Two years rituximab maintenance vs. observation after first-line treatment with bendamustine plus rituximab (B-R) in patients with mantle cell lymphoma: First results of a prospective, randomized, multicenter phase II study (a subgroup study of the StiL NHL7-2008 MAINTAIN trial).

7503Background: Rituximab maintenance is part of a standard treatment approach for follicular lymphoma. In mantle cell lymphoma (MCL), however, it is not yet common practice. In this study we compared the effect of rituximab maintenance vs observation after first-line treatment with B-R in patients with previously untreated MCL. Methods: Patients were required to have stage II (with bulky disease > 7 cm), III, or IV disease for registration in this study. Primary endpoint was progression free survival (PFS). Secondary endpoints included response rates, overall survival (OS), time to progression, event free survival, toxicity. Patients were treated with up to 6 cycles of B-R plus 2 additional rituximab cycles. 120 Patients who have responded to B-R were then randomized to either rituximab maintenance (375 mg/m2every 2 months for a total of 2 years) or observation only. Results: A total of 120 patients were evaluable for the analysis, 59 (49%) were randomized to maintenance with rituximab and 61 (51%) to ob...