IDH1 and central nervous system cancer: In this study we used a recently demonstrated 3D MRS imaging (MRSI) method for 2HG detection27 to assess the pharmacodynamic effects of the new investigational drug IDH305 (Novartis Pharmaceuticals) in mutant IDH1 glioma patients enrolled in an open label first-in-human Phase I clinical trial (ClinicalTrials.gov identifier: NCT02381886).