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PRETZCEL: CD8 minibody repeatability study

Positron emission tomography Repeatability Evaluation of Tissue Zirconium 89ZR CrEfmirLimab berdoxam uptake (PRETZCEL)

Status
Active, not recruiting
Phases
Phase 3
Study type
Interventional
Source
ISRCTN
Registry ID
ISRCTN71215418
Enrollment
12
Registered
2022-10-03
Start date
2022-12-15
Completion date
Unknown
Last updated
2026-05-25

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Melanoma, renal cell carcinoma Cancer

Interventions

Each participant will undergo two PET scans over a 4 to 8 week period depending on patient cohort. The scans will be done on each occasion about 24 h after the injection of the radiotracer, 8?Zr crefm

Sponsors

ImaginAb (United States)
Lead Sponsor

Eligibility

Sex/Gender
All
Age
18 Years to 100 Years

Inclusion criteria

Inclusion criteria: All participants: 1. Aged =18 years 2. =1 imageable primary or metastatic lesion =1 cm in the lymph nodes or soft tissue excluding bone on the most recent standard of care imaging done within the last 3 months 3. Agree to follow contraceptive advice while on study until 33 days after ending participation Cohort 1: 1. Melanoma on single or multiple agent Immune Checkpoint Blockade (ICB) therapy with stable response status following initiation of therapy 2. Stable disease observed over =2 consecutive standard of care CT scans (usually done 8-12 weeks apart) after initiation of therapy Cohort 2: 1. Untreated renal cell carcinoma on active surveillance

Exclusion criteria

Exclusion criteria: 1. Uncontrolled infection or other concurrent malignancies or conditions that may confound interpretation of the scans in the opinion of the study doctor 2. Urinary catheters or stoma bags 3. Patients who have received a COVID vaccine can be included in the study but can only be scanned after a washout period of 2 weeks after the vaccine. If patients have a COVID vaccine after the first PET-CT scan, the second PET-CT scan will be delayed for =2 weeks after the COVID vaccine. 4. Taking steroids, except those on replacement dose of steroids for adrenal or pituitary insufficiency. Patients requiring steroids as therapy for an unresolved immune therapy related adverse event will be excluded. 5. Taking immunosuppressive medication e.g. cyclosporine, azathioprine, or janus kinase inhibitors 6. Enrolled in another therapeutic intervention study 7. Any other contraindication that makes the patient unsuitable to take part in the study in the opinion of the investigator 8. Women of child bearing potential who are pregnant or breastfeeding on study entry 9. Unable to provide informed consent

Design outcomes

Primary

MeasureTime frame
1. Differences in normal tissue, and tumor uptake, measured standardized uptake values (SUV mean, SUVmax, and SUVpeak) between the two PET-CT scans at baseline and 4-8 weeks 2. Differences in normal tissue, and tumor uptake normalized to a reference region measured as standardized uptake value ratio between the two PET-CT scans at baseline and 4-8 weeks

Secondary

MeasureTime frame
Safety measured using the incidence of adverse events collected between the start of the trial and 33 days after the participants' last PET-CT scan

Countries

England, United Kingdom

Outcome results

None listed

Source: ISRCTN (via WHO ICTRP) · Data processed: May 30, 2026