Phase II Study of Chlorambucil and Subcutaneous Rituximab in Patients With Extranodal MALT Lymphoma

Single arm phase II study of Chlorambucil in combination with subcutaneous Rituximab followed by maintenance therapy with subcutaneous Rituximab in patients with histologically proven diagnosis of CD20-positive marginal zone B-cell lymphoma of MALT type arisen at any extranodal site, either de novo, or relapsed following local therapy (including surgery, radiotherapy and antibiotics for H. pylori-positive gastric lymphoma).

The study consists in three parts. In Part A (induction phase I) patients will be treated with Chlorambucil 6 mg/m2 daily p.o for 42 consecutive days (weeks 1-6) in combination with intravenous Rituximab 375mg/m2 on day 1 week 1 followed by subcutaneous Rituximab 1400mg on days 8, 15 and 22 (day 1 of weeks 2, 3 and 4). After restaging (CT scan to be performed during weeks 7-8, i.e. between d42 and d55), responding patients (CR, CRu, PR) and those with stable disease will be treated in part B (induction phase II). In part B, starting from d56, (month 3) patients will receive Chlorambucil 6 mg/m2 daily p.o for 14 consecutive days (d1-14) every 28 days for 4 cycles in combination with subcutaneous Rituximab 1400mg on day 1 of each 28-day cycle. After restaging (CT scan to be performed at the end of month 6) responding patients and those with stable disease will be treated in part C. In Part C (maintenance phase) patients will be treated with subcutaneous Rituximab 1400mg every two months for 2 years (in total 12 injections). During maintenance phase, CT scans will be performed every 12 months and patients responding or with stable disease will stay on treatment for a total of two years as above reported.