Refining the Mantle Cell Lymphoma Paradigm: Impact of Novel Therapies on Current Practice

Although mantle cell lymphoma (MCL) is a rare subtype of non-Hodgkin lymphoma, proactive research efforts fueled by challenges in the management of MCL have led to an increase in median overall survival (OS) of 2.5 years in the mid 1990s to beyond 5 years nowadays. This improvement is due mostly to the use of dose-intensive strategies, particularly cytarabine-containing regimens [with or without high-dose therapy (HDT) followed by autologous stem cell transplantation (ASCT) consolidation], which are associated with deeper remission (and higher molecular complete response rate), as well as better salvage therapies. Along this line, MCL became the first lymphoma for which four novel agents have been approved in the relapsed/refractory setting: temsirolimus, lenalidomide, ibrutinib, and bortezomib (the last agent approved both in relapsed/refractory disease and in first-line combination therapy). In addition, the use of rituximab maintenance has helped reduce relapse rates and improve outcome. However, in routine practice (i.e., outside clinical trials), the outcome of MCL remains overall unchanged with standard immunochemotherapy, and even after HDT-ASCT, most patients still relapse and frequently develop chemoresistance. The persistent lack of consensus for the treatment of MCL explains the rather impressive variability in management of these patients. The integration of newer therapies, either in combination with immunochemotherapy or as consolidation/maintenance postinduction, offers new opportunities for patients with MCL. This review highlights how such developments can help refine the current MCL paradigm.