Tumor Rejection Induced by CD70-mediated Quantitative and Qualitative Effects on Effector CD8+ T Cell Formation

In vivo priming of antigen-specific CD8(+) T cells results in their expansion and differentiation into effector T cells followed by contraction into a memory T cell population that can be maintained for life. Recent evidence suggests that after initial antigenic stimulation, the magnitude and kinetics of the CD8(+) T cell response are programmed. However, it is unclear to what extent CD8(+) T cell instruction in vivo is modulated by costimulatory signals. Here, we demonstrate that constitutive ligation of the tumor necrosis factor receptor family member CD27 by its ligand CD70 quantitatively augments CD8(+) T cell responses to influenza virus infection and EL-4 tumor challenge in vivo by incrementing initial expansion and maintaining higher numbers of antigen-specific T cells in the memory phase. Concomitantly, the quality of antigen-specific T cells improved as evidenced by increased interferon (IFN)-γ production and a greater cytotoxic potential on a per cell basis. As an apparent consequence, the superior effector T cell formation induced by CD70 protected against a lethal dose of poorly immunogenic EL4 tumor cells in a CD8(+) T cell– and IFN-γ–dependent manner. Thus, CD70 costimulation enhances both the expansion and per cell activity of antigen-specific CD8(+) T cells

Rituximab Maintenance Treatment of Relapsed/Resistant Follicular Non-Hodgkin's Lymphoma: Long-Term Outcome of the EORTC 20981 Phase III Randomized Intergroup Study

Purpose In 2006, we published the results of the European Organisation for Research and Treatment of Cancer phase III trial EORTC 20981 on the role of rituximab in remission induction and maintenance treatment of relapsed/resistant follicular lymphoma (FL). At that time, the median follow-up for the maintenance phase was 33 months. Now, we report the long-term outcome of maintenance treatment, with a median follow-up of 6 years. Patients and Methods Overall, 465 patients were randomly assigned to induction with either six cycles of cyclophosphamide, doxorubicin, vincristine, prednisone (CHOP) or rituximab plus CHOP (R-CHOP). Those in complete remission or partial remission after induction (n = 334) were randomly assigned to maintenance treatment with rituximab (375 mg/m(2) intravenously once every 3 months) or observation. Results Rituximab maintenance significantly improved progression-free survival (PFS) compared with observation (median, 3.7 years v 1.3 years; P <.001; hazard ratio [HR], 0.55), both after CHOP induction (P <.001; HR, 0.37) and R-CHOP (P = .003; HR, 0.69). The 5-year overall survival (OS) was 74% in the rituximab maintenance arm, and it was 64% in the observation arm (P = .07). After progression, a rituximab-containing salvage therapy was given to 59% of patients treated with CHOP followed by observation, compared with 26% after R-CHOP followed by rituximab maintenance. Rituximab maintenance was associated with a significant increase in grades 3 to 4 infections: 9.7% v 2.4% (P = .01). Conclusion With long-term follow-up, we confirm the superior PFS with rituximab maintenance in relapsed/resistant FL. The improvement of OS did not reach statistical significance, possibly because of the unbalanced use of rituximab in post-protocol salvage treatmen

Pharmacokinetics and pharmacokinetic/pharmacodynamic associations of ofatumumab, a human monoclonal CD20 antibody, in patients with relapsed or refractory chronic lymphocytic leukemia: a phase 1-2 study

International audienceThe purpose of this phase 1-2 study was to investigate the association between pharmacokinetic (PK) properties of ofatumumab, a human monoclonal CD20 antibody, and outcomes in 33 patients with relapsed/refractory chronic lymphocytic leukemia receiving 4 weekly infusions of ofatumumab. The ofatumumab concentration profiles were fitted well by a two-compartment model with different elimination rate constant at first infusion compared to the remaining infusions in line with the observed rapid and sustained B-cell depletion. Exposure to ofatumumab was linked to clinical outcomes: high exposure was associated with higher probability of overall clinical response and longer progression free survival. This association still remained statistically significant even when adjusting for relevant baseline covariates including tumor burden. The trial was registered at www.clinicaltrials.gov (NCT00093314)

BCL-2/IgH polymerase chain reaction status at the end of induction treatment is not predictive for progression-free survival in relapsed/resistant follicular lymphoma: results of a prospective randomized EORTC 20981 phase III intergroup study.

Item does not contain fulltextPURPOSE: The prognostic value of residual BCL2/immunoglobulin heavy chain (BCL2/IgH) -positive cells in peripheral blood (PB) or bone marrow (BM) after induction treatment in follicular lymphoma (FL) is still controversial. In a prospective randomized phase III intergroup trial of 465 patients with relapsed/resistant follicular lymphoma (FL), we showed that addition of rituximab to cyclophosphamide, doxorubicin, vincristine, and prednisone induction results in increased overall and complete response rates, and that rituximab maintenance strongly improves median progression-free survival (PFS) as well as overall survival. Here, we studied whether BCL2/IgH major break point levels in PB/BM correlated with response rates/quality for the induction phase and PFS for the maintenance phase. PATIENTS AND METHODS: Samples were obtained before and after induction therapy and at the end of the 2 years maintenance/observation period. BCL2/IgH major break point-positive cells were quantified by genomic quantitative polymerase chain reaction in 792 samples from 238 patients. RESULTS: Pretreatment BCL2/IgH levels had no significant prognostic value for overall response or complete remission rates after induction treatment, but pretreatment positive BM results had an adverse prognostic value for PFS from first randomization (P = .023). Importantly, BCL2/IgH levels at the end of induction treatment had no prognostic value for PFS from second randomization. The highly significant improved PFS by rituximab maintenance was observed in both BCL2/IgH PB/BM-positive and -negative groups. CONCLUSION: Postinduction BCL2/IgH major break point status in BM/PB is not useful for decisions on subsequent therapy for patients with relapsed/resistant FL