The Design of Potent, Selective and Drug-Like RGD αvβ1 Small-Molecule Inhibitors Derived from non-RGD α4β1 Antagonists

Up to 45 % of deaths in developed nations can be attributed to chronic fibroproliferative diseases, highlighting the need for effective therapies. The RGD (Arg-Gly-Asp) integrin alpha v beta 1 was recently investigated for its role in fibrotic disease, and thus warrants therapeutic targeting. Herein we describe the identification of non-RGD hit small-molecule alpha v beta 1 inhibitors. We show that alpha v beta 1 activity is embedded in a range of published alpha 4 beta 1 (VLA-4) ligands; we also demonstrate how a non-RGD integrin inhibitor (of alpha 4 beta 1 in this case) was converted into a potent non-zwitterionic RGD integrin inhibitor (of alpha v beta 1 in this case). We designed urea ligands with excellent selectivity over alpha 4 beta 1 and the other alpha v integrins (alpha v beta 3, alpha v beta 5, alpha v beta 6, alpha v beta 8). In silico docking models and density functional theory (DFT) calculations aided the discovery of the lead urea series.