Excellent Tolerance of Rituximab when Given After Mitoxantrone/cyclophosphamide: an Effective and Safe Combination for Indolent Non-Hodgkin's Lymphoma

Treatment for extensive indolent lymphoma should provide optimization of efficacy while avoiding excessive toxicity. Rituximab may be an ideal agent to combine with chemotherapy because of its lack of classical myelotoxicity. In this study, 27 patients with a variety of histologies of indolent B-cell non-Hodgkin's lymphoma have been treated utilizing a novel three-drug combination. Nine patients had relapsed disease and 18 were previously untreated. Patients first received cyclophosphamide 800 mg/m(2) and mitoxantrone 8 mg/m(2) i.v. on day 1, every 3 weeks for 2 cycles. Subsequently, patients received rituximab 375 mg/m(2) followed by mitoxantrone 8 mg/m2 every 2 weeks for 4 cycles. This regimen and, in particular, the rituximab infusion were extremely well tolerated. Only two of 27 patients experienced a grade 1/2, infusion-related reaction during the first rituximab infusion. Grade 4 neutropenia was noted at some point in 16 patients who were then offered granulocyte-macrophage colony-stimulating factor support for improvement of neutropenia. No infections were noted. Alopecia was minimal. Of 27 patients, 19 achieved a complete response (CR), one achieved an unconfirmed CR (CRu), and five patients achieved a partial response, for an overall response rate of 92.5%. Molecular remissions were noted in seven of 12 tested patients in CR. We concluded that the cyclophosphamide/mitoxantrone/rituximab (CyMiR) regimen is effective and extremely well tolerated. Furthermore, rituximab infusion-associated morbidity is markedly reduced.