Phase II Trial of Upfront Bevacizumab, Irinotecan, and Temozolomide for Unresectable Glioblastoma

Abstract

Abstract Lessons Learned Trials focusing on unresectable multifocal glioblastoma are needed because of the extremely poor prognosis and challenges in receiving standard therapy, such as concurrent radiation and chemotherapy. Developing a strategy to chemically debulk tumors before radiation and/or surgery is warranted. Background. Extent of resection remains a key prognostic factor in glioblastoma (GBM), with gross total resection providing a better prognosis than biopsy or subtotal resection. We conducted a phase II trial of upfront therapy with bevacizumab (BV), irinotecan (CPT-11), and temozolomide (TMZ) prior to chemoradiation in patients with unresectable, subtotally resected, and/or multifocal GBM. Methods. Patients received up to 4 cycles of TMZ at 200 mg/m2 per day on days 1–5 (standard dosing) and BV at 10 mg/kg every 2 weeks on a 28-day cycle. CPT-11 was given every 2 weeks on a 28-day cycle at 125 mg/m2 or 340 mg/m2 depending on antiepileptic drugs. Magnetic resonance imaging of the brain was done every 4 weeks, and treatment continued as long as there was no tumor progression or unmanageable toxicity. The primary endpoint was tumor response rate, with a goal of 26% or greater. Results. Forty-one patients were enrolled from December 2009 to November 2010. Radiographic responses were as follows: 9 patients (22.0%) had partial respons!e, 25 (61.0%) had stable disease, and 2 (4.9%) had progression; 5 patients were not assessed. Cumulative response rate was 22%. Median overall survival was 12 months (95% confidence interval: 7.2–13.5 months). Conclusion. Upfront treatment with BV, TMZ, and CPT-11 is tolerable and can lead to radiographic response in unresectable and/or subtotally resected GBM.