26 | Tumor size may predict early response to sonidegib in locally advanced basal cell carcinoma: clinical and histopathological correlates from a monocentric case series

Background: Sonic Hedgehog (SHH) inhibitors, including sonidegib, have emerged as effective therapies for locally advanced basal cell carcinoma (LA-BCC). However, variability in clinical response has been observed. Objective: to evaluate the correlation between clinical and histopathological characteristics and the initial response to sonidegib in a monocentric series of LA-BCC cases.Methods: A retrospective analysis of 15 patients with LA-BCC treated with sonidegib was conducted. Tumor subtypes and clinical features were correlated with time to initial response using ERIVANCE BCC composite criteria.Results: The mean time to initial clinical response was 15.4 weeks. Tumors >3 cm showed significantly faster response (13.4 weeks) compared to tumors <3 cm (24 weeks), a finding not previously reported. Pigmentation and patient age also showed moderate impact on response time, while histological subtype and other features had less influence.Conclusions: Tumor size appears to be an important predictor of early response to sonidegib. (Fig.1). Larger lesions may exhibit greater metabolic activity, enhancing drug response. These findings merit further validation in larger cohorts.