Abstract 3221: Patients with glioblastoma (GBM) treated with tumor treating fields (TTFields) therapy: post-marketing safety data over the last decade
Authors: Mrugala Maciej M. , Shi Wenyin , Iwamoto Fabio , Lukas Rimas V. , Palmer Joshua D. , Suh John H. , Glas Martin 
Published: April 2023

Patients with glioblastoma (GBM) face poor outcomes; the 5-year survival rate is 7% with standard of care treatments, which are frequently associated with systemic toxicity. Tumor Treating Fields (TTFields) are electric fields that disrupt critical cancer cell processes. The TTFields therapy device consists of a portable electric field generator and arrays placed on the patient’s scalp, thus delivery is locoregional and noninvasive. Currently, TTFields therapy is approved for recurrent and newly diagnosed GBM, based on the phase 3 EF-11 (TTFields 200 kHz) and EF-14 studies (TTFields therapy 200 kHz + temozolomide), respectively. These studies confirmed that TTFields therapy had a tolerable safety profile with mild-to-moderate localized skin adverse events (AEs) being the most common related AEs. Here, we present an updated analysis of the largest global real-world evidence dataset of patients with brain tumors receiving TTFields therapy over an 11-year time period. Unsolicited safety data were obtained from routine post-marketing activities, including published literature and interactions with patients, caregivers, and healthcare professionals. Safety data were grouped according to age, diagnosis, and sex. AEs were categorized using MedDRA version 25. Data from 25,898 patients were included in this analysis; median age was 59 years (range: 3-103) for patients with known age. Diagnoses were ndGBM (67.7%), rGBM (26.1%), anaplastic astrocytoma/oligodendroglioma (4.2%) and other (2.1%). Most (n=17,817, 68.8%) patients were 18-65 years of age; n=93 (0.4%) were pediatric/adolescent patients (&lt;18 years), and n=7,808 (30.2%) were elderly patients (&gt;65 years). For 130 patients (0.5%) age was not known. Two-thirds of patients were male, which reflects the preponderance of CNS tumors in males. Most patients were based in North America (72.1%), followed by Europe, the Middle East and Africa (23.3%), and Japan (4.6%). Overall, 72.4% of patients experienced at least one AE, with 55.9% being related to TTFields therapy. The most common AEs (overall and related to TTFields therapy) were skin reactions (42.0%), electric (tingling) sensations (13.5%), and heat (warmth) sensations (11.8%). The percentage of patients experiencing ≥1 AE in the pediatric/adolescent, 18-65, and elderly groups was 63.4%, 74.6%, and 68.4%, respectively. The percentage of females and males experiencing ≥1 AE was 75.2% and 70.9%, respectively. These long-term, real-world data from the largest global dataset of patients with brain tumors using TTFields therapy to date demonstrate a tolerable safety profile consistent with pivotal clinical studies. There were no new safety signals, and most AEs were manageable localized mild-moderate skin events that can be resolved. The distribution of AEs between age and sex was similar, with broad applicability among different patient groups.

Citation Format: Maciej M. Mrugala, Wenyin Shi, Fabio Iwamoto, Rimas V. Lukas, Joshua D. Palmer, John H. Suh, Martin Glas. Patients with glioblastoma (GBM) treated with tumor treating fields (TTFields) therapy: post-marketing safety data over the last decade [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 3221.