INNV-38. 3 Days-On-1 Day-Off Fractionated Use Protocol For Improved Compliance and Preventative Skin Safety For Use of Tumor Treating Fields: Practice Improvement Strategy in Neuro-Oncology

Abstract

BACKGROUND: Compassionate care delivery requires that providers understand patient values and adopt practices aimed to improve the quality of extended survival. Many brain tumor clinical trials measure survival outcomes based on therapeutic interventions, but often fail to anticipate patient noncompliance and the provider’s ability to communicate the plan. Tumor Treating Fields (TTFields) is an FDA-approved locoregional, noninvasive therapy worn on the scalp to treat glioblastoma (GBM). When worn, TTFields therapy disrupts cancer cell viability and delays tumor progression but is complicated by mild-moderate skin irritation and real-world inconvenience of the unclear recommendation to wear the device an average of “≥18 hours/day or 75% of the time”. We simplified the physician instructions to encourage patient compliance and skin safety on TTFields. METHODS: Adults with GBM were provided an easy-to-follow flow chart and advised across multiple centers to follow the 3-days-on (72 hours) and 1-day-off (16–24 hours) TTFields therapy use schedule and given skin-specific wound prevention guidance (cleansing selenium-based shampoo and reparative skin-barrier moisturizing) during the ‘off day’. We evaluated the ease to explain the 3-on-1-off schedule, patient adherence, and the presence and severity of skin AEs during follow-up visits. REAL-WORLD PRACTICE OUTCOMES: Seventy-six patients received TTFields therapy using the 3-on-1-off protocol between 2015 and 2021 at two US healthcare centers. The median age was 57 years (range 25–81). The mean time on TTFields therapy was 73 weeks. Skin AEs occurred in 5% of patients on the 3-on-1-off protocol, as compared to 16% and 52% reported on EF-11 (NCT00379470) and EF-14 (NCT00916409) GBM studies, respectively. Majority of AEs were mild, and no patients discontinued TTFields therapy or modified electrode placement due to skin AEs while on the 3-on-1-off protocol. CONCLUSION: We report real-world data confirming a practice improvement for patient compliance using a novel 3-on-1-off protocol which minimizes skin AEs and treatment interruptions to improves patient outcomes. An ounce of prevention is worth a pound of cure.