 30 days prior to Day 0.
• Females of childbearing age are willing to use appropriate contraception
• Subject age appropriate assent and parent or legal guardian informed consent to participate

Exclusion Criteria:

• Pregnant or nursing.
• Have received treatment with belimumab (BENLYSTA®) at any time. (BENLYSTA® is a registered trademark of the GSK group of companies.)
• Treatment with any B cell targeted therapy (for example, rituximab) or an investigational biological agent in the past year.
• Have received anti-TNF therapy; Interleukin-1 receptor antagonist; IVIG; or plasmapheresis within 90 days of Day 0.
• Have received high dose prednisone or equivalent (>1.5mg/kg/day) within 60 days of baseline.
• Have received intravenous (IV) cyclophosphamide within 60 days of Day 0.
• Have received any new immunosuppressive/immunomodulatory agent, anti-malarial agent within 60 days of baseline.
• Have severe lupus kidney disease.
• Have active central nervous system (CNS) lupus.
• Have had a major organ transplant.
• Have significant unstable or uncontrolled acute or chronic diseases or conditions not due to SLE.
• Have a planned surgical procedure.
• History of malignant neoplasm within the last 5 years.
• Have required management of acute or chronic infections in the past 60 days.
• Have current drug or alcohol abuse or dependence.
• Have a historically positive test, or test positive at screening for HIV, Hepatitis B, or Hepatitis C.
• Have an IgA deficiency.
• Have severe laboratory abnormalities.
• Have had anaphylactic reaction to X-ray contrast agents or biologic agents.
• Suicidal behavior or ideation.
• Children in Care(CiC): a child who has been placed under the control or protection of an agency, organisation, institution or entity by the courts, the government or a government body, acting in accordance with powers conferred on them by law or regulation.

Study Plan

How is the study designed?

Design Details

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

Number of Arms

4

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Placebo Comparator: Part A: Placebo; Participants received saline infusion (placebo) intravenously monthly for 48 weeks on a background of standard of care.	Other: Placebo; Placebo was administered; Other Names: Normal Saline
Experimental: Part A: Belimumab 10 mg/kg; Participants received 10 milligrams per kilograms (mg/kg) reconstituted solution intravenously monthly for 48 weeks on a background of standard of care.	Drug: Belimumab 10 mg/kg; Belimumab was administered.
Experimental: Part B: Open-Label Belimumab; Participants who entered Part B after completing 48 weeks of belimumab or placebo on a background of standard of care and the Week 52 assessments in Part A, received 10 mg/kg belimumab intravenously monthly up to 10 years from the first administration of belimumab.	Drug: Belimumab 10 mg/kg; Belimumab was administered.
No Intervention: Part C: Safety Follow-up Phase; Participants who entered Part C after discontinuing study intervention in Part A or Part B were included in this arm.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Percentage of Participants With SLE Responder Index (SRI) Response at Week 52	SRI response is defined as >=4 point reduction, from Baseline in safety of estrogen in lupus national assessment (SELENA) systemic lupus erythematosus disease activity index (SLEDAI) score, no worsening (increase of <0.30 points from Baseline) in physician's global assessment (PGA) and no new British Isles Lupus Assessment Group of SLE clinics (BILAG) A organ domain score or 2 new BILAG B organ domain scores compared with Baseline. Analysis was performed using a logistic regression model for the comparison between belimumab and placebo with covariates treatment group, Baseline SELENA SLEDAI score (<=12 vs. >=13). Percentage of participants with SRI response at Week 52 of Part A were reported. Intent-to-Treat Population comprised of all participants who were randomized and treated with at least one dose of study agent in Part A. One participant had missing data at Baseline and therefore, could not be included in the analysis.	Week 52

