P01.076 Experience with tumor treating fields (TTFields, Optune®) in Israel - patient compliance and adverse effects

Abstract

Background

TTFields are low intensity, intermediate frequency alternating electric fields, delivered through a portable, non-invasive device (Optune, Novocure ^TM). The EF-14 phase III trial showed significant prolongation of both progression-free and overall survival in newly diagnosed glioblastoma (GBM) patients. This is the first report on clinical experience with 110 patients treated with TTFields in Israel, focusing on safety and patient acceptance in our country.

Material and Methods

Patients received Optune-prescription in 6 neuro-oncology centers in Israel and used the device for at least one month. The cohort included both newly diagnosed (n=53) and recurrent GBM (n=57) patients. The male/female ratio was 74/36 with a median age of 58.0 (18–82) years at start of treatment. Of patients with recurrent GBM, 51% were treated at first progression.

Results

Our data shows a high acceptance, with a compliance rate (monthly usage of the device) within the first 3 months of 80% for newly diagnosed GBM and 66% for recurrent GBM. Median treatment compliance was independent of age, sex and stage of disease. In addition, our data indicates that the compliance is not negatively correlated with time on treatment, as the median compliance for newly diagnosed GBM patients was still at 79% within the first 6 months. With regards to device-related side effects, data shows that in total 30 patients (27%) experienced mild-moderate skin irritations that were usually manageable with local steroid creams and did not cause significant treatment breaks despite the warm climate in Israel. Other side effects related to the device were heat sensation in 10 patients (9%) and electric sensation in 9 patients (8%) that did not cause significant treatment interruption.

Conclusion

The accumulating clinical experience shows that TTFields are well-tolerated by patients in Israel without any major deviation from reported treatment-related side effects. Treatment compliance remains stable during a 6-month period.