FIGURE 1.
89Zr-2109A specifically targets human PCa xenografts in vivo. (A) Representative coronal and transverse slices of intact male mice harboring CWR22Pc tumors (n = 5) show onset of 89Zr-2109A accumulation at tumor over time. Arrows indicate position of subcutaneous tumor. (B) Biodistribution data (n = 5/time point) for selected tissues over full time course of study show rate of clearance from circulation, and accumulation at tumor, for 89Zr-2109A. There is minimal uptake of radiotracer in muscle, as well as little activity in bone, even at later time points during which radiotracer metabolism can result in free 89Zr4+ salts. (C) Summary of tumor-associated activity of 89Zr-2109A shows suppression with excess cold antibody (89Zr-2109A + 2109A) and low uptake in human PCa xenografts expressing little to no detectable STEAP1 protein. Inset shows representative immunoblot of relative expression of STEAP1 in models used in this study. %ID/g = percentage injected dose per gram; Trans. = transverse.