This is a double-blind, dose escalating, randomized, vehicle-controlled study designed to compare the efficacy and safety of patidegib gel 2% and 4% applied once or twice daily in comparison with that of vehicle in patients with Basal Cell Carcinoma. One investigational center (metasite) in the United States will participate in this study. Approximately 36 subjects who meet the study entry criteria will be enrolled into one of four sequential cohorts. Within each cohort subjects will be randomized in a 2:1 ratio to receive active or vehicle gel.