Rituximab for the treatment of diffuse large B-cell lymphomas

For more than 25 years, the combination of cyclophosphamide, doxorubicin, vincristine and prednisone (CHOP) was considered the gold standard for the treatment of aggressive lymphomas, 90% of which are diffuse, large B-cell lymphomas (DLBCLs). Attempts to improve results by more intensive chemotherapy regimens, including high-dose chemotherapy approaches necessitating stem-cell support, have not convincingly shown improved outcome of DLBCL. The chimeric monoclonal antibody rituximab, which binds to the CD20 antigen expressed on normal B cells and the malignant cells of more than 90% of DLBCLs, and mediates lysis of these cells by direct induction of apoptosis, activation of complement- and antibody-dependent cellular cytotoxicity in vitro, is an attractive candidate for the treatment of B-cell lymphomas. Initial studies in follicular lymphoma demonstrated its efficacy as a single agent or in combination with chemotherapy without adding relevant toxicity. After the demonstration of rituximab single-agent activity in DLBCL, a pivotal trial in elderly patients demonstrated that combining rituximab with eight applications of CHOP significantly improved complete remission, event-free and overall survival rates when compared with CHOP alone. These positive results have meanwhile been confirmed by two additional randomized trials in elderly patients and have been extended to young patients with good-prognosis DLBCL by a fourth trial. While not yet formally established in young, poor-prognosis patients, rituximab in combination with CHOP has become accepted worldwide as the new standard for the treatment of DLBCL. Questions remain concerning the optimal dosage and schedule of rituximab for DLBCL, as well as the optimal chemotherapy regimen partner for rituximab. Rituximab is the first monoclonal antibody to consistently improve survival rates of patients with a malignant disease. Its excellent efficacy in combination with cytotoxic chemotherapy, together with its favorable toxicity profile, establishes rituximab as an indispensable component of modern standard immunochemotherapy of DLBCL.     

Rituximab for the treatment of diffuse large B-cell lymphomas

For more than 25 years, the combination of cyclophosphamide, doxorubicin, vincristine and prednisone (CHOP) was considered the gold standard for the treatment of aggressive lymphomas, 90% of which are diffuse, large B-cell lymphomas (DLBCLs). Attempts to improve results by more intensive chemotherapy regimens, including high-dose chemotherapy approaches necessitating stem-cell support, have not convincingly shown improved outcome of DLBCL. The chimeric monoclonal antibody rituximab, which binds to the CD20 antigen expressed on normal B cells and the malignant cells of more than 90% of DLBCLs, and mediates lysis of these cells by direct induction of apoptosis, activation of complement- and antibody-dependent cellular cytotoxicity in vitro, is an attractive candidate for the treatment of B-cell lymphomas. Initial studies in follicular lymphoma demonstrated its efficacy as a single agent or in combination with chemotherapy without adding relevant toxicity. After the demonstration of rituximab single-agent activity in DLBCL, a pivotal trial in elderly patients demonstrated that combining rituximab with eight applications of CHOP significantly improved complete remission, event-free and overall survival rates when compared with CHOP alone. These positive results have meanwhile been confirmed by two additional randomized trials in elderly patients and have been extended to young patients with good-prognosis DLBCL by a fourth trial. While not yet formally established in young, poor-prognosis patients, rituximab in combination with CHOP has become accepted worldwide as the new standard for the treatment of DLBCL. Questions remain concerning the optimal dosage and schedule of rituximab for DLBCL, as well as the optimal chemotherapy regimen partner for rituximab. Rituximab is the first monoclonal antibody to consistently improve survival rates of patients with a malignant disease. Its excellent efficacy in combination with cytotoxic chemotherapy, together with its favorable toxicity profile, establishes rituximab as an indispensable component of modern standard immunochemotherapy of DLBCL.     

Treatment strategies in follicular lymphomas: current status and future perspectives.

Although little progress has been made in the treatment of follicular lymphomas (FL) within the last few decades, several new therapeutic modalities have recently demonstrated promising activity. These include myeloablative therapy followed by autologous stem cell transplantation in younger patients in first remission revealing a significant prolongation of remission duration in three prospective randomized trials, whereas the impact on overall survival still needs to be determined. Adding the anti-CD20 antibody rituximab to conventional chemotherapy resulted in a significant increase in remission rate, remission duration and in two of four currently available prospective randomized studies even in a longer overall survival. A prolongation of remission duration was also seen when rituximab was administered as maintenance after cytoreductive therapy or by prolonged application as a single agent. Radioimmunotherapy (RIT) with radioisotopes coupled to monoclonal antibodies revealed encouraging data in several phase II studies. Prospective randomized studies are warranted, however, to define the impact of RIT on FL therapy. New therapeutic perspectives also emerge from increasing insights into the biology of the disease that unravel molecular targets for novel agents, some of which have entered clinical evaluation already.     

