PB-TT012

PB-TT012 is a preclinical-stage radioligand therapy (RLT) being developed by Primo Biotechnology for the treatment of metastatic colorectal cancer (mCRC). The drug consists of a targeting moiety specific to Folate Hydrolase 1 (FOLH1), also known as Prostate-Specific Membrane Antigen (PSMA), which is highly expressed in the neovasculature of various solid tumors, including colorectal cancer. PB-TT012 is conjugated to Terbium-161 (161Tb), a therapeutic radioisotope that emits beta particles as well as a high yield of Auger and conversion electrons. This combination is designed to deliver localized, high-energy radiation directly to FOLH1-expressing cells and tumor neovasculature, inducing DNA double-strand breaks and subsequent tumor cell death. The use of Terbium-161 potentially offers enhanced therapeutic efficacy over traditional Lutetium-177-based therapies due to the short-range, high-linear energy transfer (LET) provided by its Auger electron emission.