Due to the presence of an albumin-binding entity and the resulting increased blood circulation time, maximum tumor uptake of [177Lu]Lu-Ibu-PSMA-02 was reached at 24 h p.i. and was ~2.5-fold higher than the maximum tumor uptake of [177Lu]Lu-PSMA-617 which was reached at 4 h p.i. Off-target accumulation of [177Lu]Lu-Ibu-PSMA-02 as well as of [177Lu]Lu-Ibu-PSMA-01 was, however, also higher than for [177Lu]Lu-PSMA-617 at all investigated timepoints (Figure 4, Supplementary Materials, Tables S1‒S3). This evidence concerns the gene ALB and neoplasm.