Allogeneic hematopoietic transplantation for mantle-cell lymphoma: molecular remissions and evidence of graft-versus-malignancy

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.

Reduced-intensity or myeloablative allogeneic hematopoietic cell transplantation for mantle cell lymphoma: a systematic review

Allogeneic hematopoietic cell transplantation (allo-HCT) is the only known treatment that can offer a cure in mantle cell lymphoma, but it is unclear if regimen dose-intensity offers any advantage. We performed a systematic review/meta-analysis to assess efficacy of allo-HCT using myeloablative or reduced-intensity conditioning. We report results according to the Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines. On the basis of a relatively lower nonrelapse mortality and a slightly better progression-free survival/event-free survival and overall survival rates, reduced-intensity allo-HCT regimens appear to be the preferred choice when an allo-HCT is being considered for mantle cell lymphoma. The higher rate of relapse when offering reduced-intensity regimens cannot be ignored but certainly highlights opportunities to incorporate post-transplant strategies to mitigate this risk. A prospective comparative study is ultimately needed to generate more conclusive evidence.

Mantle cell lymphoma: biology, clinical presentation, and therapeutic approaches

Mantle cell lymphoma is molecularly characterized by the chromosomal translocation t(11;14) (q13;q32) that results in a constitutional overexpression of the cell cycle regulator protein cyclin D1. Generally, the disease is characterized by rapid relapses and poor long-term outcome. However, a subset of patients with indolent disease has been identified. Randomized trials have demonstrated the superiority of dose intensified, cytarabine-containing induction with or without autologous stem cell transplantation in younger patients. In elderly patients, a rituximab-based maintenance has significantly prolonged progression-free and overall survival after treatment with rituximab, cyclophosphamide, doxorubicin hydrochloride, vincristine, and prednisone (R-CHOP). Unfortunately, the vast majority of patients will eventually relapse. Numerous molecular targeting strategies (bortezomib, lenalidomide, temsirolimus, and especially inhibitors of the B-cell receptor pathway) have achieved high response rates in phase II studies and should be strongly considered in relapsed disease.

Long-term sustained disease control in patients with mantle cell lymphoma with or without active disease after treatment with allogeneic hematopoietic cell transplantation after nonmyeloablative conditioning

BACKGROUND

Previously, early results were reported for allogeneic hematopoietic cell transplantation (HCT) after nonmyeloablative conditioning with 2 Gy of total body irradiation with or without fludarabine and/or rituximab in 33 patients with mantle cell lymphoma (MCL).

METHODS

This study examined the outcomes of 70 patients with MCL and included extended follow-up (median, 10 years) for the 33 initial patients. Grafts were obtained from human leukocyte antigen (HLA)-matched, related donors (47%), unrelated donors (41%), and HLA antigen-mismatched donors (11%).

RESULTS

The 5-year incidence of nonrelapse mortality was 28%. The relapse rate was 26%. The 5-year rates of overall survival (OS) and progression-free survival (PFS) were 55% and 46%, respectively. The 10-year rates of OS and PFS were 44% and 41%, respectively. Eighty percent of surviving patients were off immunosuppression at the last follow-up. The presence of relapsed or refractory disease at the time of HCT predicted a higher rate of relapse (hazard ratio [HR], 2.94; P = .05). Despite this, OS rates at 5 (51% vs 58%) and 10 years (43% vs 45%) were comparable between those with relapsed/refractory disease and those undergoing transplantation with partial or complete remission. A high-risk cytomegalovirus (CMV) status was the only independent predictor of worse OS (HR, 2.32; P = .02). A high-risk CMV status and a low CD3 dose predicted PFS (HR, 2.22; P = .03).

CONCLUSIONS

Nonmyeloablative allogeneic HCT provides a long-term survival benefit for patients with relapsed MCL, including those with refractory disease or multiple relapses.

Non-myeloablative allogeneic hematopoietic stem cell transplantation for adults with relapsed and refractory mantle cell lymphoma: a single-center analysis in the rituximab era

