SURG-06. THE SAFETY PROFILE OF TUMOR TREATING FIELDS (TTFIELDS; 200 KHZ) CONCOMITANT WITH VENTRICULO-PERITONEAL SHUNTS IN PATIENTS WITH GLIOBLASTOMA AND HYDROCEPHALUS

Abstract

Abstract INTRODUCTION Hydrocephalus is a common development in patients with glioblastoma (GBM) requiring treatment with ventriculo-peritoneal (VP)-shunts (programmable/non-programmable). To maximize outcomes in this high-risk population, evaluation of VP-shunt usage concomitant with GBM treatments is necessary. Tumor Treating Fields (TTFields; 200 kHz; anti-mitotic, loco-regional cancer modality) non-invasively delivers continuous, alternating electrical fields per scalp-placed arrays. TTFields treatment has obtained FDA-approval/CE-mark in adult patients with newly-diagnosed GBM (ndGBM) and recurrent GBM (rGBM). Due to insufficient TTFields/VP-shunt usage data, label does not currently advise concurrent use. We report on safety data from adult patients utilizing TTFields/VP-shunts in the real-world, clinical-setting. METHODS This retrospective, post-marketing, safety surveillance analysis evaluated unsolicited data from adult patients with GBM/hydrocephalus who were TTFields-treated in the presence of a VP-shunt. Available data from >18,000 patients with GBM prescribed TTFields (November 1, 2012 to April 15, 2021 [cut-off date]) were screened for eligibility. Included were 156 adult patients (≥ 18 years of age) with confirmed GBM/hydrocephalus and TTFields/VP-shunt (46 programmable; 110 non-programmable/unknown) usage. Patients were further analyzed by diagnosis (ndGBM, n=92; rGBM, n=64). RESULTS Of 156 TTFields/VP-shunt-treated patients (median age 52), 66% were male and 81% from the United States (19%; Europe/Middle-east/Africa). Overall, no TTFields-related shunt-failures or differences by GBM diagnosis in shunt-type and TTFields-related AEs were observed. Commonly-reported TTFields-related adverse events (AEs) >10% were beneath-array skin reactions (∼43%), electric sensations (∼14%; tingling), headache (∼13%), fatigue/malaise (∼12%), and heat sensation (∼11%; warmth); headache and fatigue/malaise are also associated with other concomitant treatments/disease burden. There were 5 serious AEs (all skin AEs) potentially-related to TTFields at the shunt-site (2 events, wound dehiscence; 3 events, skin erosion). CONCLUSIONS Adult patients with GBM/hydrocephalus treated with TTFields (200 kHz)/VP-shunts in the real-world, clinical-setting suggests feasibility and a tolerable safety profile; with no evidence of disrupted VP-shunt effectiveness. TTFields safety profile was consistent with prior-studies.