Facial Palsy As a Side Effect of Vemurafenib Treatment in Patients With Metastatic Melanoma

Effect of Vemurafenib Treatment in Patients With Metastatic MelanomaCase Report A 63-year-old man (Table 1) presented in June 2009 with a large destructive lesion in the right calcaneus, which was confirmed as metastatic melanoma that was positive for the melanocyte differentiation antigens HMB-45 and S100 on immunohistochemical staining.Additional metastatic sites included the right femur, right deltoid muscle, right axillary lymph nodes, right atrium, and a large mediastinal mass.There was no previous melanoma history, and a primary melanoma could not be identified at the time of diagnosis.The right foot was amputated for pain control, and palliative radiotherapy was administered to the axillary and femoral metastases.The soft tissue metastasis from the deltoid muscle was surgically removed and molecular testing demonstrated the presence of a BRAF V600E mutation.After two cycles of dacarbazine chemotherapy, there was progressive disease with a new left-sided rib metastasis.The patient was enrolled in the BRAF in Melanoma Phase 2 (BRIM2) clinical trial of the potent BRAF inhibitor vemurafenib. 1 After 8 weeks of therapy, an acute complete right-sided facial palsy developed, followed 10 days later by a facial palsy on the contralateral side (Fig 1A).A detailed clinical examination by a consultant neurologist revealed no other neurologic deficits, and a magnetic resonance imaging scan of the brain was unremarkable apart from an enhancement of the right seventh cranial nerve in the facial canal.The clinical findings and investigations were in keeping with idiopathic bilateral peripheral facial nerve palsy (Bell's palsy).Vemurafenib was