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Percentage of Participants Meeting Pediatric Rheumatology International Trials Organization (PRINTO)/ American College of Rheumatology (ACR) Juvenile SLE Response Evaluation Criteria for Improvement in Juvenile SLE at Week 52 Using Definition 1 and 2	Percentage of participants meeting PRINTO/ACR Juvenile SLE Response Evaluation criteria for improvement in juvenile SLE using two different PRINTO/ACR Juvenile SLE Response Evaluation definitions of improvement that is Definition 1: At least 50% improvement in any 2 of 5 endpoints below and no more than 1 of the remaining worsening by more than 30% and Definition 2: At least 30% improvement in 3 of 5 endpoints below and no more than 1 of the remaining worsening more than 30%. Endpoints were: 1. Percent change in Parent's Global Assessment (ParentGA) at Week 52, 2. Percent change in PGA at Week 52, 3. Percent change in SELENA SLEDAI score at Week 52, 4. Percent change in Pediatric Quality of Life Inventory (PedsQL) physical functioning domain at Week 52, 5. Percent change in 24 hour proteinuria at Week 52 (gram/24hour equivalent by spot urine protein to creatinine ratio).	Week 52
Percent Change From Baseline in ParentGA at Week 52	ParentGA assesses the participant's overall well-being at the moment rated on a 21-numbered circle visual analog scale (VAS; 0 - very well, 10 - very poorly). Baseline was defined as measurements at Day 0. Percent change from Baseline was calculated by subtracting the Baseline value from value at Week 52 divided by the Baseline value X 100. Last Observation Carried Forward (LOCF) was used. Eight participants had a score of zero at Baseline and therefore, could not be included in the analysis.	Baseline (Day 0) and Week 52
Percent Change From Baseline in PGA at Week 52	The PGA is a 10 centimeter (cm) visual analogue scale (VAS), anchored at 0 (none) and 3 (severe), designed for the physician to indicate the participant's overall disease activity at a particular visit as part of the validated SELENA SLEDAI index. Primary investigator or a subinvestigator scored the PGA for the participant, and same person evaluated the participant each time. Baseline was defined as measurements at Day 0. Percent change from Baseline was calculated by subtracting the Baseline value from value at Week 52 divided by the Baseline value X 100. LOCF was used.	Baseline (Day 0) and Week 52
Percent Change From Baseline in SELENA SLEDAI at Week 52	The SELENA SLEDAI score is a weighted index for assessing SLE disease activity in which signs and symptoms, laboratory tests and physician's assessment for each of 9 organ system were given a weighted score and summed if present at the time of the visit or in the preceding 10 days. A SELENA SLEDAI score of 0 would suggest no lupus activity; while a score of 105 is the maximum calculable if all items were scored as being present from active lupus. A decrease of 4 points or more equates to a clinically meaningful improvement. Baseline was defined as measurements at Day 0. Percent change from Baseline was calculated by subtracting the Baseline value from value at Week 52 divided by the Baseline value X 100. One participant had missing data at Baseline and therefore, could not be included in the analysis.	Baseline (Day 0) and Week 52
Percent Change From Baseline in PedsQL Physical Functioning Domain Score at Week 52	The PedsQL is a generic quality of life scale validated for the pediatric population which consists of 23 items, encompassing 4 health domains: Physical Functioning (8 items), Emotional Functioning (5 items), Social Functioning (5 items), and School Functioning (5 items). From the raw scores of the 23 items, a total summary score and individual domain scores can be calculated. The total and domain scores are each transformed on a 0 to 100 score with higher scores indicating higher quality of life. For Physical Functioning Domain scale, score was from 0 to 100 where, 0 indicates lower quality of life and 100 indicates greater quality of life. Baseline was defined as measurements at Day 0. Percent change from Baseline was calculated by subtracting the Baseline value from value at Week 52 divided by the Baseline Value X 100. LOCF was used.	Baseline (Day 0) and Week 52
Percent Change From Baseline in Proteinuria at Week 52	Percent change from Baseline in proteinuria was calculated. The percent change from baseline to Week 52 in 24 hour proteinuria was analyzed using summary statistics and 95% confidence intervals, without any adjustment for covariates. Baseline was defined as measurements at Day 0. Percent change from Baseline was calculated by subtracting the Baseline value from value at Week 52 divided by the Baseline Value X 100. LOCF was used.	Baseline (Day 0) and Week 52
Percentage of Participants With a Sustained SRI Response	Sustained SRI response was defined as having a response on the primary efficacy endpoint at Weeks 44, 48, and 52. Data for percentage of participants with a sustained SRI response was presented. Drop Outs and Treatment Failures were considered Non-Responders. Only those participants with data available at specific time point were analyzed.	Up to 52 weeks
Percentage of Participants With a Sustained ParentGA Response	Sustained ParentGA response was defined as having >0.7 improvement at Weeks 44, 48, and 52 compared at Baseline. Data for percentage of participants with a sustained ParentGA response was presented. Thirteen participants had a score of <=0.7 at Baseline and therefore, could not be included in the analysis.	Up to 52 weeks
Number of Participants With Adverse Events (AEs) and Serious Adverse Events (SAEs)	An AE is any untoward medical occurrence in a clinical investigation participant, temporarily associated with the use of a medicinal product, whether or not considered related to the medicinal product. Any untoward event resulting in death, life threatening, requires hospitalization or prolongation of existing hospitalization, results in disability/incapacity, congenital anomaly/birth defect, any other situation according to medical or scientific judgment or all events of possible drug-induced liver injury with hyperbilirubinemia were categorized as SAE. Number of participants with AEs and SAEs have been reported.	Up to 60 weeks
Maximum Concentration at Steady State (Cmax, ss) and Minimum Concentration at Steady State (Cmin, ss)	The pharmacokinetic (PK) population comprised all participants included in the As- Treated population for whom at least one post belimumab treatment PK sample was obtained and analyzed. The PK model was fitted to the observed serum concentration-time data. The maximum (Cmax) and minimum (Cmin) concentrations reported in this table are model derived values at ss, assuming a 10 mg/kg dose administered once every 28 days.	28-days dosing interval at steady state
Area Under Curve of Belimumab at Steady State (AUC, ss)	The PK model was fitted to the observed serum concentration-time data. The AUC values reported in this table are model derived values at ss, assuming a 10 mg/kg dose administered once every 28 days.	28-days dosing interval at steady state

