The primary objective of the Phase I study, which was conducted in Canada, was to determine the cutaneous and systemic toxicity of the topically-applied photoactive drug, SL017, with and without photoactivation. The exploratory objective was to evaluate the efficacy of SL017 with and without photoactivation in the treatment of actinic keratosis.
The study met all the objectives addressing the clinical safety endpoints. There were no observed clinically relevant adverse events associated with the treatment at all the concentrations (0 to 40mg of SL017) and light doses (10 to 20joules/cm) administered. The light treatment, conveniently administered in a dermatology clinic, was well tolerated.
The therapeutic potential of SL017 was evidenced by the expected photodynamic therapy (PDT) effects, such as redness, edema, occasional blisters, stinging and burning. The clinical correlates of dyskeratosis and inflammation were likewise appropriately noted on skin biopsy. Clinical and pathological results correlated very well, and conformed not only to the expected effects of PDT but also to the dosage of the drug and light energy administered.
The study suggests that a 2% topical formulation of SL017 and a fluence of 20joules/cm provide expected PDT outcomes. Importantly, this Phase I study did not identify any safety concerns with respect to the parameters evaluated at the dosages of drug and light employed.
Madi Madiyalakan, CEO of Quest, said: “This trial successfully demonstrated that cutaneous PDT with SL017 appears safe and is well tolerated. In addition, our unique approach is designed to overcome some of the limitations associated with other commercially available PDT treatments for actinic keratosis.”