Low-Dose Vismodegib as Maintenance Therapy After Locally Advanced Basal Cell Carcinoma Complete Remission: High Efficacy with Minimal Toxicity.

introductionLocally advanced basal cell carcinoma (laBCC) has always represented an uncommon, difficult-to-treat form of skin cancer, but approval of the Hedgehog inhibitor (HHI) vismodegib has provided an effective, well-tolerated therapy. While this drug has been shown to be a safe and effective during treatment, to date the effect of its prolonged use at a low dose after complete remission (CR) of laBCC has not been described. The aim of this study was to report our experience regarding the long-term efficacy of low-dose vismodegib as maintenance therapy in patients with CR of the disease during a 1-year follow-up period.

methodsAn observational retrospective study was conducted at the Non-Melanoma Skin Cancer Unit of the University of Federico II (Naples). Patients who reported complete regression of their advanced BCC after vismodegib treatment were included in the study and subsequently separated into two groups. One group of patients continued with the "drug holiday" regimen consisting of a once-weekly maintenance dosage of 150 mg vismodegib for 1 year after CR of their BCC; the second group comprised patients who decided not to take a maintenance dosage following complete regression of their BCC.

resultsA total of 42 patients (35 males, 7 females) with a median age of 75.2 years and complete regression of their advanced BCC after treatment with vismodegib were included in the study. Of these, 27 (64%) patients continued with the "drug holiday" regimen, receiving a once-weekly maintenance dosage of 150 mg vismodegib for 1 year after CR of their BCC, and 15 (36%) patients decided not to take the maintenance dosage. Patients who continued to receive the low-dose vismodegib treatment did not present any BCC recurrence during 1-year follow-up period, while those who discontinued vismodegib treatment reported a BCC recurrence rate of 26.6% (4/15 patients) during the 1-year follow-up period.

conclusionsOur retrospective analysis focused on the use of a novel therapeutic scheme based on prolonged use of vismodegib after CR of the laBCC. The results demonstrate that the maintenance dose of vismodegib described herein effectively eliminated skin tumor recurrence and reduced the severity of common adverse events, thus increasing patient compliance.