prodrug of the nucleoside cndac 1 2 c cyano 2 deoxy u03b2 d arabino pentafuranosyl cytosine 1 2 c cyano 2 dioxy u03b2 d arabino pentofuranosyl n 4 palmitoyl cytosine i has a unique mode of action over other nucleoside metabolites such as gemcitabine in that it has a spontaneous dna strand breaking action resulting in potent anti tumour activity in a variety of cell lines xenograft and metastatic cancer model 1 2 c cyano 2 dioxy u03b2 d arabino pentofuranosyl n 4 palmitoyl cytosine i has been the focus of a number of studies in view of its oral bioavailability and its improved activity over gemcitabine the leading marketed nucleoside analogue and 5 fu a widely used antimetabolite drug based on preclinical data in solid tumours recently investigators reported that i exhibited strong anticancer activity in a model of colon cancer in the same model i was found to be superior to either gemcitabine or 5 fu in terms of increasing survival and also preventing the spread of colon cancer metastases to the liver wu m et al cancer research 2003 63 2477 2482 to date phase i data from patients with a variety of cancers suggest that i is well tolerated in humans with myelosuppression as the dose limiting toxicity preferably the cdk inhibitor is an.