SRP138987 PRJNA449238 GSE112838 Genomic and epigenomic predictors of response to Guadecitabine in relapsed/refractory Acute Myelogenous Leukemia Guadecitabine is a second generation DNA methylation inhibitor with improved pharmacokinetics and clinical activity in relapsed/refractory AML (rrAML). Here we report genome-wide DNA methylation profiles in pre-treatment samples from 116 rrAML patients treated at therapeutic doses of guadecitabine in a phase I/II study. Response rate to guadecitabine was 22 % (16CR, 42 12CRi/CRp). There were no strong mutation or methylation predictors of response. Gene expression defined a subset of patients (~20%) that had (i) high DNMT3B and low CDKN2B, CTCF and CDA expression, (ii) enrichment for KRAS/NRAS mutations, (iii) frequent CpG island hypermethylation (iv) low LINE1 hypomethylation after treatment and (v) resistance to guadecitabine in both phase I (response rate 0 % vs 33 %, p=0.07) and phase II components of the study (response rate 5 % vs. 30 %, p=0.02). Multivariate analysis identified peripheral blood blasts and hemoglobin as predictors of response and cytogenetics, gene expression, RAS mutations and hemoglobin as predictors of survival. Thus, a subset of patients (? 20%) with rrAML are unlikely to benefit from single agent guadecitabine. In the remaining 80%, guadecitabine is a viable option with a median survival of ? 8 months and a three year survival rate of over 20%. Overall design: Digital restriction enzyme analysis of methylation (DREAM) was performed to determine the methylation profile of human genomic DNA from the whole blood of 116 patients with relapsed/refractory acute myeloid leukemia (rrAML) and peripheral blood from 5 healthy controls. Briefly, genomic DNA was sequentially digested by SmaI and XmaI, which both recognize the sequence CCCGGG. SmaI is methylation sensitive, where XmaI is methylation insensitive. Distinct signatures, 5'-GGG at unmethylated sites or 5'-CCGGG at methylated sites were created by enzyme digestion and ultimately high througput sequencing was used to map these sites to the genome. Methylation ratios for each individual CCCGGG site were calculated as a proportion of methylated counts to the sum of unmethylated and methylated counts, and subsequently adjusted for differences in restriction enzyme efficiency using values obtained from spiked in standards. GSE112838 pubmed 31331399