Phase 2 Study of Bevacizumab in Children and Young Adults With NF 2 and Progressive Vestibular Schwannomas

Subjects will be treated with open-label bevacizumab 10 mg/kg every 2 weeks for 24 weeks (induction therapy). Clinical response will be assessed by audiology and MRI at weeks 12 and 24. Subjects with hearing decline at weeks 12 or 24 will be taken off of protocol. At week 24, patients with a clinical response or stable disease (together comprising "clinical benefit") will transition to maintenance therapy with bevacizumab. During the maintenance phase, subjects will be treated with open-label bevacizumab 5 mg/kg every 3 weeks for up to 72 weeks. Subjects will be followed with audiology and MRI scans every 12 weeks. The total time of the study will be 96 weeks (24 weeks induction + 72 weeks maintenance). Subjects will be allowed to increase their bevacizumab dose to 10 mg/kg every 2 weeks during maintenance therapy if they experience hearing decline during maintenance therapy (defined as decrease in word recognition score below the 95% critical difference compared with the word recognition score at baseline, Appendix A). Subjects will be taken off of study if their word recognition score does not remain within the 95% critical difference after receiving bevacizumab 10 mg/kg every 2 weeks.