The aim of this study was to evaluate the prognostic value of recurrent molecular abnormalities in patients with CLL. Therefore, we assessed their incidences and associations with other clinical and genetic markers in the prospective multicenter COMPLEMENT1 trial (treatment naive patients not eligible for intensive treatment randomized to chlorambucil (CHL) vs. ofatumumab-CHL (O-CHL))….Analyses of both treatment arms separately generally reiterated the results obtained for the total cohort, with mutations in SF3B1 and TP53 being associated with shorter PFS.