Mapping B-cell Biology Across the Cardiovascular Territories of Giant Cell Arteritis: Towards a New Therapeutic Approach (RituxiMAP GCA)

NCT07269938 | Not Yet Recruiting

• 1 other identifier: AC25173
• Study Type: observational
• Target: 30
• Locations: 1 country
• Sites: 1

Brief Summary

B cells are a component of the immune system which appear be important in causing all forms of cardiovascular disease. Until now, it has not been possible to directly study these cells in living patients (essential to assess their potential as the target of new treatments). For the first time in any cardiovascular disease, this study will apply cutting edge scanning technology to visualise B cells in the blood vessels of giant cell arteritis (GCA) patients. GCA is a common and potentially deadly disorder of the blood vessels which is caused by abnormalities of the immune system. Current treatments are mainly limited to steroids. Unfortunately, these drugs bring tremendous side effects and so there is an urgent requirement to discover alternatives. Laboratory investigations tell us that B cells are highly present in GCA and so if the proposed scanning technology fails to identify these cells in the blood vessels of participants, then the technology is unlikely to be useful for other cardiovascular diseases. If, however, the study does successfully visualise B cells, this knowledge could pave the way for clinical trials of B cell targeted treatments (already established in other conditions) as steroid alternatives in GCA. This study aims to map the distribution of the radiotracer zirconium-89 labelled rituximab within the blood vessels of patients with newly diagnosed GCA and compare this with two separate control groups without the condition. This will allow us to determine the role of B cells within this condition, and whether patients would benefit from B cell-depleting treatments such as rituximab.

Conditions

Giant Cell Arteritis (GCA)

Keywords

Giant cell arteritis; Vasculitis; Rituximab; PET scanning

Outcome Measures

Primary Outcomes (1)

• Quantification of vascular 89Zr-RTX uptake

  Quantification of vascular 89Zr-RTX uptake compared between: A) those with LV-GCA before and after treatment with steroids B) those with LV-GCA and a control group

  0-4 months

Secondary Outcomes (2)

• Correlation between vascular 89Zr-RTX uptake and peripheral blood B cell populations

  0-4 months

• Correlation between vascular 89Zr-RTX uptake and temporal artery B cell populations

  0-4 months

Study Arms (3)

LV-GCA group

Patients with a diagnosis of active, large vessel GCA

Diagnostic Test: Zirconium Zr 89 labelled rituximab

AA control group

Patients with a diagnosis of atherosclerotic aortic aneurysm

Diagnostic Test: Zirconium Zr 89 labelled rituximab

BCMID control group

Patients with a diagnosis of a B-cell mediated inflammatory disorder

Diagnostic Test: Zirconium Zr 89 labelled rituximab

Interventions

Zirconium Zr 89 labelled rituximab DIAGNOSTIC_TEST

All participants will receive a PET scan with zirconium Zr-89 labelled rituximab. Those in the LV-GCA group will receive a follow-up scan after a period of treatment.

AA control group; BCMID control group; LV-GCA group

Eligibility Criteria

• Age: 50 Years+
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64), Older Adult (65+)
• Sampling Method: Non-Probability Sample

Study Population

For GCA group: 1. Adults ≥ 50 years at the time of enrolment 2. Meets 2022 American College of Rheumatology/EULAR classification criteria for giant cell arteritis 3. Imaging evidence of active LV-GCA in the previous 4 weeks 4. Will be managed with corticosteroid monotherapy by the standard care team. For BCMID group: 1. Adults ≥ 18 years at the time of enrolment 2. Meets criteria for a diagnosis of a B-cell mediated immune disorder 3. Considered to have active disease by referring team 4. Will be managed as per standard of care by referring team For AA group: 1. Adults ≥ 50 years at the time of enrolment 2. Imaging evidence of atherosclerotic aortic aneurysm

You may qualify if:

• For GCA group:
• Adults ≥ 50 years at the time of enrolment
• Meets 2022 American College of Rheumatology/EULAR classification criteria for giant cell arteritis
• Imaging evidence of active LV-GCA in the previous 4 weeks
• Will be managed with corticosteroid monotherapy by the standard care team.
• For BCMID group:
• Adults ≥ 18 years at the time of enrolment
• Meets criteria for a diagnosis of a B-cell mediated immune disorder
• Considered to have active disease by referring team
• Will be managed as per standard of care by referring team
• For AA group:
• Adults ≥ 50 years at the time of enrolment
• Imaging evidence of atherosclerotic aortic aneurysm

You may not qualify if:

• Participants receiving corticosteroids for \>4 weeks immediately prior to baseline
• Previous diagnosis of GCA
• History of any major morbidity which the clinical investigator considers contraindicated to study entry
• Pregnancy or breastfeeding
• Advanced renal dysfunction (eGFR \<15ml/min/1.73m2)
• Patients without mental capacity or willingness to provide informed consent
• Inability or unwillingness to comply with the radiation protection advice

Sponsors & Collaborators

• University of Edinburgh: lead

Study Sites (1)

University of Edinburgh

Edinburgh, City of Edinburgh, EH16 4TJ, United Kingdom

Location

Biospecimen

Retention: SAMPLES WITH DNA

Blood and urine

MeSH Terms

Conditions

Giant Cell Arteritis; Vasculitis

Condition Hierarchy (Ancestors)

Vasculitis, Central Nervous System; Autoimmune Diseases of the Nervous System; Nervous System Diseases; Cerebrovascular Disorders; Brain Diseases; Central Nervous System Diseases; Vascular Diseases; Cardiovascular Diseases; Arteritis; Skin Diseases, Vascular; Skin Diseases; Skin and Connective Tissue Diseases; Autoimmune Diseases; Immune System Diseases

Central Study Contacts

Neeraj Dhaun, MBChB PhD

CONTACT

+441312426777; bean.dhaun@ed.ac.uk

Study Design

• Study Type: observational
• Observational Model: CASE CONTROL
• Time Perspective: PROSPECTIVE
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: November 25, 2025
• First Posted: December 8, 2025
• Study Start: April 1, 2026
• Primary Completion (Estimated): April 1, 2029
• Study Completion (Estimated): June 1, 2029
• Last Updated: December 17, 2025

Record last verified: 2025-11

Data Sharing

• IPD Sharing: Will not share

Locations

GB (1)