Prior Therapy with Rituximab (R) in Patients (pts) with Diffuse Large B-Cell Lymphoma (DLBCL) Does Not Affect Disease-Free (DFS) or Overall Survival (OS) Following High Dose Therapy (HDT) and Autologous Stem Cell Transplantation (ASCT).

The addition of R to first line chemotherapy regimens for DLBCL has resulted in improvements in DFS and OS. HDT and ASCT have been shown to improve outcome for pts with relapsed DLBCL compared with conventional dose salvage regimens. The effectiveness of HDT and ASCT in pts with DLBCL who have received prior therapy including R is unknown. We reviewed 257 consecutive pts with DLBCL treated with ASCT from 1/94–12/02. Of these, 161 (63%) had received R as part of their initial therapy and 65 (25%) had not received prior R. A third group (N = 31, 12%) who had been treated with R as part of salvage therapy prior to ASCT were excluded from further analysis. Patient characteristics are shown in Table 1. All patients received a preparative regimen of Busulfan, Cyclophosphamide, and Etoposide. Greater than 75% of patients in both groups had evidence of disease at time of transplant. Univariable and multivariable analyses demonstrated no difference between the pts previously treated with R and those not treated with R. After median follow up of 76 months (13–142) no statistical difference in DFS or OS was observed between the two groups. Patients were then adjusted for age, gender, stage, prior chemotherapy/radiation, time from diagnosis to CR, IPI, and disease status and compared again. The matched propensity analysis also showed no significant difference in DFS (p=0.87) and OS (p=0.22) (Figures 1 and 2). Despite concerns that pts with DLBCL previously treated with regimens containing R may have more resistant disease at relapse, our results suggest that HDT and ASCT is equally effective for these pts compared with those who have not received prior R. A prospective analysis is needed to confirm these results. Table 1. Patient Characteristics Categories No Rituximab (n=65) Rituximab (n=161) Age-median (range) 48 (19–70) 53 (23–72) Gender (M/F) 42/23 93/68 Stage IV (n) 75% (49) 61% (98) Prior Chemo Regimens-median (range) 2 (1–4) 2 (1–6) Prior Radiation (n) 25% (16) 32% (51) IPI (Low/Low-Intermediate vs High-Intermediate/High) 66% vs 34% 55% vs 45% CD34 collection (x 10^6)-median (range) 8.3 (2.9–39.2) 4.4 (0–52.8) Time to Transplant (mos)-median (range) 14.7 (2.8–274.3) 14.5 (5.1–192.6) Diffuse Large B-cell Lymphoma - Matched Groups Diffuse Large B-cell Lymphoma - Matched Groups Diffuse Large B-cell Lymphoma - Matched Groups Diffuse Large B-cell Lymphoma - Matched Groups