Study overview and predictive markers of response to decitabine and ipilimumab treatment. (A) The ETCTN/CTEP 10026 study consisted of a cohort of relapsed AML after HSCT (arm A) and transplant-naïve AML/MDS (arm B) with morphologic disease. Following baseline assessment at study entry (Screening), a priming cycle of decitabine monotherapy (Lead-in) was administered. Subsequent cycles of therapy were given as a combination of decitabine and ipilimumab (C1, C2, …). Biopsies were also acquired at end of treatment. The swimmer plots indicate clinical course and duration of treatment for responders (blue) and nonresponders (red). Performed assays are indicated. (B) Median variant allele frequency of recurrent somatic mutations in bone marrow aspirates at screening grouped by response status across both arms (response [n = 16] and non-response [n = 25] according to study protocol) and study arm. Statistical testing using 2-sided t-test. (C) Changes of HSC score (van Galen et al³¹) throughout the study. Blue indicates responders; red indicates nonresponders. Statistical testing using Wilcoxon rank-sum test. (D,E) Differential gene-expression analysis of bone marrow core biopsies between responders (n = 6) and NRs (n = 18) across both arms according to study protocol (D) and gene set enrichment analysis (E) FDR, false discovery rate.