Chemotherapy with rituximab followed by high-dose therapy and autologous stem cell transplantation in patients with mantle cell lymphoma

Mantle cell lymphoma

MCL is a well-characterized generally aggressive lymphoma with a poor prognosis. However, patients with a more indolent disease have been reported in whom the initiation of therapy can be delayed without any consequence for the survival. In 2017 the World Health Organization updated the classification of MCL describing two main subtypes with specific molecular characteristics and clinical features, classical and indolent leukaemic nonnodal MCL. Recent research results suggested an improving outcome of this neoplasm. The addition of rituximab to conventional chemotherapy has increased overall response rates, but it did not improve overall survival compared to chemotherapy alone. The use of intensive frontline therapies including rituximab and consolidation with autologous stem cell transplantation ameliorated response rate and prolonged progression-free survival in young fit patients, but any impact on survival remains to be proven. Furthermore, the optimal timing, cytoreductive regimen and conditioning regimen, and the clinical implications of achieving a disease remission even at molecular level remain to be elucidated. The development of targeted therapies as the consequence of better understanding of pathogenetic pathways in MCL might improve the outcome of conventional chemotherapy and spare the toxicity of intense therapy in most patients. Cases not eligible for intensive regimens, may be considered for less demanding therapies, such as the combination of rituximab either with CHOP or with purine analogues, or bendamustine. Allogeneic SCT can be an effective option for relapsed disease in patients who are fit enough and have a compatible donor. Maintenance rituximab may be considered after response to immunochemotherapy as the first-line strategy in a wide range of patients. Finally, since the optimal approach to the management of MCL is still evolving, it is critical that these patients are enrolled in clinical trials to identify the better treatment options.

Strategies to improve outcomes of autologous hematopoietic cell transplant in lymphoma

High-dose chemotherapy and autologous hematopoietic cell transplantation (HDT-AHCT) remains an effective therapy in lymphoma. Over the past several decades, HDT with BEAM (carmustine, etoposide, cytarabine, and melphalan) and CBV (cyclophosphamide, carmustine, and etoposide) have been the most frequently used preparatory regimens for AHCT in Hodgkin (HL) and non-Hodgkin lymphoma (NHL). This article reviews alternative combination conditioning regimens, as well as novel transplant strategies that have been developed, to reduce transplant-related toxicity while maintaining or improving efficacy. These data demonstrate that incorporation of maintenance therapy posttransplant might be the best way to improve outcomes.

High-Dose Chemotherapy and Autologous Stem Cell Transplant in Older Patients with Lymphoma

High-dose chemotherapy followed by autologous hematopoietic stem cell transplant (HDT/ASCT) can improve survival in patients with lymphoma. Limited experience is available on the safety and efficacy of HDT/ASCT in elderly patients. In this article, we review the published data on the role of HDT/ASCT in management of lymphoma in older patients. Based on available data, evaluation of comorbidities, functional status, and comprehensive geriatric assessment (CGA) will help identify those who can benefit most from this intervention. Prospective clinical trials focusing on HDT/ASCT in older patients with lymphoma are needed to establish optimal management protocols in this select population.

Lifting the mantle: Unveiling new treatment approaches in relapsed or refractory mantle cell lymphoma

The management of relapsed/refractory mantle cell lymphoma (MCL) remains a clinical challenge. A standard second-line treatment for relapsed/refractory MCL does not exist. Management of relapsed/refractory MCL requires an individualized treatment approach, incorporating factors such as: functional status, prior treatments, response to prior therapies, and disease biology. Generally, there are two categories of salvage therapy; the first, non-cross-resistant cytotoxic chemotherapeutic agents and, the second, pathway-targeted agents. For transplant eligible patients, the optimal therapy usually consists of salvage, remission re-induction phase followed, whenever possible, by a consolidation phase. Bendamustine and/or high dose cytarabine plus rituximab based chemotherapy represent the most common salvage therapy with an overall response rate of 70-80%. Consolidation with a reduced intensity conditioning allogeneic stem cell transplantation represents the only potentially curative treatment. Overall survival ranges from 30% to 50% at 5 years with this approach. For transplant ineligible patients, ibrutinib is the most effective treatment with an overall response rate of almost 70% and median response duration of 17.5 months. Lacking an effective consolidation, this approach is not considered curative. In this review we characterize the main therapeutic approaches available in this setting and summarize our preferred clinical treatment approach.

