RT Journal Article SR Electronic T1 DNA methylation-based prediction of response to immune checkpoint inhibition in metastatic melanoma JF Journal for ImmunoTherapy of Cancer JO J Immunother Cancer FD BMJ Publishing Group Ltd SP e002226 DO 10.1136/jitc-2020-002226 VO 9 IS 7 A1 Katharina Filipski A1 Michael Scherer A1 Kim N. Zeiner A1 Andreas Bucher A1 Johannes Kleemann A1 Philipp Jurmeister A1 Tabea I. Hartung A1 Markus Meissner A1 Karl H. Plate A1 Tim R. Fenton A1 Jörn Walter A1 Sascha Tierling A1 Bastian Schilling A1 Pia S. Zeiner A1 Patrick N. Harter YR 2021 UL http://jitc.bmj.com/content/9/7/e002226.abstract AB Background Therapies based on targeting immune checkpoints have revolutionized the treatment of metastatic melanoma in recent years. Still, biomarkers predicting long-term therapy responses are lacking.Methods A novel approach of reference-free deconvolution of large-scale DNA methylation data enabled us to develop a machine learning classifier based on CpG sites, specific for latent methylation components (LMC), that allowed for patient allocation to prognostic clusters. DNA methylation data were processed using reference-free analyses (MeDeCom) and reference-based computational tumor deconvolution (MethylCIBERSORT, LUMP).Results We provide evidence that DNA methylation signatures of tumor tissue from cutaneous metastases are predictive for therapy response to immune checkpoint inhibition in patients with stage IV metastatic melanoma.Conclusions These results demonstrate that LMC-based segregation of large-scale DNA methylation data is a promising tool for classifier development and treatment response estimation in cancer patients under targeted immunotherapy.Data are available in a public, open access repository. All data relevant to the study are included in the article or uploaded as supplementary information. All data analyzed and/or generated within this study are included in the article and the supplementary data files. Raw data IDAT files as well as processed data of the ICI cohort are accessible via Gene Expression Omnibus (GEO, https://www.ncbi.nlm.nih.gov/geo/ ; GSE175699). Any other relevant data are available upon reasonable request.