Topical Chemotherapy
Mechlorethamine
Brand name: Valchlor®

Mechlorethamine, also known as nitrogen mustard (NM), is one of the oldest and best-studied medications for cutaneous T-cell lymphoma (CTCL). Mechlorethamine is an anti-cancer drug that works in part by blocking DNA replication in tumor cells. Mechlorethamine was originally developed as an intravenous cancer chemotherapy (Mustargen®), but is very safe and effective when used topically (externally), as with Valchlor®, for early stage (Stage IA, IB, and IIA) CTCL.

Topical mechlorethamine is available as a compounded (mixed) product from specialty pharmacies or as a pre-made gel (Valchlor®). Improvement in CTCL with mechlorethamine has been observed as soon as one month, with peak responses occurring after 6-18 months.

Mechlorethamine should be applied to a dry skin surface area at a time when it can remain on the skin for at least four hours. It need not be washed off after application. Hands should be washed after application.

The most frequent complication of topical mechlorethamine therapy is the development of an irritant reaction (redness, itching or stinging) which usually subsides with a dose or application frequency adjustment. Approximately ten percent of individuals may develop an allergic reaction (allergic contact dermatitis) which usually occurs within three to six weeks after initiation of treatment. Symptoms of allergic contact dermatitis include redness, burning, stinging, or itching. In severe cases, the skin may develop blisters, like a poison ivy reaction. 

Topical mechlorethamine is often combined with topical steroids to minimize irritation, and may be combined with systemic (internal) agents.