Topical photochemotherapy of vitiligo with a new khellin formulation preliminary clinical results

The benefits of using topical photochemotherapy for the treatment of vitiligo are the avoidance of systemic effects and a reduction in carcinogenic potential, but it can produce severe phototoxic reactions. Since khellin has phototherapeutic properties similar to those of the psoralens without the phototoxic effects and without the formation of detectable DNA mutations, it has been used in the treatment of vitiligo with controversial results. The aim of this study was to evaluate the efficacy of a novel gel formulation of khellin, based upon a water/2-propanol/propylene glycol (WPG) ternary system, in the topical phototherapy of vitiligo. A total of 36 patients suffering from different types of vitiligo underwent a 6-month period of treatment. A 1% gel formulation of WPG and khellin was applied to one side of the body and as a control only the WPG vehicle to the other side, 30 min before UVA exposure. The khellin-WPG preparation showed increased solubility with enhanced patient compliance. Repigmentation (> 10% of the initially affected area) occurred in 86.1% of the khellin-WPG-treated sides vs 66.6% of the placebo-treated sides (P < 0.01). Young patients with a short duration of disease demonstrated a better response. Our results indicate that treatment with topical khellin-WPG gel preparation combined with UVA significantly improves the clinical outcome of patients with vitiligo by facilitating the availability of the drug in the skin.