The combination of ibrutinib and rituximab demonstrates activity in first‐line follicular lymphoma
Nathan Fowler, Loretta J. Nastoupil, Sven de Vos, Mark Knapp, Ian W. Flinn, Robert Chen, Ranjana H. Advani, Sumeet Bhatia, Peter Martin, Raul Mena, R. Eric Davis, Sattva S. Neelapu, Karl Eckert, Jerry Ping, Melannie Co, Darrin M. Beaupre, Jutta K. Neuenburg, M. Lia Palomba
Abstract
Summary This phase 2 study evaluated the activity and safety of ibrutinib, a Bruton’s tyrosine kinase inhibitor, plus rituximab in adults with previously untreated follicular lymphoma. Patients received once‐daily ibrutinib 560 mg continuously plus once‐weekly rituximab 375 mg/m 2 for 4 weeks beginning Week 1 (Arm 1, n = 60) or Week 9 (following an 8‐week ibrutinib lead‐in) to explore biomarkers (Arm 2, n = 20). The primary endpoint was the best overall response rate (ORR). The median age was 58 years; most had an Eastern Cooperative Oncology Group Performance Status of 0 (74%) and Stage III/IV disease (84%). At a median study follow‐up of 34 months in Arm 1 and 29 months in Arm 2, ORRs were 85% [95% confidence interval (CI) 73–93] and 75% (95% CI 51–91), respectively, with complete responses in 40% and 50%. The median duration of response was not reached in either arm; 30‐month progression‐free and overall survival rates were 67% and 97% (Arm 1) and 65% and 100% (Arm 2). The most common adverse events were fatigue, diarrhoea and nausea. Higher grade (Grade 3/4) haematological, haemorrhagic and cardiac events occurred infrequently. Ibrutinib plus rituximab was active and tolerable in first‐line follicular lymphoma.