The effect of Rituximab on patients with follicular and mantle-cell lymphoma

Background: Clinical activity of the anti CD-20 monoclonal antibody Rituxim ab has been reported in patients with follicular lymphoma (FL) and mantle-c ell lymphoma (MCL). Patients and methods: 120 patients with bi-dimensionally measurable FL or M CL (R.E.A.L. Classification) were treated with Rituximab 375 mg/m(2)/week f or 4 weeks. A central pathology review confirmed the diagnosis of FL in 76 of 78 and of MCL in 39 of 42 cases. The response was evaluated after 8 week s and confirmed after 12 weeks from the start of treatment. Results: The toxicity of the treatment was, as expected, grade 1-2 fever an d rigors during the first infusion and mild asthenia during the treatment p eriod. Serious adverse events, probably or possibly related to the study tr eatment, included four deaths (3 of cardiac origin, 1 caused by P, carinii pneumonia) and 10 further nonfatal cases, including a permanent agranulocyt osis and one case of heart failure. Response rate at week 12 was 52% for FL and 22% for MCL. After treatment, the BCL-2 rearrangement disappeared in 1 5 of 29 blood but only in 5 of 23 bone marrow samples; BCL-1 disappeared in 5 of 12 blood and 0 of 7 bone marrow specimens, as determined by PCR. Conclusions: Rituximab is an active agent for the treatment of FL. while it s efficacy is modest in MCL. The effect in reducing minimal residual diseas e is more pronounced on the blood than it is on the bone marrow.