First-line response-adapted treatment with the combination of bendamustine and rituximab in patients with mucosa-associated lymphoid tissue lymphoma (MALT2008-01): a multicentre, single-arm, phase 2 trial

Resumen:
Background No standard first-line systemic treatment for mucosa-associated lymphoid tissue (MALT) lymphoma is available. In a phase 2 study we aimed to assess the safety and activity of a response-adapted combination of bendamustine plus rituximab as upfront treatment for this type of lymphoma. Methods In a multicentre, single-arm, non-randomised, phase 2 trial, we enrolled patients with MALT lymphoma at any site and stage and treated them with bendamustine (90 mg/m(2) on days 1 and 2) plus rituximab (375 mg/m(2) on day 1), every 4 weeks. Inclusion criteria were measurable or evaluable disease, age 18-85 years, and unequivocal active lymphoma; we also enrolled patients with MALT lymphoma arising in the stomach after failure of Helicobacter pylori eradication and primary cutaneous cases after failure of local therapies. Exclusion criteria included evidence of histological transformation, CNS involvement, and active hepatitis B or C virus or HIV infection. After three cycles, patients achieving complete response received one additional cycle (total four cycles) and those achieving partial response received three additional cycles (total six cycles). The primary endpoint was 2-year event-free survival. Analysis was by modified intention to treat. This trial is registered with ClinicalTrials.gov, number NCT01015248. Findings 60 patients from 19 centres in Spain were enrolled between May 27, 2009, and May 23, 2011, and received treatment; 57 patients were evaluable for the primary endpoint. Only 14 (25%) patients needed more than four cycles of treatment. After a median follow-up of 43 months (IQR 37-51), median event-free survival was not reached. Event-free survival at 2 years was 93% (95% CI 84-97) and at 4 years was 88% (95% CI 74-95). The most frequently observed grade 3-4 adverse events were haematological: lymphopenia in 20 (33%) patients, neutropenia in 12 (20%) patients, and leucopenia in three (5%) patients. Grade 3-4 febrile neutropenia or infections were reported in three (5%) and four (7%) patients, respectively. Interpretation This response-adapted schedule of bendamustine plus rituximab appears to be an active and well tolerated first-line treatment for patients with MALT lymphoma.