UC Irvine

Abstract

INTRODUCTION

Tumor Treating Fields (TTFields) are approved for glioblastoma (GBM) based on two randomized phase 3 trials. The Optune system non-invasively administers TTFields at 200kHz via transducer arrays placed upon a shaved scalp. Despite advancements in the molecular characterization of anaplastic gliomas (AGs), there remains a paucity of treatment options. While Optune is not FDA-approved for AGs, there are several open clinical trials. To further characterize potential safety risks in AG, post-marketing surveillance data are reported for patients with AGs treated with TTFields.

METHODS

A review of adverse events in patients with a diagnosis of anaplastic astrocytoma or anaplastic oligodendroglioma treated with TTFields. Post-market surveillance data were analyzed based on the MedDRA body system (system organ class) preferred terms.

RESULTS

A total of 498 patients with AGs were treated with TTFields in the United States and Europe. Of these, 262 patients (53%) experienced at least 1 adverse event (AE). These included heat sensation in 50 (10%), electric sensation in 36 (7%), headache in 41 (8%) and fatigue in 14 (3%). Skin toxicity was the most common type of AE reported in 152 patients (31%) and included skin reaction (30%), skin ulcer (3%), hyperhidrosis (3%), and rash (<1%). These findings as well as the incidence of other reported AEs were in line with glioblastoma phase 3 trials.

CONCLUSION

In this retrospective review of available post-marketing surveillance data, there were no unexpected adverse events when TTFields were used in patients with AGs. The incidence of the most common AE, skin reaction, as well as other reported AEs were comparable with rates observed in the EF-11 trial for patients with recurrent GBM, and the EF-14 trial for patients with newly diagnosed GBM. This data supports further investigation on safety and efficacy of TTFields in patients with AGs, and prospective studies are currently planned.