Correlative Biomarker Analysis of PSMA Expression on CTCs and PSMA Imaging in a Phase I Study of PSMA Targeted Tubulysin Conjugate EC1169

Key Points

• Significant heterogeneity in PSMA expression was observed on circulating tumor cells, indicating diverse biological characteristics.
• Among patients with predominantly PSMA-positive lesions on SPECT, the variation in CTC levels reflects differences in tumor behavior.
• Assessment using imaging and CTC analyses underscores the complexity of PSMA expression in cancer diagnosis and treatment.
• Highlights the necessity for validating both biomarker platforms to enhance future clinical research efficacy.