Vaccination strategies in the treatment of lymphomas

Malignant lymphomas are clonal neoplasms of lymphoid origin. By definition, all cells of the malignant clone have undergone the same rearrangement of antigen receptor genes and express identical antigen receptor molecules (immunoglobulin for B cell lymphomas, T cell receptor for T cell lymphomas). The hypervariable stretches within the variable regions of these receptors are considered true tumor-specific antigens ('idiotypes'). In several animal models, protective humoral or cellular immunity can be induced against the malignant lymphoma by vaccination with the tumor-derived idiotype. Successful experimental immunization strategies in animals include idiotype protein vaccines combined with various adjuvants, genetically or immunologically modified lymphoma cells, idiotype-presenting dendritic cells, idiotype-encoding viral vectors, and DNA immunization. Firm evidence for the induction of lymphoma-specific immunity has also been obtained from human idiotype vaccination trials. Furthermore, some trials have provided strong but hitherto formally unproven evidence for clinical benefit of idiotype-vaccinated patients. Alternative vaccination approaches are based on immunologically modified tumor cells. Current research efforts concentrate on the identification of the most efficacious vaccination route, on definitive proof of clinical efficacy, and on the development of convenient methods to manufacture individual idiotype vaccines.     

Idiotype vaccine strategies for treatment of follicular lymphoma

Follicular lymphoma is an indolent lymphoma associated with a relapsing course. Immunization with tumor B cell idiotype (Id; a unique variable region of surface B cell immunoglobulin) may induce humoral and cellular immune response against the tumor. Based on promising results from early phase clinical trials with Id vaccine, three Phase III trials were initiated, which, despite failing to meet their primary end points, still provided a glimmer of optimism. This article describes the clinical development of the Id vaccine against follicular lymphoma, outlines the outcomes of clinical trials and delineates the future prospects for the integration of the idiotype vaccine into follicular lymphoma treatment.     

滤泡性淋巴瘤治疗中的疑惑和应对策略

 【摘要】 在过去的5年中,滤泡性淋巴瘤的治疗发生了很大的变化。很多抗肿瘤新药应用到一线治疗和维持治疗中,对于复发难治的滤泡性淋巴瘤的治疗策略也有了新的改变。尽管在国际上能够看到这些新的进展,但临床上仍有很多问题有待解决。本文对利妥昔单抗应用的有效性和安全性进行了讨论,对复发难治的滤泡性淋巴瘤的治疗策略进行了整理和展望,并对近年来开展的新药临床试验进行了介绍。     

Long-term results of treatment of patients with follicular lymphomas

The management of patients with follicular lymphoma is controversial, particularly in those with follicular small cleaved cell (FSCC) or nodular poorly differentiated lymphoma (NPDL). Some advocate no treatment until symptoms arise, while others prefer to treat with intensive combination regimens and others with single agents. We reviewed the long-term effects of two types of combination chemotherapy on relapse-free survival and survival on 91 patients (88 were stages III-IV) who had received no previous chemotherapy. Those patients with FSCC lymphoma obtaining a complete remission had a significantly longer median survival than did those obtaining a partial remission (13 years versus 2 years). An adriamycin-containing regimen appeared to be the key factor in obtaining a complete remission in FSCC after taking into consideration prognostic factors. Not only was the complete response rate significantly higher for patients receiving adriamycin, but so too was the median survival and relapse-free survival. BCG immunotherapy appeared to be important in preventing relapse in some of the complete responders with NPDL who received adriamycin.     

Rituximab combined with a small dose of melphalan for a refractory follicular lymphoma patient

A 48-year-old male patient with follicular lymphoma, grade II, stage IV, was treated with CHOP, ESHAP and MACOP-B, resulting in partial remission. After 9 months, the disease progressed and several chemotherapy agents, including three courses of rituximab combined with etoposide, sobuzoxane or methotrexate, only resulted in a stable disease response. However, the fourth course of rituximab combined with a small dose of melphalan produced excellent results and the complete response continued for more than 15 months. It is possible that these two drugs may act synergistically.     

