An Applicational Observation of Low-Dose Rituximab in Elderly Patients with Nodal Marginal Zone Lymphomas.

Background: Single-agent rituximab was shown to prolong overall response rate (ORR) in marginal zone lymphomas. However, despite the confirmed activity of this immuno-biologic agent a significant number of adverse events were reported in this commonly considered indolent lymphoma entity. Methods: To reduce the impact of rituximab toxicity we investigated the activity of low-dose rituximab infusions in 3 consecutive elderly patients (over 70 years) with nodal marginal zone lymphomas. All patients (Ann Arbor stage IV with bone marrow (BM) involvement, age range from 71 to 84 years, normal LDH and WHO performance status = 0) were treated with weekly low-dose rituximab (75 mg/m2) administred for 6 consecutive weeks. Results: All patients complleted the treatment program. No complete response were observed. All patients confirmed a partial response (PR) with reduction of symptoms and disease related BM involvement. The median response duration was 14 months. At a median follow-up of 18 months, 2 patients relapsed and one patient (chemiotherapy naive) is still responding. The 3 patients did not experienced any adverse events and depsite the older age of patients, no expected infusion-related side effects were recorded. Conclusion: This investigative report demostrated the efficacy and the well tolerability of low-dose rituximab (75 mg/m2 administreted weekly for 6 consecutive weeks) in elderly patients with well defined diagnosis of nodal marginal zone lymphoma. These observations can lead to the hypothesis that the dose and the schedule of rituximab should be redefined in this lymphoma entity.