Rituximab long-term maintenance therapy after autologous stem cell transplantation in patients with B-cell non-Hodgkin's lymphoma.

Treatment of B-cell non-Hodgkin's lymphomas (NHL) with either Rituximab alone or in combination with cytotoxic chemotherapy has been effective without major side effects. Thus, Rituximab maintenance therapy after autologous peripheral blood stem cell transplantation (PBSCT) might represent an improvement in NHL therapy. We therefore retrospectively analyzed the efficacy and side effects of monthly long-term Rituximab maintenance therapy after PBSCT in 27 patients with NHL. In median 10 infusions of Rituximab were given after PBSCT in time intervals of 1 month. Molecular monitoring of t(14;18) was performed using nested as well as quantitative real time polymerase chain reaction (RT-PCR) based on the LightCycler technology. Side effects according to common toxicity criteria (CTC) > II did mainly affect the hematopoietic system. In total, 10 patients (37%) suffered form grade III-IV hematotoxicity. Except for two patients with cutaneous Varicella-Zoster infection no serious infectious complications (CTC grade III/IV) occurred. No patient died because of treatment-related causes. This adverse event data compared favorably to the published data. Three patients had t(14;18) nested RT-PCR positive results before Rituximab therapy and converted to negativity after Rituximab therapy. We conclude that a prolonged Rituximab maintenance therapy after PBSCT with monthly administration is reliable and safe.