ENRICH trial: Ibrutinib + rituximab vs immunochemotherapy in MCL

Results from the randomized, international phase II/III ENRICH trial (EudraCT 2015–000832–13) comparing ibrutinib + rituximab (n = 199) vs immunochemotherapy (rituximab + cyclophosphamide + doxorubicin + vincristine + prednisone [R-CHOP; n = 53] or bendamustine + rituximab [BR; n = 145]) in 397 patients aged ≥60 years with previously untreated mantle cell lymphoma (MCL) were recently published in The Lancet by Lewis et al. The median age was 74 years.

Key data: After a median follow-up of 47.9 months, median progression-free survival (PFS) with ibrutinib + rituximab was superior to immunochemotherapy (65.3 months vs 42.4 months; hazard ratio [HR], 0.69; 95% confidence interval [CI], 0.52–0.90; p = 0.0034). For those with pre-randomization choice R-CHOP, the HR was 0.37 (95% CI, 0.22–0.62), and with BR, the HR was 0.91 (95% CI, 0.66–1.25). Grade ≥3 adverse events (AEs) were reported in 67% and 70% of patients assigned to ibrutinib + rituximab and immunotherapy, respectively. 

Key learning: Ibrutinib + rituximab demonstrated significant improvement in PFS compared with immunochemotherapy in older patients with previously untreated MCL, primarily driven by improved outcomes vs R-CHOP, and should be considered as a potential new standard of care option for first-line treatment in this patient population.