Intraventricular application of rituximab as a treatment option in patients with CNS lymphoma and leptomeningeal disease

Abstract

1521 Background: Most patients (pts) with primary central nervous system lymphoma (PCNSL) relapse after initial response to treatment, often presenting with leptomeningeal disease. Since the majority of PCNSL are B-cell neoplasms expressing the CD20 surface antigen treatment with the chimeric monoclonal antibody (Mab) rituximab might be reasonable. The primary objective was to evaluate feasibility and safety of direct administration of the anti-CD20 antibody into the cerebro spinal fluid (CSF). Methods: Pts with intracranial lesions and/or leptomeningeal involvement of B-cell neoplasms expressing the CD20 surface antigen were included. In order to define the tolerated single dose, injections of 10–40 mg rituximab in a volume of 1–4 ml were administered over two minutes via an ommaya reservoir (n=4) or intrathecally (n=2). Drug clearance from the CSF was determined by measuring rituximab levels in the CSF and blood by ELISA. Results: Treatment with rituximab at single dosis of up to 35mg thrice weekly was ...