Phase I study to assess safety, biodistribution and radiation dosimetry for 89Zr-girentuximab in patients with renal cell carcinoma.

Purpose: In this phase I study, we evaluated the safety, biodistribution and dosimetry of [⁸⁹Zr]Zr-DFO-girentuximab (⁸⁹Zr-girentuximab) PET/CT imaging in patients with suspicion of clear cell renal cell carcinoma (ccRCC). Methods: Ten eligible patients received an intravenous administration of 37 MBq (± 10%) of ⁸⁹Zr-girentuximab at mass doses of 5 mg or 10 mg. Safety was evaluated according to the NCI CTCAE (version 4.03). Biodistribution and normal organ dosimetry was performed based on PET/CT images acquired at 0.5, 4, 24, 72 and 168 h post-administration. Additionally, tumour dosimetry was performed in patients with confirmed ccRCC and visible tumour uptake on PET/CT imaging. Results: ⁸⁹Zr-girentuximab was administered in ten patients as per protocol. No treatment-related adverse events ≥ grade 3 were reported. ⁸⁹Zr-girentuximab imaging allowed successful differentiation between ccRCC and non-ccRCC lesions in all patients, as confirmed with histological data. Dosimetry analysis using OLINDA/EXM 2.1 showed that the organs receiving the highest doses (mean ± SD) were the liver (1.86 ± 0.40 mGy/MBq), the kidneys (1.50 ± 0.22 mGy/MBq) and the heart wall (1.45 ± 0.19 mGy/MBq), with a mean whole body effective dose of 0.57 ± 0.08 mSv/MBq. Tumour dosimetry was performed in the 6 patients with histologically confirmed ccRCC resulting in a median tumour-absorbed dose of 4.03 mGy/MBq (range 1.90–11.6 mGy/MBq). Conclusions: This study demonstrates that ⁸⁹Zr-girentuximab is safe and well tolerated for the administered activities and mass doses and allows quantitative assessment of ⁸⁹Zr-girentuximab PET/CT imaging in patients with suspicion of ccRCC. Trial registration: NCT03556046—14th of June, 2018 [ABSTRACT FROM AUTHOR]