IDH1 and glioblastoma: Moreover, a retrospective review of GBM patients at MDACC between 2006 and 2012, which identified 330 recurrent GBM patients, reported that the median OS for trials at the first recurrence was 9.8 months for IDH1-wildtype GBM, while that for IDH1-mutant GBM was 19.32 months3.