This is a Phase II, 28 month, randomized, two arm multicenter clinical study design. During the initial 7 months of the study, all 24 subjects will receive vismodegib, 150mg/day. They then will be randomized in a 1:1 ratio to receive intermittent vismodegib, 150 mg/day, during months 10-13, 16-19, and 22-25 or to receive treatment with PDT at month 10 and at three month intervals thereafter. The safety and efficacy of intermittent vismodegib and of PDT will be assessed at the time of the subjects' visits to the Study Center and at the time of telephone contacts. A Data Safety Monitoring Board (DSMB) will review results for an interim analysis when 12 subjects have completed 28 months. The DSMB review will focus on adverse events and efficacy results. Subjects will be monitored for the presence of surrogate endpoint biomarkers (SEBs) at each Study visit.
The purpose of this study is to evaluate and compare the safety and efficacy of intermittent vismodegib and of Photodynamic Therapy (PDT).