Abstract CT138: Open-label personalized targeted intervention to maximize TTFields intensity in recurrent GBM (OptimalTTF Trial)

Introduction Tumor Treating Fields (TTFields) is approved for the treatment of recurrent glioblastoma (rGBM). Skull remodeling surgery involves formation of strategically placed craniectomies, burr holes or skull thinning, in order to facilitate electric current flow into the tumor region. Preclinical studies have indicated that these procedures provide a marked and focal enhancement (~100%) of TTFields intensity without significantly compromising patient safety. In this open-label phase 1 investigator-initiated interventional trial, we test the safety, feasibility and efficacy of TTfields plus personalized targeted skull remodeling surgery and best choice chemotherapy. We believe this study has high-impact potential at a low clinical risk and may advance current state-of-the-art therapy of GBM therapy. Methods The trial will include fifteen patients. Major eligibility criteria include age > 18 years, first recurrence of supratentorial GBM, Karnofsky performance score (KPS) > 60, focal tumor < 2 cm to cortical surface, and lack of uncontrollable epilepsy or significant co-morbidity. Upon inclusion, personalized field calculations will be performed to validate TTFields enhancement > 25% due by skull remodeling surgery. The primary endpoint is toxicity assessed by CTCAEv4.0. Secondary endpoints include overall survival, progression free survival (PFS), PFS at six months (PFS6), objective response rate, quality of life (EORTC QLQ-C30 and BN20), KPS, and steroid dose. Follow-up is 18 months and includes regular toxicity assessment (6-week intervals) as well as quality of life and response assessments (3-month intervals). Endpoint data will be collected at the end of scheduled follow-up, occurrence of suspected unexpected serious adverse reactions (SUSARs) or unacceptable serious adverse events (SAEs), withdrawal of consent, or loss to follow-up. Interim analysis will be performed upon endpoint registration for the first five-10 patients. Citation Format: Nikola Mikic, Anders Rosendal Korshøj. Open-label personalized targeted intervention to maximize TTFields intensity in recurrent GBM (OptimalTTF Trial) [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr CT138.