An international analysis evaluating frontline bendamustine with rituximab in extranodal marginal zone lymphoma.

Overview

abstract

Extranodal marginal zone lymphoma (EMZL) is a heterogeneous non-Hodgkin lymphoma. No consensus exists regarding the standard-of-care in patients with advanced-stage disease. Current recommendations are largely adapted from follicular lymphoma for which bendamustine with rituximab (BR) is an established approach. We analyzed the safety and efficacy of frontline BR in EMZL using a large international consortium. We included 237 patients with a median age of 63 years (range 21 to 85). Most patients presented with Eastern Cooperative Oncology Group (ECOG) performance status (PS) 0-1 (n=228, 96.2%), stage III/IV (n=179, 75.5%), and intermediate (49.8%) or high (33.3%) Mucosa Associated Lymphoid Tissue International Prognosis Index (MALT-IPI). Patients received a median of 6 (range 1 to 8) cycles of BR, and 20.3% (n=48) received rituximab maintenance. Thirteen percent experienced infectious complications during BR therapy. Herpes-zoster (4%) was the most common. Overall response rate was 93.2% with 81% complete responses. Estimated 5-year progression-free survival (PFS) and overall survival (OS) were 80.5% (95%CI 73.1-86%) and 89.6% (95%CI 83.1-93.6%), respectively. MALT-IPI failed to predict outcomes. In the multivariable model, the presence of B symptoms was associated with shorter PFS. Rituximab maintenance was associated with longer PFS (HR=0.16, 95%CI 0.04-0.71; P=0.016) but did not impact OS. BR is a highly effective upfront regimen in EMZL providing durable remissions and overcoming known adverse prognosis factors. This regimen is associated with occurrence of herpes-zoster and thus prophylactic treatment may be considered.