Silicon-fluoride acceptor substituted radiopharmaceuticals and precursors thereof

Abstract

A ligand-SiFA conjugate compound represented by formula (1) wherein: Ris a ligand moiety which is capable of binding to prostate-specific membrane antigen (PSMA); Ris a silicon-fluoride acceptor (SiFA) moiety which can be labeled withF or which is labeled withF; L is a linking moiety; Ris a hydrophilic moiety which comprises (i) a linear or branched sequence of 2 to 10 hydrophilic amino acid units A, each of which is independently derived from a natural or non-natural amino acid carrying a hydrophilic side chain, and optionally one amino acid unit Aderived from a natural or non-natural amino acid which is devoid of a hydrophilic side chain, wherein the hydrophilic amino acid units and, if present, the unit A, are bound to each other via a direct covalent bond or via a coupling unit; and which optionally further comprises (ii) one or more hydrophilic residues R, each of which may be bound to an amino group, a carboxylic acid group, or to a hydrophilic side chain of an amino acid unit; or a pharmaceutically acceptable salt thereof.