Mechlorethamine gel for the topical treatment of stage IA and IB mycosis fungoides-type cutaneous T-cell lymphoma.

Mycosis fungoides (MF) is an extranodal non-Hodgkins lymphoma of T-cell origin. MF is the most common type and can be stratified as early (IA-IIA) or late (IIB or greater) stage disease. Patients with patch disease usually have a benign, chronic course. Patients with plaques have a worse prognosis and need more aggressive therapy. Topical nitrogen mustard ([NM]; mechlorethamine hydrochloride) has been used for MF since the 1950s. Complete response rates reported for stage IA are 76-80% and 35-68% for stage IB. Most common toxicities reported are irritant contact dermatitis, allergic reaction and hyperpigmentation. There is a potential for risk of non-melanoma skin cancers reported with NM use in patients who used multiple skin damaging therapies. This article focuses on the clinical trial that led to the US FDA approval of VALCHLOR for stage IA and IB MF in 2013 after one prior treatment (excluding NM within 2 years or carmustine therapy ever).