Combination of rituximab with chemotherapy in diffuse large B-cell lymphoma. Evaluation in daily practice before and after approval of rituximab in this indication

Prognostic significance of Epstein-Barr virus DNA detection in pretreatment serum in diffuse large B-cell lymphoma

It is still a matter of debate whether detection of Epstein-Barr virus (EBV) DNA in pretreatment serum has clinical implications for diffuse large B-cell lymphoma. For this study, we measured EBV DNA load in pretreatment serum from 127 diffuse large B-cell lymphoma patients without any underlying immunodeficiency to evaluate its effects on clinical manifestations and prognosis. Anthracycline-based chemotherapy in combination with rituximab was given as initial therapy for 119 patients (94%). Epstein-Barr virus DNA was detected in 15 patients (12%), who were older (P = 0.005) and tended to be at a more advanced disease stage (P = 0.053). They showed significantly worse progression-free survival (PFS) and overall survival (OS) than other patients (P < 0.001 each). This effect remained significant (P = 0.004 and P = 0.027, respectively) after adjustment for age, lactate dehydrogenase, performance status, stage, and extranodal sites. The status of EBV-encoded small RNA in situ hybridization was known for 123 patients; 6 of 8 positive patients (75%) and 9 of 115 negative patients (8%) had detectable EBV DNA in pretreatment serum. While patients positive for EBV-encoded small RNA had significantly worse PFS and OS than negative patients (P = 0.001 and P = 0.029, respectively), EBV DNA detection in pretreatment serum was associated with poorer PFS and OS even for the 115 patients negative for EBV-encoded small RNA (P < 0.001 each). These findings suggest that EBV DNA detection in pretreatment serum may have an adverse prognostic impact for patients with diffuse large B-cell lymphoma.

Impact of the introduction of rituximab in first-line follicular lymphoma: a retrospective study of 247 unselected patients referred to a single institution with a long-term follow-up

Rituximab was approved in France in 2004, following randomized trials that demonstrated efficacy in newly diagnosed high tumour burden follicular lymphoma (FL). This retrospective study compared the management and outcome of FL in unselected patients treated in a single institution before and after rituximab approval. Two hundred and forty-seven adult patients were referred with first-line FL between 1996 and 2010 and are included in this study. The 103 pre-rituximab patients comprising cohort 1 were diagnosed between January 1996 and December 2003; cohort 2 includes the 144 patients diagnosed after the approval of rituximab between January 2004 and December 2010. Baseline clinical and biological data, type of therapy, treatment response, progression-free survival (PFS) and overall survival (OS) rates were compared. There were no statistically significant differences between the two cohorts with respect to baseline clinical and disease characteristics, including FL International Prognostic Index score. The major difference between the two cohorts is the use of rituximab in first line. Seventy-one per cent of patients in cohort 2 received rituximab (19% alone, 52% with chemotherapy) versus 10% in cohort 1 (2% alone, 8% with chemotherapy; p < 0.0001). The objective response rate (ORR) was significantly higher for cohort 2 (ORR 84% compared with 72% for cohort 1; p = 0.03). The PFS and OS rates were also significantly better: 3-year PFS 72% [95% confidence interval (CI) 64-80%] versus 55% (95% CI 45-64%), p = 0.0039 and 3-year OS 98% (95% CI 94-99%) versus 83% (95% CI 74-90%), p = 0.0007. Effect of period of study is significant when using multivariate analysis on PFS and OS and lactate dehydrogenase level (PFS and OS) and age (OS). These data from everyday practice confirm the benefit for patients with FL treated in the last decade through availability of rituximab in first line used alone or in association with various chemotherapy regimens.

Self-assembled antibody multimers through peptide nucleic acid conjugation

With the recent clinical success of bispecific antibodies, a strategy to rapidly synthesize and evaluate bispecific or higher order multispecific molecules could facilitate the discovery of new therapeutic agents. Here, we show that unnatural amino acids (UAAs) with orthogonal chemical reactivity can be used to generate site-specific antibody-oligonucleotide conjugates. These constructs can then be self-assembled into multimeric complexes with defined composition, valency, and geometry. With this approach, we generated potent bispecific antibodies that recruit cytotoxic T lymphocytes to Her2 and CD20 positive cancer cells, as well as multimeric antibody fragments with enhanced activity. This strategy should accelerate the synthesis and in vitro characterization of antibody constructs with unique specificities and molecular architectures.

Manganese porphyrin, MnTE-2-PyP5+, Acts as a pro-oxidant to potentiate glucocorticoid-induced apoptosis in lymphoma cells

Using current chemotherapy protocols, over 55% of lymphoma patients fail treatment. Novel agents are needed to improve lymphoma survival. The manganese porphyrin, MnTE-2-PyP(5+), augments glucocorticoid-induced apoptosis in WEHI7.2 murine thymic lymphoma cells, suggesting that it may have potential as a lymphoma therapeutic. However, the mechanism by which MnTE-2-PyP(5+) potentiates glucocorticoid-induced apoptosis is unknown. Previously, we showed that glucocorticoid treatment increases the steady state levels of hydrogen peroxide ([H(2)O(2)](ss)) and oxidizes the redox environment in WEHI7.2 cells. In the current study, we found that when MnTE-2-PyP(5+) is combined with glucocorticoids, it augments dexamethasone-induced oxidative stress however, it does not augment the [H(2)O(2)](ss) levels. The combined treatment depletes GSH, oxidizes the 2GSH:GSSG ratio, and causes protein glutathionylation to a greater extent than glucocorticoid treatment alone. Removal of the glucocorticoid-generated H(2)O(2) or depletion of glutathione by BSO prevents MnTE-2-PyP(5+) from augmenting glucocorticoid-induced apoptosis. In combination with glucocorticoids, MnTE-2-PyP(5+) glutathionylates p65 NF-κB and inhibits NF-κB activity. Inhibition of NF-κB with SN50, an NF- κB inhibitor, enhances glucocorticoid-induced apoptosis to the same extent as MnTE-2-PyP(5+). Taken together, these findings indicate that: 1) H(2)O(2) is important for MnTE-2-PyP(5+) activity; 2) Mn-TE-2-PyP(5+) cycles with GSH; and 3) MnTE-2-PyP(5+) potentiates glucocorticoid-induced apoptosis by glutathionylating and inhibiting critical survival proteins, including NF-κB. In the clinic, over-expression of NF-κB is associated with a poor prognosis in lymphoma. MnTE-2-PyP(5+) may therefore, synergize with glucocorticoids to inhibit NF-κB and improve current treatment.