SB939

SB939 is a novel potent and orally active histone deacetylase with high tumor exposure and efficacy in mouse models of colorectal cancer. The IC50 value for HDAC1 is 52 nM. In vitro, SB939 inhibits class I, II and IV HDACs, with no effects on other zinc binding enzymes, and shows significant antiproliferative activity against a wide variety of tumor cell lines. It has very favorable pharmacokinetic properties after oral dosing in mice, with >4-fold increased bioavailability and 3.3-fold increased half-life over suberoylanilide hydroxamic acid (SAHA).