RCCB6

RCCB6 is a novel **single-domain antibody (sdAb)** specifically designed to target **CD70**, a potential biomarker relevant to various cancers, including clear cell renal cell carcinoma (ccRCC). It serves as the antibody component in **CD70-targeted radiotracers** used for **immunoPET/CT imaging**. When labeled with radioisotopes like fluorine-18 or gallium-68, it forms radiotracers such as [18F]RCCB6 or [68Ga]Ga-NOTA-RCCB6, which enable the visualization and detection of CD70-expressing tumors and metastases using PET/CT. Preclinical studies with [18F]RCCB6 in patient-derived xenograft models of ccRCC showed **high tumor-to-background ratios** and superior diagnostic potential due to high tumor uptake and low bone accumulation compared to other tracers. Clinical translation of [18F]RCCB6 imaging has demonstrated **promising results** for identifying recurrence and metastasis in ccRCC patients, potentially offering **advantages over traditional [18F]FDG PET/CT** for clinical staging, therapeutic evaluation, and restaging of renal cell carcinoma. Clinical trials are ongoing to further evaluate RCCB6-based imaging in renal cell carcinoma, and proof-of-concept studies have also explored its use in other cancers like nasopharyngeal carcinoma.