A dinucleotide antimetabolite of a decitabine linked via phosphodiester bond to a guanosine, with potential antineoplastic activity. Following metabolic activation by phosphorylation and incorporation into DNA, SGI-110 inhibits DNA methyltransferase, thereby causing genome-wide and non-specific hypomethylation and inducing cell cycle arrest at S-phase. This agent is resistant to cytidine deaminase, hence may result in gradual release of decitabine both extra- and intracellularly, leading to more prolonged exposures to decitabine.