ZIRCON
A single PET scan with a radioactive antibody (89Zr-girentuximab, brand TLX250-CDx) can tell whether an unexplained kidney lump is a clear cell kidney cancer before surgery, so some patients might be spared an unnecessary biopsy or operation.
Overview
ZIRCON was a prospective, open-label, multicentre phase 3 trial across 36 sites in nine countries that evaluated [89Zr]Zr-girentuximab PET-CT, a radiolabelled monoclonal antibody targeting carbonic anhydrase IX (CAIX), in patients with an indeterminate renal mass (cT1, up to 7 cm) scheduled for nephrectomy. Patients received a single dose (37 MBq, 10 mg girentuximab) five days before abdominal PET-CT, and blinded central histopathology from the resected specimen served as the reference standard.
Of 371 patients screened, 300 received the tracer and 284 were evaluable for the primary analysis. Mean sensitivity was 85.5% and mean specificity was 87.0%, both exceeding the prespecified thresholds for all three independent readers; performance was maintained in the cT1a (up to 4 cm) subgroup. Safety was favourable, with most adverse events attributable to the subsequent surgery rather than the tracer.
The result supports use of CAIX PET as a non-invasive complement to cross-sectional imaging for risk-stratifying small renal masses, potentially reducing biopsies and overtreatment of benign lesions. TLX250-CDx has not yet received FDA or EMA marketing approval as of this record's date; ZIRCON is the pivotal trial underpinning that filing.
- 85.5 out of 100 people reached this endpoint with 89Zr-girentuximab PET-CT.
- 87 out of 100 people reached this endpoint with 89Zr-girentuximab PET-CT.
- There was no comparison group, so this number cannot tell you how much of the effect is due to the treatment.
- This endpoint is not one of the standard survival or response measures; read it alongside the trial's primary result.
- These results apply to the people the trial enrolled: Adults with a single indeterminate renal mass (cT1, up to 7 cm) suspicious for clear cell renal cell carcinoma, scheduled for nephrectomy; a diagnostic (imaging) trial, not a treatment line. People in a different situation may not see the same effect.
Numbers are from the trial as recorded here; see the source links in the table below. This is orientation, not medical advice: ask your team how closely the trial population matches you.
300 enrolled.
95% CI 81.5-89.6, mean of 3 independent readers
Source95% CI 81.0-93.1, mean of 3 independent readers
SourceSimilar pages
not linked directly; found by shared links- Key paperZIRCON: [89Zr]Zr-girentuximab PET-CT for detecting clear-cell renal cell carcinoma
Shares Zirconium-89 girentuximab, CAIX PET (89Zr-girentuximab), Telix Pharmaceuticals, Zirconium-89 and the tag renal cell carcinoma.
- Trial89Zr-TLX250 for PET/CT Imaging of ccRCC - ZIRCON-CP Study
Shares Zirconium-89 girentuximab, Telix Pharmaceuticals, Zirconium-89, Renal cell carcinoma.
- TargetCAIX (carbonic anhydrase IX)
Shares Zirconium-89 girentuximab, CAIX PET (89Zr-girentuximab), Telix Pharmaceuticals, Renal cell carcinoma and the tag renal cell carcinoma.
- OpportunityCAIX imaging of the indeterminate renal mass
Shares Zirconium-89 girentuximab, CAIX PET (89Zr-girentuximab), Zirconium-89, Renal cell carcinoma.
- IdeaCAIX theranostics: 89Zr-girentuximab PET and 177Lu/225Ac-girentuximab therapy
Shares CAIX PET (89Zr-girentuximab), Telix Pharmaceuticals, Zirconium-89, Renal cell carcinoma.
- PathwayVHL / HIF oxygen sensing
Shares CAIX PET (89Zr-girentuximab), Zirconium-89, Renal cell carcinoma.
- TechnologyImmuno-PET
Shares Zirconium-89 girentuximab, CAIX PET (89Zr-girentuximab), Zirconium-89.