Rituximab maintenenance therapy in CD20+ B-cell non-Hodgkin’s-lymphoma: First interim results of a prospective randomised phase II study

Abstract

6722 Background: Clinical and pharmacokinetic data suggest that the effect of rituximab could be improved by prolonged exposure to the drug. Methods: To test for this hypothesis we performed a prospective randomized trial of rituximab maintenance therapy in patients with CD20+ B-cell Non-Hodgkins-Lymphoma. After completion of standard treatment patients were randomized to either observation or maintenance therapy with rituximab (375 mg/m2) every 3 months for 2 years. Patients with aggressive lymphoma were enrolled if they had achieved a complete response (CR) after initial treatment. Patients with aggressive lymphoma with residual tumor mass were examined with positrone emission tomography (PET) and qualified for randomization if PET showed no signs of tumor activity. Patients with indolent lymphoma qualified for the study if at least a partial response (PR) was achieved. Results: So far 44 patients (pts) with CD20+ B-cell Non-Hodgkins-Lymphoma were enrolled in this trial. Histological subtypes included diffuse large cell lymphoma (21 pts), follicular lymphoma (10 pts), mantle cell lymphoma (6 pts), primary mediastinal lymphoma (5 pts), marginal zone lymphoma (1 pt) and unclassified B-cell lymphoma (1 pt). No severe adverse events were observed during rituximab maintenance therapy. To date, all patients in the rituximab maintenance treatment arm are in continuous clinical remission. Importantly, in the observation arm 3 patients have relapsed. Conclusions: We conclude that rituximab maintenance therapy is feasable, safe and well tolerated in patients with CD20+ B-cell Non-Hodgkins-Lymphoma and might protect against tumor relapse. Patient recruitment for this study is ongoing. No significant financial relationships to disclose.