Beta-Glucan and Rituximab in Treating Young Patients With Relapsed or Progressive Lymphoma or Leukemia, or Lymphoproliferative Disorder Related to Donor Stem Cell Transplantation

Overview

RATIONALE: Monoclonal antibodies such as rituximab can locate cancer cells and either kill them or deliver cancer-killing substances to them without harming normal cells. Beta-glucan may increase the effectiveness of rituximab by making cancer cells more sensitive to the monoclonal antibody. PURPOSE: This phase I trial is studying the side effects and best dose of beta-glucan when given together with rituximab in treating young patients with relapsed or progressive lymphoma or leukemia or with lymphoproliferative disorder related to donor stem cell transplantation.

OBJECTIVES: Primary * Determine the maximum tolerated dose of beta-glucan when given in combination with rituximab in pediatric patients with relapsed or progressive CD20-positive lymphoma or leukemia or post-allogeneic stem cell transplant-related lymphoproliferative disorder. * Determine the toxicity of this regimen, with special emphasis on the degree of B-cell depletion and immune suppression, in these patients. * Determine the effects of beta-glucan on leukocyte-mediated cytotoxic effects in patients treated with this regimen. Secondary * Determine the antitumor effect of this regimen in these patients. OUTLINE: This is a dose-escalation study of beta-glucan. Patients are assigned to 1 of 2 treatment groups according to diagnosis. * Group I (lymphoma or leukemia): Patients receive rituximab IV on days 1, 8, 15, and 22 and oral beta-glucan once daily on days 1-28 (days 8-28 of course 1). Treatment repeats every 42 days for 4 courses in the absence of disease progression or unacceptable toxicity. * Group II (post-allogeneic stem cell transplant-related lymphoproliferative disorder): Patients receive rituximab IV on days 1, 4, 8, 15, and 22 and oral beta-glucan once daily on days 8-28. Beginning on day 42, patients with responding disease may receive monthly rituximab prophylaxis until their CD4 cell count is \> 200/mm\^3. Cohorts of 6 patients receive escalating doses of beta-glucan until the maximum tolerated dose (MTD) is determined. The MTD is defined as the dose preceding that at which 2 of 6 patients experience dose-limiting toxicity. Patients are followed every 3 months for 2 years. PROJECTED ACCRUAL: A total of 6-24 patients will be accrued for this study within 2 years.