Relapsed and refractory (rel/ref) mantle cell lymphoma (MCL) portends a dismal prognosis. Allogeneic hematopoietic stem cell transplantation (allo-HSCT) represents the only potentially curative therapy in this setting. We analyzed survival outcomes of 29 recipients of non-myeloablative allo-HSCT for rel/ref MCL, and studied possible prognostic factors in this setting. The cumulative incidence of disease progression and non-relapse mortality at 3 years were 28% (95% confidence interval [CI]: 13-46%) and 29% (95%CI: 13-47%), respectively. The cumulative incidence of grade II-IV acute graft-versus-host disease (GVHD) at days +100 and +180 were 34% (95%CI: 18-52%) and 45% (95%CI: 26-62%), respectively. With a median follow-up in survivors of 53 (range 24-83) months, the 3-year overall survival (OS) and progression-free survival (PFS) were 54% (95%CI: 38-76%) and 41% (95%CI: 26-64%), respectively. In vivo T-cell depletion with alemtuzumab (n=6) was associated with inferior 3-year PFS (0% vs. 51%, p=0.007) and OS (17% vs. 64%, p=0.014). Conversely, a second line international prognostic index (sIPI) at transplantation equal to 0 (no risk factors) was associated with an improved 3-year PFS (52% vs. 22%, p=0.020) and OS (71% vs. 22%, p=0.006) compared to sIPI ≥1. Performing an allo-HSCT before 2007 was associated with a decreased 3-year OS (25% vs. 76%, p=0.015) but not with a significantly inferior PFS (17% vs. 59%, p=0.058). In this single center series, we report encouraging results with allo-HSCT for patients with rel/ref MCL. High alemtuzumab doses should probably be avoided in this context.

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.

Long-Term Results of Fludarabine/Melphalan as a Reduced-Intensity Conditioning Regimen in Mantle Cell Lymphoma: The GELTAMO Experience

BACKGROUND

We herein report the long-term results of an allogeneic reduced-intensity conditioning (allo-RIC) protocol used in 21 consecutive patients (16 males, median age 56 years, 71% in complete remission) diagnosed with mantle cell lymphoma (MCL).

METHODS

The allo-RIC consisted of fludarabine plus melphalan and peripheral blood hematopoietic stem cells (PBSCs) from human leukocyte antigen (HLA)-identical siblings were used in all cases. Median CD34+ infused cells was 5.8 times 10(6)/kg. All patients engrafted promptly.

RESULTS

Early toxicity included mild/moderate mucositis (43%), febrile neutropenia (33%) and bacterial infections (19%). With a median follow up of 48 months, four deaths were reported, all due to infections and/or graft-versus-host disease (GVHD), yielding a 3-year cumulative incidence of nonrelapse mortality of 19.5%. Grade III-IV acute GVHD occurred in 15% and chronic GVHD in 78%, being extensive in 39%. The 5-year progression-free survival (PFS) and overall survival (OS) were both 80% (95% CI: 63-97%). Age was the only possible prognostic factor for OS, which was 43% for those aged more than 60 years and 100% for those younger (p < 0.001).

CONCLUSIONS

Our data confirm that allo-RIC offers a low toxicity profile and a chance for prolonged long-term disease-free survival in MCL, particularly in younger patients.

ESMO Consensus conferences: guidelines on malignant lymphoma. part 2: marginal zone lymphoma, mantle cell lymphoma, peripheral T-cell lymphoma

To complement the existing treatment guidelines for all tumour types, ESMO organizes consensus conferences to focus on specific issues in each type of tumour. In this setting, a consensus conference on the management of lymphoma was held on 18 June 2011 in Lugano, next to the 11th International Conference on Malignant Lymphoma. The conference convened ∼30 experts from all around Europe, and selected six lymphoma entities to be addressed; for each of them, three to five open questions were to be addressed by the experts. For each question, a recommendation should be given by the panel, referring to the strength of the recommendation based on the level of evidence. This consensus report focuses on the three less common lymphoproliferative malignancies: marginal zone lymphoma, mantle cell lymphoma, and peripheral T-cell lymphomas. A first report had focused on diffuse large B-cell lymphoma, follicular lymphoma, and chronic lymphocytic leukaemia.

Allogeneic hematopoietic cell transplantation in mantle cell lymphoma

Mantle cell lymphoma (MCL) is a high-risk non-Hodgkin lymphoma that is considered incurable with standard chemotherapy. While autologous hematopoietic cell transplantation (autoHCT) can provide lengthy disease-free survival in select patients, cure generally is not an expected outcome with this approach. Allogeneic hematopoietic cell transplantation (alloHCT), which can exploit the potential benefits of graft-versus-lymphoma (GVL) effect, has been shown in multiple studies to yield a small but reproducible portion of patients with long-term remission more suggestive of cure. Historically, alloHCT for MCL was administered after myeloablative conditioning, but this approach was limited by early non-relapse mortality. Development of reduced-intensity (RI)-alloHCT has abrogated some of the early post-transplant risks, allowing this potentially effective therapy to be offered to a larger number of affected individuals. The trends in published data reflect a preference toward using RI-alloHCT for MCL, often because patients in whom alloHCT is being considered have relapsed disease following myeloablative autoHCT. Further efforts to spare the effects of graft-versus-host disease (GVHD) while still evoking GVL remain a focus of investigation in this area. In this review, we will discuss the application of alloHCT in the management of MCL, the factors associated with outcome, the different methods in which it can be performed, and the strategies that can be employed in post-alloHCT relapse.

