Efficacy of Autologous Stem-Cell Transplantation in Patients with Relapsed or Refractory Aggressive B-Cell Lymphoma in the Rituximab Era. A Multicenter Geltamo Study.

Recent studies indicate that the use of highly effective rituximab (R)-containing primary therapy in Diffuse Large B-cell Lymphoma (DLBCL) makes it more difficult to salvage patients who are refractory or who relapse. To date, peripheral-blood autologous stem-cell transplantation (PBASCT) is the reference treatment for these patients, but the impact of previous exposure to R on the ulterior results of ASCT is still unknown.

We have retrospectively analysed 252 patients (pts) with DLBCL or grade 3B follicular lymphoma with relapsed or refractory disease after at least one rituximab-containing regimen (“R+” group) who received PBASCT in 17 GELTAMO centers, in comparison to a control group of 127 patients who received APBSCT as salvage therapy without previous exposure to rituximab (“R-” group). Patients with refractory disease at transplant were excluded from the analysis.

No significant differences between R+ and R- groups were found with respect to age-adjusted IPI at transplant, disease status at salvage therapy and at transplant, nor number or prior chemotherapy regimens. More patients in the R+ group were ≥60 years (30% vs 19%, p=.02). Complete response (CR) (69% v 70%) and overall response (84% v 83%) rates to PBASCT were similar in R+ and R- groups. In multivariate analysis, factors with significant influence on CR rates were: age-adjusted IPI at diagnosis (<2), number of prior chemotherapy lines (<3), and disease status at transplant (CR). Median follow-up was 35 (1–130) and 121 (2–214) months in the R+ and R- groups, respectively. Patients in the R+ group had a significantly better progression-free survival (PFS) (63% v 48% at 5 years, p=.041) and a non-significantly better overall survival (OS) (71% v 61% at 5 years, p=.098) as compared with patients in the R- group. In multivariate analysis, independent factors with favourable influence on both PFS and OS were disease status at salvage therapy (first partial response or late relapse, in comparison to primary refractory disease or early relapse), previous exposure to R, and age <60 years, whereas the number of previous chemotherapy lines (<3) influenced only PFS.

Our results show that, in patients with chemosensitive relapsed or refractory aggressive B-cell lymphoma, PBASCT is at least as effective in patients pre-treated with R-containing therapy as compared to R-naive patients. Thus, PBASCT in still the reference treatment for these patients in the rituximab era.

No relevant conflicts of interest to declare.