Search

Animal brain-tumor models have demonstrated a synergistic interaction between radiation therapy and a ketogenic diet (KD). Metformin has in-vitro anti-cancer activity, through AMPK activation and mTOR inhibition. We hypothesized that the metabolic stress induced by a KD combined with metformin would enhance radiation’s efficacy. We sought to assess the tolerability and feasibility of this approach. A single-institution phase I clinical trial. Radiotherapy was either 60 or 35 Gy over 6 or 2 weeks, for newly diagnosed and recurrent gliomas, respectively. The dietary intervention consisted of a Modified Atkins Diet (ModAD) supplemented with medium chain triglycerides (MCT). There were three cohorts: Dietary intervention alone, and dietary intervention combined with low-dose or high-dose metformin; all patients received radiotherapy. Factors associated with blood ketone levels were investigated using a mixed-model analysis. A total of 13 patients were accrued, median age 61 years, of whom six had newly diagnosed and seven with recurrent disease. All completed radiation therapy; five patients stopped the metabolic intervention early. Metformin 850 mg three-times daily was poorly tolerated. There were no serious adverse events. Ketone levels were associated with dietary factors (ketogenic ratio, p

Background Animal brain-tumor models have demonstrated a synergistic interaction between radiation therapy and a ketogenic diet (KD). Metformin has in-vitro anti-cancer activity, through AMPK activation and mTOR inhibition. We hypothesized that metabolic stress (moderate hypoglycemia) would enhance the anti-tumor efficacy of concurrent DNA damage. We further hypothesized that concurrent metformin would decrease insulin resistance and consequently elevate ketone blood level. We performed a formal prospective phase I dose-escalation trial to assess the tolerability and feasibility of this approach. Methods A prospective single-institution phase I clinical trial of combined metabolic therapy and radiotherapy. Radiotherapy was either 60Gy over six weeks or 35Gy over two weeks for newly diagnosed and recurrent gliomas, respectively. The dietary intervention consisted of a KD supplemented with medium chain triglycerides (MCT). There were three cohorts 1) dietary intervention alone, 2) low-dose metformin (850mg twice-daily) combined with dietary intervention and 3) high-dose metformin (850mg three-times daily) combined with dietary intervention. Statistics: The prediction of blood ketones levels was performed using a mixed-model univariate analysis methodology. Clinicaltrials.gov NCT02149459. Results A total of 13 patients were accrued, median age 61 years, of whom 6 had newly diagnosed and 7 with recurrent disease. All completed radiation therapy; 5 patients stopped the metabolic intervention early. Metformin 850mg three-times daily was poorly tolerated. There were no grade 4/5 adverse events. Median levels of β-hydroxybutyrate increased from 0.09 mmol/l at baseline to 0.59 mmol/l during the trial (p=0.006). Ketone levels were associated with dietary factors (ketogenic ratio, p < 0.001), use of metformin (p = 0.02) and low insulin levels (p = 0.002). Median progression free survival was 10 months for newly diagnosed disease and 4 months for recurrent disease.Conclusions The intervention was fairly well tolerated. Metformin use and dietary intake were associated with higher serum ketone levels. The recommended phase II dose is the 8 weeks of a KD combined with 850mg metformin twice daily. The trial was supported by the EU FP7 Marie Curie program FP7-MC-CIG 303795, and the Rosetrees Trust. The MCT oil was provided by Nutricia, Netherlands. Citation Format: Yaacov R. Lawrence, Keren Porper, Yael Shpatz, Luba Plotkin, Ronit Pechthold, Alisa Talianski, Zvi Symon, uri Amit, Zvi Cohen, Hili Gnessin, Yair Anikster, Yael Mardor, Leor Zach. A Phase I clinical trial of dose-escalated metabolic therapy combined with concomitant radiation therapy in high-grade glioma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr CT142.

