Positive Results for Mechlorethamine Gel in Cutaneous T-Cell Lymphoma
FDA submission expected in early 2013 (Jan. 30)
The results of a pivotal trial comparing a gel formulation of mechlorethamine hydrochloride 0.02% (Ceptaris Therapeutics) with pharmacy-compounded mechlorethamine 0.02% ointment for the treatment of early-stage mycosis fungoides — the most common form of cutaneous T-cell lymphoma (CTCL) — have been published in JAMA Dermatology.
Topical mechlorethamine preparations are currently recommended as first line-treatment for early-stage CTCL by the National Comprehensive Cancer Network (NCCN). However, no FDA approved topical mechlorethamine products are currently available, and clinicians must use pharmacy-compounded preparations.
The pivotal trial was a randomized, observer-blinded clinical study designed to determine whether mechlorethamine gel was non-inferior to a pharmacy-compounded ointment in patients with mycosis fungoides. The study enrolled 260 patients with stages IA, IB, or IIA disease. Mechlorethamine was applied once daily for up to 12 months. Tumor response and adverse events were assessed every month between months 1 and 6, and every 2 months between months 7 and 12.
The study met or exceeded the prespecified criteria for non-inferiority. Response rates were 58.5% for the mechlorethamine gel versus 47.7% for the compounded ointment, as determined by the Composite Assessment of Index Lesion Severity, and 46.9% versus 46.2%, respectively, as determined by the Modified Severity-Weighted Assessment Tool. The ratio of the gel response rate to the ointment response rate was 1.23, as determined by the Composite Assessment of Index Lesion Severity. Time-to-response analyses demonstrated the superiority of mechlorethamine gel over the ointment preparation (P < 0.01).
Most adverse events related to mechlorethamine gel were characterized as local skin irritation. Approximately 20% of patients treated with the gel withdrew from the study because of these events.
U.S. regulatory submission is expected in early 2013.