Collaborators and Investigators

• Sponsor: GlaxoSmithKline
• Collaborators: Human Genome Sciences Inc., a GSK Company
• Investigators: Study Director: GSK Clinical Trials, GlaxoSmithKline

Publications and helpful links

General Publications

• Hannon CW, McCourt C, Lima HC, Chen S, Bennett C. Interventions for cutaneous disease in systemic lupus erythematosus. Cochrane Database Syst Rev. 2021 Mar 9;3(3):CD007478. doi: 10.1002/14651858.CD007478.pub2.
• Brunner HI, Abud-Mendoza C, Viola DO, Calvo Penades I, Levy D, Anton J, Calderon JE, Chasnyk VG, Ferrandiz MA, Keltsev V, Paz Gastanaga ME, Shishov M, Boteanu AL, Henrickson M, Bass D, Clark K, Hammer A, Ji BN, Nino A, Roth DA, Struemper H, Wang ML, Martini A, Lovell D, Ruperto N; Paediatric Rheumatology International Trials Organisation (PRINTO) and the Pediatric Rheumatology Collaborative Study Group (PRCSG). Safety and efficacy of intravenous belimumab in children with systemic lupus erythematosus: results from a randomised, placebo-controlled trial. Ann Rheum Dis. 2020 Oct;79(10):1340-1348. doi: 10.1136/annrheumdis-2020-217101. Epub 2020 Jul 22.
• Brunner HI, Abud-Mendoza C, Mori M, Pilkington CA, Syed R, Takei S, Viola DO, Furie RA, Navarra S, Zhang F, Bass DL, Eriksson G, Hammer AE, Ji BN, Okily M, Roth DA, Quasny H, Ruperto N. Efficacy and safety of belimumab in paediatric and adult patients with systemic lupus erythematosus: an across-study comparison. RMD Open. 2021 Sep;7(3):e001747. doi: 10.1136/rmdopen-2021-001747.
• Zhou X, Lee TI, Zhu M, Ma P. Prediction of Belimumab Pharmacokinetics in Chinese Pediatric Patients with Systemic Lupus Erythematosus. Drugs R D. 2021 Dec;21(4):407-417. doi: 10.1007/s40268-021-00363-2. Epub 2021 Oct 9.
• Arends EJ, Zlei M, Tipton CM, Cotic J, Osmani Z, de Bie FJ, Kamerling SWA, van Maurik A, Dimelow R, Gregan YI, Fox NL, Rabelink TJ, Roth DA, Sanz I, van Dongen JJM, van Kooten C, Teng YKO. Disruption of memory B-cell trafficking by belimumab in patients with systemic lupus erythematosus. Rheumatology (Oxford). 2024 Sep 1;63(9):2387-2398. doi: 10.1093/rheumatology/keae286.

Study record dates

Study Major Dates

• Study Start (Actual): September 7, 2012
• Primary Completion (Actual): January 24, 2018
• Study Completion (Actual): September 30, 2025

Study Registration Dates

• First Submitted: July 23, 2012
• First Submitted That Met QC Criteria: July 23, 2012
• First Posted (Estimated): July 25, 2012

Study Record Updates

• Last Update Posted (Actual): April 20, 2026
• Last Update Submitted That Met QC Criteria: March 26, 2026
• Last Verified: March 1, 2026

More Information

Terms related to this study

• Keywords: Lupus; safety; Pharmacokinetics; placebo; efficacy; SRI; belimumab; Systemic Lupus Erythematosus (SLE); PGA; BLyS; SLE Flare Index; BILAG; B lymphocyte; SELENA SLEDAI; PRINTO
• Additional Relevant MeSH Terms: Connective Tissue Diseases; Autoimmune Diseases; Immune System Diseases; Skin and Connective Tissue Diseases; Lupus Erythematosus, Systemic; Pharmaceutical Preparations; Crystalloid Solutions; Isotonic Solutions; Solutions; Saline Solution; belimumab
• Other Study ID Numbers: 114055; 2011-000368-88 (EudraCT Number); 2024-512730-15-00 (Ctis)

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: YES
• IPD Plan Description: Study Sponsor will assess requests from qualified researchers for anonymized individual patient-level data and related study documents. Data sharing is subject to certain criteria, conditions, and exceptions. For further information, refer to https://d3l8i7lo48obsd.cloudfront.net/gsk-patient-level-data-sharing-july2025-1-Bgwa1UthxvluYbWYTThw.pdf
• IPD Sharing Time Frame: Anonymized IPD will be made available within 6 months of publication of primary, key secondary and safety results for studies in product with approved indication(s) or asset(s) with development terminated across all indications.
• IPD Sharing Access Criteria: Anonymized IPD is shared with researchers whose proposals are approved by an Independent Review Panel and after a Data Sharing Agreement is in place. Access is provided for an initial period of 12 months, but an extension may be granted, when justified, for up to 6 months.
• IPD Sharing Supporting Information Type: STUDY_PROTOCOL; SAP; ICF; CSR