[ ⁶⁸ Ga] Ga-NYM096 PET/CT in patients with primary and metastatic clear cell renal cell carcinoma: A preliminary study.

Abstract

4537 Background: With limitations of conventional imaging and biopsy, accurate, non-invasive techniques to detect in patients with primary and metastatic clear cell renal cell carcinoma (ccRCC) remain an unmet need. Carbonic anhydrase IX (CAIX) is a tumour antigen highly expressed in ccRCC. NYM096 is a new-generation CAIX targeting small molecule that can be labeled with 68 Ga. It has a higher affinity (almost 100-fold) for CAIX compared to NYM005. This study aims to assess the efficacy of [ 68 Ga]Ga-NY096 PET/ CT to identify ccRCC. Methods: This is an open-label, multicenter study. Patients with primary and metastatic ccRCC were prospectively recruited in the study. A wash-out of 7 days was required if the patients were on tyrosine kinase inhibitors. All patients received an intravenous injection of [ 68 Ga]Ga-NYM096 at a dose of 1-7 mCi and underwent whole body PET/CT scan using a total-body PET/CT scanner at 60 min after injection. They were further divided into two groups: group 1, patients with primary renal mass and group 2, patients with suspected/confirmed metastatic ccRCC, who were scheduled for surgery or biopsy. In some patients, 18 F-FDG PET/CT was also performed within one week before or after [ 68 Ga]Ga-NYM096 PET/CT. The diagnostic efficacy of 68 Ga-NYM096 was compared with that of 18 F-FDG. Results: A total of 24 patients (mean age, 56.7 years±14.4, 18 men) were recruited in this preliminary study. Including 23 patients in group 1 and 1 patient in group 2. All patients had 68 Ga-NYM096 PET/CT, and all patients also had 18 F-FDG PET/CT. The patient-level sensitivity, specificity, and accuracy of [ 68 Ga]Ga-NY096 PET scan was 100%, 90.0%, 95.7% for all patients, and 100%, 90.0%, 95.5% for group 1. One patient in Group 2 was confirmed as a true positive case by histopathological examination. Among patients with positive PET findings, the SUV max of the single most active lesion ranged from 4.9 to 111.8, with a mean (± SD) of 52.2 ± 34.1. This value was significantly higher than the mean SUV max of 5.5 ± 2.9 observed with 18 F-FDG (p < 0.001). The tumor-to- kidney ratio was also higher (3.3 ± 3.0 versus 1.7 ± 3.0, p＜0.05). Conclusions: 68 Ga-NYM096 PET/CT has high diagnostic efficacy for primary ccRCC patients, and its diagnostic efficacy is significantly better than that of 18 F-FDG. It has the potential to become a diagnostic product for both primary and metastatic ccRCC.