Are there any other FDA-approved treatments for cutaneous T-cell lymphoma?

Yes. Denileukin diftitox (Ontak) is interleukin-2 (IL-2) conjugated to diphtheria toxin. The drug is given intravenously only to patients whose malignant cells express CD25, the IL-2 receptor. The drug can be associated with significant toxicity, including capillary leak syndrome, acute hypersensitivity–type reactions, hypoalbuminemia, and hypotension. Flulike symptoms for several weeks following infusion are frequently noted. Partial responses are reported in 30% and complete responses in 10% of patients.

Histone deacetylase inhibitors (HDACi) inhibit the deacetylation of histone proteins associated with DNA and nonhistone proteins. The exact mechanism involving the treatment of CTCL is unknown, but DNA microarray studies show that HDACi affects the expression of numerous genes and proteins involved in cell proliferation, migration, and apoptosis. Oral Vorinostat (suberoylanilide hydroxamic acid) targets HDAC class 1 and class 2 HDAC enzymes and is FDA-approved for the treatment of refractory CTCL, with response rates of 24% to 30%. Ongoing studies are looking at HDACi used in combination with other therapies (phototherapy, ECP, and oral bexarotene).

Gardner JM, Evans KG, Musiek A, et al: Update on treatment of cutaneous T-cell lymphoma, Curr Opin Oncol 21(2):131–137, 2009.