PEP005 (ingenol mebutate) gel for the topical treatment of superficial basal cell carcinoma: Results of a randomized phase IIa trial

Objectives: To evaluate the safety of two applications of PEP005 (ingenol mebutate) gel in superficial basal cell carcinoma. Efficacy was a secondary end-point. Methods: Randomized, vehicle-controlled, phase IIa study conducted at eight private dermatology clinics in Australia. A total of 60 patients with histologically confirmed superficial basal cell carcinoma (lesion size, 4-15 mm) were randomized to treatment on days 1 and 2 (Arm A) or days 1 and 8 (Arm B) and, within each arm, to ingenol mebutate gel, 0.0025%, 0.01% or 0.05%, or vehicle gel. The main outcome measures were the incidence and severity of adverse events and local skin responses in Arms A and B; lesion clearance at day 85 was a secondary measure. Results: The incidence of adverse events was low. One patient treated with ingenol mebutate gel, 0.05% in Arm A experienced severe flaking/scaling/dryness extending beyond the application site. Non-severe, potentially treatment-related events included erythema extending beyond the application site, application-site pain and headache in two patients each. Six patients in Arm A had one or more severe local skin responses. Efficacy appeared to be dose-related and there was a trend towards higher clinical and histological lesion clearance rates in Arm A compared with Arm B. Histological clearance occurred in five of eight patients (63%) randomized to ingenol mebutate gel, 0.05% in Arm A. Conclusions: Two applications of ingenol mebutate gel, 0.05%, are safe and have efficacy in patients with superficial basal cell carcinoma.