Minimal residual disease detection in mantle cell lymphoma: technical aspects and clinical relevance

The prognostic impact of minimal residual disease (MRD) has been demonstrated for several hematologic malignancies. While in acute lymphoblastic leukemias MRD assessment by polymerase chain reaction (PCR)-based methods has been established as an important tool for clinical risk assessment and is part of clinical management, data demonstrating a prognostic value of MRD in mantle cell lymphoma (MCL) were sparse and results from randomized trials have been published only recently. In the present review technical aspects of different MRD detection methods are discussed, as well as the prognostic relevance of MRD in the context of clinical trials in patients with MCL. Furthermore, recommendations are given for workflow and useful implication of MRD in future clinical trials design.

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.

Tackling mantle cell lymphoma (MCL): Potential benefit of allogeneic stem cell transplantation

Mantle cell lymphoma (MCL) is a type of non-Hodgkins lymphoma (NHL) associated with poor progression-free and overall survival. There is a high relapse rate with conventional cytotoxic chemotherapy. Intensive combination chemotherapy including rituximab, dose intense CHOP- (cyclophosphamide-doxorubicin-vincristine-prednisone) like regimens, high dose cytarabine, and/or consolidation with autologous stem cell transplant (autoSCT) have shown promise in significantly prolonging remissions. Data from phase II studies show that even in patients with chemotherapy refractory MCL, allogeneic stem cell transplant (alloSCT) can lead to long term disease control. Most patients with MCL are not candidates for myeloablative alloSCT due to their age, comorbidities, and performance status. The advent of less toxic reduced intensity conditioning (RIC) regimens, which rely more on the graft-versus-lymphoma (GVL) effect, have expanded the population of patients who would be eligible for alloSCT. RIC regimens alter the balance of toxicity and efficacy favoring its use. Treatment decisions are complicated by introduction of novel agents which are attractive options for older, frail patients. Further studies are needed to determine the role and timing of alloSCT in MCL. Currently, for selected fit patients with chemotherapy resistant MCL or those who progress after autoSCT, alloSCT may provide long term survival.

Lymphoma immunotherapy: vaccines, adoptive cell transfer and immunotransplant

Therapy for non-Hodgkin lymphoma has benefited greatly from basic science and clinical research such that chemotherapy and monoclonal antibody therapy have changed some lymphoma subtypes from uniformly lethal to curable, but the majority of lymphoma patients remain incurable. Novel therapies with less toxicity and more specific targeting of tumor cells are needed and immunotherapy is among the most promising of these. Recently completed randomized trials of idiotype vaccines and earlier-phase trials of other vaccine types have shown the ability to induce antitumor T cells and some clinical responses. More recently, trials of adoptive transfer of antitumor T cells have demonstrated techniques to increase the persistence and antitumor effect of these cells. Herein, we discuss lymphoma immunotherapy clinical trial results and what lessons can be taken to improve their effect, including the combination of vaccination and adoptive transfer in an approach we have dubbed 'immunotransplant'.

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.

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.

Diagnosis and treatment of acquired aplastic anemia

Acquired severe aplastic anemia can be treated successfully with either immunosuppressive therapy or bone marrow transplantation. Although immunosuppressive therapy can be readily administered to all patients, it is not a curative approach and is associated with a higher risk of clonal evolution than is transplantation, which yields rapid and long-lasting hematologic remission. This article reviews the key diagnostic and prognostic factors that influence the choice of therapy in patients with acquired aplastic anemia.

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.