Favorable outcomes in elderly patients undergoing high-dose therapy and autologous stem cell transplantation for non-Hodgkin lymphoma

High-dose therapy and autologous stem cell transplantation (HDT-ASCT) can offer potential long-term remission or cure in patients with non-Hodgkin lymphoma (NHL). Limited experience is available on the safety and efficacy of HDT-ASCT in elderly patients. This is a single-center, retrospective study examining outcomes of HDT-ASCT for 202 NHL patients, ages 60 years and older, between January 2001 and December 2012. Overall survival (OS) and progression-free survival (PFS) were analyzed according to age at HDT-ASCT, hematopoietic cell transplantation comorbidity index (HCT-CI), NHL histology, and remission status at the time of HDT-ASCT. The median age was 65 years (range, 60 to 74) and the majority had either diffuse large B cell lymphoma (n = 73, 37%) or mantle cell lymphoma (n = 69, 34%). One hundred and fifteen patients (57%) had high HCT-CI scores at the time of HDT-ASCT. With a median follow-up of 3.6 years (range, 4 to 11.9 years) for survivors, PFS and OS at 3 years were 60% (95% confidence interval [CI], 53% to 68%) and 73% (95% CI, 67% to 80%), respectively. Transplantation-related mortality (TRM) was 4% both at 100 days and at 1 year after HDT-ASCT. Age and HCT-CI score were not associated with OS or PFS, and high HCT-CI did not correlate with TRM. Seven patients (4%) developed secondary myelodysplastic syndrome or acute myeloid leukemia at a median of 35 months (range, 6 to 48) after HDT-ASCT. In this single-center cohort of elderly patients with NHL undergoing HDT-ASCT, this intervention was proven tolerable and effective, with results similar to those of historic controls in younger patients. Our data suggest that age alone should not preclude HDT-ASCT in elderly patients.

Current and emerging therapies in mantle cell lymphoma

Mantle Cell Lymphoma, characterized by the t(11;14)(q13; q32) chromosomal translocation and cyclin D1 expression, remains one of the most challenging lymphoma subtypes to treat. Therapy can be divided into treatment modalities for younger, stem cell transplant (SCT)-eligible patients vs older, SCT-ineligible patients. For clinically fit patients younger than 60-65 years of age we recommend cytarabine-containing induction and conditioning regimens such as Rituximab (R)-CHOP alternating with R-DHAP followed by autologous SCT consolidation. Elderly patients benefit from R-bendamustine or R-CHOP with maintenance rituximab following induction therapy, especially after R-CHOP. While standard chemoimmunotherapy provides high overall response rates, the responses are not durable and sequential therapies are thus necessary. MCL is proving to be sensitive to novel therapies that may in the near future become useful adjuncts to standard regimens. For example, bortezomib, lenalidomide, and temsirolimus each have single-agent efficacy in relapsed and refractory disease. Several targeted agents are emerging that likewise may transform management of MCL. The B-cell receptor pathway appears to be critical in the pathogenesis of MCL, and novel agents such as ibrutinib and idelalisib that target this signaling pathway are highly active in relapsed and refractory MCL. Similarly, cell cycle inhibitors targeting cyclin dependent kinases as well as HDAC inhibitors have shown promise in early studies.

Initial therapy of mantle cell lymphoma

Mantle cell lymphoma is a well-recognized distinct clinicopathologic subtype of B-cell non-Hodgkin lymphoma. The current World Health Organization (WHO) classification subdivides this entity into aggressive and other variants. The disease has a predilection for older males, and patients typically present at an advanced stage with frequent splenomegaly and extranodal involvement including bone marrow, peripheral blood, gastrointestinal, and occasional central nervous system involvement. Early studies of therapy outcomes in this disease revealed that while response rates where high, relapse was expected after a limited period of time. Prolonged survival was uncommon, with initial median survival rates typically in the 3-4-year range. Those with a high proliferative rate, blastoid morphology, and selected clinical features were recognized as having a worse prognosis. Therapeutic approaches have diverged into aggressive therapies with high response rates and promising progression free survival rates, which may be applied to younger healthy patients, and less aggressive approaches. Aggressive therapies include intensive chemotherapy alone or chemotherapy followed by autologous stem cell transplant, which has been shown to be most effective when applied in first remission. Whether these more intense therapies result in improved survival as compared with less aggressive therapies is not well established. Allogeneic transplant has also been investigated, although high treatment-related mortality and the risk of chronic graft versus host disease and the relatively advanced age of this patient population have tempered enthusiasm for this approach. A number of less aggressive therapies have been shown to produce promising results. Consolidation and maintenance strategies are an active area of investigation. A number of newer agents have shown promising activity in relapsed disease, and are being investigated in the front-line setting. Overall survival rates are improving in this disease, with current studies suggesting a median survival of 5 or more years.

A multicenter phase II trial (SAKK 36/06) of single-agent everolimus (RAD001) in patients with relapsed or refractory mantle cell lymphoma

BACKGROUND

Mantle cell lymphoma accounts for 6% of all B-cell lymphomas and is generally incurable. It is characterized by the translocation t(11;14) leading to cyclin D1 over-expression. Cyclin D1 is downstream of the mammalian target of rapamycin threonine kinase and can be effectively blocked by mammalian target of rapamycin inhibitors. We set out to examine the single agent activity of the orally available mammalian target of rapamycin inhibitor everolimus in a prospective, multicenter trial in patients with relapsed or refractory mantle cell lymphoma (NCT00516412).

DESIGN AND METHODS

Eligible patients who had received a maximum of three prior lines of chemotherapy were given everolimus 10 mg for 28 days (one cycle) for a total of six cycles or until disease progression. The primary endpoint was the best objective response. Adverse reactions, progression-free survival and molecular response were secondary endpoints.

RESULTS

Thirty-six patients (35 evaluable) were enrolled and treatment was generally well tolerated with Common Terminology Criteria grade ≥ 3 adverse events (>5%) including anemia (11%), thrombocytopenia (11%) and neutropenia (8%). The overall response rate was 20% (95% CI: 8-37%) with two complete remissions and five partial responses; 49% of the patients had stable disease. At a median follow-up of 6 months, the median progression-free survival was 5.5 months (95% CI: 2.8-8.2) overall and 17.0 (6.4-23.3) months for 18 patients who received six or more cycles of treatment. Three patients achieved a lasting complete molecular response, as assessed by polymerase chain reaction analysis of peripheral blood.

CONCLUSIONS

Everolimus as a single agent is well tolerated and has anti-lymphoma activity in relapsed or refractory mantle cell lymphoma. Further studies of everolimus in combination with chemotherapy or as a single agent for maintenance treatment are warranted.

Rituximab plus HyperCVAD alternating with high dose cytarabine and methotrexate for the initial treatment of patients with mantle cell lymphoma, a multicentre trial from Gruppo Italiano Studio Linfomi

This study investigated the clinical activity and toxicity of R-HCVAD-AM [rituximab plus HyperCVAD (R-HCVAD) alternating with high-dose cytarabine and methotrexate (AM)] in patients with newly diagnosed Mantle Cell Lymphoma (MCL). Patients aged ≤70years with confirmed MCL received four alternating cycles each of R-HCVAD and AM. Patients who obtained a partial response proceeded to autologous stem cell transplant. Sixty-three patients were enrolled and 60 were fully eligible. Median age was 57years (22-66); 60%, 33% and 7% were classified at low (L)-, intermediate (I)- or high (H)-risk, respectively, according to the MCL International Prognostic Index (MIPI). Only 22 patients (37%) completed the four cycles and three patients died during therapy. Overall response and complete response rates were 83% and 72% respectively. After a median follow-up of 46months (range 1-72) the estimated 5-year overall survival (OS) and progression-free survival rates were 73% [95% confidence interval (CI) 59-83%], and 61% (95%CI 45-73%) respectively. MIPI maintained the prognostic value with an estimated 5-year OS of 89%, 80% and 24% for L, I, and H groups respectively (P<0·001). This multicentre study confirms that R-HCVAD-AM is an active regimen for the initial treatment of patients with MCL, but is associated with significant toxicity.

Mantle cell lymphoma

MCL is a well-characterized clinically aggressive lymphoma with a poor prognosis. Recent research findings have slightly improved the outcome of this neoplasm. The addition of rituximab to conventional chemotherapy has increased overall response rates, but it does not improve overall survival with respect to chemotherapy alone. The use of intensive frontline therapies including rituximab and consolidated by ASCT ameliorates response rate and prolongs progression-free survival, but any impact on survival remains to be proven. Furthermore, the optimal timing, cytoreductive regimen and conditioning regimen, and the clinical implications of achieving a disease remission even at molecular level remain to be elucidated. The development of targeted therapies as the consequence of better dissection of pathogenetic pathways in MCL might improve the outcome of conventional chemotherapy in most patients and spare the toxicity of intense therapy in a minority of MCL patients characterized by a relatively indolent disease. Patients not eligible for intensive regimens, such as hyperC-VAD, may be considered for less demanding therapies, such as the combination of rituximab either with CHOP or with purine analogues, or bendamustine. Allogeneic SCT can be an effective option for relapsed disease in patients who are fit enough and have a compatible donor. Maintenance rituximab may be considered after response to immunochemotherapy for relapsed disease, although there are currently no data to recommend this approach as the first-line strategy. As the optimal approach to the management of MCL is still evolving, it is critical that these patients be enrolled in clinical trials to identify better treatment options.

Transplantation for non-Hodgkin lymphoma

High-dose therapy followed by autologous hematopoietic stem cell transplantation (auto-HCT) has become the treatment of choice for patients with relapsed aggressive non-Hodgkin lymphoma (NHL). However, relapse remains the most common cause of treatment failure after auto-HCT. More intensive regimens incorporating radioimmunotherapy into high-dose regimens have been developed to prevent relapse. The role of auto-HCT for follicular lymphoma and mantle cell lymphoma remain inconclusive. Since prognosis of patients with peripheral T-cell lymphoma, not otherwise specified are very poor with conventional chemotherapy, auto-HCT during first remission is being explored in peripheral T-cell lymphoma. Given the lower risk of relapse after allogeneic HCT (allo-HCT) in NHL, allo-HCT has been performed in patients with refractory or relapsed NHL, especially after auto-HCT failure. However, the transplant-related mortality remains high after myeloablative allo-HCT. Reduced-intensity conditioning followed by allo-HCT has been shown to reduce transplant-related mortality but graft-versus-host disease continues to be the major problem, thus the role of allo-HCT in NHL remains an investigational approach for NHL. The outcomes of auto-HCT and allo-HCT for various lymphomas are reviewed.

The role of rituximab in autologous and allogeneic hematopoietic stem cell transplantation for non-Hodgkin's lymphoma

The addition of rituximab to chemotherapy has substantially changed the treatment strategies for patients with B-cell lymphomas. Rituximab, combined with standard chemotherapy regimens, shows consistently improved results compared with chemotherapy alone and has been extensively employed in both newly diagnosed and relapsed patients with B-cell lymphoma. Because of its low toxicity profile and its potent antilymphoma activity mediated through direct apoptotic and indirect effector mechanisms, rituximab also has been actively incorporated into stem cell transplantation (SCT) protocols to attain a state of minimal disease, provide a safe and effective method for in vivo purging prior to autologous SCT, and promote graft-versus-lymphoma effects in allogeneic SCT. This review compiles the still immature but rapidly growing data on this combined modality.

Ten-year follow-up after intense chemoimmunotherapy with Rituximab-HyperCVAD alternating with Rituximab-high dose methotrexate/cytarabine (R-MA) and without stem cell transplantation in patients with untreated aggressive mantle cell lymphoma

Mantle cell lymphoma (MCL) has a poor overall survival after treatment with conventional chemotherapy. Intense chemoimmunotherapy without consolidation stem cell transplantation is a potential therapeutic option. We report on a prospective Phase II study with rituximab in combination with fractionated cyclophosphamide, vincristine, doxorubicin and dexamethasone (R-Hyper-CVAD) alternating with rituximab in combination with high-dose methotrexate-cytarabine (R-MA) in untreated patients with diffuse and nodular MCL and their blastoid variants. Ninety-seven patients were treated, of whom 97% responded and 87% achieved a complete remission. At 10 years of follow up (median 8 years), the median overall survival (OS) for all patients had not been reached and the median time to failure (TTF) for all patients was 4.6 years, without a plateau in the curves. For the group of patients aged 65 years or younger, the median OS had not been reached and the median TTF was 5.9 years. Multivariate analysis revealed pre-treatment serum levels of beta(2) microglobulin, International Prognostic Index (IPI) score and mantle cell IPI (MIPI) score, as predictive of both OS and TTF. We conclude that intense chemoimmunotherapy without stem cell transplantation is effective for untreated aggressive MCL.

[Mantle cell lymphoma: an overview from diagnosis to future therapies]

Mantle cell lymphoma (MCL) is a rare non-Hodgkin lymphoma (NHL) entity. The translocation between chromosomes 11 and 14 is the cytogenetics hallmark of MCL. This translocation leads to the dysregulation of the CCDN1 gene, and overexpression of cyclin D1 which promotes cell cycling. Despite a classical phenotype (CD19+, CD20+, CD5+, CCND1+, CD10-, CD23-, Bcl-2+, Ig at the membrane, mainly IgM), MCL is not a homogeneous disease and several cytological, phenotypic, cytogenetic and clinical variants have been described. MCL represents 5 % of NHLs with its incidence constantly increasing over the last years. Median age at diagnosis is 68 years. Stage III-IV disease is observed in more than 80 % of patients at presentation, with intestinal and bone marrow being the most frequently involved organs, while the spleen is enlarged in half of cases. Intensive strategies including high-dose chemotherapy, followed by autologous stem cell transplantation have significantly improved the outcome of MCL patients. Median overall survival rate increased from 3 to 5 years during the last decade. At present, induction chemotherapy followed by high-dose chemotherapy and autologous stem cell transplantation is the standard regimen in younger patients. However, most of MCL patients will experience relapse. Thus, close monitoring of minimal residual disease (currently under evaluation) may represent a valuable tool for assessment of disease response during follow-up. Future innovative therapies that are being presently investigated in prospective trials include transduction pathways inhibitors, proteasome inhibitors, pro-apoptotic molecules, immunotherapy and/or radiolabeled immunotherapy, and will likely open a new era for targeted therapies in MCL.

Mantle cell lymphoma: state-of-the-art management and future perspective

Mantle cell lymphoma (MCL) is a unique subtype of B-cell non-Hodgkin lymphomas (NHL) characterized in almost all cases by the chromosomal translocation t(11;14)(q13;q32) and nuclear cyclin D1 overexpression. Most patients present with advanced stage disease, often with extranodal dissemination, and typically pursue an aggressive clinical course. Recent improvement has been achieved by the successful introduction of monoclonal antibodies and dose-intensified approaches including autologous stem cell transplantation strategies. However, with the exception of allogeneic hematopoietic stem cell transplantation, current treatment approaches are not curative and the corresponding survival curve is characterized by a relatively steep and continuous decline, with a median survival of about 4 years and <15% long-term survivors. Despite its rarity, MCL is of particular clinical and scientific interest by providing a paradigm for neoplasms with dysregulated control of cell cycle machinery and impaired apoptotic pathways. Recently gained insights into underlying pathobiology unravel numerous promising molecular targeting strategies, however their introduction into clinical practice and current treatment algorithms remains a challenge. This article will provide relevant information for decision making in clinical practice and give a perspective on upcoming management strategies.

Autologous and allogeneic stem cell transplantation: rising therapeutic promise for mantle cell lymphoma

Mantle cell lymphoma (MCL) is currently an incurable neoplasm with a median survival duration of 3-5 years. The clinical results of therapy with cyclophosphamide, doxorubicin, vincristine, and prednisone or similar regimens are inadequate,leading to widespread exploration of the use of autologous stem cell transplantation (ASCT) during the first remission. In the pre-rituximab era, early ASCT extended the median remission duration by 1-2 years, but most patients eventually experienced relapse. With the advent of rituximab and its incorporation into stem cell mobilization and conditioning regimens, several research groups have reported improved outcomes, including the emergence of early survival curve plateaus that suggest a cured fraction. Intensive chemoimmunotherapy with rituximab and hyperfractionated cyclophosphamide,vincristine, doxorubicin, and dexamethasone has been reported to have similarly favorable results. Therefore, the addition of rituximab to intensive chemotherapy or ASCT regimens may be curative in patients undergoing frontline treatment for MCL. In the relapsed or refractory disease setting, the clinical results of ASCT remain inadequate. However, the increasing safety and high efficacy of non-myeloablative stem cell transplantation (SCT) suggests that it is the most appropriate transplantation modality in patients with relapsed or refractory MCL when a suitable donor is available.

Effect of remission status and induction chemotherapy regimen on outcome of autologous stem cell transplantation for mantle cell lymphoma

We analysed the outcomes of autologous stem cell transplantation (ASCT) following high-dose therapy with respect to remission status at the time of transplantation and induction regimen used in 56 consecutive patients with mantle cell lymphoma (MCL). Twenty-one patients received induction chemotherapy with HyperCVAD with or without rituximab (+/-R) followed by ASCT in first complete or partial remission (CR1/PR1), 15 received CHOP (+/-R) followed by ASCT in CR1/PR1 and 20 received ASCT following disease progression. Estimates of overall and progression-free survival (PFS) at 3 years among patients transplanted in CR1/PR1 were 93% and 63% compared with 46% and 36% for patients transplanted with relapsed/refractory disease, respectively. The hazard of mortality among patients transplanted with relapsed/refractory disease was 6.09 times that of patients transplanted in CR1/PR1 (P = 0.006). Patients in the CHOP (+/-R) group had a higher risk of failure for PFS compared with patients in the HyperCVAD (+/-R) group, though the difference did not reach statistical significance (hazard ratio 3.67, P = 0.11). These results suggest that ASCT in CR1/PR1 leads to improved survival outcomes for patients with MCL compared to ASCT with relapsed/refractory disease, and a HyperCVAD (+/-R) induction regimen may be associated with an improved PFS among patients transplanted in CR1/PR1.

Ki67 and PIM1 expression predict outcome in mantle cell lymphoma treated with high dose therapy, stem cell transplantation and rituximab: a Cancer and Leukemia Group B 59909 correlative science study

The proliferation index in mantle cell lymphoma (MCL) has not been validated in the context of aggressive therapy regimens in the rituximab era. We assessed Ki67 and PIM1 (a cell cycle-related gene upregulated in blastoid MCL) expression by immunohistochemistry in a phase II study Cancer and Leukemia Group B 59909 of aggressive chemotherapy and rituximab followed by autologous stem cell transplantation plus rituximab in untreated MCL patients <70 years of age. As a continuous variable or using a cutoff of 35%, higher image analysis (IA Ki67, n = 52) was associated with shorter progression free survival (PFS) (P < or = 0.030) and event free survival (EFS) (P < or = 0.017). PIM1 expression (n = 50) was associated with PFS (P = 0.033) and EFS (P = 0.043). Bivariate Cox models showed IA Ki67 and PIM1 were independent of clinical factors. High Ki67 (>35%) is an important independent prognostic marker in aggressively treated MCL in the rituximab era. PIM1 expression predicts poor outcome and, given its potential role as a therapeutic target, deserves further study.

Therapeutic options in mantle cell lymphoma

Mantle cell lymphoma (MCL) is an aggressive lymphoma requiring intensive chemotherapy +/- autologous stem cell transplantation (SCT) to achieve optimal rates of progression-free survival. Here we review the treatment options for patients with newly-diagnosed or relapsed MCL and discuss recent advances in management, including the role of autologous and allogeneic SCT.

Immunotherapy in mantle cell lymphoma: anti-CD20-based therapy and beyond

Mantle cell lymphoma (MCL), an aggressive non-Hodgkin's lymphoma characterized by t(11; 14)(q13; q32) chromosomal translocation and overexpression of cyclin D1, has the worst prognosis among all lymphomas. Recent advances in biology, genetics, and immunology have supported the development of immunotherapy in MCL. Rituximab monotherapy in MCL has limited activity. It is more effective when used in combination with chemotherapy such as R-CHOP, R-hyperCVAD/MTX-Ara-C, or R-FCM as front-line or salvage therapy for mantle cell lymphoma. Maintenance with Rituximab was shown to prolong response duration. Although most results have suggested that combining autologous stem cell transplantation with Rituximab may lead to durable remission, the sample size was not sufficient to declare survival benefit. Anti-CD20 radioimmunoconjugates (RICs) (90)Yttrium-ibritumomab tiuxetan and (131)Iodine-tositumomab have been used in mantle cell lymphoma even when patients are relatively resistant to Rituximab-based therapy. Allogeneic stem cell transplantation is a treatment modality in advanced or relapsed MCL, particularly using reduced-intensity conditioning. MCL may have high response rates and sustained remissions after donor lymphocyte infusion. Dendritic cells (DCs) fused with MCL cells for immunostimulation have preliminarily shown anti-lymphoma effects as well. Idiotype vaccination in MCL patients following Rituximab-containing chemotherapy induced tumor-specific T-cell immunity in the absence of B cells. Other immunotherapy, such as the combination of thalidomide with Rituximab, has shown substantial antitumor activity. A Phase I/II study is ongoing to determine the maximum tolerated dose (MTD) and the efficacy of lenalidomide in combination with Rituximab for relapsed/refractory MCL. This review summarizes the latest and exciting advances in MCL.

Treatment of non-Hodgkin's lymphoma: a look over the past decade

The past decade has seen enormous changes in our understanding of lymphomas with a better classification (World Heath Organization) and identification of better prognostic factors; however, important genetic prognostic factors have not been completely analyzed. The appearance of rituximab and other monoclonal antibodies has completely revolutionized the treatment of this disease. If monoclonal antibodies have activity when used alone, most patients experienced relapse after such a treatment, even after maintenance therapy. The combination of rituximab with chemotherapy has now been shown in several randomized studies to increase the response rate, decrease the relapse rate, and prolong progression-free survival and overall survival. Rituximab plus CHOP (cyclophosphamide/doxorubicin/prednisone/vincristine; R-CHOP) has become the standard for patients with diffuse large B-cell lymphoma. Rituximab chemotherapy, probably with the CHOP regimen, is slowly gaining importance as the standard for patients with follicular lymphoma. Although little is known for other indolent lymphomas and mantle cell lymphoma, progress has been made there, too. Several questions remain for future randomized studies to continue our search toward cure.

