NCT05835310 · AstraZeneca
An Efficacy and Safety Study of Intravenous Anifrolumab to Treat Systemic Lupus Erythematosus in Pediatric Participants
(BLOSSOM)
What this study is about
A Study to evaluate the PK, PD, effectiveness, and safety of Anifrolumab in children with moderate to severe active SLE
View original scientific description
A Study to evaluate the PK, PD, efficacy, and safety of Anifrolumab in children with moderate to severe active SLE
Interventions
BIOLOGICAL
Anifrolumab
Participants will receive anifrolumab via IV infusion.
DRUG
Placebo
Participants will receive matching placebo via IV infusion
Primary outcome measures
Part A- Anifrolumab serum concentration
Time frame: Pre-dose Day 29
The serum concentration will be characterised and the dose of anifrolumab will be defined in pediatric participants with moderate to severely active SLE.
Part A - Maximum observed serum (peak) drug concentration (Cmax)
Time frame: Up to Day 29
The serum PK will be characterised and the dose of anifrolumab will be defined in pediatric participants with moderate to severely active SLE.
Part A - Area under the serum concentration curve (AUC)
Time frame: Up to Day 29
The serum PK will be characterised and the dose of anifrolumab will be defined in pediatric participants with moderate to severe active SLE.
Part A - Minimum observed serum concentration (Cmin)
Time frame: Up to Day 29
The serum PK will be characterised and the dose of anifrolumab will be defined in pediatric participants with moderate to severe active SLE.
Part B - Number of participants who are British Isles Lupus Assessment Group-based Composite Lupus Assessment (BICLA) responders (yes/no)
Time frame: At Week 52
BICLA response is defined as: * Reduction of all baseline British Isles Lupus Assessment Group BILAG-2004 A to B/C/D and B to C/D, and no BILAG-2004 worsening in other organ systems, as defined by ≥ 1 new BILAG-2004 A or ≥ 2 new BILAG- 2004 B. * No worsening from baseline in Systemic Lupus Erythematosus Disease Activity Index 2000 (SLEDAI-2K), defined as an increase from baseline of \> 0 points. * No worsening from baseline in participant's lupus disease activity, defined by an increase ≥ 0.30 points on a Physician's Global Assessment (PGA) 3-point visual analogue scale (VAS).
Who can participate
This study lists these criteria on ClinicalTrials.gov. A study coordinator reviews eligibility during screening — this page does not determine whether you qualify.
Inclusion criteria
- Participant's parent/caregiver/legally authorized representative and participant (if required per local country regulation) capable of giving signed informed consent, which includes compliance with the requirements and restrictions listed in the ICF and in this protocol. Informed assent is to be provided by the participant per local country regulation.
- Diagnosis of SLE according to the 2019 European League Against Rheumatism/American College of Rheumatology (EULAR/ACR) criteria for at least 3 months prior to signing the ICF.
- At Screening, participant must have moderate to severe active SLE disease, as adjudicated by the Central Adjudication Committee, defined as: (a) SLEDAI-2K activity of: (i) ≥ 6 points with at least 4 points (≥ 4 points) coming from the following clinical components ('Clinical' SLEDAI-2K score): arthritis, myositis, rash, alopecia, mucosal ulcers, pleurisy, pericarditis, or vasculitis and excluding points attributed to a fever, SLE headache, and organic brain syndrome (ii) Clinical SLEDAI score of ≥ 4 points verified at Day 1 (b) BILAG-2004 activity of: (i) ≥ 1 BILAG A score; or (ii) ≥ 2 BILAG B scores (c) PGA score ≥ 1.0 on a 0 to 3 VAS
- Participant should meet all of following tuberculosis (TB) criteria: A. No signs or symptoms of active TB B. No medical history or past physical examinations suggestive of active TB C. No recent contact with a person with active TB or if there has been such contact, referral to a TB specialist for evaluation and initiation of treatment for latent TB, if warranted, prior to the first administration of study intervention in accordance with local SoC D. No history of latent TB without documented completion of treatment prior to initial screening visit
- Female participants of childbearing potential must have a negative serum pregnancy test at screening and negative urine pregnancy test at randomization.
- Female participants of childbearing and male participants must adhere to the contraception methods.
Exclusion criteria
- Known diagnosis of an IFN-mediated autoinflammatory interferonopathy.
- History of, or current diagnosis of, clinically significant non-SLE-related vasculitides.
- In participants aged 11 years and above: history or evidence of suicidal ideation.
- History of any non-SLE disease that has required treatment with oral or parenteral corticosteroids for more than a total of 2 weeks within the last 24 weeks prior to signing the ICF.
- Any positive result on screening for human immunodeficiency virus.
- Active hepatitis B surface antigen OR hepatitis B core antibody (HBcAb), hepatitis C virus (HCV) antibody and detectable HCV ribonucleic acid (RNA) or any active or recent case of Herpes Zoster infection.
- Any clinical cytomegalovirus or Epstein-Barr virus infection that has not completely resolved within 12 weeks prior to signing the ICF.
- History of severe COVID-19 infection requiring hospitalization, intensive care unit care, or assisted ventilation or any prior COVID-19 infection with unresolved sequelae. Any mild/asymptomatic COVID-19 infection (laboratory confirmed or suspected based on clinical symptoms).
- Prior use of anifrolumab.
- Prior treatment with directly acting cytotoxic B-cell depleting therapeutics (eg, rituximab) \< 26 weeks prior to ICF signature.
- Blood transfusion or receipt of blood products except albumin within 4 weeks prior to signing the ICF.
Where
- Phoenix, Arizona
- Los Angeles, California
- Washington D.C., District of Columbia
- Chicago, Illinois
- New Orleans, Louisiana
- Bethesda, Maryland
- Saint Paul, Minnesota
- New Hyde Park, New York
- New York, New York
- The Bronx, New York
- Valhalla, New York
- Durham, North Carolina
And 9 more locations — see the full list below.
Related conditions & keywords
Frequently asked questions
What is a clinical trial?
A clinical trial is a research study that tests new medical treatments, drugs, devices, or procedures to determine their safety and effectiveness. Trials are carefully designed and monitored to protect participants while advancing medical knowledge.
Is it safe to participate?
Clinical trials follow strict safety guidelines and ethical standards. Trials must be reviewed and approved, and participants are closely monitored by medical professionals throughout the study. You can withdraw at any time if you choose.
Will I be compensated?
Many clinical trials offer compensation for your time, travel expenses, and inconvenience. The specific compensation varies by study and will be discussed during the screening process. All study-related medical care is typically provided at no cost to participants.
Will I receive a placebo instead of treatment?
When effective treatment exists, participants typically receive either the standard treatment plus the study intervention, or the standard treatment plus placebo. You would not be denied effective care. Placebos are primarily used when no proven treatment is available, or in addition to standard care. Your trial consent form will clearly explain what treatments you may receive.
Can I leave a trial if I change my mind?
Absolutely. Participation in clinical trials is completely voluntary. You have the right to withdraw from the study at any time, for any reason, without penalty or loss of benefits to which you are otherwise entitled.
How long does a clinical trial last?
Trial duration varies widely depending on the study design and purpose. Some trials last just a few weeks, while others may continue for months or years. The study coordinator will provide specific timeline information during your screening call.
Data: ClinicalTrials.gov · synced Sep 30, 2026 · Source of record for eligibility and locations