Rituximab in combination with fludarabine and cyclophosphamide in the treatment of patients with recurrent follicular lymphoma

BACKGROUND: The current study was conducted to asses the safety profile and clinical activity of rituximab in combination with fludarabine and cyclophosphamide in patients with recurrent follicular lymphoma (FL). METHODS: This study was a noncomparative, multicenter, phase II study. Between March 2000 and December 2002, 54 patients with recurrent FL were enrolled in the FC+R trial. Patients received fludarabine at a dose of 25 mg/m(2) and cyclophosphamide at a dose of 300 mg/m(2) daily for 3 consecutive days, every 3 weeks for 4 cycles. Rituximab was administered at a dose of 375 mg/m(2) beginning 2 weeks after the first course of fludarabine and cyclophosphamide and then on Day 1 of each cycle thereafter. The planned treatment duration was 10 weeks. RESULTS: Overall, 92% of patients completed the planned therapy in 10 to 14 weeks and 74% achieved a complete response (CR). Among patients with BCL2-positive bone marrow, 86% obtained a molecular disease remission (MR). The median survival from treatment (SFT), the duration of disease remission (DR), and time to disease progression (TTP) had not been reached after a median follow-up of 45 months. Of the baseline characteristics, >2 previous treatments, BCL2-positive bone marrow, and low Follicular Lymphoma International Prognostic Index (FLIPI) score were found to be associated with better DR and/or TTP. Hematologic toxicity was transient and reversible, with the exception of 3 patients with severe and prolonged neutropenia. Three patients presented with infections, 1 of whom died of bronchopneumonia. CONCLUSIONS: The FC+R scheme, a nonanthracycline-containing regimen lasting up to 10 weeks, was found to be relatively well-tolerated and demonstrated significant antilymphoma activity with excellent clinical CR and molecular response rates.     

A pilot study of suramin in the treatment of progressive refractory follicular lymphomas.

Ten patients with progressive follicular lymphomas (seven with follicular mixed lymphomas, three with follicular, small cleaved cell lymphomas) with clinical indications for systemic therapy received parenteral suramin. Each had failed from one to six prior chemotherapeutic regimens and three had in addition received prior radiation therapy. All had measurable disease and nine of the ten had documented bone marrow involvement at the start of therapy. Suramin was administered at an initial infusion rate of 350 mg/m2/day, which was then modified on the basis of subsequent weekly plasma suramin concentrations in order to reach a final plasma concentrations of 250-350 micrograms/ml. Treatment cycles were repeated at eight week intervals. Nine of ten patients are evaluable for response. Five of nine evaluable patients achieved a partial remission as defined by a greater than 50% decrease in the sum of the product of all measurable lesions. Sites of response include: Peripheral (five patients) and central (four patients) adenopathy, disappearance of biopsy-proven skin involvement (one patient), malignant pleural effusions (one patient) and shrinkage of an enlarged spleen (two patients). Disappearance of B symptoms occurred in the one responder with these symptoms. Response duration varied from 3 to 9 months (mean 5.6 months) with time to subsequent systemic therapy varying from 5 to 12 months (mean 8 months). Drug related toxicity included the development of polyradiculopathy (one case), liver function abnormalities (three cases), thrombocytopenia (five cases), vortex keratopathy (two cases) and bacterial infection (two cases). We conclude that suramin has significant activity against follicular lymphomas refractory to standard chemotherapy and that its precise role in the treatment of lymphoproliferative neoplasms in general warrants further investigation.     

Rituximab maintenance for the treatment of patients with follicular lymphoma: an updated systematic review and meta-analysis of randomized trials

In a previous systematic review and meta-analysis of five randomized controlled trials comparing rituximab maintenance with no maintenance (observation or rituximab at progression) for patients with follicular lymphoma, we reported that rituximab maintenance treatment improved the overall survival of patients. In this study, we did a similar search of the electronic databases updated through December 31, 2010, and included nine trials and 2586 follicular lymphoma patients. Hazard ratios (HRs) for time-to-event data were estimated and pooled using the inverse variance method. Risk ratios for dichotomous data were pooled using a fixed effect model. Patients treated with rituximab maintenance had improved overall survival (pooled HR of death = 0.76, 95% confidence interval [CI] = 0.62 to 0.92) compared with patients in the no maintenance group. Patients with refractory or relapsed (ie, previously treated) follicular lymphoma treated with rituximab maintenance had improved overall survival (pooled HR of death = 0.72, 95% CI = 0.57 to 0.91), whereas previously untreated patients had no survival benefit (pooled HR of death = 0.86, 95% CI = 0.60 to 1.25). The rate of infection-related adverse events was higher in the rituximab maintenance group (pooled risk ratio = 1.67, 95% CI = 1.40 to 2.00). These results further support the use of rituximab maintenance in the standard of care for refractory or relapsed follicular lymphoma.     

