Clofarabine and Rituximab in Treating Patients With Relapsed Non-Hodgkin Lymphoma

• The Maximum Tolerated Dose (MTD) of Oral Clofarabine in Adult Patients With Relapsed CD20+ Non-Hodgkin Lymphoma(NHL) [ Time Frame: 14 days for up to 8 cycles (1 cycle equals 14 days on drug, 14 days off drug) for a total of up to 224 days ] [ Designated as safety issue: Yes ]

  Initially, 3 patients will be enrolled into a dose level during the dose-escalation portion:

  • If no patient experiences dose-limiting toxicities during the first 4 weeks, then 3 patients will be enrolled into the next dose level.
  • If one of the three patients develops dose-limiting toxicities, then 3 additional patients will be enrolled in that cohort. If none of the additional 3 patients experiences dose-limiting toxicities, then further dose-escalation occurs.
  • If one additional patient experiences dose-limiting toxicities, then the maximum tolerated dose is exceeded.
  
  
• Estimate Objective Response Rates of Oral Clofarabine in Combination With Rituximab in Relapsed CD20+NHL [ Time Frame: Oral Clofarabine x 14 days for up to 8 cycles (1 cycle equals 14 days on drug, 14 days off drug) for a total of up to 224 days AND Rituximab weekly for 4 weeks than monthly for up to 8 cycles on day 1 of cycle ] [ Designated as safety issue: No ]
  

• Determine One-year Progression Free Survival Using the MTD of Clofarabine With Rituximab in Relapsed CD20+NHL [ Time Frame: One year after study drug(s) have been given. Duration of study up to 1 year. ] [ Designated as safety issue: No ]
  
• Determine the Safety and Efficacy of Clofarabine in Combination With Rituximab [ Time Frame: Duration of the study, up to 1 year. ] [ Designated as safety issue: Yes ]
  
• Whether Clofarabine Acts as an Inhibitor of DNA Methylation Similar to Cladribine by Performing Scientific Correlates [ Time Frame: Duration of the study, up to 1 year. ] [ Designated as safety issue: No ]
  
• Whether Response to Clofarabine Alone or in Combination With Rituximab Correlates With Changes in Global Serum DNA Methylation Index [ Time Frame: Duration of the study, up to 1 year. ] [ Designated as safety issue: No ]
  
• Identity of the Gene Activated by Clofarabine Therapy by Using Genomic DNA and RNA Array Technology [ Time Frame: Twice monthly at standard of care visits for 3 months post last cycle of chemotherapy. ] [ Designated as safety issue: No ]
  

Biological: rituximab
Administered weekly times 4 weeks and then monthly during the study for up to 8 cycles and will be given on day 1 of clofarabine. A peripheral or central intravenous (IV) line will be established. The initial dose rate at the time of the first infusion should be 50/mg/hr for the first hour. If no toxicity is seen, the dose rate may be gradually escalated (50 mg/hr increments at 30 minute intervals) to a maximum of 300 mg/hr. If the first dose of rituximab is well tolerated, the starting flow rate for the administration of subsequent doses will be 100 mg/hr then gradually increased (100 mg/hr increments at 30 minute intervals) not to exceed 400 mg/hr.
Drug: clofarabine
Phase 1 dosing: Initially, 3 patients will be enrolled into a dose level during the dose escalation portion. Level 1: 2mg fixed dose times 14 days for up to 8 cycles. Level 2: 4mg fixed dose times 14 days for up to 8 cycles. Level 3: 6mg fixed dose times 14 days for up to 8 cycles. Phase II dosing: The phase II dose of oral clofarabine will be determined from the phase 1.
Genetic: DNA methylation analysis
We will use an HPLC assay developed by Yu et al31 to determine the DNA methylation (DMI) index in peripheral blood and bone marrow of patients entering this trial and after treatment with clofarabine and rituxan
Genetic: gene expression analysis
Total RNA will be processed for determination of gene expression by microarray
Genetic: microarray analysis
we will scan the microarray slides with an Axon scanner, and quantify data using the GeneSight software. Local background is subtracted and data points with no signal, high background, or spot asymmetry are eliminated. We will adjust genes with low expression and low signal intensity to a minimal raw value of 5: This avoids unwarranted mathematical distortions due to division by decimals << 1. After calculating the ratio of the Cy5 /Cy3 fluorescence signal intensity for each gene, we normalize the data relative to the mean intensity from all genes.
Genetic: polymerase chain reaction Other: high performance liquid chromatography
Fifteen µg of DNA will be sonicated for 60 seconds on ice into 200 bp-1000 bp fragments. Samples are then denatured at 1000C for 5 minutes and cooled on ice to prevent re-annealing. Sixty units of nuclease S1 (Invitrogen) and 112.5 mu of snake venom phosphodiesterase I (Sigma) in 12 µl of S1 dilution buffer is then added to the samples and incubated at 370C for 18 hours. Samples are reheated to 1000C for 5 minutes, snap cooled again on ice, and another sixty units of nuclease S1 and 112.5 mu of snake venom phosphodiesterase I are added and incubated at 370C for another 4 to 6 hours. The pH of each sample was raised to 8.5 with 0.5 M Tris, pH 10. Two and a half units of alkaline phosphatase (Sigma) are added and incubated for 2 additional hours at 370C. One hundred µl of 0.05M potassium phosphate, pH 7 is added to final samples before 50 µl of the clear supernatant is injected into the reverse-phase high performance liquid chromatography (HPLC).
Other: laboratory biomarker analysis
50 µl of the clear supernatant is injected into the reverse-phase high performance liquid chromatography (HPLC).
Other Name: High Performance Liquid Chromatography (HPLC)

OBJECTIVES:

Primary

• To determine the maximum tolerated dose of clofarabine in adult patients with relapsed CD20-positive B-cell non-Hodgkin lymphoma (NHL).
• To estimate objective response rates of clofarabine in combination with rituximab in these patients.

Secondary

• To determine the 1-year progression-free survival of this regimen using the mean tolerated dose in these patients.
• To determine the safety and efficacy of this regimen in these patients.
• To determine if clofarabine acts as an inhibitor of DNA methylation similar to cladribine by performing scientific correlates.
• To determine whether response to clofarabine alone or in combination with rituximab correlates with changes in global serum DNA methylation index.
• To identify the gene activated by clofarabine therapy by using genomic DNA and RNA array technology.

OUTLINE: This is a phase I, dose-escalation study of clofarabine followed by a phase II study.

Patients receive oral clofarabine once daily on days 1-14 of all courses and rituximab IV on days 1, 8, 15, and 22 of course one and then on day 1 of courses 2-8. Courses repeat every 4 weeks. After 2 courses of therapy, patients who are eligible for stem cell transplantation may either undergo transplantation or continue receiving study drugs until disease progression or unacceptable toxicity for up to a total of 8 courses of treatment.

Patients undergo blood sample collection periodically for correlative studies. Samples are analyzed to identify global DNA methylation differences and correlate changes in methylation index (MI) with patient outcome after treatment with clofarabine with or without rituximab via high performance liquid chromatography (HPLC); to determine differences in gene expression via microarray analysis and micro-RNA (miRNA) expression via quantitative polymerase chain reaction (PCR) in patients with high compared to low global DNA methylation index and miRNA expression for CD5+ B-lymphocytes obtained from pediatric tonsils and from B-lymphocytes of 5 healthy controls; and to determine gene expression and miRNA profiles in patients before and after treatment with clofarabine with or without rituximab via genomic DNA arrays.

After completion of study treatment, patients are followed once a year for 2 years.