PRIMARY OBJECTIVE:~I. To evaluate the ability of ibrutinib-based induction therapy to prolong progression free survival (PFS) compared to standard fludarabine phosphate, cyclophosphamide, and rituximab (FCR) chemoimmunotherapy for younger patients with chronic lymphocytic leukemia (CLL).~SECONDARY OBJECTIVES:~I. Evaluate overall survival (OS) of patients based on treatment arm. II. Monitor and assess toxicity of treatment with ibrutinib-based induction relative to standard FCR chemotherapy.~III. To compare quality of life (QOL) in CLL patients during the first 6 months of treatment among patients receiving ibrutinib-based induction therapy relative to standard FCR chemoimmunotherapy.~IV. To compare QOL over the long-term in CLL patients receiving continuous therapy using ibrutinib to that of CLL patients who completed FCR therapy.~V. Determine the effect of pretreatment clinical and biological characteristics (e.g. disease stage, immunoglobulin heavy chain variable region gene [IGHV] mutation status, fluorescent in situ hybridization [FISH]) on clinical outcomes (e.g. complete response, PFS) of the different arms.~VI. Determine if the minimal residual disease (MRD) status as assessed by flow cytometry at different time points during and after treatment is an effective surrogate marker for prolonged PFS and overall survival.~VII. Compare the genetic abnormalities and dynamics of intra-clonal architecture of CLL patients before and after treatment with chemoimmunotherapy (CIT) and non-CIT approaches and explore relationships with treatment resistance.~VIII. Explore the effects of FCR and ibrutinib-based therapy on T-cell immune function.~IX. Conduct confirmatory validation genotyping of single nucleotide polymorphisms (SNPs) associated with the efficacy and toxicity of fludarabine-based therapy as in a prior Eastern Cooperative Oncology Group (ECOG) genome-wide association study (GWAS) analysis in the E2997 trial.~X. Evaluate the ability of prognostic model that incorporates clinical and biologic characters to predict a response to therapy and clinical outcome (PFS, OS).~XI. Evaluate signaling networks downstream of the B-cell receptor in patients receiving ibrutinib-based therapy.~XII. Collect relapse samples to study mechanisms of resistance to both FCR and ibrutinib-based therapy.~OUTLINE: Patients are randomized to 1 of 2 treatment arms.~ARM A: Patients receive ibrutinib orally (PO) once daily (QD) on days 1-28. Beginning cycle 2, patients also receive rituximab intravenously (IV) over 4 hours on days 1 and 2 of cycle 2, and day 1 of cycles 3-7. Treatment repeats every 28 days for 7 cycles in the absence of unacceptable toxicity. In the absence of disease progression, patients may continue ibrutinib PO QD.~ARM B: Patients receive rituximab IV over 4 hours on days 1 and 2 of cycle 1, and day 1 of cycles 2-6. Patients also receive fludarabine phosphate IV over 30 minutes and cyclophosphamide IV over 30 minutes on days 1-3. Treatment repeats every 28 days for 6 cycles in the absence of unacceptable toxicity.~After completion of study treatment, patients are followed up for 10 years.
This phase III trial studies ibrutinib and rituximab to see how well they work compared to fludarabine phosphate, cyclophosphamide, and rituximab in treating patients with untreated chronic lymphocytic leukemia or small lymphocytic lymphoma. Ibrutinib may stop the growth of cancer cells by blocking some of the enzymes needed for cell growth. Chemotherapy drugs, such as fludarabine phosphate and cyclophosphamide, work in different ways to stop the growth of cancer cells, either by killing the cells, by stopping them from dividing, or by stopping them from spreading. Rituximab is a monoclonal antibody. It binds to a protein called CD20, which is found on B cells (a type of white blood cell) and some types of cancer cells. This may help the immune system kill cancer cells. It is not yet known whether fludarabine phosphate, cyclophosphamide, and rituximab may work better than ibrutinib and rituximab in treating patients with untreated chronic lymphocytic leukemia or small lymphocytic lymphoma.