Allogeneic hematopoietic cell transplantation for metastatic breast cancer

We reviewed 66 women with poor-risk metastatic breast cancer from 15 centers to describe the efficacy of allogeneic hematopoietic cell transplantation (HCT). Median follow-up for survivors was 40 months (range, 3-64). A total of 39 patients (59%) received myeloablative and 27 (41%) reduced-intensity conditioning (RIC) regimens. More patients in the RIC group had poor pretransplant performance status (63 vs 26%, P=0.002). RIC group developed less chronic GVHD (8 vs 36% at 1 year, P=0.003). Treatment-related mortality rates were lower with RIC (7 vs 29% at 100 days, P=0.03). A total of 9 of 33 patients (27%) who underwent immune manipulation for persistent or progressive disease had disease control, suggesting a graft-vs-tumor (GVT) effect. Progression-free survival (PFS) at 1 year was 23% with myeloablative conditioning and 8% with RIC (P=0.09). Women who developed acute GVHD after an RIC regimen had lower risks of relapse or progression than those who did not (relative risk, 3.05: P=0.03), consistent with a GVT effect, but this did not affect PFS. These findings support the need for preclinical and clinical studies that facilitate targeted adoptive immunotherapy for breast cancer to explore the benefit of a GVT effect in breast cancer.

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.

Morphologic examination of sequential bone marrow biopsies after nonmyeloablative stem cell transplantation complements molecular studies of donor engraftment

CONTEXT

Nonmyeloablative stem cell transplantation (NMSCT) is a mode of immunotherapy increasingly employed in treating hematologic, lymphoid, and solid tumors. Patients are monitored principally by molecular analysis of donor engraftment.

OBJECTIVE

To determine the role of morphologic examination of bone marrow after NMSCT.

DESIGN

Seventy-three patients undergoing NMSCT under the Campath 1H (humanized anti-CD52 antibody) protocol were studied. Pretransplant and sequential posttransplant bone marrow specimens were evaluated and the findings were correlated with corresponding engraftment data.

RESULTS

Pretransplant bone marrow specimens from 43% of the patients were involved by disease, and these marrow specimens were significantly more cellular than those that were free of disease. Morphologically detectable disease was still present in day 14 posttransplant marrow specimens in more than one half of these patients, but there was no difference in engraftment in those with or without marrow disease. Early posttransplant marrow in nearly one half of the patients showed myeloid hyperplasia and atypical localization of immature myeloid precursors. Marrow cellularity for the first 2 months after NMSCT was significantly lower in those patients receiving stem cells mismatched at 1 to 3 loci as compared with those who received fully matched grafts (mean cellularity, 38.1% vs 54.1% at day 14). Marrow failure without recurrent disease at 3 to 6 months after transplant was detected by engraftment study in only approximately 15% of cases. Similarly, early recurrence of disease was detected first by morphologic examination in 4 of 13 cases before a decline in donor engraftment occurred.

CONCLUSION

Morphologic examination of bone marrow provides additional information that is complementary to donor engraftment analysis for optimal management after NMSCT.

Reduced-intensity transplantation for lymphoma

Non-myeloablative stem cell transplantation was clinically introduced nearly a decade ago to circumvent the need for intensive preparative transplant regimens and instead rely on graft-versus-malignancy effects to eradicate disease. The general concept is to provide a sufficiently immunosuppressive and moderately myelosuppressive treatment regimen to allow donor and host hematopoietic coexistence, or chimerism. Because not all regimens are truly "non-myeloablative," a more appropriate term is reduced-intensity transplantation (RIT), which is used throughout this review. The most popular regimens incorporate a purine analog (such as fludarabine) and an alkylating agent (such as cyclophosphamide or melphalan), with or without low-dose total body irradiation. The addition of T-cell-depleting monoclonal antibodies, such as alemtuzumab, appears to reduce the incidence of acute graft-versus-host disease. For non-Hodgkin's lymphomas, the precise role of RIT continues to be defined. There are many questions regarding the optimal population and the timing of the modality. There is ample support that graft-versus-lymphoma (GVL) is a true phenomenon, but the specific contribution of GVL to outcomes after RIT is still in question, and some subtypes appear more susceptible to GVL than others. Clearly, the procurement of an uncontaminated graft plays a role. Supportive care remains a critical component of management because the reduced-intensity regimens do not completely abrogate the risk of serious infection and many do not appear to decrease the incidence of chronic graft-versus-host disease. Thus, transplant-related morbidity and mortality and graft-versus-host disease remain major obstacles, and future efforts should focus on minimizing risks and more clearly identifying patient-specific and disease-specific predictors of outcome.

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.

Efficacy of high-dose therapy and hematopoietic stem cell transplantation for mantle cell lymphoma

Conventional treatment of mantle cell lymphoma (MCL) yields modest responses and short remissions. We report 30 hematopoietic stem cell transplants (HSCT) for MCL: 13 autologous, 10 allogeneic myeloablative, and 7 nonablative. After a median 1.2 years from diagnosis (range 0.5 to 4.7) and a median of 2 pre-HSCT chemotherapeutic regimens (range 1 to 5), their median age at HSCT was 52 years (range 37 to 67). Eleven patients (41%) were in first remission, 11 (41%) were in second remission, and 7 (25%) had resistant disease. Four died early. Nineteen achieved CR (83%) and 4 PR (17%). With median 2.7 years of follow-up, 5-year overall survival (OS) was 42% (95% CI 11-73%) after autologous versus allogeneic at 49% (95% CI 22-76%). Five-year progression-free survival (PFS) was 31% (95% CI 3-59%) and 50% (95% CI 24-76%) for autologous and allogeneic HSCT, respectively. Fourteen died: 3 from sepsis, 1 acute GVHD, 10 MCL. No autologous transplant-related deaths occurred. Allogeneic transplant-related mortality was 29% (95% CI 6-52%) at 1 and 5 years. HSCT for MCL can yield extended disease control and long-term survival.

Stem cell transplantation for mantle cell lymphoma: if, when and how?

Although the prognosis for mantle cell lymphoma (MCL) patients has improved in recent years, the outlook for those with advanced or recurrent disease remains poor. High-dose chemotherapy and autografting performed early in responding patients appears to be a method to extend progression-free survival (PFS) and overall survival (OS). The use of monoclonal antibody therapy added into the initial therapy and in the peritransplant period may improve on these results. Myeloablative allogeneic transplant appears to be a modality capable of providing curative therapy, but is plagued by a high treatment-related mortality, especially in older patients. Reduced-intensity conditioning allografting have fewer problems associated with the initial phase of transplant and hence may be preferred for those patients for whom an allograft is considered but have comorbid conditions or age issues that preclude a full allograft. Long-term results are lacking and the side effects associated with chronic GVHD may be as significant and debilitating. Trials designed to look at newly diagnosed patients with MCL examining the outcomes after planned autologous and allogeneic transplant as part of the initial management are needed to confirm the role of these various modalities in the overall therapy of this poor-outcome lymphoma.

Detection and monitoring of minimal residual disease by quantitative real-time PCR

BACKGROUND

The detection of malignant cells by quantitative real-time PCR has become state of the art for diagnosis, monitoring response to treatment and detection of minimal residual disease (MRD) in patients with leukemia or lymphoma. In order to be used in high-throughput analyses technical details have to be standardized to improve reproducibility and comparability of quantitative results obtained in different laboratories.

METHODS

Molecular monitoring of disease activity during and after treatment based on the detection of malignant cells in circulation or bone marrow by quantitative real-time PCR will be helpful to develop individualized treatment strategies for every patient.

CONCLUSIONS

The effectiveness of any kind of innovative treatment with specific antibodies, cellular immunotherapy or molecules designed for specific targets of tumor cells can be controlled at a very high level of sensitivity and accuracy. Based on quantitative results indicative for success or treatment failure, therapeutic changes upon the detection of progressive disease at the molecular level can be made even before symptoms or signs of clinical relapse occur. Hopefully, this will lead to higher cure rates and improved long-term survival.

Complete and durable remission of refractory mantle cell lymphoma with repeated rituximab monotherapy

We encountered a 53-year-old man with general fatigue. Bone marrow investigations revealed an infiltration of CD20+CD5+CD23- cells and the presence of cyclin D1 lymphoid cells, leading to a diagnosis of mantle cell lymphoma, clinical stage IV. The first 2 lines of chemotherapy, CyclOBEAP (cyclophosphamide, vincristine, bleomycin, etoposide, doxorubicin, and prednisolone) and fludarabine-cyclophosphamide, produced only a transient decrease in serum lactic dehydrogenase levels, without a clinical remission. Because of the persistence of bone marrow hypoplasia, monotherapy with 375 mg/m2 rituximab was administered. The pancytopenia gradually improved, and a complete remission was obtained after 4 cycles of rituximab. The patient remains in complete remission 21 months after the third rituximab therapy for maintenance.

Primary Allogeneic T-Cell Responses against Mantle Cell Lymphoma Antigen-Presenting Cells for Adoptive Immunotherapy after Stem Cell Transplantation

PURPOSE

In patients treated with allogeneic stem cell transplantation for advanced mantle cell lymphoma (MCL), complete sustained remissions have been observed illustrating susceptibility of MCL cells to a graft-versus-lymphoma effect. To potentiate this graft-versus-lymphoma effect, adoptive transfer of in vitro selected MCL-specific CTL can be an attractive approach. The lack of expression of costimulatory molecules on MCL cells hampers the generation of MCL-reactive T-cell responses. The purpose of this study was to modify MCL cells into antigen-presenting cells (APC) and to use these MCL-APCs to induce allogeneic MCL-reactive T-cell responses.

