(UroToday.com) Targeting the PSMA protein is one of the most promising emerging approaches to treating advanced prostate cancer.  PSMA, the Prostate Specific Membrane Antigen, is expressed predominantly on prostate cells, as well as to a lesser degree in proximal tubules of the kidney, the small intestine, and oromaxillary glands.  As expression is further increased with prostate carcinogenesis, targeting of PSMA has been increasingly enticing.  Several approaches including small molecule- and antibody-based technologies1,2 have emerged carrying a “payload” of chemo- or radiotherapy or engineered to bring immune effector cells in close proximity to prostate cancer cells.  Last year, the authors (Dr. Hofman et al.) presented the results of the randomized phase II study, TheraP, which compared 177Lu-PSMA-617 to cabazitaxel in the treatment of post-docetaxel metastatic castration resistant prostate cancer (mCRPC).1  There, the small molecule 617 was conjugated to a beta-emitting radionuclide (177Lu) and they reported improved activity (via PSA50), improved PSA-PFS, and fewer Grade 3 or 4 adverse events, as compared to cabazitaxel therapy.