Abstract CT113: Safety and efficacy of Tumor Treating Fields (TTFields) combined with bevacizumab and systemic chemotherapy in recurrent GBM
Authors: Kang Xun , Cai Zehao , Chen Feng , Zhang Botao , Jiang Bo , Li Wenbin 
Published: April 2023

Background: The treatment of recurrent glioblastoma faces many challenges. The development of new therapeutic approaches and the exploration of biomarkers of therapeutic effectiveness will provide a basis for better tumor control and individualized diagnosis and treatment. TTFields therapy, bevacizumab and second-line chemotherapy are the alternative treatment methods for recurrent gliomas. Especially, the introduction of TTFields has prolonged the tumor control of patients. Clinical studies have shown that bevacizumab combined with chemotherapy can improve the prognosis of patients. In this study, the randomized controlled principle was used to compare TTFields plus second-line chemotherapy and combined chemotherapy on the basis of both, and to explore the safety and effectiveness of combined treatment for patients with recurrent glioblastoma.

Objectives: 1. To evaluate the safety and efficacy of TTFields, bevacizumab, and second-line chemotherapy in the treatment of relapsed GBM. 2. To evaluate the effects of TTFields, bevacizumab and their combination on the permeability of the blood-brain barrier. 3. To explore the correlation between serum VEGF, plasma MMP-2, MMP-3 and other factors and the efficacy of combination therapy.

Methods: A total of 40 patients who met the inclusion criteria were planned to be recruited and randomly assigned to two experimental groups, with 20 patients in each group. On the basis of second-line chemotherapy, patients in each group were treated with TTFields alone, TTFields combined with BEV, respectively. The 6-month survival rate was used as the primary outcome, and the median OS and median PFS were used as the secondary outcomes. The effectiveness and safety of each regimen was evaluated and compared. Krans, CBV, CBF, MTT and other imaging indicators were used to evaluate vascular permeability and blood flow. To compare the differences between BEV alone and BEV combined with TTFields, and to evaluate the efficacy prediction of these hematologic molecules in the combined regimen. Moreover, imaging and hematological indicators were combined to construct a prognostic model that could predict the efficacy of the combined regimen.

Key Issues to be Resolved: 1. To evaluate the comprehensive effect of TTFields combined with BEV treatment on blood-brain barrier permeability and blood perfusion. 2. A prognostic prediction model will be established by combining imaging features and hematological indicators. 3. Preliminarily determine the direction of optimization of the combined treatment program.

Citation Format: Xun Kang, Zehao Cai, Feng Chen, Botao Zhang, Bo Jiang, Wenbin Li. Safety and efficacy of Tumor Treating Fields (TTFields) combined with bevacizumab and systemic chemotherapy in recurrent GBM [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 2 (Clinical Trials and Late-Breaking Research); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(8_Suppl):Abstract nr CT113.