Resolution of Odontogenic Keratocysts of the Jaw in Basal Cell Nevus Syndrome With GDC-0449

Background: Odontogenic keratocysts of the jaw are a central feature of basal cell nevus syndrome (BCNS) and arise from the basal cell layer of the surface epithelium. Although they are benign, they tend to be aggressive, with local invasion of bony structures, extensive growth, and potential for substantial disfigurement and speech dysfunction. Complete surgical resection is the current standard of care; however, the procedures are often technically challenging and are followed by high recurrence rates. Observations: We report the case of a 55-year-old man with a long-standing history of BCNS. Over a 25-year period, this patient had been treated for many basal cell carcinomas (BCCs). He also had multiple large odontogenic keratocysts in the mandible that had previously been treated using surgical, chemotherapeutic, and radiation treatment techniques. He had also undergone a right inguinal lymph node dissection after BCC metastasis was diagnosed within a lymph node. Owing to the recalcitrant nature of his condition and his history of BCC metastasis, the patient was started on a daily regimen of a new oral drug, GDC-0449, which inhibits the hedgehog signaling pathway, a key genetic contributor in the oncogenesis of BCCs. In addition to complete resolution of all his BCCs at 12-week follow-up, nearly complete resolution of 3 odontogenic keratocysts was documented by serial dental radiographs after 2 years of therapy. Conclusions: We report the nearly complete regression of multiple BCNS-associated odontogenic keratocysts following nonsurgical treatment with GDC-0449. This novel drug, useful for the treatment of BCC, also appears to be effective for treatment of odontogenic keratocysts.