Follow-up of patients receiving rituximab for diffuse large B cell lymphoma: an overview of systematic reviews

Development of combinatorial antibody therapies for diffuse large B cell lymphoma

Diffuse large B-cell lymphoma (DLBCL), the most common form of lymphoma, is typically treated with chemotherapy combined with the immunotherapy rituximab, an antibody targeting the B cell receptor, CD20. Despite the success of this treatment regimen, approximately a third of DLBCL patients experience either relapse or have refractory disease that is resistant to rituximab, indicating the need for alternative therapeutic strategies. Here, we identified that CD74 and IL4R are expressed on the cell surface of both CD20 positive and CD20 negative B cell populations. Moreover, genes encoding CD74 and IL4R are expressed in lymphoma biopsies isolated from all stages of disease. We engineered bispecific antibodies targeting CD74 or IL4R in combination with rituximab anti-CD20 (anti-CD74/anti-CD20 and anti-IL4R/anti-CD20). Bispecific antibody function was evaluated by measuring direct induction of apoptosis, antibody-dependent cellular phagocytosis (ADCP), and antibody-dependent cellular cytotoxicity in both rituximab-sensitive and rituximab-resistant DLBCL cell lines. Both anti-CD74/anti-CD20 and anti-IL4R/anti-CD20 were able to mediate ADCC and ADCP, but CD74-targeting therapeutic antibodies could also mediate direct cytotoxicity. Overall, this study strongly indicates that development of bispecific antibodies that target multiple B cell receptors expressed by lymphoma could provide improved defense against relapse and rituximab resistance.

Rituximab maintenance therapy for patients with diffuse large B-cell lymphoma: A meta-analysis

Purpose

The addition of rituximab to standard chemotherapy has significantly improved survival in patients with lymphoma. Recently, maintenance therapy with rituximab has been shown to prevent relapse and provide survival benefits for patients with follicular or mantle cell lymphoma. However, the effects of rituximab in patients with diffuse large B-cell lymphoma (DLBCL) remain unclear. Two new studies involving rituximab in the treatment of DLBCL were performed this past year. We performed a meta analysis to evaluate the effects of rituximab maintenance treatment of patients with DLBCL.

Methods

Several databases (PubMed, MEDLINE, EMBASE, and Cochrane Central Register of Controlled Trials) databases were reviewed for relevant randomized controlled trials published prior to May, 2016. Two reviewers assessed the quality of the included studies and extracted data independently. The hazard ratios (HRs) for time-to-event data and relative risks (RRs) for the other data were pooled and estimated.

Results

Totally 5 studies including 1740 patients were eligible for the meta-analysis. Compared to the observation group, patients who received rituximab maintenance therapy had significantly improved event-free survival (EFS) (HR = 0.80, 95% CI: 0.65–0.98) and progression-free survival (PFS) (HR = 0.72, 95% CI: 0.54–0.94). However, there was no statistically significant difference in overall survival (OS) (HR = 0.66, 95% CI: 0.27–1.29). A subgroup analysis suggested that male patients may benefit from rituximab maintenance therapy with a better EFS (HR = 0.53, 95% CI: 0.34–0.82-), while this advantage was not observed in female patients (HR = 0.99, 95% CI: 0.64–1.52).

Conclusions

Rituximab maintenance may provide survival benefits beyond that afforded by first- and second-line chemotherapy alone, especially in male patients. However, maintenance rituximab treatment may cause more adverse events. It is recommended that both survival benefits and adverse events should be taken into consideration when making treatment decisions.

Role of Rituximab and Rituximab Biosimilars in Diffuse Large B-Cell Lymphoma

Diffuse large B-cell lymphoma (DLBCL), an aggressive non-Hodgkin lymphoma (NHL), is the most-common subtype of NHL. DLBCL can be classified into at least 3 major immunologically distinct types, which contributes to considerable variation in disease prognosis and response to treatment. DLBCL potentially is curable, even when diagnosed at advanced stages. The current standard of care for most patients with untreated or relapsed/refractory DLBCL is chemoimmunotherapy containing rituximab, an anti-CD20 monoclonal antibody. With advanced understanding of the molecular mechanisms involved in the pathogenesis of DLBCL and specific signaling pathways that are activated in different subtypes, potential new therapeutic targets have been identified, some of which are at the late stages of clinical development. This review summarizes the critical role of rituximab in the current standard of care treatment for DLBCL and discusses why rituximab is likely to remain an important component of treatment options for DLBCL in the foreseeable future. In addition, current and emerging therapeutic agents, including potential benefits of rituximab biosimilars, for patients with DLBCL are discussed. The advent of rituximab biosimilars may facilitate accessibility of rituximab-based chemotherapies to patients with DLBCL and has potential cost-saving benefits for healthcare systems globally.

Rituximab as consolidation therapy did not improve outcome in patients with diffuse large B-cell lymphoma at complete response after dose-dense chemotherapy (CHOP-14)

The authors started a clinical trial to assess the efficacy and toxicity of rituximab (R) as consolidation in patients with diffuse large B-cell lymphoma, with poor prognostic factors, who were in complete response (CR) after dose-dense chemotherapy (CHOP-14). Four hundred sixty-five untreated patients, with advanced stages (III and IV), older (median age >60 years old), and high clinical risk, were treated with dose-dense CHOP-14 (cyclophosphamide 1500 mg/m(2), i.v., day 1; vincristine 2 mg, i.v., standard dose, day 1; epirubicin 120 mg/m(2), i.v., day 1; and prednisone 60 mg/m(2), p.o., days 1-5) every 14 days for six cycles. If CR was achieved, the patients were allocated to receive R (375 mg/m(2), days 1, 8, 15, and 22) at 3 and 9 months after chemotherapy. Three hundred twenty-five patients achieved CR (70%) and were allocated to receive R (151 patients) or not (174 patients). Actuarial curves at 5 years showed that progression-free survival (PFS) was 51% (95% confidence interval [CI]: 44%-58%) in the R group and 53% (95% CI: 47%-59%) in the observation group (p=0.8). Overall survival (OS) was 65% (95% CI: 58%-71%) and 66% (95% CI: 59%-72%), respectively (p=0.78). Late toxicities were more frequent in the R group. The authors showed that the use of R as a consolidation treatment was not useful to improve PFS and OS and toxicity secondary to R was frequent. They did not recommend the use of R as consolidation in this patient setting.

Rituximab treatment strategy for patients with diffuse large B-cell lymphoma after first-line therapy: a systematic review and meta-analysis

BACKGROUND

Rituximab in combination with cyclophosphamide, doxorubicin, vincristine, and prednisone (CHOP) significantly prolonged event-free survival in first-line chemotherapy for patients with diffuse large B-cell lymphoma (DLBCL). But relapse and refractory DLBCL occur frequently. Although rituximab is effective, its role in salvage therapy after autologous transplant remains unclear. Maintenance therapy with rituximab in responding patients after first line chemotherapy may be a useful novel approach capable of eradicating minimal residual disease and to bring survival benefit. This systematic review and meta-analysis evaluated the effects of rituximab maintenance treatment and salvage therapy of patients with DLBCL.

METHODS

We performed a systematic review and meta-analysis of randomized controlled trials and compared rituximab maintenance or salvage therapy at relapse with observation. We searched the Cochrane Library, PubMed, EMBASE, conference proceedings, databases of ongoing trials, and references of published trials. Two reviewers independently assessed the quality of the trials and extracted data. Hazard ratios for time-to-event data were estimated and pooled.

RESULTS

Seven trials including 1470 DLBCL patients were included in this systematic review and meta-analysis. Patients treated with maintenance rituximab have better overall survival (OS) and event-free survival (EFS) than patients in the observation arm, but there was no statistical significance. Patients who received rituximab salvage therapy for relapse or refractory DLBCL have statistically significantly better OS [HR of death = 0.72, 95% CI (0.55-0.94), P = 0.02], progression-free survival (PFS) [HR = 0.61, 95% CI (0.52-0.72), P < 0.05], odds ratio (OR) [RR = 1.26, 95% CI (1.07-1.47), P = 0.004] than patients in the observation arm. The rate of infection-related adverse events was higher with rituximab treatment [RR = 1.37, 95% CI = (1.14 - 1.65) P =0.001].

CONCLUSIONS

After first-line chemotherapy, the two rituximab-combined treatment strategies, including maintenance and salvage therapies can bring survival benefit. But due to the few studies, the low methodological quality assessment and the low outcome evidence quality, it's not confirmed that the two strategies are better than normal chemotherapy regimens. More high-quality randomized controlled trials are still needed to provide reliable evidence. The higher rate of infections after rituximab therapy should be taken into consideration when making treatment decisions.

Trends in quality of non-Hodgkin's lymphoma care: is it getting better?

This study outlines trends in quality of delivered non-Hodgkin’s lymphoma (NHL) care in the Netherlands between 2007 and 2011 and to what extend this was influenced by the national Visible Care program, which aimed at increasing transparency by providing insight into the quality of healthcare. We analyzed data collected from medical records in two observational studies, combined into 20 validated quality indicators (QIs) of which 6 were included in the national program. A random sample of 771 patients, diagnosed with NHL in 26 Dutch hospitals, was examined. Multilevel regression analyses were used to assess differences in quality of NHL care and to provide insight into the effect of the national program. We reported improved adherence to only 3 out of 6 QIs involved in the national program and none of the other 14 validated QIs. Improvement was shown for performance of all recommended staging techniques (from 26  to  43 %), assessment of International Prognostic Index (from 21  to  43 %), and multidisciplinary discussion of patients (from 23  to  41 %). We found limited improvement in quality of NHL care between 2007 and 2011; improvement potential (<80 % adherence) was still present for 13 QIs. The national program seems to have a small positive effect, but has not influenced all 20 indicators which represent the most important, measurable parts in quality of NHL care. These results illustrate the need for tailored implementation and quality improvement initiatives.