Tucidinostat is a potent and orally bioavailable HDAC enzymes class I (HDAC1/2/3) and class IIb (HDAC10) inhibitor, with IC50s of 95, 160, 67 and 78 nM, less active on HDAC8 and HDAC11 (IC50s, 733 nM, 432 nM, respectively), and shows no effect on HDAC4/5/6/7/9. HDAC3|67 nM (IC50)|HDAC10|78 nM (IC50)|HDAC1|95 nM (IC50)|HDAC2|160 nM (IC50)|HDAC11|432 nM (IC50)|HDAC8|733 nM (IC50)

Tucidinostat (Chidamide/CS055/HBI-8000) is a potent and orally bioavailable HDAC enzymes class I (HDAC1, 2, 3) and class IIb (HDAC10) inhibitor, with IC50s of 95, 160, 67 and 78 nM, less active on HDAC8 and HDAC11 (IC50s, 733 nM, 432 nM, respectively), and shows no effect on HDAC4/5/6/7/9 (IC50s, >30 μM). Tucidinostat shows potent antitumor activity, and inhibits several human derived tumor cell lines, such as HL-60, U2OS, LNCaP with GI50s of 0.4 ± 0.1, 2.0 ± 0.6, and 4.0 ± 1.2 μM, respectively. In addition, Tucidinostat shows less toxic to normal cells from human fetal kidney (CCC-HEK) and liver (CCCHEL)[1].

Tucidinostat (12.5-50 mg/kg, p.o.) dose-dependently reduces tumor size and tumor weight in mice bearing HCT-8 colorectal carcinoma, A549 lung carcinoma, BEL-7402 liver carcinoma, and MCF-7 breast carcinoma, and with no obvious body loss[1].

[1]. Ning ZQ, et al. Chidamide (CS055/HBI-8000): a new histone deacetylase inhibitor of the benzamide class with antitumor activity and the ability to enhance immune cell-mediated tumor cell cytotoxicity. Cancer Chemother Pharmacol. 2012 Apr;69(4):901-9.