Since inhibitors based on small molecules and macromolecules are not selective and potent enough, new compounds, including bicyclic peptides, have been developed in recent years.
Bicyclic peptides are new generation therapeutic molecules which exhibit properties typical of monoclonal antibodies (high affinity and specificity of the target) and of small molecules (high plasma stability and good tissue penetration).
Computational design implementation has led to the synthesis of peptide libraries with 2 to 17 times the potency of the most promising compound found so far. These patented bicyclic peptides can detect and inhibit the human urokinase enzyme uPA, a serine protease that stimulates cancer cell motility and is involved in the process of tumor metastasis. Bicyclic peptides generally have low toxicity and immunogenicity and can be formulated in pharmaceutical compositions for parenteral administration, also in combination with other active principles.