Current Pharmaceutical Design - Volume 8, Issue 25, 2002

Improvements in our understanding of the intrinsic aberrancies in cancer cells have enabled the design and development of novel therapeutics that specifically target these changes. Among the many complex cellular pathways and mechanisms which have been unveiled by new molecular techniques, RAS-mediated signal transduction is one met with tremendous research interests. Activation of RAS initiates several signalin Read More

Adult acute myeloid leukemia (AML) and the myelodysplastic syndromes (MDS) remain a formidable therapeutic challenge. Although 30-40% of young adults with AML may have prolonged remissions, following either intensive chemotherapy or bone marrow transplantation, the remainder relapse and ultimately die of their disease. Older adults, or those with leukemia following an antecedent hematologic disorder such as M Read More

Various signalling pathways can confer the malignant phenotype to a cell. Ras signalling proteins have been found to play an important role in controlling cellular growth. Raf-1 is a protein kinase that exerts its effects downstream of Ras in the mitogen-activated protein kinase pathway and is thus likely to be crucial in the development of the malignant phenotype. BAY 43-9006 is an orally administered selective inhibitor of Ra Read More

The drug design and discovery efforts described in the previous section led to the development of a novel, small molecule Raf-1 kinase inhibitor, BAY 43-9006, which belongs to a class that can be broadly described as bis-aryl ureas (Figure 1) [1]. BAY 43-9006 was identified during a large medicinal chemistry optimization program, and this compound was selected for further pharmacological characterization based on its p Read More

Ras genes encode proteins that activate in an intracellular signaling network controlling differentiation, proliferation and cell survival. Mutated Ras oncogenes encoding proteins that are constitutively active can induce malignancies in a variety of laboratory models. In human malignancies, Ras mutations are common, having been identified in approximately 30% of cancers. Given the importance of Ras and downstream targets Read More

Raf kinase, an enzyme which acts downstream in the Ras signaling pathway, is involved in cancerous cell proliferation. Thus, small molecule inhibitors of Raf kinase activity may be important agents for the treatment of cancer. A novel class of Raf-1 inhibitors was discovered, using a combination of medicinal and combinatorial chemistry approaches. This effort culminated in the identification of the clinical candidate B Read More

Investigators involved in the development of cancer therapeutics are testing new trial designs and endpoints in order to accommodate the perceived challenges in defining appropriate doses and schedules for further testing. Many new agents with specific molecular targets have entered clinical development or are being considered for development. While some of the agents have both toxicity and antitumour effi Read More