A midstage trial of a chemotherapy-free combination of ibrutinib with rituximab included 50 treatment-naive patients older than 65 with mantle cell lymphoma, which resulted in a complete response rate of 62% and an overall response rate of 90%. Patients with cardiac risk factors could be at risk of atrial fibrillation, said study author Preetesh Jain of the University of Texas MD Anderson Cancer Center.