Efficacy and Safety of Obinutuzumab Preemptive Treatment at the Time of the Molecular Relapse

The objective of the study is the evaluation of efficacy and safety of obinutuzumab preemptive treatment at the time of the molecular relapse after first line immunochemotherapy with autologous stem cell transplantation in mantle cell lymphoma patients.

Patients with evidence of MCL molecular relapse defined as an increasing copy number in quantitative real-time polymerase chain reaction (RQ-PCR) of clone-specific immunoglobulin heavy chain (IGH) gene rearrangements or BCL1-IGH fusion genes according to BIOMED-2 methodology and protocols in peripheral blood or/and bone marrow without evidence of clinical relapse/progression after auto-HCT procedure with all inclusion and no exclusion clinical trial criteria will receive 4 weekly infusions of obinutuzumab (1000 mg, iv) on day 1, 8, 15, 22.Response assessment in bone marrow and/or peripheral blood and CT/MRI imaging will be performed 2 months after the obinutuzumab preemptive treatment. Patients with subsequent molecular remission in peripheral blood and/or bone marrow confirmed in RQ-PCR (with 10-4 level of sensitivity) assessment and no signs of relapse/progression according to the Lugano Classification will be further followed. From this moment, evaluation of response will be performed every 6 months with computed tomography/magnetic resonance (CT/MR) imaging and bone marrow aspiration to detect classical relapse/progression and/or to detect subsequent molecular relapse by quantitative real-time polymerase chain reaction (RQ-PCR) of clone-specific immunoglobulin heavy chain (IGH) gene rearrangements or BCL1-IGH fusion genes with the use of consensus JH probes and specific ASO primers. Patients will be monitored every 3 months (outpatient visits with peripheral blood samples for MRD assessment to detect molecular relapse by quantitative RQ-PCR of clone-specific immunoglobulin heavy chain (IGH) gene rearrangements or BCL1-IGH fusion genes). Preemptive treatment can be administered in subsequent molecular relapses/progressions.