EXPERIMENTAL DESIGN

Interleukin (IL)-4, IL-10, CpG, and CD40 activation were tested for their capacity to up-regulate costimulatory molecules on MCL cells. Primary MCL cells or the modified MCL-APCs were then used to evaluate the induction of MCL-reactive T-cell responses in HLA-matched donors.

RESULTS

Ligation of CD40 on MCL cells was essential to up-regulate costimulatory molecules and to induce production of high amounts of IL-12. In contrast to primary MCL cells, MCL-APC cells as stimulators were capable of inducing CD8+ CTL lines from HLA class I-matched donors. High numbers of CTL clones could be generated capable of efficiently killing the primary MCL cells and MCL-APC but not donor-specific targets.

CONCLUSION

These results show the feasibility to generate primary allogeneic T-cell responses against MCL-APC, and may provide new immunotherapeutic tools to further exploit the graft-versus-lymphoma effect following allogeneic stem cell transplantation in patients with MCL.

Control of advanced and refractory acute myelogenous leukaemia with sirolimus-based non-myeloablative allogeneic stem cell transplantation

Non-myeloablative conditioning has extended the use of allogeneic haematopoietic transplant to many previously ineligible patients. We added the immunosuppressive and antitumour agent sirolimus (rapamycin) to an established transplant regimen of fludarabine 25 mg/m(2) days -7 through -3 and cyclophosphamide 1000 mg/m(2) days -7 and -6, with tacrolimus and methotrexate immunoprophyllaxis. A total of 23 patients with acute myelogenous leukaemia (AML) were treated, with a median age of 59 years (range: 28-72) at transplant. Only seven patients in total were in complete remission prior to transplantation. Nine patients were in chemotherapy-refractory progression and seven were primarily refractory to induction therapy. Six patients received matched sibling, 11 unrelated donor, 1-5/6 matched and five haploidentical (haplo - three of six or four of six matched) transplants. The haplo-recipients also received antithymocyte globulin, all patients engrafted. Only two, both recipients of haploidentical cells, have died from transplant-related causes. Twelve of 23 patients survived at 198-1162-d post-transplant (median 578). Four of 12 survivors relapsed at 83, 88, 243 and 508 d and three were in remission after chemotherapy and donor lymphocyte infusion. Although follow up is short, this data suggests that non-myeloablative haematopoietic cell transplantation with sirolimus (rapamycin)-based immunosuppression may provide disease control over several years in some patients with advanced and poor prognosis AML.

Outcomes of autologous and allogeneic blood or marrow transplantation for mantle cell lymphoma

To evaluate high-dose therapy and autologous or allogeneic blood or marrow transplantation (BMT) for mantle cell lymphoma, patients receiving BMT for newly diagnosed or relapsed mantle cell lymphoma were identified through the registry at Johns Hopkins. The pathologic diagnostic criteria were reviewed, and details of the presentation, transplant procedure, and survival outcomes were determined. Fifty-eight patients were identified, of whom 64% underwent transplantation in first remission and 12% had primary induction failure. Nineteen patients (one third) received an allograft. Preparative regimens consisted of cyclophosphamide in combination with either busulfan or total body irradiation. On multiple regression analysis, transplantation after 1 or more relapses (hazard ratio, 2.98; P = .02), primary induction failure (hazard ratio, 5.39; P = .002), and allogeneic transplantation (hazard ratio, 3.03; P = .007) were associated with an inferior event-free survival (EFS). However, EFS curves were not statistically different for autologous and allogeneic BMT performed in first remission, with an estimated 3-year EFS approaching or equaling 70%. Primary induction failure and residual bone marrow involvement were the only statistically significant predictors of relapse on multiple regression analysis. At 3 years, the estimated EFS for the entire cohort after BMT was 51%, the probability of relapse was 31%, and the overall survival was 59%. The benefit of autologous or allogeneic BMT for mantle cell lymphoma is thus most apparent when transplantation is performed in first remission. Whether allogeneic BMT ultimately confers an advantage because of a graft-versus-lymphoma effect remains to be determined.

Hematopoietic stem cell transplantation in mantle cell lymphoma

BACKGROUND

Patients with mantle cell lymphoma (MCL) have in general, lower response rates and overall survival (OS) than those with other B-cell non-Hodgkin's lymphomas. The role of hematopoietic stem cell transplantation (HSCT) in MCL is unclear. Hence we decided to study the clinical course of patients who received autologous and allogeneic HSCT for MCL.

METHODS

Ninety-seven patients, (80 patients-autologous; 17 patients-allogeneic) who received a HSCT for mantle cell lymphoma were included in the study.

RESULTS

The complete response rates at day 100 between the two groups were similar (73% vs. 62%). Day-100 mortality was higher in the allogeneic HSCT group (19% vs. 0%) (P < 0.01). The estimated 5-year relapse rates, 5-year event-free survival (EFS) and 5-year OS among the allogeneic HSCT patients were 21%, 44% and 49%, respectively, similar to 56%, 39% and 47% in the autologous group. Ten patients received HyperCVAD (hyperfractionated cyclophosphamide, vincristine, doxorubicin and dexamethasone + high-dose methotrexate and cytarabine) +/- rituximab prior to transplant. There have been no relapses or deaths amongst these patients at a median follow-up of 16 months.

CONCLUSIONS

Patients treated with allogeneic HSCT had a lower relapse rate, but similar EFS and OS to autologous HSCT. Treatment of MCL with HyperCVAD +/- rituximab followed by HSCT seems promising.

Blastoid variant of mantle cell lymphoma: late progression from classical mantle cell lymphoma and quantitation of minimal residual disease

OBJECTIVES

Classical mantle cell lymphoma (MCL) and its blastoid variant (MCL-BV) are characterized by an extremely poor prognosis. Long-time survivors are rare, only very few patients with an overall survival over 10 years have been reported. We present a case of a 41-year-old male with a 12 yr history of MCL stage I to show, that very late relapses in MCL are possible and may present as a transformation into an aggressive blastoid variant and to illustrate the value of quantitative minimal residual disease (MRD) monitoring for treatment guidance.

METHODS

Diagnostic lymph node and bone marrow samples were investigated by immunohistochemistry. Clonality analysis was performed by immunoglobulin heavy chain gene (IGVH) and t(11;14) PCR. The MRD assessment was done by real-time quantitative PCR (RQ-PCR) on available follow-up samples.

RESULTS

By histologic review and sequencing of the clonal IGVH and t(11;14) PCR products we demonstrated a common clonal origin of the leucemic MCL-BV and the classical MCL diagnosed 12 yr earlier. Quantitative MRD assessment revealed significant MRD levels after intensive conventional chemotherapy including Rituximab. Therefore, treatment was early intensified by myeloablative radio-chemotherapy and allogeneic peripheral stem cell transplantation from an unrelated HLA-identical donor. This did not translate into a sustained remission as reflected by persisting MRD levels after transplantation and the patient died from rapid progressive disease 3.5 months after transplant.

CONCLUSION

This report presents a rare case of long-term survivor of MCL with a progression of the original MCL cell clone to MCL-BV and demonstrates the clinical value of quantitative MRD assessment for optimized therapeutic management.

The role of allogeneic transplantation in non-Hodgkin's lymphoma

The evolution of combination chemotherapy regimens, combined with improvements in supportive care, has incrementally improved survival outcomes for patients with non-Hodgkin's lymphomas (NHL). Although 40-60% of younger patients with diffuse large cell lymphoma can now expect to be cured, significant numbers will either fail to achieve a remission or relapse after attaining a remission. In addition, certain histological subtypes are associated with particularly poor prognoses with combination chemotherapy alone (e.g. mantle cell lymphoma, B-cell prolymphocytic leukaemia). Relatively few of these patients can achieve long-term responses. Other NHL subtypes, whilst associated with more favourable prognoses in terms of overall survival, are rarely, if ever, cured (e.g. most low grade NHL including follicular lymphoma, chronic lymphocytic leukaemia and small lymphocytic lymphoma). For these reasons dose escalation and allogeneic transplantation have been investigated as potential ways of improving outcome, although this has mainly been in the setting of advanced disease. Any possible benefits have frequently been out-weighed by procedural morbidity and mortality. The parallel development of transplantation approaches that limit procedural toxicity along with advances in supportive care require that the role of allogeneic haematopoietic stem cell transplantation in the management of lymphoma be re-evaluated.

Graft-versus-lymphoma effects: clinical review, policy proposals, and immunobiology

The indubitable existence of a graft-versus-lymphoma (GVL) effect is difficult to prove directly. This article reviews the difficulties in interpreting the current literature in this field and, with a number of caveats, argues for the existence of a clinically meaningful GVL effect in follicular, mantle cell, small lymphocytic, and Hodgkin lymphomas. The evidence, however, for a potent GVL effect in diffuse large-cell lymphoma and Burkitt lymphoma is not convincing. Policies for allografting in lymphoma are proposed on the basis of this evidence. The immunobiology of GVL effects is discussed--in particular, the expression of HLA class I and II and co-stimulatory molecules on lymphomas that influence the generation of alloreactive T cells--together with future directions in immunotherapy that may help to eradicate chemoresistant disease.