Background Animal brain-tumor models have demonstrated a synergistic interaction between radiation therapy and a ketogenic diet (KD). Metformin has in-vitro anti-cancer activity, through AMPK activation and mTOR inhibition. We hypothesized that metabolic stress (moderate hypoglycemia) would enhance the anti-tumor efficacy of concurrent DNA damage. We further hypothesized that concurrent metformin would decrease insulin resistance and consequently elevate ketone blood level. We performed a formal prospective phase I dose-escalation trial to assess the tolerability and feasibility of this approach. Methods A prospective single-institution phase I clinical trial of combined metabolic therapy and radiotherapy. Radiotherapy was either 60Gy over six weeks or 35Gy over two weeks for newly diagnosed and recurrent gliomas, respectively. The dietary intervention consisted of a KD supplemented with medium chain triglycerides (MCT). There were three cohorts 1) dietary intervention alone, 2) low-dose metformin (850mg twice-daily) combined with dietary intervention and 3) high-dose metformin (850mg three-times daily) combined with dietary intervention. Statistics: The prediction of blood ketones levels was performed using a mixed-model univariate analysis methodology. Clinicaltrials.gov NCT02149459. Results A total of 13 patients were accrued, median age 61 years, of whom 6 had newly diagnosed and 7 with recurrent disease. All completed radiation therapy; 5 patients stopped the metabolic intervention early. Metformin 850mg three-times daily was poorly tolerated. There were no grade 4/5 adverse events. Median levels of β-hydroxybutyrate increased from 0.09 mmol/l at baseline to 0.59 mmol/l during the trial (p=0.006). Ketone levels were associated with dietary factors (ketogenic ratio, p < 0.001), use of metformin (p = 0.02) and low insulin levels (p = 0.002). Median progression free survival was 10 months for newly diagnosed disease and 4 months for recurrent disease. Conclusions The intervention was fairly well tolerated. Metformin use and dietary intake were associated with higher serum ketone levels. The recommended phase II dose is the 8 weeks of a KD combined with 850mg metformin twice daily. The trial was supported by the EU FP7 Marie Curie program FP7-MC-CIG 303795, and the Rosetrees Trust. The MCT oil was provided by Nutricia, Netherlands. Citation Format: Yaacov Lawrence, Keren Porper, Yael Shpatz, Uri Amit, Zvi Symon, Leor Zach. A phase I clinical trial of dose-escalated metabolic therapy combined with concomitant radiation therapy in high-grade glioma [abstract]. In: Proceedings of the AACR Virtual Special Conference on Radiation Science and Medicine; 2021 Mar 2-3. Philadelphia (PA): AACR; Clin Cancer Res 2021;27(8_Suppl):Abstract nr PO-004.

BACKGROUND Animal brain-tumor models have demonstrated a synergistic interaction between radiation therapy and a ketogenic diet (KD). Metformin has in-vitro anti-cancer activity, through AMPK activation and mTOR inhibition. We sought to assess the feasibility of combined radiation, KD and metformin in adults with high grade gliomas. METHODS A prospective single-institution phase I clinical trial of combined metabolic therapy and radiotherapy. Radiotherapy was either 60Gy over six weeks or 35Gy over two weeks for newly diagnosed and recurrent gliomas, respectively. The dietary intervention consisted of a KD supplemented with medium chain triglycerides (MCT). There were three cohorts 1) dietary intervention alone, 2) low-dose metformin combined with dietary intervention and 3) high-dose metformin combined with dietary intervention. Clinicaltrials.gov NCT02149459. RESULTS A total of 13 patients were accrued, median age 61 years, of whom 6 had newly diagnosed and 7 with recurrent disease. All completed radiation therapy; 5 patients stopped the metabolic intervention early. Metformin 850mg three-times daily was poorly tolerated. There were no grade 4 / 5 adverse events, and only one grade 3 event (nausea). The median level of ketones during the intervention was 0.5 mM. Ketone levels were associated with dietary factors (high fat, low carbohydrates, MCT intake), use of metformin and low insulin levels. Median progression free survival was 10 months for newly diagnosed disease and 4 months for recurrent disease. CONCLUSIONS The intervention was fairly well tolerated, however only moderate ketones levels were obtained. Metformin use and dietary intake were associated with higher serum ketone levels. The recommended phase II dose is the 8 weeks of a low-carbohydrate diet combined with 850mg metformin twice daily.