Telomere length and DNA methylation epitype both provide independent prognostic information in CLL patients; data from the UK CLL4, ARCTIC and ADMIRE clinical trials

Patients with chronic lymphocytic leukaemia (CLL) exhibit varied clinical paths; some have indolent courses, while others experience aggressive disease.¹ Despite numerous molecular and cellular biomarkers being discovered, only TP53 aberrations (TP53ab: TP53 deletion and/or mutations) and unmutated IGHV status (U-CLL) are used for treatment stratification.^{2, 3} Other biomarkers have not been adopted due to a lack of independent prognostic or predictive value. Validating new biomarkers in large phase II/III trials with extensive molecular characterization and long-term follow-up is crucial. This study aims to validate the clinical relevance of two CLL biomarkers, methylation-based epitype (DME) and telomere length (TL), using large trial cohorts.