2. Time to initiation of maintenance therapy. Patients may start maintenance therapy as early as 60 days post-transplant and up to 180 days post-transplant; as long as they meet the following criteria: * Platelet count >/= 100,000/mm^3. Platelet transfusions to help patients meet eligibility criteria are not allowed within 3 days before study enrollment. * Neutrophil count >/= 1000/mm^3. (No growth factors within 5 days prior to first dose of the study drug.) * Total bilirubin </= 1.5 x ULN * Alanine aminotransferase (ALT) and aspartate aminotransferase (AST) </= 3 x ULN * Creatinine < 2.5 mg/dL * Recovered (ie, </= Grade 1 toxicity) from the reversible effects of autologous stem cell transplant.