gms | German Medical Science

Objective: Current treatment of glioblastoma (GBM) includes surgery followed by concomitant radiochemotherapy and adjuvant chemotherapy. Treatment of recurrent tumors is still in the focus of controversy and in the absence of standards, it varies between different centers. Recently, antiangiogenetic therapy regimens have gained special attention. The AVAglio trial and RTOG 0825 offered new insights into combined first-line treatment with bevacizumab. The aim of this study was to analyze the clinical course of patients, who have been treated with bevacizumab in an “off label” monotherapy approach in tumors progressive under second or third line chemotherapy without surgical options.

Method: Data of 23 patients with recurrent gliomas, who received bevacizumab after tumor recurrence were obtained from an institutional database application. A retrospective chart analysis of all malignant glioma patients treated with adjuvant bevacizumab monotherapy in a recurrent situation was performed with respect to relevant aspects like Karnofsky performance score (KPS), prior therapy regimens and therapy-associated haematotoxicity, dexamethasone dosage and co-morbidity.

Results: 23 patients (19 GBM, 4 anaplastic gliomas), having failed first-line radiochemotherapy and various second line treatments with progressive tumors received bevacizumab monotherapy. In all patients bevacizumab was well tolerated and a mean of 11.1 cycles (range 2-33) was given. Major complications were thrombosis (n=2) and gastro-intestinal hemorrhage (n=2). 15 of 23 patients received dexamethasone before bevacizumab therapy, in 10 (66.67%) cases the dosage could be reduced or stopped after 4 bevacizumab cycles. Mean time to progression under bevacizumab was 135 d (range 70-250). Although neuro-imaging showed clear progression, bevacizumab was continued because of clinically stable situation in 10 patients. Despite radiographic progression,a mean KPS of 66% (range 60-80) remained stable for a mean of 6,2 cycles (range 2-19) of continued bevacizumab.

Conclusions: In this cohort bevacizumab monotherapy in progressive malignant gliomas was well tolerated. 74% of patients clinically and radiographically responded to the salvage treatment. The dexamethasone dose could be reduced in the majority of cases. The performance status of patients remained stable well beyond radiographic progression. Therefore bevacizumab monotherapy in progressive recurrent tumors is a well tolerated salvage therapy which in many cases prolongs time to neurological deterioration.