The European Commission approved Actelion’s Ledaga® (chlormethine gel) for the topical treatment of mycosis fungoides type cutaneous T-cell lymphoma (MF-CTCL) in adults. The firm said it now has to fulfill a list of post-approval measures that have been agreed with the EC’s Committee for Medicinal Products for Human Use (CHMP) and doesn’t anticipate launching Ledaga in Europe before 2018.

European marketing authorization was based on data from the pivotal, 12-month 201 study, which compared treatment using chlormethine gel with topical chlormethine HCl 0.02% compounded in Aquaphor® ointment. The results found that 77% of evaluable patients treated with chlormethine gel achieved a clinical response (at least a 50% improvement in the Composite Assessment of Index Lesion Severity, or CAILS, score), compared with 59% of patients treated using the compounded control. Actelion claims the trial, involving 260 patients with Stage I and IIA MF-type CTCL, represents the largest randomized controlled study conducted to date in early-stage MF-CTCL.

Chlormethine gel has been commercially available in the U.S., as Valchlor® (mechlorethamine) since 2013 and and in Israel since 2016 through a special import authorization procedure. Patients in France have had access to the drug since 2014 under a temporary authorization for use (ATU) program.

In January, Actelion and Johnson & Johnson announced a $30 billion takeover deal for the Swiss firm, through which Actelion will spin out its drug discovery and early clinical assets into a new biopharma company.

Actelion has a marketed portfolio of oral, inhaled, and intravenous drugs for treating pulmonary arterial hypertension (PAH), along with marketed drugs for rare diseases, including type 1 Gaucher disease, Niemann Pick type C disease, and digital ulcers in patients with systemic sclerosis and MF-CTCL. The firm reported total product sales of CHF2.4 billion (approximately $2.37 billion) in 2016, up 15% at CER on 2015 sales.