Langerbeins P, et al. - In early stage CLL patients with increased risk of progression, researchers assessed whether ibrutinib prolongs event-free survival (EFS) [defined as the time from randomization until the occurrence of active disease according to iwCLL guidelines, new CLL treatment or death]. For this investigation, study participants with intermediate, high and very high risk were randomized 1:1 to receive ibrutinib 420 mg per day or placebo. To receive ibrutinib or placebo, a total of 182 or 181 patients were assigned respectively. In patients with treatment-naïve early stage CLL, ibrutinib significantly improves EFS, progression-free survival and time to next treatment when compared to placebo. No significant difference was found in non-serious and serious adverse events in ibrutinib and placebo-treated patients respectively.