Tyrosine kinase inhibitors.

Over the last ten years, several new and therapeutically relevant cancer drugs targeting tyrosine kinases signaling pathways have been developed. Tyrosine kinase inhibitors (TKIs) are a pharmaceutical class of small molecules, orally available, well-tolerated, worldwide approved drugs for the treatment of several neoplasms, including lung, breast, kidney and pancreatic cancer as well as gastro-intestinal stromal tumors and chronic myeloid leukemia. This comprehensive review focuses on the most relevant members of the first and the second generation TKIs designed to interact with receptor and nonreceptor TKs. Attention is mainly focused on molecular mechanisms in in vitro and in vivo models related to the clinical activity of the drugs and to the development of resistance to treatment, still the major challenge in cancer research and care.