Rituximab Maintenance Therapy in CD20+ B-Cell Non-Hodgkin’s Lymphoma.

Purpose: Clinical and pharmacokinetic data suggest that high serum concentrations of rituximab and prolonged exposure to rituximab are associated with higher response rates and improved quality of response. We used rituximab-maintenance therapy to target minimal residual disease, with the aim of increasing the duration of remissions achieved following initial treatment.

Methods: During 2001–2005, 14 patients with CD20+ B-cell non-Hodgkin’s lymphoma (seven with diffuse large B cell lymphoma [DLBCL] and seven with follicular lymphoma [FL]) were enrolled in the study. Patients with DLBCL and FL were required to have a CR or PR, respectively, following initial treatment. The most common initial treatments were R-CHOP, R-FC or CHOP. Rituximab-maintenance therapy was administered as 375mg/m² doses every 3 months for 2 years. Three patients with aggressive DLBCL were treated with high-dose chemotherapy/autologous stem-cell transplantation (HDT/ASCT) and received rituximab-maintenance therapy every 2 months for four doses in total.

Results: Most patients had disease of Ann Arbor stage ≥ 3 (two FL patients stage I). In patients with DLBCL, median event-free and overall survivals were 22.1 months and 22.3 months, respectively, with the corresponding values being 20.6 months and 26.1 months in patients with FL. To date, 13 patients are in continuous clinical remission and only one patient has relapsed.

Conclusions: Rituximab-maintenance therapy is effective and well tolerated in this setting. Recruitment for this study is ongoing and evaluation of a larger patient population, together with a longer follow-up, will determine whether this treatment approach has curative potential.