Open Access

Jan Moritz Middeke, Klaus Hans Metzeler, Christoph Röllig, Michael Krämer, Jan-Niklas Eckardt, Sebastian Stasik, Philipp Greif, Karsten Spiekermann, Maja Rothenberg-Thurley, Utz Krug, Jan Braess, Alwin Krämer, Andreas Hochhaus, Tim Henrik Brümmendorf, Ralph Naumann, Björn Steffen, Hermann Einsele, Markus Schaich, Andreas Burchert, Andreas Neubauer, Dennis Görlich, Cristina Sauerland, Kerstin Schäfer-Eckart, Christoph Schliemann, Stefan W. Krause, Mathias Hänel, Norbert Frickhofen, Richard Noppeney, Ulrich Kaiser, Martin Kaufmann, Désirée Kunadt, Bernhard Wörmann, Katja Sockel, von Malte Bonin, Tobias Herold, Carsten Müller-Tidow, Uwe Platzbecker, Wolfgang E. Berdel, Hubert Serve, Claudia Baldus, Gerhard Ehninger, Johannes Schetelig, Wolfgang Hiddemann, Martin Bornhäuser, Friedrich Stölzel, Christian Thiede

• Mutations of the isocitrate dehydrogenase-1 (IDH1) and IDH2 genes are among the most frequent alterations in acute myeloid leukemia (AML) and can be found in ∼20% of patients at diagnosis. Among 4930 patients (median age, 56 years; interquartile range, 45-66) with newly diagnosed, intensively treated AML, we identified IDH1 mutations in 423 (8.6%) and IDH2 mutations in 575 (11.7%). Overall, there were no differences in response rates or survival for patients with mutations in IDH1 or IDH2 compared with patients without mutated IDH1/2. However, distinct clinical and comutational phenotypes of the most common subtypes of IDH1/2 mutations could be associated with differences in outcome. IDH1-R132C was associated with increased age, lower white blood cell (WBC) count, less frequent comutation of NPM1 and FLT3 internal tandem mutation (ITD) as well as with lower rate of complete remission and a trend toward reduced overall survival (OS) compared with other IDH1 mutation variants and wild-type (WT) IDH1/2. In our analysis, IDH2-R172K was associated with significantly lower WBC count, more karyotype abnormalities, and less frequent comutations of NPM1 and/or FLT3-ITD. Among patients within the European LeukemiaNet 2017 intermediate- and adverse-risk groups, relapse-free survival and OS were significantly better for those with IDH2-R172K compared with WT IDH, providing evidence that AML with IDH2-R172K could be a distinct entity with a specific comutation pattern and favorable outcome. In summary, the presented data from a large cohort of patients with IDH1/2 mutated AML indicate novel and clinically relevant findings for the most common IDH mutation subtypes.