The RESONATE phase III trial (NCT01578707) investigated whether treatment with ibrutinib as a monotherapy results in a clinically significant improvement in progression-free survival (PFS) as compared to treatment with ofatumumab in patients with relapsed or refractory chronic lymphocytic leukemia (R/R CLL). Alessandra Tedeschi, MD, of the Niguarda Cancer Center, Milan, Italy, discusses the results of a five-year follow-up of this study at the 24th Congress of the European Hematology Association (EHA) 2019, held in Amsterdam, Netherlands.