Table 2: Major HDAC inhibitors: Targets and current status in cancer chemotherapy.

Class Compounds HDACs Status Reference Aliphatic acid Valproic acid Class I, IIa Phase II clinical trials [62] Benzamide MGCD0103 Class I, II Phase II clinical trials [63] Cyclic peptide FK228 Class I, II FDA approved for CTCL [64] Hydroxamates SAHA Class I, II FDA approved for CTCL [63] LBH589 Class I, II Phase II and III clinical trials [23] Trichostatin A Class I, II Experimental use [65, 66] Others AR-42 Class I, II Started clinical trials [67] CUDC101 Class I, II Started clinical trials [68]

Note: Valproic acid has been in use as an anticonvulsant and mood stabilizing drug in the treatment of epilepsy and bipolar disorder.