The U.S. Food and Drug Administration has approved Valchlor (mechlorethamine) gel to treat patients with stages IA and IB mycosis fungoides-type cutaneous T-cell lymphoma (CTCL) who have received prior skin-directed therapy. Mechlorethamine-a non-greasy, quick-drying gel applied once daily-is a chemotherapeutic agent previously approved for intravenous treatment of mycosis fungoides, the most common type of CTCL.
Topical mechlorethamine preparations are currently recommended for the treatment of early stage CTCL by the National Comprehensive Cancer Network. But, prior to the approval of Valchlor, there were no FDA-approved topical mechlorethamine products-only non-standardized, pharmacy-compounded petroleum ointment or aqueous-based topical preparations were available.
The drug's approval is based on a randomized, observer-blinded, non-inferiority trial comparing Valchor to a pharmacy-compounded mechlorethamine preparation in 260 patients with stages IA-IIA CTCL who had received at least one prior skin-directed therapy (which included topical corticosteroids, phototherapy, Targretin gel, and topical mechlorethamine). Patients were not required to be refractory to or intolerant of prior therapies. Sixty percent of the patients treated with Valchlor had a confirmed response at 12 months (defined as reduction of at least 50 percent in the Composite Assessment of Index Lesion Severity score), while 48 percent of those treated with the compounded control achieved a confirmed response.
The most common side effects associated with Valchlor were local skin reactions (including dermatitis), pruritus, bacterial skin infections, skin ulceration, and skin hyperpigmentation. No systemic absorption of mechlorethamine was detected with Valchlor treatment.