Rituximab plus short-duration chemotherapy as first-line treatment for follicular non-Hodgkin's lymphoma: a phase II trial of the minnie pearl cancer research network.

PURPOSE: To evaluate the feasibility and efficacy of rituximab with short-duration chemotherapy in the first-line treatment of patients with follicular non-Hodgkin's lymphoma (NHL). PATIENTS AND METHODS: Patients with previously untreated stage II-IV follicular NHL, grade 1 or 2, were eligible for this multicenter phase II trial. All patients received four weekly doses of rituximab (375 mg/m(2) intravenous), followed by three courses of combination chemotherapy (either cyclophosphamide, doxorubicin, vincristine, and prednisone [CHOP], or cyclophosphamide, vincristine, and prednisone [CVP]) plus rituximab. Patients were evaluated for response after completing treatment, and were then followed up at 3-month intervals. RESULTS: Between January 2000 and July 2001, 86 patients were treated. Eight-two patients (95%) completed treatment; no patient was withdrawn due to toxicity. The overall response rate was 93%, with 55% complete responses. After a median follow-up of 42 months, the 3- and 4-year actuarial progression-free survivals were 71% and 62%, respectively. Five patients (6%) died from lymphoma; the overall actuarial survival at 3 years was 95%. Grade 3/4 leukopenia occurred in 53% of patients, but only six patients (7%) had neutropenia or fever. Grade 3/4 nonhematologic toxicities were uncommon. CONCLUSION: Rituximab plus short-course chemotherapy is well tolerated as first-line treatment for patients with follicular NHL. The overall and complete response rates are similar to those reported with chemotherapy/rituximab combinations of longer duration. The actuarial progression-free survival of 62% at 4 years is encouraging, but further follow-up is necessary. Rituximab plus short-course chemotherapy may prove to be as effective as longer-duration chemotherapy and currently provides an attractive option for first-line treatment of elderly patients and others who tolerate chemotherapy poorly.     

Pediatric T- and NK-cell lymphomas: new biologic insights and treatment strategies

T- and natural killer (NK)-cell lymphomas are challenging childhood neoplasms. These cancers have varying presentations, vast molecular heterogeneity, and several are quite unusual in the West, creating diagnostic challenges. Over 20 distinct T- and NK-cell neoplasms are recognized by the 2008 World Health Organization classification, demonstrating the diversity and potential complexity of these cases. In pediatric populations, selection of optimal therapy poses an additional quandary, as most of these malignancies have not been studied in large randomized clinical trials. Despite their rarity, exciting molecular discoveries are yielding insights into these clinicopathologic entities, improving the accuracy of our diagnoses of these cancers, and expanding our ability to effectively treat them, including the use of new targeted therapies. Here, we summarize this fascinating group of lymphomas, with particular attention to the three most common subtypes: T-lymphoblastic lymphoma, anaplastic large cell lymphoma, and peripheral T-cell lymphoma-not otherwise specified. We highlight recent findings regarding their molecular etiologies, new biologic markers, and cutting-edge therapeutic strategies applied to this intriguing class of neoplasms.     

Safety of rituximab maintenance therapy in follicular lymphomas

The human/mouse chimeric monoclonal antibody rituximab has been used extensively in treatment of hematologic malignancies, and its efficacy and safety are well established, both as single-agent therapy and when used in combination with chemotherapy. Mild-to-moderate, transient infusion-related reactions are the most common adverse event, and rituximab does not add significantly to the toxicity of chemotherapy. Rituximab maintenance therapy has now emerged as an effective treatment for follicular lymphoma. Patients on rituximab maintenance therapy receive regular doses of rituximab for periods up to 2 years after initial induction therapy and are completely depleted of B-cells throughout this time, although B-cells eventually recover when maintenance treatment is stopped. In randomized trials of rituximab maintenance therapy versus observation after induction with single-agent rituximab, standard chemotherapy or rituximab plus chemotherapy, patients receiving rituximab maintenance therapy did not experience significantly greater toxicity than those in the observation arms, and no cumulative or unexpected toxicities were observed. Findings to date thus indicate that rituximab maintenance therapy is well tolerated, but further assessment of the long-term effects of prolonged B-cell depletion is still required.