A phase II, multicenter, open-label, 3-cohort trial evaluating the efficacy and safety of vismodegib in operable basal cell carcinoma

Abstract

BackgroundVismodegib is approved for treatment of advanced basal cell carcinoma.ObjectiveWe sought to characterize vismodegib efficacy and safety in operable basal cell carcinoma.MethodsPatients with new, operable, nodular basal cell carcinoma received vismodegib (150 mg/d) followed by excision and Mohs micrographic surgery to ensure clear margins. Cohort 1 received vismodegib for 12 weeks; cohort 2 received vismodegib for 12 weeks, then 24 weeks of observation before excision; and cohort 3 received vismodegib for 8 weeks on/4 weeks off/8 weeks on.ResultsIn all, 24 patients enrolled in cohort 1, and 25 in cohorts 2 and 3. Complete histologic clearance was achieved by 42%, 16%, and 44% of patients in cohorts 1, 2, and 3, respectively. Muscle spasms (76%), alopecia (58%), and dysgeusia (50%) were the most frequent adverse events (AEs). Five (7%) patients discontinued treatment because of an AE. AE reversibility was evaluated in cohort 2 with 24 weeks of observation after treatment discontinuation.LimitationsNonrandomized, small cohort sizes, and short observation durations for some patients are limitations.ConclusionPrimary efficacy end points were not met (predefined complete histologic clearance rate: >50% in cohorts 1 and 3; >30% in cohort 2). Safety was comparable when dosed continuously versus intermittently. Posttreatment reversibility of vismodegib-related AEs was demonstrated. Vismodegib is approved for treatment of advanced basal cell carcinoma. We sought to characterize vismodegib efficacy and safety in operable basal cell carcinoma. Patients with new, operable, nodular basal cell carcinoma received vismodegib (150 mg/d) followed by excision and Mohs micrographic surgery to ensure clear margins. Cohort 1 received vismodegib for 12 weeks; cohort 2 received vismodegib for 12 weeks, then 24 weeks of observation before excision; and cohort 3 received vismodegib for 8 weeks on/4 weeks off/8 weeks on. In all, 24 patients enrolled in cohort 1, and 25 in cohorts 2 and 3. Complete histologic clearance was achieved by 42%, 16%, and 44% of patients in cohorts 1, 2, and 3, respectively. Muscle spasms (76%), alopecia (58%), and dysgeusia (50%) were the most frequent adverse events (AEs). Five (7%) patients discontinued treatment because of an AE. AE reversibility was evaluated in cohort 2 with 24 weeks of observation after treatment discontinuation. Nonrandomized, small cohort sizes, and short observation durations for some patients are limitations. Primary efficacy end points were not met (predefined complete histologic clearance rate: >50% in cohorts 1 and 3; >30% in cohort 2). Safety was comparable when dosed continuously versus intermittently. Posttreatment reversibility of vismodegib-related AEs was demonstrated.