High-dose chemoradiotherapy and anti-B-cell monoclonal antibody-purged autologous bone marrow transplantation in mantle-cell lymphoma: no evidence for long-term remission

Recent advances in genomics and therapeutics in mantle cell lymphoma

Over the past decades, significant strides have been made in understanding the pathobiology, prognosis, and treatment options for mantle cell lymphoma (MCL). The heterogeneity observed in MCL's biology, genomics, and clinical manifestations, including indolent and aggressive forms, is intricately linked to factors such as the mutational status of the variable region of the immunoglobulin heavy chain gene, epigenetic profiling, and Sox11 expression. Several intriguing subtypes of MCL, such as Cyclin D1-negative MCL, in situ mantle cell neoplasm, CCND1/IGH FISH-negative MCL, and the impact of karyotypic complexity on prognosis, have been explored. Notably, recent immunochemotherapy regimens have yielded long-lasting remissions in select patients. The therapeutic landscape for MCL is continuously evolving, with a shift towards nonchemotherapeutic agents like ibrutinib, acalabrutinib, and venetoclax. The introduction of BTK inhibitors has brought about a transformative change in MCL treatment. Nevertheless, the challenge of resistance to BTK inhibitors persists, prompting ongoing efforts to discover strategies for overcoming this resistance. These strategies encompass non-covalent BTK inhibitors, immunomodulatory agents, BCL2 inhibitors, and CAR-T cell therapy, either as standalone treatments or in combination regimens. Furthermore, developing novel drugs holds promise for further improving the survival of patients with relapsed or refractory MCL. In this comprehensive review, we methodically encapsulate MCL's clinical and pathological attributes and the factors influencing prognosis. We also undertake an in-depth examination of stratified treatment alternatives. We investigate conceivable resistance mechanisms in MCL from a genetic standpoint and offer precise insights into various therapeutic approaches for relapsed or refractory MCL.

Long-Term Survival of Patients with Mantle Cell Lymphoma after Total Body Irradiation, High-Dose Chemotherapy and Stem Cell Transplantation: A Monocenter Study

INTRODUCTION

In patients with mantle cell lymphoma (MCL), long-term remissions can be achieved by stem cell transplantation (SCT). Different conditioning treatment protocols exist with or without total body irradiation (TBI). There are few data published on the role of TBI before autologous stem cell transplantation (autoSCT) or allogenic stem cell transplantation (alloSCT). We report on the long-term survival data of patients treated by TBI prior to autologous or allogenic SCT at our center.

PATIENTS

In a retrospective analysis, the data of patients treated at the University Hospital of Muenster from May 2004 to February 2015 were collected and evaluated. For the analysis, all data of patients who were histopathologically diagnosed with MCL and underwent TBI prior to stem cell transplantation (SCT) were evaluated.

RESULTS

A total of 22 patients (19 men and 3 women) were treated with a TBI-based conditioning prior to SCT. The median age at initial diagnosis was 57.5 years (38-65 years). Seventeen patients had Ann Arbor stage IV, two patients had Ann Arbor stage III, and three patients Ann Arbor stage II disease. AutoSCT was performed in 19 patients and alloSCT was performed in 3 patients. In 18 patients, autoSCT was applied as part of first-line therapy, and in one patient after relapse. Two patients received alloSCT after relapse of MCL, and one patient received alloSCT during first-line therapy after an inadequate treatment response. TBI was performed in 12 patients with 10 Gy and in 6 patients with 12 Gy, these patients subsequently received autoSCT. In the group of four patients who received TBI with four Gy, four patients subsequently received alloSCT and one patient received autoSCT. Median overall survival after autoSCT and previous TBI was 11.4 years (142 months). In total, 11 out of 19 patients treated with autoSCT lived longer than 6.8 years (82-202 months). After alloSCT and previous TBI, the median overall survival was 3.25 years (14-59 months).

