European Commission approves Ledaga (chlormethine gel) to treat mycosis fungoides-type cutaneous T-cell lymphoma. -Actelion

Actelion Ltd announced that the European Commission has granted marketing authorization for the use of Ledaga (chlormethine gel) 160 micrograms/g (Valchlor in the US) for the treatment of mycosis fungoides-type cutaneous T-cell lymphoma (MF-CTCL).MF-CTCL is a rare, potentially life-threatening immune system cancer that is chronic and usually progresses slowly. The course of disease in individual patients is unpredictable. In about 34% of cases, a progression of the disease is observed, and in the most advanced stages, MF-CTCL cells can metastasize to other body tissues, including the liver, spleen and lungs.

Ledaga is indicated for the topical treatment of mycosis fungoides-type cutaneous T-cell lymphoma (MF type CTCL) in adult patients. The market authorization for Ledaga is based on the results of the pivotal 201 study, the largest randomized controlled study ever conducted in early stage MF-CTCL, involving 260 patients. In this study, within the efficacy evaluable (EE) population, 77% of patients who were treated for at least 6 months with chlormethine gel achieved a clinical response in the Composite Assessment of Index Lesion Severity (CAILS) score, while 59% of those treated with the compounded control had a clinical response. A response was defined as at least a 50% improvement in the baseline CAILS score. Complete response was achieved in 19% of patients treated with chlormethine gel in the EE population versus 15% of patients treated with the compounded control. Reductions in mean CAILS scores were seen as early as four weeks into the study, with further reductions observed with continuing therapy.

Comment:The cause of mycosis fungoides remains unknown and there is no known cure. Unlike most non-Hodgkin's lymphomas, mycosis fungoides is caused by a mutation of T-cells. The malignant T-cells in the body initially migrate to the skin, causing various lesions, which typically begin as what appears to be a rash and may progress to form plaques and disfiguring tumours.

Comment: Chlormethine gel, under the brand name Valchlor (mechlorethamine) is commercially available in the US (since 2013) and in Israel through special import authorization procedure (since 2016). In France, patients benefit from the drug under a temporary authorization for use ("ATU") program initiated during the second half of 2014.