Clinical trial NCT06335888: A Clinical Trial to Investigate 18F-AzaFol in the Diagnosis of Large Vessel Vasculitis
Official title: Cross-over, Randomized, Open-label, Single-centre, Phase II Clinical Trial to Investigate 18F-AzaFol in the Diagnosis of Large Vessel Vasculitis
Study type: INTERVENTIONAL
Overall status: RECRUITING
Phase: PHASE2
Conditions: Giant Cell Arteritis
Keywords: Tracer
PET imaging
Lead sponsor: Insel Gruppe AG, University Hospital Bern
Sponsor class: OTHER
Collaborators: name: Paul Scherrer Institut, Center for Proton Therapy
First posted: 2024-03-28
Enrollment: 70
Sex: ALL
Minimum age (years): 50
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: no
Allocation: RANDOMIZED
Intervention model: CROSSOVER
Intervention model description: Cross-over, randomized, open label, single-centre
Primary purpose: DIAGNOSTIC

Brief summary: The goal of this open-label clinical trial is to evaluate the efficacy of AzaFol-PET/CT in the diagnosis of GCA (giant cell arteritis), to compare AzaFol- with 2-\[18F\]FDG-PET/CT, and to assess the safety and tolerability of AzaFol in subjects with suspicion of GCA.

Participants will undergo AzaFol-PET/CT imaging at a single timepoint.

Detailed description: Giant cell arteritis (GCA) is the most common systemic vasculitis in the elderly population. 2-\[18F\]Fluor-2-desoxy-D-glucose (2-\[18F\]FDG) positron emission tomography (PET)/ computed tomography (CT) is performed to diagnose GCA (standard of care, SOC) but unable to reliably distinguish atherosclerosis from vasculitis. Activated macrophages express folate receptor (FR)-β and are enriched in inflamed vascular tissue in GCA. 3'-Aza-2'-\[18F\]Fluoro-Folic Acid (AzaFol) is a nuclear tracer targeting FRβ. The investigators hypothesize that AzaFol is a specific and reliable tracer to visualize activated macrophages in GCA and therefore might improve the discrimination of vasculitic and atherosclerotic lesions as compared to 2-\[18F\]FDG-PET/CT.

Eligibility criteria: Inclusion Criteria:

* Individuals ≥ 50 years with clinical suspicion of GCA
* Women of childbearing potential must not have a positive serum pregnancy test at the Screening Visit
* Subjects must be able to understand and adhere to all protocol requirements and must voluntarily sign and date an informed consent, approved by an independent ethics committee (IEC)/institutional review board (IRB), prior to the initiation of any screening or study-specific procedures.
* Are willing and able to comply with procedures required in this protocol.

Exclusion Criteria:

1. Folate deficiency
2. Female subjects who are pregnant, breastfeeding, or considering becoming pregnant during the study or within 30 days after the last dose of study drug
3. Concomitant treatment with medications that lead to a significant impairment of folic acid levels (methotrexate, pemetrexed, raltitrexed)
4. Concomitant glucose-containing infusion or parental nutrition within 6 hours prior to 2-\[18F\]FDG tracer application
5. Glucose level \> 10 mmol/l at the timepoint of 2-\[18F\]FDG PET/CT
6. Unable to remain in the PET/CT for the duration of the examination
7. Unable to lie still for the duration of the examination (45 min)
8. Unable not to eat or drink (except water) for 6 hours prior to 2-\[18F\]FDG tracer application
9. Prior PET-imaging within 60 days before baseline
10. Intake of vitamin supplements containing \> 1mg/day folic acid within 48 h prior to the PET/CT with AzaFol
11. Known hypersensitivity or allergy to folic acid
12. Enrolment of the investigator, his/her family members, employees and other dependent persons
13. Participation in another study with investigational drug within the 7 days preceding and during the present study.

Primary outcomes:
measure: Specificity of the GCA-diagnosis at the patient level
timeFrame: Baseline
Secondary outcomes:
measure: Lesion detection rate (visual analysis)
timeFrame: Baseline
measure: Lesion detection rate (semiquantitative analysis)
timeFrame: Baseline
measure: Sensitivity of the GCA-diagnosis at the patient level
timeFrame: Baseline
Other outcomes:
Locations:
city: Bern
country: Switzerland
facility: Department of Rheumatology and Immunology, University Hospital Bern, Inselspital
Study officials:
affiliation: Department of Rheumatology and Immunology, Inselspital, University of Bern, Bern, Switzerland
name: Britta Maurer
role: PRINCIPAL_INVESTIGATOR
References: