Frankel, Stanley R.

Abstract E1496 is a phase III trial designed to evaluate the ability of 2 years (yr) of maintenance rituximab (MR) to prolong progression-free survival (PFS) after CVP (cyclophosphamide 1 G/m2 day [d] 1, vincristine 1.4 mg/m2 [max = 2 mg] d 1, prednisone 100 mg/m2 d 1–5) chemotherapy in stage III–IV follicular grade 1 and 2 and small lymphocytic lymphoma. After CVP treatment to maximum response, (6–8 cycles), stable and responding patients (pt) were randomized to MR (375 mg/m2 weekly x 4) every 6 months x 4 or observation (OBS). Stratification factors included histology, response and residual disease after CVP. With 3-yr median follow-up, survivals (from time of randomization, one-sided logrank p values) for all pt (n=304) favored MR for PFS (p = 3 x 10–8; hazard rate {HR} = 0.38 [0.28;0.54, 95% confidence intervals]) and OS (p = 0.09; HR = 0.66 [0.36–1.22]). Because the large majority of pt have FL and because rituximab efficacy is notably greater in FL, we focused in this report on the 237 FL pt. Median age was 58 yr, 65% were stage IV, 64% had marrow disease, 64% had high tumor burden and 37% had high-risk disease by the follicular lymphoma prognostic index. PFS after randomization was significantly longer for MR vs OBS (p = 3 x 10-7; HR = 0.39 [0.27;0.57]). The estimated PFS at 4 yr (~4.5 yr after start of treatment) was 56% for MR vs 33% for OBS. Differences in PFS were significant within the predefined strata and the differences were most significant in favor of MR for pt with high initial tumor burden and minimal residual disease after CVP. Overall survival was superior for MR (p = 0.03; HR = 0.51 [0.25;1.04]. Estimated OS at 4 yr (~4.5 years after start of treatment) was 88% for MR vs 72% for OBS. Of 33 deaths, 21 occurred on the OBS arm. These data demonstrate that maintenance rituximab not only significantly delays disease progression in FL compared with OBS but that a substantial proportion of patients treated with MR remain disease-free at 4 years after the completion of CVP. These are the first data to strongly suggest a survival benefit with a therapy that includes rituximab and CVP and the first to strongly suggest a survival benefit with maintenance rituximab in FL.

8004 Background: To determine optimal induction and the role of maintenance, the E1496 study randomized patients (pts) to induction CVP (cyclophosphamide, vincristine, prednisone) versus CF (cyclophosphamide 1 G/m2 d1, fludarabine 20 mg/m2 d1–5 every 28 d) for 2 cycles beyond best response (maximum 8). Responding and stable pts were secondarily randomized to MR (375 mg/m2 weekly × 4 every 6 months for 2 years [yr]) or observation (OBS). Methods: Due to early deaths the CF arm was closed to accrual with 115 pts randomized to CF and 119 pts to CVP (thereafter all pts were assigned to CVP prior to maintenance randomization). The results presented here compare the outcome of CF patients with the subset of E1496 pts randomized to CVP (CVPR). Results: Median follow-up on pts randomized to induction is 6.5 yr. Toxic deaths occurred in 8 (7%) CF pts during induction and 4 additional deaths (1 OBS, 3 MR) occurred among the 69 (6%) CF pts randomized to MR or OBS. Causes of death were infection (9), liver failure (2), CNS gliosis (1). CF pts received a median of 5 cycles compared to 7 cycles for CVPR. The CR rate was 51% vs 22% (p=0.00001) and the PR rate was 35% vs 55% for CF vs. CVPR, respectively. Four-yr PFS for CF vs. CVPR was 49% vs 45% (p=0.19) and OS was 66% vs. 81% (p=0.12), respectively. Of 45 CF deaths, 23 (51%) occurred without lymphoma progression compared to 5 (13%) of 38 CVPR deaths (p=0.0004). More than 90% of CF patients randomized to maintenance achieved protocol-defined minimal residual disease compared with 64% CVPR pts. Maintenance therapy had no impact on 2 yr PFS for the 67 evaluable randomized CF pts, which was 74% for MR vs. 73% for OBS (p=0.19). In contrast, 2 yr PFS was 73% for MR and 42% for OBS in randomized CVPR pts (p=0.004). Survival at 2 yr for MR vs OBS was: CF 79% vs 91% (p=0.19) compared with CVP 98% vs 93% (p=0.21). Conclusions: Induction with CF results in higher CR and miminal residual disease rates than CVP. However, gains in remission quality with CF (in the dose and schedule used here) were offset by early and late deaths in the absence of progressive lymphoma. In E1496, the benefit of MR was influenced by the induction chemotherapy. [Table: see text]

