To report the feasibility of treatment with the modified Akins diet in combination with bevacizumab in recurrent glioblastoma patients.

We report results of a feasibility trial of the modified Atkins diet (MAD) combined with bevacizumab (Bev) for recurrent GBM. The rationale for a KD includes the reduction of glucose availability to this highly glycolytic tumor, reduction of GBM growth signaling pathways, and increase in tumor-reactive immune responses. Clinical and laboratory data indicate the combination of KD and Bev is more effective than either treatment alone (Reiger et al 2014). Because adherence to the MAD and Bev in patients with GBM cannot be predicted, we performed a measure of treatment compliance before proceeding to an efficacy trial.

Feasibility study in 12 Bev naïve recurrent GBM patients. Bev was administered in standard doses biweekly. Primary objective was to document compliance with MAD in at least 60% of the patients (7/12) at least 80% of the time at 12 weeks. Secondary objectives included adverse events, tumor response, PFS, OS. Monitoring of MAD biologic effects included serum glucose and urine ketones daily and serum B- hydroxybutyrate biweekly. Compliance was determined by review of daily food diary and ketone levels.

Each of 12 patients was compliant with the study treatment. All achieved ketosis. Three others were removed from study: grade 3 hypertension related to Bev, grade 3 seizures related to tumor, and tumor progression at 71 days.

We document the feasibility of the MAD and Bev in recurrent GBM. We will present correlations of treatment outcome with serum levels of ketosis, glucose, and insulin and with tumor MCT4 expression and IDH1 mutation status.