CONCLUSIONS

A large proportion of patients with advanced MCL survived remarkably longer than 11.4 years after high-dose chemotherapy, TBI, and SCT. The present results of multimodal treatment support the published reports that TBI-based high-dose therapy followed by autoSCT is highly effective in this prognostically unfavorable disease situation.

Key Clinical and Translational Research Questions to Address Unmet Needs in Mantle Cell Lymphoma

Survival for patients with mantle cell lymphoma has improved dramatically over the last 2 decades owing to a better understanding of disease biology and the development of more effective treatment regimens for patients with untreated and relapsed disease. With these advancements, we are now poised to ask questions that challenge old treatment strategies, use new technologies, and improve our understanding of disease heterogeneity. This article focuses on questions that we believe will drive the future of mantle cell lymphoma treatment. Although not an exhaustive list, we review current literature, ongoing studies, and provide expert opinion on future trial design.

Mantle Cell Lymphoma: Which Patients Should We Transplant?

PURPOSE OF REVIEW

Mantle cell lymphoma is a CD5+ non-Hodgkin lymphoma associated with suboptimal outcome. Young, fit patients are generally offered intensive induction followed by autologous hematopoietic cell transplantation (AHCT) in first remission. Some patients may not benefit from this strategy.

RECENT FINDINGS

Recent studies have investigated the role of AHCT in the modern era. First, an analysis of the National Cancer Database demonstrated improved progression-free survival (PFS) for consolidative AHCT. Second, a multi-center study associated consolidative AHCT with improved PFS even after propensity-weighted analysis. Improved overall survival (OS) for certain subgroups was suggested. Third, patients with p53 mutations derive little benefit from AHCT. Finally, retrospective series suggest certain high-risk patients may be considered for allogenic HCT. AHCT consolidation in first remission is associated with improved PFS even after adjustment for disease severity. An overall survival benefit has not been definitively shown. Patients with p53 mutations should be treated with novel agents.

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.

Hematopoietic stem cell transplantation for blood cancers in the era of precision medicine and immunotherapy

Hematopoietic stem cell transplantation (HCT) has been an integral component in the treatment of many hematologic malignancies. Since the development of HCT nearly 50 years ago, the role of this modality has evolved as newer treatment approaches have been developed and integrated into the standard of care. In the last decade, novel and highly active targeted therapies and immunotherapies have been approved for many hematologic malignancies, raising the question of whether HCT continues to retain its prominent role in the treatment paradigms of various hematologic malignancies. In this review, the authors have described the current role of autologous and allogeneic HCT in the treatment of patients with acute leukemias, aggressive B-cell lymphomas, and multiple myeloma and discussed how novel targeted therapies and immunotherapies have changed the potential need, timing, and goal of HCT in patients with these diseases.

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.

Paramount therapy for young and fit patients with mantle cell lymphoma: strategies for front-line therapy

The natural history of mantle cell lymphoma (MCL) is a continuous process with the vicious cycle of remission and recurrence. Because MCL cells are most vulnerable before their exposure to therapeutic agents, front-line therapy could eliminate MCL cells at the first strike, reduce the chance for secondary resistance, and cause long-term remissions. If optimized, it could become an alternative to cure MCL. The key is the intensity of front-line therapy. Both the Nordic 2 and the MD Anderson Cancer Center HCVAD trials, with follow-up times greater than 10 years, achieved long-term survivals exceeding 10 years. But the Achilles heel in both trials were the severe toxicities, such as secondary malignancies including myelodysplastic syndromes /leukemia. Therefore, intensive therapies can act as a double-edged sword providing long term survival at the cost of severe toxicities. In our opinion, although intensive chemotherapy can cause detrimental side effects, it is indispensable given that we run the risk of sacrificing long-term survivals in these young and fit patients. We must seek for a powerful alternative at the front-line. Furthermore, minimal residual disease negativity should be the optimal therapeutic goal to achieve before and after autologous stem cell transplantation. Some novel therapeutic strategies have shown to improve outcomes, but it is not yet clear as to how these results translate in population. Of note, MCL patients need to be stratified at diagnosis and be provided with different intensities of front-line regimen. In this review, we discuss current strategies for the treatment of young patients with newly diagnosed MCL.

Current Approaches to Mantle Cell Lymphoma: Diagnosis, Prognosis, and Therapies

Mantle cell lymphoma (MCL) is a unique lymphoma subtype, both biologically and clinically. Virtually all cases are characterized by a common genetic lesion, t(11;14), resulting in overexpression of cyclin D1. The clinical course is moderately aggressive, and the disease is considered incurable. Considerable biologic and clinical heterogeneity exists, with some patients experiencing a rapidly progressive course, while others have disease that is readily managed. New tools exist for risk stratification and may allow for a more personalized approach in the future. Landmark studies have been completed in recent years and outcomes appear to be improving. Randomized clinical trials have clarified the role of high-dose cytarabine (Ara-C) for younger patients and have demonstrated a role for maintenance rituximab therapy. Multiple areas of uncertainty remain, however, and are the focus of ongoing research. This review focuses on (1) strategies to differentiate between aggressive and less aggressive cases, (2) understanding who should receive hematopoietic stem cell transplantation, and (3) the role for maintenance therapy in MCL.

The role of targeted treatment in mantle cell lymphoma: is transplant dead or alive?

Based on the profound biological insights of the last years into the molecular pathogenesis of mantle cell lymphoma and the clinical introduction of new targeted drugs, with high efficacy and a good safety profile, the therapeutic scenario for this tumor has been shown to be thoroughly favourable. No longer characterized by a uniformly dismal prognosis, mantle cell lymphoma has been revealed as a spectrum of different diseases, ranging from very indolent cases to highly aggressive and refractory ones. Thus, there is an urgent need to adapt therapy to accommodate the diverse presentations of the disease. High-dose chemotherapy, followed by autologous stem cell transplantation is the current standard of care for younger patients, generally providing high responses and long survival rates, but hampered by acute and long-term toxicity. In addition, some patients may be overtreated, while others could benefit from targeted approaches, based on the new, molecular-directed compounds. Such a personalized treatment based on the specific characteristics of individual patients may be guided by validated prognostic tools, such as the Mantle Cell Lymphoma International Prognostic Index and the Ki-67 Proliferative Index, as well as by early predictors of treatment response, like minimal residual disease analysis. Moreover, mutation screening of distinctive genomic alterations may provide new, predictive biomarkers, with an additional impact on clinical practice. Only after tailoring treatment according to the clinical and biological heterogeneity of the disease the role of transplantation and modern therapeutic options will be redefined in mantle cell lymphoma.

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.

Specific features identify patients with relapsed or refractory mantle cell lymphoma benefitting from autologous hematopoietic cell transplantation

Outcomes with autologous hematopoietic cell transplantation (auto HCT) for relapsed and/or refractory mantle cell lymphoma (MCL) are typically poor. We hypothesized that certain factors could predict which patients experience a favorable outcome with this approach. We thus developed a predictive score from a cohort of 67 such patients using 3 factors independently associated with progression-free survival (PFS): (1) simplified Mantle Cell Lymphoma International Prognostic Index score before auto HCT (hazard ratio [HR], 2.9; P = .002); (2) B symptoms at diagnosis (HR, 2.7; P = .005); and (3) remission quotient, calculated by dividing the time, in months, from diagnosis to auto HCT by the number of prior treatments (HR, 1.4; P = .02). The estimated 5-year PFS for favorable-risk patients (n = 23) and unfavorable-risk patients (n = 44) were 58% (95% confidence interval [CI], 34% to 75%) and 15% (95% CI, 6% to 28%), respectively. These factors also independently predicted overall survival. In summary, we have defined 3 simple factors that can identify patients with relapsed/refractory MCL who derive a durable benefit from salvage auto HCT.

Clinical practice guidelines for diagnosis, treatment, and follow-up of patients with mantle cell lymphoma. Recommendations from the GEL/TAMO Spanish Cooperative Group

Mantle cell lymphoma (MCL) is considered a distinct type of B-cell lymphoma genetically characterized by the t(11;14) translocation and cyclin D1 overexpression. There is also a small subset of tumors negative for cyclin D1 expression that are morphologically and immunophenotypically indistinguishable from conventional MCL. Although in the last decades, the median overall survival of patients with MCL has improved significantly, it is still considered as one of the poorest prognoses diseases among B-cell lymphomas. Election of treatment for patients with MCL is complex due to the scarcity of solid evidence. Current available data shows that conventional chemotherapy does not yield satisfactory results as in other types of B-cell lymphomas. However, the role of other approaches such as autologous or allogenic stem cell transplantation, immunotherapy, the administration of consolidation or maintenance schedules, or the use of targeted therapies still lack clear indications. In view of this situation, the Spanish Group of Lymphomas/Autologous Bone Marrow Transplantation has conducted a series of reviews on different aspects of MCL, namely its diagnosis, prognosis, first-line and salvage treatment (both in young and elderly patients), new targeted therapies, and detection of minimal residual disease. On the basis of the available evidence, a series of recommendations have been issued with the intention of providing guidance to clinicians on the diagnosis, treatment, and monitoring of patients with MCL.

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.

Patterns and outcome of relapse after autologous stem cell transplantation for mantle cell lymphoma

BACKGROUND

Autologous stem cell transplantation (autoSCT) has improved the outcome of patients with mantle cell lymphoma (MCL) considerably. However, little is known about the patterns and outcome of MCL recurrence after autoSCT.

METHODS

The authors conducted a retrospective study of 118 patients with MCL who underwent autoSCT from August 1992 to August 2008 at 3 different referral centers in Germany.

RESULTS

Fifty-two relapses occurred for a cumulative incidence of 46% after 5 years. Only 3 patients relapsed after 5 years (at 90 months, 91 months, and 171 months) after undergoing autoSCT. A Cox regression analysis of the incidence of relapse identified not receiving rituximab before autoSCT and undergoing salvage autoSCT as predictive factors for relapse, whereas cytosine arabinoside intensification; a total body irradiation-based, high-dose regimen; patient age; and year of transplantation had no influence. The median overall survival (OS) after relapse was 23 months. Twenty patients (39%) underwent allogeneic stem cell transplantation (alloSCT) for relapse, and 11 of those patients remained in ongoing complete remission at the time of the current report. It is noteworthy that there were 4 long-term survivors who lived for >5 years after relapse even without undergoing alloSCT. A Cox regression analysis of OS after relapse revealed that the response duration after autoSCT was an adverse predictor of OS, whereas alloSCT was associated with a significantly longer OS after relapse.

CONCLUSIONS

The current results indicated that autoSCT was capable of inducing long-term remission up to 16 years after treatment, but the outcome of patients with MCL who relapsed after autoSCT was poor, especially if their response duration after autoSCT was short. However, for a subset of patients with relapsed MCL, alloSCT may offer the possibility of durable survival, and individual patients can enjoy long-term survival after relapse even without undergoing alloSCT.

Temsirolimus in the treatment of relapsed or refractory mantle cell lymphoma

Mantle cell lymphoma (MCL) is a rare and aggressive subtype of lymphoma associated with a poor prognosis. Chemotherapy is the mainstay of frontline treatment for patients with this disease. Despite high response rates to combination chemotherapy regimens, the majority of patients relapse within a few years of treatment. Therefore, finding efficacious treatments for relapsed or refractory disease has become a growing area of clinical research. The mammalian target of rapamycin (mTOR) is responsible for integrating cell signals from growth factors, hormones, and nutrients and communicating energy status. Scientific research on aberrant molecular pathways in cancer has revealed that several proteins along the mTOR pathway may be upregulated in this and other types of lymphoma. Temsirolimus is the first mTOR inhibitor that has shown clinical efficacy in treating MCL that has relapsed after frontline treatments.

Predictors of high yield and purify of CD34(+) cell-selected PBPC, collected from patients with multiple myeloma

BACKGROUND

Wide ranges i n cell recovery and purity may be observed following CD34(+) cell selection of mobilized HPC componetns. Characteristics of the mobilized HPC, associated with isolation of a high CD34(+) cell yield and purity following cell selection, have yet to be defined.

METHODS

Cell number and purities were determined before and after 56 CD34(+) cell-selection procedures, performed using the CellPro Ceprate SC system from April 1997 to February 1998. HPC were collected from 28 patients with multiple myeloma, following cyclophosphamide (60mg/kg) and G-CSF (10microg/kg) mobilization.

RESULTS

A medium of 47.9% (range 1.5-109.6%) CD34(+) cells were recovered in the enriched (ENR) fraction. A linear correlation existed between total CD34(+) cells in the ENR fraction and total CD34(+) cells in the START fraction (R2=0.93); there was a logarithmic correlation between CD34 ENR fraction purity and START fraction purity (R2=0.73). A START CD34(+) cell purity > 0.42% improved purity in the ENR fraction. A median of one (range one to nine) procedure was required to isolate 2 x 10 6 CD34(+) cells/kg. Three patients pretreated with alkylating agents failed to mobilized adequate numbers of HPC.

DISCUSSION

Isolation of highly purified CD34(+) cell-selected components using the Ceprate SC system in dependent on the CD34(+) purity of the lekapheresis component collected. Mobilization regimens should be used to maximize CD34(+) cell purity in stem cell authografts if CD34(+) cell selection is to be performed. Similar strategies should be used to evaluate other cell-selection devices as they become available.

Non-Hodgkin's lymphoma in the elderly

The expansion of older population segments and the continuous increase in the incidence of non-Hodgkin's lymphoma (NHL) makes this group of neoplasms an important and growing problem. Older NHL patients have increased risk of therapy-related toxicity as a result of age-related physiological changes and frequent co-morbidities. A functional assessment of the elderly patient is necessary to determine the likelihood of tolerating and responding to therapy. The comprehensive geriatric assessment (CGA) is one multidisciplinary tool that has been applied successfully to older cancer patients and aids in identification of subjects who will or will not benefit from anti-neoplastic treatment. Although indolent lymphomas present more frequently at advanced stage, randomized trials do not show better outcomes with early therapy, supporting close observation until specific therapeutic indications arise. Use of the monoclonal antibody rituximab as a single agent or in combination with chemotherapy improves survival and has become the standard of care in first-line treatment. Radioimmunoconjugates, bendamustine, and other monoclonal antibodies as well as novel targeted agents also are active against indolent lymphomas. Diffuse large B-cell lymphoma is an aggressive but potentially curable disease. Several trials performed exclusively in elderly patients have demonstrated improved response rates and survival with the addition of rituximab to CHOP (cyclophosphamide, doxorubicin [adriamycin], vincristine, prednisone) chemotherapy in the front-line setting. Salvage chemotherapy followed by autologous haematopoietic cell transplant (autoHCT) has been shown to have better failure-free and overall survival in randomized trials involving younger patients. Highly selected individuals up to age 70 years may attain long-term survival benefit from autoHCT, although transplant-related mortality is higher than in younger patients.

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.

Evaluation of the (R)VAD+C regimen for the treatment of newly diagnosed mantle cell lymphoma. Combined results of two prospective phase II trials from the French GOELAMS group

Background There is currently no international consensus for first-line treatment (prior to autologous stem cell transplantation) in mantle cell lymphoma patients. Here, we investigated the efficacy and tolerance of VAD associated with chlorambucil (VAD+C) and rituximab or not before autologous stem cell transplantation.

DESIGN AND METHODS

Between 1996 and 2005, 113 previously untreated mantle cell lymphoma patients were enrolled in two consecutive prospective phase II studies. Responses and response factors to the (R)VAD+C regimen were evaluated. The survival prognostic value of the MIPI score and Ki67 were also analyzed.

RESULTS

The induction phase of 4 courses of (R)VAD+C showed very low hematologic and extra-hematologic toxicity (grade 3-4 thrombopenia and neutropenia, 9% and 2.7%, respectively and grade 3-4 extra-hematologic toxicities, 1.6%). Overall and complete response rates were 73% and 46%, respectively, and rose to 83% and 51% for the 70% of patients with less than two independent response factors (LDH, B symptoms and lymphocytosis). At the end of treatment, 65% of patients were in complete remission. Progression free and overall survival were significantly better in the transplanted population. The MIPI score was confirmed as a predictor of survival. Ki67, serum LDH, Performance Status (PS) and B symptoms were identified as independent prognostic factors of survival. A prognostic scoring system could stratify patients into three risk groups with markedly different median overall survival of 112, 44 and 11 months, respectively. Conclusions The (R)VAD+C is an effective regimen with very low toxicity. In addition to the MIPI score, Ki67 expression provides additional independent prognostic information for the prediction of overall survival (ClinicalTrials.gov Identifier: NCT00285389).

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.

Immunotoxin BL22 induces apoptosis in mantle cell lymphoma (MCL) cells dependent on Bcl-2 expression

Mantle cell lymphoma (MCL) is an incurable mature B cell proliferation, combining the unfavourable clinical features of aggressive and indolent lymphomas. The blastic variant of MCL has an even worse prognosis and new treatment options are clearly needed. We analysed the effects of BL22, an immunotoxin composed of the Fv portion of an anti- CD22 antibody fused to a 38-kDa Pseudomonas exotoxin-A fragment on four MCL cell lines as well as on primary cells of four MCL patients. Apoptosis induction by BL22 was much more pronounced in MCL cell lines with low Bcl-2 expression (NCEB-1, JeKo-1 and JVM-2) compared to Granta-519 cells with high Bcl-2 expression. While the expression of the antiapoptotic protein Mcl-1 declined (NCEB-1, Granta-519), Bcl-2 levels remained unchanged in Granta-519 cells. However transfection of BCL2 cDNA into NCEB-1, JeKo-1 and JVM-2 cells significantly reduced BL22-mediated toxicity. Accordingly we examined the effects of Bcl-2 inactivation in Granta-519 cells using siRNA. Indeed, apoptosis induction was strongly enhanced in Granta-519 cells with silenced Bcl-2. Our results were confirmed in freshly isolated MCL-cells from patients with leukaemic MCL. We conclude that Bcl-2 expression is important for mediating resistance against the immunotoxin BL22 in MCL cells.

Gemcitabine and Oxaliplatinum: An Effective Regimen in a Patient with Progressive Refractory Mantle Cell Lymphoma

We report here a 68-year-old man with progressive refractory Mantle cell Lymphoma stage IV-A, treated with different chemotherapeutic drugs. With no therapeutic options we decided to treat him with oxaliplatinum-gemcitabine regimen, based on the proven efficacy and synergy of these drugs in other tumors and lymphomas. Treatment was well tolerated and patient achieved a maintained complete remission with 6 months of follow up. We consider that this may be a salvage therapeutic option for patients with mantle cell lymphoma.

Allogeneic stem cell transplantation for mantle cell lymphoma--does it deserve a better look?

Mantle cell lymphoma is a subtype of non-Hodgkin's lymphoma. Mantle cell is generally considered incurable with a median overall survival of about 3 years. It is most common in 50 - 70 year old individuals and for this reason transplantation is not a common therapeutic option. Autologous stem cell transplantation does not appear to improve survival with most patients relapsing after transplant and no disease-free plateau. We present 6 mantle cell patients that had a mean of 3 different types of therapy prior to allogeneic transplantation. Allogeneic transplantation is associated with substantial mortality post-transplant from acute toxicity and GVHD. Despite the extensive amount of pretransplant therapy in our patient population, there was no transplant related mortality. All patients are alive and in remission a median of 4.3 plus years after transplantation. Survival from the date of diagnosis is a median of 6.5 plus years. The results of this series would suggest that in a selected group of patients allogeneic stem cell transplantation may be the treatment of choice for lymphomas not curable by standard therapy or autotransplant.

Targeting the proteasome in mantle cell lymphoma: A promising therapeutic approach

Mantle cell lymphoma (MCL) is a distinctive non-Hodgkin's lymphoma sub-type, characterized by over-expression of cyclin D1 as a consequence of chromosomal translocation t(11;14)(q13;q32). MCL remains an incurable disease, combining the unfavorable clinical features of aggressive and indolent lymphomas. The blastic variant of MCL, which is often associated with additional cytogenetic alterations, has an even worse prognosis and new treatment options are clearly needed. The 26S proteasome is a large multi-catalytic multi-protein complex, present in all eukaryotic cells. It is responsible for the degradation of a variety of short-lived proteins and exhibits a key position in cellular processes including apoptosis and cell cycle progression. Targeting the ubiquitin - proteasome pathway has only recently been identified as a promising new therapeutic option for cancer patients. Interestingly, an increased activity of the proteasome pathway has been described in MCL cells and the inhibition of the proteasome seems to be a promising therapeutic approach for this incurable disease.

Long-term survival and late relapse in 2-year survivors of autologous haematopoietic cell transplantation for Hodgkin and non-Hodgkin lymphoma

This study described long-term outcomes of autologous haematopoietic-cell transplantation (HCT) for advanced Hodgkin (HL) and non-Hodgkin lymphoma (NHL). The study included recipients of autologous HCT for HL (N = 407) and NHL (N = 960) from 1990-98 who were in continuous complete remission for at least 2 years post-HCT. Median follow-up was 104 months for HL and 107 months for NHL. Overall survival at 10-years was 77% (72-82%) for HL, 78% (73-82%) for diffuse large-cell NHL, 77% (71-83%) for follicular NHL, 85% (75-93%) for lymphoblastic/Burkitt NHL, 52% (37-67%) for mantle-cell NHL and 77% (67-85%) for other NHL. On multivariate analysis, mantle-cell NHL had the highest relative-risk for late mortality [2.87 (1.70-4.87)], while the risks of death for other histologies were comparable. Relapse was the most common cause of death. Relative mortality compared to age, race and gender adjusted normal population remained significantly elevated and was 14.8 (6.3-23.3) for HL and 5.9 (3.6-8.2) for NHL at 10-years post-HCT. Recipients of autologous HCT for HL and NHL who remain in remission for at least 2-years have favourable subsequent long-term survival but remain at risk for late relapse. Compared to the general population, mortality rates continue to remain elevated at 10-years post-transplantation.

Controversies in lymphoma: the role of hematopoietic cell transplantation for mantle cell lymphoma and peripheral T cell lymphoma

Mantle cell lymphoma (MCL) and peripheral T cell lymphoma (PTCL) are distinct lymphoma subtypes that each comprise about approximately 10% of the non-Hodgkin lymphomas. Although both subtypes are characterized by high remission rates to frontline chemotherapy, the prognosis is generally poor because of inevitable relapse within 1-2 years or less, depending on the specific histology. Patients with MCL who achieve a complete remission with upfront conventional chemotherapy currently have several options for consolidative therapy including maintenance therapy with rituximab, autologous hematopoietic cell transplantation (HCT), and more recently, allogeneic HCT utilizing a reduced intensity conditioning (RIC) regimen. In the autologous HCT setting, the added efficacy of rituximab is under active investigation as a method of in vivo purging during hematopoietic cell mobilization, as part of the conditioning regimen and as post-HCT maintenance therapy. For patients with PTCL, autologous HCT is commonly offered at relapse but there are a few prospective series utilizing autologous HCT as consolidation of CR1 with encouraging results. There is no conclusive evidence regarding the efficacy of allogeneic HCT, but outcomes with RIC regimens appear promising. This review summarizes the current role of HCT for patients with MCL in first remission and for patients with PTCL as consolidation and for relapsed/refractory disease.

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.

Mantle cell lymphoma: advances in biology and therapy

PURPOSE OF REVIEW

Mantle cell lymphoma is characterized by dysregulation of cyclin D1, but this is not sufficient for lymphoma development. It is a difficult disease to treat, being incurable with standard chemotherapy and having a median survival of approximately 5 years. The purpose of this review is to update recent advances in mantle cell lymphoma biology with prognostic and potentially therapeutic implications, and mantle cell lymphoma treatment approaches and new agents.

RECENT FINDINGS

Genetic alterations that cooperate with cyclin D1 have been described that alter proliferation, in particular p27Kip and p16INK4, or apoptosis. Biological factors such as high-proliferation signature defined by gene expression profiles, loss of p27 and presence of mutant p53 confer poor prognosis. Proliferative rate also predicts patient outcome. Clinical criteria such as the international prognostic index, follicular lymphoma international prognostic index or a formula using age, performance status, white blood cell count and lactate dehydrogenase, separate prognostic groups. Not all patients require therapy at diagnosis. Although the best reported results have been with rituximab-hyperfractionated cyclophosphamide-vincristine-doxorubicin-dexamethasone-methotrexate/cytarabine, a cooperative group study of this regimen appears not quite as successful. Consolidation of remission after rituximab-cyclophosphamide-doxorubicin-vincristine-prednisone with high-dose therapy/stem-cell support prolongs remission and consolidation with radioimmunotherapy shows promise. Intensifying induction by alternating intensified rituximab-cyclophosphamide-doxorubicin-vincristine-prednisone with rituximab and high-dose cytarabine, followed by high-dose therapy appears quite promising. Novel agents active in relapsed disease include bortezomib, mammalian target of rapamycin inhibitors, immunomodulatory agents, antibodies and cyclin pathway-directed agents such as flavopiridol and cyclin-dependent kinase inhibitors.

SUMMARY

New insights into mantle cell lymphoma biology may lead to targeted therapy. Meanwhile, combinations of existing therapeutic approaches seem to have improved outcomes.

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.

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.

Prevention of Mantle Lymphoma Tumor Establishment by Routing Transferrin Receptor toward Lysosomal Compartments

Mantle cell lymphoma (MCL) is one of the most frequent of the newly recognized non-Hodgkin's lymphomas. The major problem of MCL therapy is the occurrence of relapse and subsequent resistance to chemotherapy and immunotherapy in virtually all cases. Here, we show that one injection of anti-human transferrin receptor (TfR) monoclonal antibody A24 totally prevented xenografted MCL tumor establishment in nude mice. It also delayed and inhibited tumor progression of established tumors, prolonging mice survival. In vitro, A24 induced up to 85% reduction of MCL cell proliferation (IC(50) = 3.75 nmol/L) independently of antibody aggregation, complement-dependent or antibody-dependent cell-mediated cytotoxicity. A24 induced MCL cell apoptosis through caspase-3 and caspase-9 activation, either alone or synergistically with chemotherapeutic agents. A24 induced TfR endocytosis via the clathrin adaptor protein-2 complex pathway followed by transport to lysosomal compartments. Therefore, A24-based therapies alone or in association with classic chemotherapies could provide a new alternative strategy against MCL, particularly in relapsing cases.