Enzyme-activated anti-tumor prodrug compounds

A prodrug compound comprising:

• a targeting-peptide chosen from SEQ ID NO:6 or SEQ ID NO:7, wherein the targeting-peptide has L or L and D amino acid residues and wherein the targeting-peptide is optionally covalently capped by a terminal amino capping group Z;
• a linker group covalently attached to the targeting-peptide at the carboxy terminus;
• and
• a cytotoxic drug covalently attached to the linker;
• wherein:
• the targeting-peptide is an amino acid sequence which is catalytically cleaved by elastase;
• the linker group is a bond or a self-immolating linker;
• and
• Z is an amino protecting group chosen from tert-butyloxycarbonyl, benzyloxycarbonyl or an adhesion peptide;
• wherein there is an optional spacer molecule between Z and the targeting-peptide.