Synthetic challenges in the development of peptidomimetic antagonists of the avb3 integrin receptor

ORGN 665

Peter G. Ruminski, peter.g.ruminski@pfizer.com, Thomas E. Rogers, Joseph G. Rico, Srinivasan R. Nagarajan, Balekudru Devadas, and Hwang-Fun Lu. Discovery Medicinal Chemistry, Pfizer Global Research and Development, Pfizer, Inc, St. Louis Laboratories, 700 Chesterfield Parkway West, Chesterfield, MO 63017
Integrins are a widely expressed family of transmembrane &alpha/&beta heterodimeric cell surface receptors that mediate cell interaction with other cells and with extracellular matrix components. The integrin &alphav&beta3 (vitronectin receptor) is expressed on a variety of cell types, including endothelial cells, osteoclasts and vascular smooth muscle cells. &alphav&beta3 is known to be involved in osteoclast mediated bone resorption and has been implicated in tumor progression, angiogenesis and restenosis. As such, antagonists of the &alphav?3 integrin would be expected to have therapeutic potential for a variety of human diseases. Many of the known integrins, including &alphav&beta3, bind to the Arg-Gly-Asp (RGD) consensus sequence found in matrix ligands. Small molecule peptidomimetics of the RGDX sequence might, therefore, be expected to disrupt this integrin-matrix interaction in a therapeutically useful manner. We have discovered potent, small molecule RGD peptidomimetic inhibitors of &alphav&beta3. The synthetic methods developed to efficiently produce these inhibitors will be discussed.