Rituximab (Mabthera) Improves the Treatment Results of DHAP-VIM-DHAP and ASCT in Relapsed/Progressive Aggressive CD20⁺ NHL. A Prospective Randomized HOVON Trial.

A total of 239 patients with relapsed/progressive aggressive CD20⁺ NHL after/during adriamycin containing regimens, were recruited to the randomized HOVON-44 trial comparing DHAP-VIM-DHAP followed by BEAM and autologous stem cell re-infusion (ASCT)(“DHAP-arm”) with DHAP-VIM-DHAP in conjunction with Rituximab (375 mg/m²) and ASCT (“R-DHAP arm”). Of the included patients, 202 were evaluable and randomized to the DHAP arm (n=101) or R-DHAP arm (n=101). Only patients with CR/PR after two courses of intensive chemotherapy were eligible for ASCT. Patients were well balanced for risk factors. In both arms the majority of patients had not been exposed to Rituximab during first line treatment. As of July 2006, median follow-up of all patients still alive is 24.5 months. After two courses of chemotherapy PR/CR was obtained in 49 % of the patients in the DHAP arm and 77% in the R-DHAP arm (p=<.01;intention to treat analysis). Post-transplantation PR/CR was obtained in 41% and 58% of the patients respectively (p=.40). A significant difference between both arms was observed for failure free survival (FFS), disease free survival (DFS) and overall survival (OS) in favor of the Rituximab arm (p<.05, table 1). The less pronounced difference in OS between both arms is most likely due to the fact that non-responding or relapsing patients in the DHAP arm received salvage treatment with a Rituximab containing regimen. Additionally, a subgroup analysis was performed according to type of response to first-line treatment:1) Response duration more than 3 months (n=138); 2) Progression or response duration less than 3 months (n=64). Within both subgroups, the hazard ratio’s for the endpoints were of equal magnitude (.40–.60), indicating that the beneficial effect of Rituximab existed in both subgroups. In conclusion these results demonstrate that the addition of Rituximab to second line of chemotherapy followed by ASCT results in a significant improved FFS, DFS, and OS in patients with relapsed/progressive aggressive CD20⁺ NHL.