177Lu-TLX591 (177Lu-Rosopatamab, 177Lu-J591, 177Lu-ATL-101) is the Lutetium-177 labeled J591 anti-PSMA antibody originally developed at the Weill Cornell Medical Center, Cornell University, New York.

J591 is an anti-PSMA (prostate-specific membrane antigen) antibody with high specificity for prostate tumor cells. PSMA (or GCPII or NAAG peptidase) is a zinc metalloenzyme that is expressed in the membranes of many cells, mainly the prostate, but also the kidney, the small intestine, and the central and peripheral nervous system. In fact, PSMA is strongly expressed in the human prostate, being a hundredfold greater than the expression in most other tissues. 177Lu-TLX591 is therefore an ideal drug for targeting of prostate cancer and its metastases.

A large-scale Phase III trial (the Prostact study) in prostate cancer patients is under protocol review and IND was submitted to FDA with first inclusion in September 2020.

Target/Mechanism: PSMA

Leading Emitter: beta electrons (β–)