Inclusion Criteria

DISEASE CHARACTERISTICS:

- Histologically or cytologically confirmed AIDS-related B-cell non-Hodgkin's lymphoma
(NHL), including any of the following subtypes:

- Grade III follicular large cell lymphoma

- Diffuse large B-cell lymphoma

- Immunoblastic lymphoma

- Plasmablastic lymphoma

- Primary effusion lymphoma

- Previously untreated disease

- Any stage disease

- CD20 positive disease

- Must have documented HIV infection

- Documentation may be by serology (enzyme-linked immunosorbent assay, western
blot), culture, or quantitative polymerase chain reaction or branched DNA assays

- Prior documentation of HIV seropositivity allowed

- Measurable or nonmeasurable disease

- Currently receiving effective highly active anti-retroviral therapy

- No primary CNS lymphoma, including parenchymal brain or spinal cord lymphoma

- No presence of leptomeningeal disease (positive cerebrospinal fluid for lymphoma) or
presence of metastatic disease to brain, in terms of any mass lesion

PATIENT CHARACTERISTICS:

- ECOG performance status (PS) 0-2 OR Karnofsky PS 50-100%

- Life expectancy ≥ 2 months

- Absolute granulocyte (neutrophil) count ≥ 1,000/mm³ (unless secondary to lymphomatous
involvement of bone marrow)

- Platelet count ≥ 75,000/mm³ (unless secondary to lymphomatous involvement of bone
marrow or due to HIV-related thrombocytopenia)

- Bilirubin ≤ 2.0 mg/dL (unless elevated secondary to lymphomatous involvement of liver
or biliary system or due to other HIV medications [e.g., indinavir, tenofavir, or
atazanavir])

- SGOT ≤ 5 times upper limit of normal

- Creatinine ≤ 2.0 mg/dL OR creatinine clearance ≥ 60 mL/min (unless secondary to renal
involvement by lymphoma)

- LVEF normal by MUGA or echocardiogram

- Not pregnant or nursing

- Negative pregnancy test

- Fertile patients must use effective contraception during and for 6 months after
completion of study treatment

- No other malignancy, except nonmelanoma skin cancer, carcinoma in situ of the cervix,
or Kaposi's sarcoma that does not require systemic therapy

- No serious, ongoing, nonmalignant disease or infection that would preclude study
compliance, in the opinion of the investigator

- No history of cutaneous or mucocutaneous reactions, or diseases in the past, due to
any cause, severe enough to cause hospitalization or an inability to eat or drink for
≥ 2 days

- No acute, intercurrent infection that would preclude study treatment

- Patients with Mycobacterium avium are eligible

- No cardiovascular problems, including any of the following:

- Myocardial infarction within the past 6 months

- New York Heart Association class II-IV heart failure

- Uncontrolled angina

- Severe uncontrolled ventricular arrhythmias

- Clinically significant pericardial disease

- ECG evidence of acute ischemic or active conduction system abnormalities.

- No shortness of breath at rest

- Arterial PO_2 ≥ 70 or pulse oximeter-derived O_2 saturation ≥ 94% on room air (unless
due to lymphomatous involvement of the lungs)

- Able to comply with study and provide adequate informed consent

PRIOR CONCURRENT THERAPY:

- See Disease Characteristics

- At least 4 weeks since prior major surgery (except diagnostic surgery)

- At least 12 months since prior rituximab unless it was only given for indications
other than the treatment of aggressive lymphoma

- No prior cytotoxic chemotherapy or radiotherapy for this lymphoma

- Concurrent radiotherapy, with or without steroids, for emergency conditions
secondary to lymphoma (i.e., CNS tumor or cord compression) allowed

- No zidovudine or zidovudine-containing regimen (including Combivir® or Trizivir®)
during and for 2 months after completion of chemotherapy

- Concurrent erythropoietin or filgrastim (G-CSF) allowed

- Growth factor therapy must be discontinued ≥ 24 hours prior to study entry