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. Approximately 36 subjects who meet the study entry criteria will be enrolled into one of four sequential cohorts. As soon as one cohort has been completely enrolled, the next cohort will be enrolled. Each subject will treat no more than two previously untreated biopsy confirmed treatment-targeted nodular BCCs. If the subject has additional non-treatment targeted BCCs they can be treated surgically prior to or during the trial. Within each cohort subjects will be randomized in a 2:1 ratio to receive active or vehicle gel. The sequential cohorts will be: