Clinical, pathologic, and radiologic response in patients with neurofibromatosis type 2 (NF2) undergoing bevacizumab treatment.

e13049 Background: NF2 is a rare inherited genetic condition characterized by multiple "benign" tumors in the peripheral and central nervous system. Profound hearing loss as a result of bilateral vestibular schwannomas is a major debilitating complication with a profound effect on quality of life. Vascular endothelial growth factor (VEGF) has been shown to be produced by vestibular schwannoma tumor cells. Bevacizumab, a humanized monoclonal antibody against VEGF, has been proposed as a treatment for patients with advanced NF2, who are poor candidates for surgery and radiation therapy. The aim of this study was to investigate and assess the benefit of treatment with bevacizumab in the treatment of patients with advanced NF2. Methods: Five patients with inoperable NF2 were assessed prospectively from 03/12-01/13. Pathological assessment of tissue for vascularity was performed in each of the patients’ tissue. Objective assessments, including audiogram and MRI brain, were performed pre- and during therapy. Qualitative assessments were undertaken to assess subjective response to treatment. Results: We identified 5 patients with advanced NF2 [n=5], 3 female 2 male with a median age 40 years [range 28 – 52] as outlined in the Table. Tumor-volume reduction of >20% was noted on MRI imaging in the vestibular schwannomas of 2 patients. 2 patients showed objective improvement on audiogram with subjective hearing improvement also noted. Other subjective responses noted include increased energy levels, less headaches, better concentration. Conclusions: Bevacizumab treatment in patients with advanced NF2 resulted in some symptomatic improvement, tumour shrinkage, improvement in disability. Patients with vestibular schwannomas appeared to receive the most benefit, and so in terms of palliation, the benefits may be most significant in patients with specific disabilities, such as hearing loss. [Table: see text]