Conventional therapy is effective for diffuse aggressive lymphomas and low grade lymphomas, but is limited by relapse occurs in 40 to 50% of subjects.

This study assesses autologous stem cell transplant (ASCT) supplemented with high-dose therapy increases the event-free survival in diffuse aggressive lymphomas and low grade lymphomas, as an alternative to the limitations of conventional therapy.

Preliminary studies with rituximab in low grade lymphomas indicate a response rate of about 50% with very little toxicity. Rituximab is hypothesized to be a candidate for post-transplant therapy because the majority of malignant lymphomas express the CD20 antigen; rituximab has impressive independent anti-tumor activity; and the antibody has little toxicity outside of the acute administration.

The first 4 subjects received rituximab weekly for 4 weeks at the standard dose of 375 mg/m2, starting 6 weeks after ASCT transplant.

After an observation period to assess acute and late toxicity for the first 4 subjects, subsequent subjects received induction as above followed by an additional 4 week course at 6-months post-ASCT.

Inclusion Criteria:

• B-cell, CD20+ NHL
• Evidence of engraftment post-autologous peripheral blood stem cell transplant (PBSC-T), aka autologous stem cell transplant (ASCT)
• Eastern Cooperative Oncology Group (ECOG) performance status 0 to 1
• Creatinine < 2 mg/dL
• Bilirubin < 2.0 mg/dL
• Liver function tests (LFTs) < 5 x upper limit of normal (ULN)

Exclusion Criteria:

• Graft source from bone marrow
• Non-responders [progressive disease (PD) or stable disease (SD)] to prior anti-CD20 therapy
• PD after ASCT
• Post-ASCT radiotherapy
• Concomitant treatment with radiotherapy, chemotherapy or immunotherapy including rituximab
• Evidence of active pneumonitis
• Evidence of active infection
• Concurrent prednisone or other systemic steroid medication
• Nitrosourea therapy within 6 weeks of the first treatment with rituximab
• Presence of anti-murine antibody (HAMA) reactivity