PSV359

PSV359 is a novel cyclic peptide-based radiopharmaceutical designed to target and deliver radioactive lead isotopes (such as 212Pb or 203Pb) to tumor sites expressing fibroblast activation protein alpha (FAP-α). FAP-α is commonly overexpressed in various cancers and cancer-associated fibroblasts within tumor lesions, where it plays a role in disease progression. Developed by Perspective Therapeutics, PSV359 was discovered using phage display methods for high affinity and specificity against human FAP (hFAP), with reported binding affinities of Kd=1.8 nM and Ki=0.4 nM. The peptide is conjugated to a lead-specific chelator via a molecular linker, enabling targeted delivery of alpha-particle therapy for image-guided treatment of solid tumors that are FAP-positive. Preclinical studies have demonstrated strong anti-tumor activity and favorable pharmacokinetics including fast renal clearance and low off-target accumulation. Clinical development is ongoing with Phase 1/2 trials in patients with solid tumors known to be FAP-positive[1][2][3][4][5][7].