ACTR-62. PHASE I TRIAL OF TG02 PLUS DOSE-DENSE OR METRONOMIC TEMOZOLOMIDE FOR RECURRENT HIGH-GRADE ASTROCYTOMA IN ADULTS

Abstract

Despite advances in the understanding of molecular pathways, the availability of NGS panels to identify potentially drugable mutations, the proliferation of targeted therapies, and the progress seen in other cancers, only one novel agent (temozolomide) has significantly improved the survival of patients with glio-blastoma in the past three decades. A major factor distinguishing brain cancer from other malignancies is the presence of the blood-brain barrier that restricts entry into the central nervous system of over 95% of drugs currently approved by the FDA. Clinical investigators have historically justified glioblastoma efficacy trials with pharmacokinetic data documenting measurable brain concentrations in animals or in contrast enhancing brain tumor specimens from patients. However , the discovery of effective therapeutic agents (whose mechanism of action requires that the drug directly reaches the cancer) will likely require that therapeutic drug concentrations (rather than measurable levels or blood:brain ratios) be delivered to non-contrast enhancing regions of the brain. The importance of delivering therapeutic concentrations of drug to non-enhancing brain is highlighted by knowledge that a gross total resection of all enhancing portions of a glioblastoma provides no chance of cure and limited improvement in overall survival. Utilizing these more stringent emerging criteria to select novel agents for efficacy studies will encourage pre-clinical and phase I studies to define the CNS penetration of new drugs and determine a therapeutic concentration for each agent. This will aid in the rational prioritization of agents selected for phase II studies. A full report of the outcome of the ABTC workshop on this topic will be presented. This will include: 1) methods to determine "therapeutic" drug concentrations for glioblastoma, 2) methods to quantify drug concentrations in non-enhancing brain, 3) pharmacokinetic and pharmacodynamic considerations, and 4) potential shortcomings of this approach. BACKGROUND: High-grade gliomas (HGG) are characterized by dysregulated metabolism, utilizing glycolysis for energy production to support unrestricted growth. BPM 31510, an ubidecarenone (coenzyme Q10) containing lipid nanodispersion, causes a switch in cancer energy sourcing from glycolysis towards mitochondrial oxidative phosphorylation in vitro, reversing the Warburg effect and suggesting potential as an anti-tumor agent. The current study is a phase I study of BPM31510 + vitamin K in GB with tumor growth after bevacizumab (BEV). METHODS: This is an open-label phase I study of BPM31510 continuous infusion with weekly vitamin K (10mg IM) in HGG patients using an mTPI design, starting at 110mg/kg, allowing for a single dose de-escalation and 2 dose-escalations. Patients had received first-line ChemoRadiation and were in recurrence following a BEV containing regimen. RESULTS: 9 eligible and evaluable patients completed the 28 day DLT period. 8 patients had primary GB, 1 had anaplastic astrocytoma with confirmed pathologic transformation to GB. Median age was 55 years (27-67) and median KPS 70 (60-90) at enrollment. 4 patients were treated at the highest dose 171mg/kg, where there was a single DLT: Grade 3 AST & ALT. The most common grade 1-2 AEs possibly, probably or definitely related to drug were elevated AST, rash, and fatigue, each occurring in 3 patients. Median OS for 9 eligible/evaluable patients was 128 days (95% CI: 48-209) while PFS was 34 days (CI of mean 8.9). 3 patients are currently alive; 2 patients have survived >1 year. PK/PD data are being processed and will be presented. CONCLUSION: This study confirms that BPM 31510 + vitamin K is safe and feasible in treatment-refractory HGG patients. Though this study demonstrates safety at 171mg/kg, the proposed dose for future studies in GB, based on additional pre-clinical and non-GB clinical data is 88mg/kg.