GTB-5550 (GT Biopharma, Inc.)

GTB-5550 (PSMA TriKE) is a trispecific killer engager (TriKE) biologic construct designed for the treatment of prostate cancer, particularly metastatic castration-resistant prostate cancer (mCRPC). It is a single-chain fusion protein comprising three distinct functional domains: a humanized camelid single-domain antibody (sdAb) targeting the CD16 receptor on natural killer (NK) cells, a wild-type human interleukin-15 (IL-15) moiety, and a single-chain variable fragment (scFv) targeting prostate-specific membrane antigen (PSMA) on tumor cells. The construct is designed to bridge NK cells and PSMA-expressing cancer cells while simultaneously providing a localized IL-15 signal to enhance NK cell activation, proliferation, and survival within the tumor microenvironment. By facilitating the formation of an immunological synapse between NK cells and tumor cells, GTB-5550 promotes targeted tumor lysis and overcomes the immunosuppressive conditions often found in advanced prostate cancer.

Other names

prostate-specific membrane antigen trispecific natural killer cell engagerPSMA-directed TriKEPSMA Tri-specific Killer Engager