Maintenance Rituximab is associated with improved clinical outcome in rituximab naı̈ve patients with Waldenstrom Macroglobulinaemia who respond

Rituximab is an active agent in the treatment of Waldenstrom macroglobulinaemia (WM), a CD20-expressing indolent B-cell disorder characterized primarily by bone marrow infiltration with lymphoplasmacytic cells, along with demonstration of an IgM monoclonal gammopathy (Owen et al, 2003). With the use of single agent rituximab, overall response rates of 20–30% have been reported with a standard induction regimen of four weekly infusions, and progression-free survival (PFS) of 1 year (Foran et al, 2000; Treon et al, 2001; Gertz et al, 2004). With the use of an extended schedule of four weekly infusions, followed by four additional weekly infusions at week 12, response rates of 40–50% and PFS of 16–30 months have been reported (Dimopoulos et al, 2002; Treon et al, 2005). Because of the non-myelosuppressive nature of rituximab, and its potential to synergize with various anti-neoplastic agents including alkylators, nucleoside analogues, immunomodulatory drugs, and proteasome inhibitors, its investigation in combination regimens has been vigorously pursued (Treon et al, 2006; Dimopoulos et al, 2009). These studies have generally revealed higher overall response rates (70–90%) Steven P. Treon, Christina Hanzis, Robert J. Manning, Leukothea Ioakimidis, Christopher J. Patterson, Zachary R. Hunter, Patricia Sheehy and Barry Turnbull Dana Farber Cancer Institute, Harvard Medical School, and BioBridges, Boston, MA, USA