P05.07 Effect of Tumor-Treating Fields plus Short-Course Radiation with or without Temozolomide in Elderly Patients with Glioblastoma (GERAS Trial)

Abstract

Abstract BACKGROUND Despite advances in the therapy of glioblastomas (GBM) in the last decades, the most common malignancy of glial origin is still associated with poor prognosis. At present, maximal safe resection followed by adjuvant chemoradiotherapy (CRT) with temozolomide (TMZ) is the standard of care. After completion of CRT, patients usually receive 6 maintenance cycles of TMZ that may be complemented by Tumor-Treating Fields (TTFields). Regardless of age and other prognostic factors, the recent EF-14 trial has shown that addition of TTFields to the maintenance therapy significantly increases overall survival in all patient subgroups. In the EF-14 trial, TTFields were used during maintenance therapy, however a potential benefit of concomitant TTFields therapy during CRT remains unclear. In elderly patients aged >65–70 years, depending on performance status, hypofractionated (chemo)radiotherapy with or without TMZ is the recommended treatment.The primary aim of the GERAS trials is to investigate the optimal time point to start TTFields therapy in elderly patients, as well as feasibility and safety of treatment with the TTFields device in elderly patients with newly diagnosed glioblastoma during hypofractionated (chemo)radiotherapy. Secondary endpoints include progression-free survival at 6 months, overall survival and quality of life during combined treatment. MATERIAL AND METHODS The GERAS trial is a single centre, randomized, two-arm, phase I/II trial that will recruit a total of 64 patients. Patients undergo stratified randomization into treatment arm A or control arm B.Patients in arm A start TTFields therapy at the beginning of hypofractionated radiotherapy with or without TMZ and continue treatment during maintenance chemotherapy. Patients in arm B receive hypofractionated radiotherapy with or without TMZ and begin TTFields therapy together with maintenance chemotherapy. Patients in both arms will be trained in using the TTFields device by certified device support specialists. Follow-up includes MRI imaging four weeks after (chemo)radiotherapy and then every 12 weeks as well as regular lab testing according to the current standard of care. Patients will be assessed for neurological status, neurocognitive function, compliance with TTFields therapy and adverse events during, four weeks after (C)RT and then every 12 weeks for up to 52 weeks. RESULTS Not applicable due to ongoing trial. CONCLUSION With TTFields, a new element in the maintenance therapy of glioblastomas has found its way into clinical routine. The GERAS trial aims to determine the optimal time point to start TTFields therapy as well as the safety and feasibility of concomitant TTFields- and hypofractionated (C)RT in elderly patients. This may lead the way for further phase II/III trials that evaluate survival benefits in this subpopulation of elderly patients treated with hypofractionated (C)RT.