{"entity":{"id":"caix-pet","kind":"technology","name":"CAIX PET (89Zr-girentuximab)","aka":[],"tldr":"CAIX PET is a scan using an antibody against a protein almost unique to clear-cell kidney cancer, to tell cancer from benign kidney lumps without a biopsy.","summary":"CAIX PET uses 89Zr-labelled girentuximab, an antibody against carbonic anhydrase IX, a HIF target expressed in more than 95% of clear-cell renal cell carcinomas because of VHL loss. Imaging 5 days after injection shows whether an indeterminate renal mass is clear-cell cancer without a biopsy. In the ZIRCON phase 3 (2023) it achieved sensitivity 86% and specificity 87%, giving histology-level specificity and whole-body staging in one scan. Telix's TLX250-CDx received an FDA complete response letter in 2025 over manufacturing, and resubmission is planned, so it is not yet approved; the five-day imaging delay and the 89Zr dose are practical limitations. The same antibody labelled with 177Lu is being tested therapeutically in the STARLITE trials, making CAIX a theranostic pair. It tells cancer from a benign kidney lump by lighting up a protein almost unique to clear-cell kidney cancer.","status":"phase-3","asOf":"2026-09-07","links":[{"label":"Shuch et al., ZIRCON: 89Zr-girentuximab PET-CT imaging of clear-cell renal cell carcinoma (Lancet Oncology 2024)","url":"https://doi.org/10.1016/S1470-2045(24)00402-9"}],"tags":[],"related":[],"cancers":["rcc"],"sections":["imaging"],"technologies":["immuno-pet","pet"],"targets":["hif2a"],"drugs":[],"companies":["telix"],"institutions":[],"pathways":["hif-vhl"],"terms":[],"trials":["nct06750419","nct03849118","nct06447103"],"people":[],"bottlenecks":[],"keyPapers":["paper-shuch-lancet-oncol"],"journals":[],"dependsOn":[],"notes":[],"principle":"89Zr-labelled anti-CAIX antibody girentuximab imaged 5 days after injection; CAIX is a HIF target expressed in >95% of clear-cell RCC via VHL loss.","strengths":["Non-invasive histology-level specificity","Whole-body staging of clear-cell disease"],"limitations":["Five-day imaging delay; 89Zr dose","Not yet approved (CRL 2025)"]},"route":"/technologies/caix-pet/","neighbours":{"cancer":[{"id":"rcc","kind":"cancer","name":"Renal cell carcinoma","route":"/cancers/rcc/"}],"section":[{"id":"imaging","kind":"section","name":"Imaging","route":"/fronts/imaging/"}],"technology":[{"id":"immuno-pet","kind":"technology","name":"Immuno-PET","route":"/technologies/immuno-pet/"},{"id":"pet","kind":"technology","name":"PET (positron emission tomography)","route":"/technologies/pet/"}],"target":[{"id":"hif2a","kind":"target","name":"HIF-2α","route":"/targets/hif2a/"}],"company":[{"id":"telix","kind":"company","name":"Telix Pharmaceuticals","route":"/companies/telix/"}],"pathway":[{"id":"hif-vhl","kind":"pathway","name":"VHL / HIF oxygen sensing","route":"/pathways/hif-vhl/"}],"trial":[{"id":"nct06750419","kind":"trial","name":"89Zr-TLX250 for PET/CT Imaging of ccRCC - ZIRCON-CP Study","route":"/trials/nct06750419/"},{"id":"nct03849118","kind":"trial","name":"89Zr-TLX250 for PET/CT Imaging of ccRCC- ZIRCON Study","route":"/trials/nct03849118/"},{"id":"nct06447103","kind":"trial","name":"An Investigational Scan (89Zr-DFO-GmAb PET/CT) Compared to Contrast-Enhanced CT for the Detection of Recurrent Clear Cell Renal Cell Cancer After Surgery Comparing Carbonic Anhydrase IX (CAIX) PET CT to Conventional PET CT for Post-Op Staging in Kidney Cancer","route":"/trials/nct06447103/"}],"paper":[{"id":"paper-shuch-lancet-oncol","kind":"paper","name":"[ 89 Zr]Zr-girentuximab for PET-CT imaging of clear-cell renal cell carcinoma: a prospective, open-label, multicentre, phase 3 trial","route":"/key-papers/paper-shuch-lancet-oncol/"}],"idea":[{"id":"idea-adjuvant-selection-rcc","kind":"idea","name":"Biomarker-selected adjuvant therapy in RCC (ctDNA, CAIX PET, gene signatures)","route":"/ideas/idea-adjuvant-selection-rcc/"},{"id":"idea-caix-theranostics","kind":"idea","name":"CAIX theranostics: 89Zr-girentuximab PET and 177Lu/225Ac-girentuximab therapy","route":"/ideas/idea-caix-theranostics/"}]}}