Quisinostat dihydrochloride (JNJ-26481585 dihydrochloride) is an orally available, potent pan-HDAC inhibitor with IC50s of 0.11 nM, 0.33 nM, 0.64 nM, 0.46 nM, and 0.37 nM for HDAC1, HDAC2, HDAC4, HDAC10 and HDAC11, respectively. Quisinostat dihydrochloride has a broad spectrum antitumoral activity.