Sonidegib is primarily used in the treatment of advanced basal cell carcinoma, a type of skin cancer, particularly in cases where the tumor has recurred after surgery or in patients who are not candidates for further surgical or radiation interventions. It functions by inhibiting the Hedgehog signaling pathway, which plays a critical role in cell differentiation and proliferation. Abnormal activation of this pathway is linked to the development of certain cancers. By targeting Smoothened, a key protein in this pathway, sonidegib helps suppress tumor growth. It is administered orally and is especially beneficial for locally advanced or metastatic forms of the disease. Its use is often considered when other treatment options are limited, offering a systemic therapy approach to control disease progression.