A retrospective analysis of irinotecan and bevacizumab combination therapy in recurrent high-grade glioma and glioblastoma multiforme

Abstract

Introduction: High-grade gliomas comprise central nervous system (CNS) World Health Organization (WHO) Grade 3 and CNS WHO Grade 4 gliomas. Recurrence is seen in almost all patients who underwent treatment. Recurrent high-grade gliomas have poor prognosis. There are phase two trials that assessed the role of irinotecan and bevacizumab as combination regimen in recurrent High-grade gliomas and showed overall survival (OS) and progression-free survival (PFS) benefit. We did a retrospective analysis of our institutional experience on treating recurrent high-grade gliomas with combination of irinotecan and bevacizumab. Materials and Methods: This was a retrospective analysis including 58 patients treated at our center from January 1, 2010 to December 31, 2020. All patients were diagnosed case of CNS WHO Grade 3 and Grade 4 glioma, who received at least one modality of treatment. All patients received inj. Irinotecan 125 mg/m2 intravenous (IV) and inj. Bevacizumab 10 mg/kg IV, every 2 weekly. A base line radiological evaluation has been done with magnetic resonance imaging brain with contrast and repeated every 3 months. Patients have been assessed both for PFS and OS. Results: Median PFS was 6 months (95% confidence interval [CI] 4.395–7.605). Median OS was 8 months (95%CI 5.894–10.106). Six months PFS rate is 49% and 6 months OS is 58%. CNS WHO Grade 3 gliomas responded better to combination therapy as compared with CNS WHO Grade 4 gliomas. Conclusion: Combination of Bevacizumab and Irinotecan is well tolerated and improves OS and PFS in patients with recurrent high-grade gliomas. The effect of combination systemic therapy is more evident in CNS WHO Grade 3 gliomas as compared with glioblastoma multiforme.