Phase II study of concurrent radiation therapy, temozolomide, and bevacizumab followed by bevacizumab/everolimus as first-line treatment for patients with glioblastoma.

PURPOSE

To evaluate the efficacy of adding bevacizumab, a vascular endothelial growth factor (VEGF) inhibitor, and everolimus, a mammalian target of rapamycin (mTOR inhibitor), to standard radiation therapy/temozolomide in the first-line treatment of patients with glioblastoma.

PATIENTS AND METHODS

Following surgical resection or biopsy, patients with newly diagnosed glioblastoma received standard radiation therapy/temozolomide plus bevacizumab 10 mg/kg intravenously (IV) every 2 weeks. Four weeks after the completion of radiation therapy, patients began oral everolimus 10 mg daily, and continued bevacizumab every 2 weeks; therapy continued until tumor progression or unacceptable toxicity.

RESULTS

Sixty-eight patients were treated, 82% of whom had previously undergone partial or complete surgical resection. Sixty-four patients completed combined modality therapy, and 57 patients began maintenance therapy with bevacizumab/everolimus. Thirty-one of 51 patients (61%) with measurable tumor had objective responses. After a median follow-up of 17 months, the median progression-free survival (PFS) was 11.3 months (95% confidence interval [CI], 9.3-13.1 months); median overall survival was 13.9 months. Toxicity was consistent with the known toxicity profile of bevacizumab; grade 3/4 toxicities during maintenance therapy related to everolimus included fatigue (27%), pneumonitis (7%), and stomatitis (5%).

CONCLUSIONS

The use of bevacizumab and everolimus as part of first-line combined modality therapy for glioblastoma was feasible and efficacious. The PFS compared favorably to previous reports with standard radiation therapy/temozolomide therapy, and is similar to results achieved in other phase II trials in which bevacizumab was added to fist-line treatment. Ongoing randomized phase III trials will clarify the role of bevacizumab in this setting.