Ofatumumab in Treating Patients With Previously Untreated Stage II, Stage III, or Stage IV Follicular Non-Hodgkin Lymphoma

DISEASE CHARACTERISTICS:

* Histologically confirmed follicular non-Hodgkin lymphoma (NHL) meeting 1 of the following criteria:

  * Bulky (i.e., single mass ≥ 7cm in any uni-dimensional measurement) stage II disease
  * Stage III or IV disease
* WHO grade 1, 2, or 3a disease
* Bone marrow biopsies allowed provided they are submitted in conjunction with nodal biopsies

  * No fine-needle aspirates for diagnosis
* Tumor tissue must express the CD20-positive antigen by flow cytometry or IHC
* At least 1 site of measurable disease that is \> 1 cm in diameter in ≥ 1 dimension present either on physical exam or imaging studies

  * Non-measurable disease alone not allowed, including the following:

    * Bone lesions (lesions if present should be noted)
    * Ascites
    * Pleural/pericardial effusion
    * Lymphangitis cutis/pulmonis
    * Bone marrow (involvement by NHL should be noted)
* Low- or intermediate-risk disease by the Follicular Lymphoma International Prognostic Index (FLIPI)

  * FLIPI score meeting 1 or 2 of the following risk factors:

    * Age \> 60 years
    * Involvement of \> 4 nodal sites
    * Stage III-IV disease
    * Hemoglobin \< 12.0 g/dL
    * LDH normal
  * Risk determined by the following:

    * Low Risk: 0-1 of the above risk factors
    * Intermediate Risk: 2 risk factors
    * Poor Risk: ≥ 3 risk factors
* No known CNS involvement

PATIENT CHARACTERISTICS:

* ECOG performance status 0-2
* ANC ≥ 1,000/μL
* Platelet count ≥ 75,000/μL
* Creatinine clearance ≥ 30 mL/min
* Bilirubin ≤ 2 times upper limit of normal (unless secondary to Gilbert syndrome or hepatic involvement of NHL)
* Not pregnant or nursing
* Negative pregnancy test
* Fertile patients must use effective contraception during and for 3 months after completion of study treatment
* Patients with HIV infection allowed provided the following criteria are met:

  * No evidence of coinfection with hepatitis B or C
  * CD4+ cell count ≥ 400/mm³
  * No evidence of resistant strains of HIV
  * HIV viral load \< 10,000 copies HIV RNA/mL if not on anti-HIV therapy OR HIV viral load \< 50 copies if on anti-HIV therapy
  * No history of AIDS-defining conditions
* No evidence of active hepatitis B (HBV) or C (HCV) infection (i.e., no positive serology for anti-HBc or anti-HCV antibodies)

  * HBV seropositivity allowed (HBsAg+) provided they are closely monitored for evidence of active HBV infection by HBV DNA testing
  * After completing treatment, HBsAg + patients must be monitored by HBV DNA testing every 2 months for 6 months post-treatment, while continuing lamivudine (required)

PRIOR CONCURRENT THERAPY:

* No prior chemotherapy or immunotherapy (e.g., monoclonal antibody-based therapy) for NHL

  * Prior involved-field radiation therapy allowed
* More than 2 weeks since prior corticosteroids except for maintenance therapy for a non-malignant disease

  * No concurrent dexamethasone or other steroids as antiemetics
* No live virus vaccination within 6 weeks prior to study entry
* No concurrent zidvoudine or stavudine