TTFields and Pulsed Bevacizumab for Recurrent Glioblastoma

Glioblastoma multiforme (GBM) is the most common and deadliest primary malignant neoplasm of the central nervous system in adults. Despite an aggressive multimodality treatment approach including surgery, radiation therapy and chemotherapy, overall survival remains poor. Novocure has shown that when properly tuned, very low intensity, intermediate frequency electric fields (TTFields) stunt the growth of tumor cells. The Optune system (NovoTTFTM Therapy) is a portable battery operated device, which produces TTFields within the human body by means of surface transducer arrays. The TTFields are applied to the patient by means of surface transducer arrays that are electrically insulated, so that resistively coupled electric currents are not delivered to the patient. Optune is currently FDA-approved as a single modality treatment for recurrent GBM when both surgical and radiotherapy options have been exhausted as well as combination with adjuvant temozolomide for newly diagnosed GBM. This research study is being performed to determine whether or not TTFields combined with pulsed bevacizumab treatment increases overall survival in patients with bevacizumab-refractory GBM compared to historical controls treated with continuous bevacizumab alone or in combination with other chemotherapy.

Subjects who have evidence of bevacizumab-refractory GBM will be eligible to participate in this research study. Subjects will undergo 12 months of planned continuous treatment with TTFields followed by pulsed bevacizumab treatment when there is evidence of further progression per RANO, with the option of extending treatment up to a total of 24 months in patients who have not progressed and/or have adequate performance status at the 12 month mark. Pulsed bevacizumab dosing is defined by at least one cycle on and at least one cycle off. A cycle is defined as 8 weeks in length. If after one cycle on, there is no evidence of a repeat response; bevacizumab will be continued for one more cycle. If after two cycles on, there is no repeat response; bevacizumab will be continued with or without other standard chemotherapy until death. If after at least one cycle on, there is evidence of repeat response, bevacizumab will be discontinued for at least one cycle or until progression is noted again per RANO, whichever is later, at which time pulsed bevacizumab will be restarted as outlined above. The investigators believe that this approach will produce peaks and troughs in mitotic activities of glioma cells that render glioma cells more sensitive to the antimitotic activity of Optune during peak growth rates, thus lowering disease burden and increasing survival. In addition, the following will be performed: Bevacizumab will be given at 10mg/kg IV every 2 weeks. Physical examination and quality of life (QoL) assessments will be performed bi-monthly. Brain MRI will be performed every 2 months.