Tyrosine kinases as targets in cancer therapy - successes and failures.
Protein kinases play a crucial role in signal transduction and also in cellular proliferation, differentiation and various regulatory mechanisms. The inhibition of growth-related kinases, especially tyrosine kinases, might therefore provide new therapies for diseases such as cancer. Due to the enormous progress that has been made in the past few years in the identification of the human genome, in molecular and cell biology technologies, in structural biology and in bioinformatics, the number of receptor and non-receptor tyrosine kinases that have been identified as valuable molecular targets has greatly increased. Currently, more than 20 different tyrosine kinase targets are under evaluation in drug discovery projects in oncology. The progress made in the crystallisation of protein kinases, in most cases complexed with ATP-site-directed inhibitors, has confirmed that the ATPbinding domain of tyrosine kinases is an attractive target for rational drug design; more than 20 ATP-competitive, low molecular weight inhibitors are in various phases of clinical evaluation. Meanwhile, clinical proof-of-concept (POC) has been achieved with several antibodies and small molecules targeted against tyrosine kinases. With Herceptin, Glivec and Iressa (registered in Japan), the first kinase drugs have entered the market. This review describes the preclinical and clinical status of low molecular weight drugs targeted against different tyrosine kinases (e.g., epidermal growth factor receptor [EGFR], vascular endothelial growth factor receptor [VEGFR], platelet-derived growth factor receptor [PDGFR], Kit, Fms-like tyrosine kinase [Flt]-3), briefly describes new targets, and provides a critical analysis of the current situation in the area of tyrosine kinase inhibitors.
Traxler
Peter
P
Novartis Pharma AG, Oncology Research, CH4002 Basel, Switzerland. peter.traxler@pharma.novartis.com
D000818:Animals; D000970:Antineoplastic Agents / Q000494:pharmacology / Q000627:therapeutic use*; D002986:Clinical Trials as Topic; D015195:Drug Design; D004354:Drug Screening Assays, Antitumor; D066246:ErbB Receptors / Q000037:antagonists & inhibitors / Q000502:physiology; D016044:Fusion Proteins, bcr-abl / Q000037:antagonists & inhibitors / Q000502:physiology; D006801:Humans; D051379:Mice; D008819:Mice, Nude; D009363:Neoplasm Proteins / Q000037:antagonists & inhibitors* / Q000502:physiology; D009369:Neoplasms / Q000188:drug therapy* / Q000201:enzymology; D047428:Protein Kinase Inhibitors / Q000494:pharmacology / Q000627:therapeutic use*; D011505:Protein-Tyrosine Kinases / Q000037:antagonists & inhibitors* / Q000502:physiology; D011743:Pyrimidines / Q000494:pharmacology / Q000627:therapeutic use; D011758:Pyrroles / Q000494:pharmacology / Q000627:therapeutic use; D020794:Receptor Protein-Tyrosine Kinases / Q000037:antagonists & inhibitors / Q000502:physiology; D040262:Receptors, Vascular Endothelial Growth Factor / Q000037:antagonists & inhibitors / Q000502:physiology; D016896:Treatment Outcome
D000970:Antineoplastic Agents; D009363:Neoplasm Proteins; D047428:Protein Kinase Inhibitors; D011743:Pyrimidines; D011758:Pyrroles; C410026:PKI 166; D066246:ErbB Receptors; D011505:Protein-Tyrosine Kinases; D020794:Receptor Protein-Tyrosine Kinases; D040262:Receptors, Vascular Endothelial Growth Factor; D016044:Fusion Proteins, bcr-abl