Pentostatin, and Rituximab With and Without Cyclophosphamide for Previously Untreated B-Chronic Lymphocytic Leukemia

• To assess the rate of complete and overall response using rituximab and pentostatin with and without cyclophosphamide. [ Time Frame: up to 5 years ] [ Designated as safety issue: Yes ]

  For this evaluation, patients will be classified as complete responders if either of the following types of response are documented

  • CCR (Clinically based complete remission) denotes NED (No Evidence of Disease) based on baseline clinical parameters.
  • CR denotes CCR and, in bone marrow, no nodules and <30% lymphocytes.
  
  

• To monitor and assess toxicity of this regimen. [ Time Frame: up to 5 years ] [ Designated as safety issue: Yes ]
  

Drug: Pentostatin
2 mg/m2 IV over 30 minutes in 250 mL NS on day 1 during cycles 1-6.
Other Name: Nipent®
Drug: Rituximab
For the first week only: Day 1 of therapy 100 mg IV over 4 hours. Day 3 of therapy 375 mg/m2 IV at 50 mg/hr and increase by 100 mg/hr at 30-minute intervals to a maximum of 400 mg/hr. Day 5 of therapy 375 mg/m2 IV at 100 mg/hr for the first 15 minutes the remainder goes in at 45 minutes. The remaining weeks 375 mg/m2 will be repeated as a single IV infusion Day 1 of Week 4, 7, 10, 13 and 16 during cycles 2-6.
Other Name: RITUXAN®
Drug: Cyclophosphamide
600 mg/m2 IV in 250 mL NS over 30 minutes on day 1 cycles 1-6
Other Name: CTX

Rationale: Research indicates that both cyclophosphamide and pentostatin work synergistically against cancer cells and have a high response rate against chronic lymphocytic leukemia (CLL) without creating severe side effects in patients. In addition, studies have shown that rituximab, a therapy that targets the immune system, has the highest efficacy against CLL and the lowest toxicity rate when compared with other immunotherapy drugs. Studies also show that rituximab enhances the efficacy of the chemotherapy agents cyclophosphamide and pentostatin. This study offers the combination of immunotherapy with two promising chemotherapy agents against CLL.

Purpose: This study is evaluating the efficacy and safety of combination treatment with cyclophosphamide, pentostatin, and rituximab in patients with CLL. Several tests evaluating the genetic and molecular components of CLL will also be performed. Some of these tests will be conducted before, during, and after treatments to assess changes resulting from the study drugs. Each patient's outcome will be assessed in relation to various aspects of their genes.