P03.11 Finding a predictive marker for compliance to TTFields therapy - the comptune study

Abstract

Abstract BACKGROUND Tumor Treating Fields (TTFields) imply the administration of alternating electric fields to induce mitotic arrest in Glioblastoma (GBM) cells. Based on the specific mode of action, which requires continuous exposure of the malignant cell pool to TTFields, compliance to TTFields treatment is a crucial parameter for treatment success. Correspondingly, a recent post hoc analysis of the EF-14 trial has demonstrated a strong correlation between TTFields compliance rate and treatment success. However, there is currently no data regarding predictive factors for individual compliance rate. We are therefore performing a prospective study designed to analyze specific parameters potentially influencing compliance to TTFields treatment employing a standardized psychological assessment battery in GBM patients who choose or not choose to undergo TTFields treatment in a longitudinal fashion. The results of the psychological profile will be correlated to the compliance rates of the individual patients. MATERIAL AND METHODS Forty adult patients treated for newly diagnosed GBM at the University Regensburg Medical Center will be recruited. The psychological assessment battery aims at assessing four categories relevant for treatment compliance: 1. Lack of communicative skills, 2. depressive and anxiety disorders, 3. interpersonal factors (e.g. social support), and 4. intrapersonal factors, (e.g. beliefs about benefit, self-efficacy). The study endpoints are: 1. willingness to undergo TTFields therapy and 2. compliance rate of the individual patient, provided by the technical support team. The first interview takes place after treatment consultation (T0), 2 weeks after diagnosis (T1), at the initiation of TTFields treatment (T2) and every 4 weeks during treatment either until second disease progression or after maximal 8 months observation time per patient. Additionally, demographic (gender, age, marital status), clinical (KPI, extent of resection) and biological factors (MGMT promoter status, IDH1 mutation) will be assessed. RESULTS The study has been approved by the local ethics committee and has recruited the first 23 patients within 8 months since initiation of the study. The most updated results will be presented at the meeting. CONCLUSION One of the most challenging aspects in the application of TTFields in clinical practice is the identification of influencing factors increasing patients’ compliance. This study is designed to provide a psychological profile predictive for high treatment compliance.