Ibrutinib in Combination With Rituximab in Patients With Indolent Clinical Forms of MCL

Patients with mantle cell lymphoma (MCL) have a median survival of 3-5 years despite treatment. Indeed, the best therapeutic approach for different patients with MCL remains to be established, coexisting different options of immunochemotherapy regimes which may include autologous transplantation in first-line treatment or rituximab maintenance. Moreover, last years MCL starts to be recognized as a heterogeneous disease both from biological and clinical stand points. For instance, MCL cases with a non-nodal clinical presentation, usually have distinctive biological features such as SOX-11 negativity, hypermutated IGHV genes and a low number of genetic lesions associated. The outcome of these cases is much more favourable compared to conventional MCL, reaching median survivals over 7 to 10 years even receiving less intensive treatments. In addition to that, up to 30% of the patients with newly diagnosed MCL can be safely deferred from initial therapy until progression . Therapeutic abstention may be prolonged for more than one year in 50% of cases. These patients usually show longer survivals from the start of treatment compared to patients immediately treated after diagnosis. Therefore, all these observations indicate that there are indolent clinical forms in MCL, so its clinico-biological identification is crucial to tailor treatment appropriately. However, at present there is no consensus on the diagnostic criteria or treatment recommendations in cases of indolent MCL. This results in difficulties for the identification of these forms in the clinical practice as well as with a certain therapeutic in definition, as indolent forms of MCL can be treated either with therapeutic abstention until progression or receive immediate treatment with conventional or more intensive immuno-chemotherapy regimes, which may even include an autologous hematopoietic stem cell transplantation. With the emergence of new biological agents in the therapeutic arsenal of MCL arises the question whether a completely different approach with new drugs and chemotherapy-free could be more appropriate in selected subsets of patients such as indolent MCL forms.