Obinutuzumab vs rituximab for transplant-eligible patients with mantle cell lymphoma

• O can safely be used in combination with chemotherapy and in maintenance after ASCT as frontline therapy in patients with MCL.

• O provides better disease control than R without additional toxicity in the MCL.

Obinutuzumab (O) and rituximab (R) are 2 CD antibodies that have never been compared in a prospective randomized trial of mantle cell lymphoma (MCL). Herein, we report the long-term outcome of the LyMa-101 trial, in which newly diagnosed patients with MCL were treated with chemotherapy plus O before transplantation, followed by O maintenance (O group). We then compared these patients with those treated with the same treatment design with R instead of O (R group). A propensity score matching (PSM) was used to compare the 2 populations (O vs R groups) in terms of measurable residual disease (MRD) at the end of induction (EOI), progression-free survival (PFS), and overall survival (OS). In LyMa-101, the estimated 5-year PFS and OS after inclusion (n = 85) were 83.4% (95% confidence interval [CI], 73.5-89.8) and 86.9% (95% CI, 77.6-92.5), respectively. At EOI, patients treated in the O group had more frequent bone marrow MRD negativity than those treated in the R group (83.1% vs 63.4%; χ², P = .007). PSM resulted in 2 sets of 82 patients with comparable characteristics at inclusion. From treatment initiation, the O group had a longer estimated 5-year PFS (P = .029; 82.8% vs 66.6%; hazard ratio [HR], 1.99; 95% confidence interval (CI), 1.05-3.76) and OS (P = .039; 86.4% vs 71.4%; HR, 2.08; 95% CI, 1.01-4.16) compared with the R group. Causes of death were comparable in the 2 groups, the most common cause being lymphoma. O before transplantation and in maintenance provides better disease control and enhances PFS and OS compared with R in transplant-eligible patients with MCL. These trials were registered at www.clinicaltrials.gov as #NCT00921414 and NCT02896582.