Identification of a novel metabolic-related mutation (<i>IDH1</i>) in metastatic pancreatic cancer

Abstract

Isocitrate dehydrogenase 1 (IDH1) is a metabolic enzyme implicated in cancer cell metabolic reprogramming. This is underscored by the detection of functional, somatic IDH1 mutations frequently found in secondary glioblastoma. To our knowledge, there has never been a reported, validated case of an IDH1 mutation in a pancreatic ductal adenocarcinoma (PDA). Herein, we present a case of a patient with metastatic PDA that harbored a potentially actionable, albeit rare, IDH1 mutation. As part of the Know Your Tumor project (Pancreatic Cancer Action Network), a 48-year-old female was diagnosed with metastatic PDA and subsequently started on standard of care chemotherapy, during which her hepatic lesions progressed. Detailed molecular profiling was performed on a biopsy from a liver lesion that demonstrated an IDH1 mutation, R132H. This mutation was confirmed by an independent sequencing reaction from the tumor sample, and by immunohistochemistry using an antibody specific for the IDH1 R132H mutation. The patient subsequently received a mutant IDH1 inhibitor (AG-120, Agios Pharmaceuticals, Cambridge, MA), but with no response. IDH1 mutations are common in certain cancer types, but have not been reported in PDA. We report the first case of an IDH1 mutation in this tumor type, perhaps providing a rare opportunity for a targeted therapy as a treatment option for PDA.