Vorinostat (rINN) or suberoylanilide hydroxamic acid (SAHA), is a drug currently under investigation for the treatment of cutaneous T cell lymphoma (CTCL). Vorinostat inhibits the enzymatic activity of histone deacetylases HDAC1, HDAC2 and HDAC3 (Class I) and HDAC6 (Class II) at nanomolar concentrations (IC50< 86 nM). These enzymes catalyze the removal of acetyl groups from the lysine residues of histones proteins. In some cancer cells, there is an overexpression of HDACs, or an aberrant recruitment of HDACs to oncogenic transcription factors causing hypoacetylation of core nucleosomal histones. By inhibiting histone deacetylase, vorinostat causes the accumulation of acetylated histones and induces cell cycle arrest and/or apoptosis of some transformed cells. The mechanism of the antineoplastic effect of vorinostat has not been fully characterized. Vorinostat is used for the treatment of cutaneous manifestations in patients with cutaneous T-cell lymphoma who have progressive, persistent or recurrent disease on or following two systemic therapies. Vorinostat is marketed under the name Zolinza by Merck for the treatment of cutaneous manifestations in patients with cutaneous T cell lymphoma (CTCL) when the disease persists, gets worse, or comes back during or after two systemic therapies.

Thalidomide is an immunomodulatory agent with a spectrum of activity that is not fully characterized. Thalidomide is racemic — it contains both left and right-handed isomers in equal amounts: one enantiomer is effective against morning sickness, and the other is teratogenic. The enantiomers are converted to each other in vivo. That is, if a human is given D-thalidomide or L-thalidomide, both isomers can be found in the serum. Hence, administering only one enantiomer will not prevent the teratogenic effect in humans. In patients with erythema nodosum leprosum (ENL) the mechanism of action is not fully understood. Available data from in vitro studies and preliminary clinical trials suggest that the immunologic effects of this compound can vary substantially under different conditions, but may be related to suppression of excessive tumor necrosis factor-alpha (TNF-a) production and down-modulation of selected cell surface adhesion molecules involved in leukocyte migration. For example, administration of thalidomide has been reported to decrease circulating levels of TNF-a in patients with ENL, however, it has also been shown to increase plasma TNF-a levels in HIV-seropositive patients. As a cancer treatment, the drug may act as a VEGF inhibitor. Thalidomide is used for the acute treatment of the cutaneous manifestations of moderate to severe erythema nodosum leprosum (ENL). Also for use as maintenance therapy for prevention and suppression of the cutaneous manifestations of ENL recurrence. Thalidomide is sold under the brand name Immunoprin, among others.

Perifosine is an orally active alkyl-phosphocholine compound with potential antineoplastic activity. Perifosine is an Akt inhibitor, which targets the pleckstrin homology domain of Akt, thereby preventing its translocation to the plasma membrane. Perifosine exerts Akt-dependent and Akt-independent effects, and although many preclinical studies have documented Akt inhibition by perifosine, clinical validation of these findings is lacking. Perifosine is in phase II and III clinical trials for the treatment of neuroblastoma, glioblastoma multiforme and other solid tumors.