• Time to treatment failure (TTF) measured from day 1 of course 1 of Cyclophosphamide, Doxorubicin, Vincristine and Prednisone (CHOP) therapy up to 3 years on study with life-long follow-up [ Designated as safety issue: No ]
  

• Complete response (CR) rate duration until first relapse [ Designated as safety issue: No ]
  
• Progression rate during treatment [ Designated as safety issue: No ]
  
• Survival [ Designated as safety issue: No ]
  
• Tumor control measured from day 1 of course 1 of CHOP therapy (non-tumor related events are censored) [ Designated as safety issue: No ]
  
• Disease-free survival measured from day 1 of course 1 of CHOP therapy [ Designated as safety issue: No ]
  
• Safety (adverse events, serious adverse events) assessed at 3 months after treatment [ Designated as safety issue: Yes ]
  

OBJECTIVES:

Primary

• Compare the efficacy of 2 different schedules of immunochemotherapy comprising rituximab, cyclophosphamide, doxorubicin hydrochloride, vincristine, and prednisone in patients with previously untreated, low-risk, aggressive B-cell non-Hodgkin's lymphoma.
• Compare acute and chronic side effects in patients treated with these regimens.
• Compare time to treatment failure in patients treated with these regimens.

Secondary

• Compare the time to progression in patients treated with these regimens.
• Compare the overall and disease-free/relapse-free survival of patients treated with these regimens.
• Compare the complete response rate in patients treated with these regimens.
• Compare the tumor control in patients treated with these regimens.
• Compare the safety of these regimens in these patients.
• Compare the pharmacoeconomics of these regimens.
• Compare patient adherence to these regimens.

OUTLINE: This is an open-label, randomized, multicenter study. Patients are stratified according to participating center. Patients are randomized to 1 of 2 treatment arms.

All patients are given the option of receiving a 1-week course of pretreatment therapy comprising vincristine IV once on day -6 and oral prednisone once daily on days -6 to 0.

• Arm I: Patients receive R-CHOP immunochemotherapy comprising rituximab IV, cyclophosphamide IV over 15 minutes, doxorubicin hydrochloride IV, and vincristine IV on day 1 and oral prednisone once daily on days 1-5. Treatment repeats every 21 days for 3 courses in the absence of disease progression or unacceptable toxicity. Patients then undergo restaging of their disease. Patients with disease progression proceed to salvage therapy off study. All other patients receive 3 more courses of R-CHOP.
• Arm II: Patients receive R-CHOP as in arm I. Treatment repeats every 21 days for 3 courses in the absence of disease progression or unacceptable toxicity. Patients then undergo restaging of their disease. Patients with disease progression proceed to salvage therapy off study. All other patients receive 1 more course of R-CHOP followed by 2 courses of rituximab alone. All patients undergo final restaging after 6 courses of rituximab. Patients with disease progression, stable disease, or partial response proceed to salvage therapy off study.

After completion of study treatment, patients are followed periodically for 5 years and then annually thereafter.

PROJECTED ACCRUAL: A total of 622 patients will be accrued for this study.