212Pb-labeled peptide

The term **212Pb-labeled peptide** in the context of the provided preclinical study refers specifically to **[212Pb]Pb-MC1L** (also known as **[212Pb]VMT01** or **lapemelanotide zapixetar**), an investigational targeted alpha-particle therapy (TAT). Developed by Viewpoint Molecular Targeting (now Perspective Therapeutics) in collaboration with the University of Iowa, this radiopharmaceutical consists of a low-molecular-weight cyclic peptide (MC1L) that selectively targets the melanocortin 1 receptor (MC1R) overexpressed on melanoma cells. The peptide is conjugated to a lead-212 (212Pb) radioactive isotope payload via a proprietary lead-specific chelator (PSC). Upon binding to MC1R, the drug is internalized, and the decay of 212Pb delivers high-energy alpha-particle radiation directly to the tumor cells, inducing lethal double-strand DNA breaks while minimizing damage to surrounding healthy tissues. It is currently being evaluated in Phase 1/2a clinical trials for the treatment of unresectable or metastatic MC1R-positive melanoma, both as a monotherapy and in combination with the immune checkpoint inhibitor nivolumab.

Other names

[212Pb]DOTA-MC1L[212Pb]Pb-MC1L[212Pb]VMT-01[212Pb]VMT01DOTA-MC1LDOTA-MC-1LDOTA-MC 1LDOTA-PEG2-alpha-MSHDOTA-PEG-2-alpha-MSHDOTA-PEG 2-alpha-MSHlapemelanotidelapemelanotide zapixetarMC1LMC-1LMC 1Lzapixetar