Background The hedgehog pathway inhibitor sonidegib demonstrated meaningful tumor shrinkage in more than 90% of patients with locally advanced basal cell carcinoma (BCC) or metastatic BCC in the BCC Outcomes with LDE225 Treatment study. Objective This report provides long-term follow-up data collected up to 12 months after the last patient was randomized. Methods In this multicenter, randomized, double-blind phase II study, patients were randomized 1:2 to sonidegib 200 or 800 mg. The primary end point was objective response rate assessed by central review. Results Objective response rates in the 200- and 800-mg arms were 57.6% and 43.8% in locally advanced BCC and 7.7% and 17.4% in metastatic BCC, respectively. Among the 94 patients with locally advanced BCC who responded, only 18 progressed or died and more than 50% had responses lasting longer than 6 months. In addition, 4 of 5 responders with metastatic BCC maintained an objective response. Grade 3/4 adverse events and those leading to discontinuation were less frequent with sonidegib 200 versus 800 mg (38.0% vs 59.3%; 27.8% vs 37.3%, respectively). Limitations No placebo or comparator arms were used because sonidegib demonstrated efficacy in advanced BCC in a phase I study, and the hedgehog pathway inhibitor vismodegib was not yet approved. Conclusion With longer follow-up, sonidegib demonstrated sustained tumor responses in patients with advanced BCC.