Blood or marrow transplantation for mantle cell lymphoma

PURPOSE OF REVIEW

Mantle cell lymphoma is a generally incurable disease for which blood or marrow transplantation is frequently considered. This review assesses the more recent literature on high-dose therapeutic approaches for mantle cell lymphoma.

RECENT FINDINGS

The benefit of transplantation is most apparent in first remission. Autologous transplantation can prolong event-free and possibly overall survival, although no plateau has been demonstrated in the survival curve. A randomized controlled trial demonstrated a significant event-free survival advantage to upfront autologous transplantation compared with interferon maintenance. The relative merit of autologous versus allogeneic transplantation remains to be better defined.

SUMMARY

The role of transplantation for mantle cell lymphoma is controversial, as the impact on overall survival is unclear. Transplantation should be considered early in the disease course. Elimination of minimal residual disease through in-vivo purging of stem cells may translate into more durable remissions. Nonmyeloablative allogeneic transplantation and high-dose radioimmunotherapy are topics of ongoing investigation.

Antiproliferative activity of RAD001 (everolimus) as a single agent and combined with other agents in mantle cell lymphoma

Mantle cell lymphoma (MCL) is an aggressive form of B-cell non-Hodgkin's lymphoma, with a mean survival of only 3-5 years and suboptimal therapeutic options. MCL is characterized by a balanced translocation t(11;14)(q13;q32), resulting in overexpression of cyclin D1, a G(1) cyclin regulated by the PI3K/Akt/mammalian target of rapamycin (mTOR) signaling pathway. As improved therapy for MCL is required and the mTOR pathway may be involved in its pathophysiology, the antiproliferative effects of RAD001 (everolimus), an mTOR inhibitor, against three MCL cell lines were investigated. As a single agent, RAD001 inhibited proliferation in MCL cell lines (Jeko1, SP49 and NCEB1) approximately 40-65% compared to diluent control cells. This was associated with G(1) cell-cycle arrest and reduced phosphorylation of the mTOR downstream target, 4E-BP1. Furthermore, combination drug studies revealed predominantly synergistic cytotoxicity with RAD001 and several secondary agents, including doxorubicin, vincristine or rituximab (components of the standard MCL regimen), as well as paclitaxel, vorinostat and bortezomib. These data indicate that single agent RAD001 is effective in inhibiting growth of MCL cells in vitro and combination studies with secondary agents further demonstrate synergistic cytotoxicity. Thus, these findings support future clinical studies of RAD001 in the treatment of MCL.

Treatment of mantle cell lymphoma: current approach and future directions

Although mantle cell lymphoma has been described as "moderately aggressive" it has become clear that it carries a worse long-term prognosis than other subtypes of non-Hodgkin's lymphoma. In recent years, this has prompted numerous clinical trials of novel and more aggressive therapies in hopes of impacting these poor outcomes. These include more intensive combination chemotherapy regimens, monoclonal antibody therapy in conjunction with other treatments or conjugated to radioactive isotopes, high-dose chemotherapy followed by autologous or allogeneic stem cell transplantation, and newer targeted therapies based on increasing understanding of the molecular pathways of this malignancy.

Advances in the treatment for haematological malignancies

Despite the progress made in the last decade in the treatment of haematological malignancies, most of the patients still have a dismal prognosis. However, the improved knowledge of tumour biology opened the possibility to develop new 'intelligent' therapeutic strategies, the so-named targeted therapies. These approaches aim to selectively kill cancer cells by basing this selectivity on both the expression of a specific molecule on their surface or the activation of particular molecular pathways secondary to malignant transformation. In this article, the authors review the main targeted therapies available in haematology, such as monoclonal antibodies, tyrosine kinase, farnesyltransferase, as well as proteasome inhibitors, antiangiogenesis compounds and antisense oligonuceotides. Finally, the authors focus on the application of imatinib mesylate in chronic myeloid leukaemia as the paradigm of molecular treatment. Although these novel therapies are beginning to fulfil their promise, continued research efforts are needed to determine the optimal role of these strategies in haemato-oncology.