Recent clinical evidence for topical mechlorethamine in mycosis fungoides

Joya Sahu, Marjan Sepassi, Mitchell Nagao & Youn H Kim

Mycosis fungoides (MF) is a rare, potentially life-threatening cutaneous T-cell lymphoma characterized by cutaneous homing of neoplastic T lymphocytes. MF can mimic other diseases; clinicopathologic evaluation and imaging studies are essential. Biopsy of suspicious skin sites is essential for diagnosis. Topical mechlorethamine has been clinically tested over decades for the treatment of MF. Safety concerns include contact dermatitis, pruritus and hyperpigmentation. Nonmelanoma skin cancers have been reported with topical mechlorethamine use, including in patients who received therapies known to cause nonmelanoma skin cancer. Noninferiority to mechlorethamine ointment in a Phase II controlled trial led to the US FDA 2013 approval of VALCHLOR™ (mechlorethamine gel) for treatment of stage IA/IB MF after prior skin-directed therapy.