Patients receive CHOP-R* therapy comprising cyclophosphamide IV over 15-45 minutes, doxorubicin IV over 5-10 minutes, vincristine IV, and rituximab IV over 30-90 minutes on day 1 and oral prednisone on days 1-5. Patients also receive oblimersen IV continuously on days -4 to 3. Treatment repeats every 21 days for 6-8 courses in the absence of disease progression or unacceptable toxicity. Patients who discontinue treatment due to unacceptable toxicity to oblimersen may continue to receive standard therapy comprising CHOP-R.