Pilot Study To Investigate Targetable Metabolic Pathways Sustaining Triple Negative Breast Cancer

One of the recognized hallmarks of cancer cells is deregulated cellular metabolism, characterized by enhanced metabolic autonomy compare with non-transformed cells. Tumor cells typically display an overall increase in glucose metabolism, associated with enhanced aerobic glycolysis and decreased oxidative phosphorylation, accompanied by a requirement for a high rate of protein, nucleotide, and fatty acid synthesis to provide the raw materials for cell division. 13C-glucose is a non-radioactive stable isotope tracer that has been widely used in vitro, in vivo, and in patients in a variety of disease settings to study glucose, amino acid, and lipid metabolism, at steady state and following intervention. [1,2-13C] glucose can provide additional information on the activity of the oxidative pentose phosphate pathway versus glycolysis. Administration of intravenous 13C-glucose is a convenient and affordable approach to analyzing the metabolomics of human cancers in their native microenvironments.

The metabolic dependencies of the various breast cancer subtypes are poorly understood. Importantly, in depth analyses of the in situ metabolic processes utilized by triple-negative breast cancers (TNBCs) using state-of-the-art in vivo [1,2-13C]-glucose infusions in patients with TNBC has never been done. In TNBC, oncogenic activation of key signaling pathways leads to altered metabolic programming resulting in an increased dependence on exogenous nutrients such as glucose and glutamine. These data further suggest a hypothesis that TNBCs may employ a cellular mechanism called macropinocytosis to ingest and degrade interstitial albumin to accumulate glutamine. This process may then be exploited for therapeutic gain through enhanced uptake by cells that utilize macropinocytosis to meet their metabolic requirements.

In this study, administration of [1,2-13C]-glucose to patients with TNBC will be done prior to patients undergoing a biopsy of their breast cancer as well as blood sample collection which will allow for in depth evaluation of glycolysis as well as lipid and amino acid metabolism by Joshua Rabinowitz, PhD, at Princeton University who is an international expert in cancer metabolomics. RAS and PI3K pathway and other genomic alterations as well as pathway activation status will be determined by next generation sequencing (NGS) and by reverse phase protein array (RPPA), and will be correlated with the metabolic findings, and both will be assessed in the context of the patients' response to standard preoperative chemotherapy.

Inclusion criteria

A patient will be considered for enrollment in this study if all the following criteria are met:

• Female patients ≥18 years of age.
• Have TNBC defined as invasive ductal cancer: ER- tumors with <10% of tumor nuclei immunoreactive; PR- tumors with <10% of tumor nuclei immunoreactive; HER2-negative defined as follows:

• FISH-negative (FISH ratio <2.0), or
• IHC 0-1+, or
• IHC 2+ AND FISH-negative (FISH ratio<2.0)
• Adequate hematologic function, defined by:

• Absolute neutrophil count (ANC) >1000/mm3
• Platelet count ≥100,000/mm3
• Hemoglobin >9 g/dL (in the absence of red blood cell transfusion)
• Adequate liver function, defined by:

• AST and ALT ≤ 5 x the upper limit of normal (ULN)
• Total bilirubin ≤1.5 x ULN
• Adequate renal function, defined by:

a. Serum creatinine ≤ 2 x ULN or calculated creatinine clearance of ≥60 ml/min

• Have blood glucose <250 mg/dL
• Willing to undergo 1 mandatory core biopsy (6 passes) for research purposes.
• All patients must be able to understand the investigational nature of the study and give written informed consent prior to study entry.

Exclusion criteria

A patient will be ineligible for inclusion in this study any of the following criteria are met:

• Patients receiving any anti-cancer therapy (chemotherapy, immunotherapy, and/or biologic therapy).
• Is currently enrolled, or will enroll in, a different clinical study in which investigational therapeutic procedures are performed or investigational therapies are administered while participating in this study.
• Has a history of insulin-dependent diabetes.
• Concomitant active malignancy
• Is pregnant or breastfeeding.