Abstract Abstract 3705 Improved outcomes were reported in USA studies in DLBCL (Habermann et al. J Clin Oncol 2006) in a two-staged randomized study of R-CHOP (rituximab, cyclophosphamide, Adriamycin, vincristine, and prednisone) versus CHOP with a second randomization assignment to maintenance rituximab (MR) or observation (OBS) (E4494) and in follicular lymphoma (FL) in patients in a trial with CVP (cyclophosphamide, vincristine, and prednisone) followed by randomization to MR versus OBS in advanced-stage indolent lymphoma (E1496) (Hochster et al. J Clin Oncol 2009). The details of the treatment regimens have been previously described. The German High Grade Lymphoma Study Group has reported differences between men and women in outcomes in DLBCL with improved outcomes in women treated with rituximab (Müller et al. Blood 2012). Methods: Survival outcomes by sex were analyzed using a stratified weighted cox regression, removing the effect of maintenance rituximab in DLBCL (E4494), and a log-rank test in patients with follicular histology (E1496). A Cox regression model was used to evaluate the differences between males and females together with weight (below or above the median). Wilcoxon test and Fisher's exact test were used to compare medians and proportions, respectively. Results: In DLBCL, there were 273 eligible males and 273 females. The median age was 69 in males and 70 in females. There were no differences in baseline patient characteristics among the male and female populations. 138 males and 129 females were treated with R-CHOP. There was no difference in treatment received, with 83% females and 75.3% males receiving 6 cycles or more of R-CHOP treatment (p=0.14). The complete remission (CR) and partial remission (PR) rates after RCHOP were higher in females (82.6%) versus males (71.5%) (P = 0.04). With a median follow-up of 9.45 years, the failure free survival (FFS) and overall survival (OS) were improved in females (P = 0.02, 0.002; HR=0.63, 0.54) compared with males in the R-CHOP group. The outcomes were not different in the CHOP group for FFS (P = 0.81) or OS (P= 0.57) between males and females. Within the R-CHOP group, the failure free survival (FFS) was significantly different between women and men (P = 0.002) and body weight (P = 0.03), but only female sex (P = 0.001) was significant and not weight (P = 0.26) for OS. Of 282 evaluable patients with advanced-stage follicular lymphoma who received initial treatment with CVP, 115 patients were randomly assigned to MR and 113 to OBS. 120 patients were male, and 108 were female. The median age was 58 years in the MR arm and 54 years in the OBS arm. At a median follow-up of 8.04 years, MR markedly improved the PFS (P=0.003) compared with OBS. There were no differences in PFS (P= 0.17) between males and females treated with MR or OS (P = 0.27). In conclusion, in induction therapy with rituximab in DLBCL there is a sex dependent effect with rituximab with males benefiting less than females. In contrast, in patients with follicular lymphoma treated with chemotherapy followed by maintenance rituximab, there were no differences. The differences in outcomes in patients of different sex with DLBCL treated with immunochemotherapy and FL treated with maintenance rituximab will require further analysis of multiple clinical and biologic variables. Disclosures: Fisher: Roche: Advisory Board Other. Cheson:Genentech: Consultancy. Kahl:Genentech, Roche: Consultancy, Research Funding. Horning:Genetech, Roche: Employment, stock (Roche) Other.