Target Antigens Determine Graft-versus-Host Disease Phenotype

Chronic graft-vs-host disease (cGVHD) is an increasingly frequent complication of allogeneic stem cell transplantation. Phenotypically, cGVHD differs from patient to patient; in particular, a subset of patients develops extensive cutaneous fibrosis. Similarly, graft-vs-host disease (GVHD) is distinct in inbred murine donor:recipient pairings, indicating a genetic component to disease phenotype. The B10.D2 -->BALB/c (H-2d) strain pairing uniquely recapitulates key pathologic features of fibrotic human cutaneous cGVHD. To distinguish whether this genetic component is due to differences in genes that modulate immune responses or to the specific Ags targeted, we asked whether skin-dominant cGVHD also develops in the B10 -->BALB.B (H-2b) and B10.BR -->BALB.K (H-2k) MHC-congenic pairings. Because each MHC haplotype presents different peptides and selects different T cell repertoires, GVHD in each donor:recipient pair undoubtedly targets different Ags. We found that, in contrast to BALB/c recipients, BALB.B mice never manifested skin disease while BALB.K mice developed a modified form of skin disease. Instead, BALB.B and BALB.K recipients developed systemic GVHD which was absent in BALB/c mice. Moreover, in (B10 x B10.D2)F1 -->(BALB.B x BALB/c)F1 H-2b/d transplants, recipients developed both cutaneous and systemic disease. Thus, the selection of immunodominant Ags determines the target and character of GVHD, providing insight into the genetic basis for different forms of GVHD.

Allogeneic Hematopoietic Stem Cell Transplantation for Lymphoma

For patients with relapsed or refractory Hodgkin's or non-Hodgkin's lymphomas, allogeneic hematopoietic stem cell transplantation (HSCT) is a treatment option when autologous HSCT fails to achieve durable remission or is deemed inappropriate. Allogeneic HSCT can result in long-term survival even in patients with refractory lymphomas. The efficacy of allogeneic HSCT is attributed, at least in part, to an immune-mediated graft-versus-lymphoma (GVL) effect that can also be associated with significant toxicity resulting from graft-versus-host disease. However, clinical evidence of a potent GVL effect is inconsistent. Reduced-intensity conditioning before allogeneic HSCT can facilitate the use of this treatment in older patients and those at high risk. The decrease in toxicity with reduced-intensity regimens may be associated with a loss of antitumor effects. Patients with lymphoma should be selected for allogeneic HSCT on the basis of characteristics that strongly influence transplant outcomes, including histology, chemosensitivity, and donor source.

An update on the role of high-dose therapy with autologous or allogeneic stem cell transplantation in mantle cell lymphoma

PURPOSE OF REVIEW

Early trials of high-dose therapy with autologous stem cell transplantation in mantle cell lymphoma were discouraging, with no clear survival advantage attributable to the procedure. Most early series were plagued by small numbers, retrospective designs, and short follow-up. Also, until recently, allogeneic stem cell transplantation was not an option for most mantle cell lymphoma patients who were too old or infirm to tolerate standard conditioning regimens.

RECENT FINDINGS

New advances in allogeneic transplantation, particularly reduced-intensity conditioning regimens, have increased the availability of this procedure to patients with mantle cell lymphoma. New evidence has emerged during the last several years that suggests autologous stem cell transplantation in first complete remission may provide a survival advantage over conventional chemotherapy in patients with mantle cell lymphoma. Additionally, investigational strategies such as in vivo purging with rituximab and the use of radioimmunotherapy in conditioning regimens may further increase response rates and, hopefully, survival in mantle cell lymphoma patients. Finally, recent studies suggest the existence of a graft-versus-lymphoma effect in mantle cell lymphoma providing strong scientific rationale for the possible curative potential of allogeneic stem cell transplantation in this disease.

SUMMARY

This review focuses on recent advances in allogeneic and autologous transplantation for mantle cell lymphoma. Particular emphasis is placed on the role of autologous transplantation in first complete remission, the role of in vivo purging with rituximab, the utility of radioimmunotherapy and, finally, the evolving strategy of reduced-intensity allogeneic stem cell transplantation.

Graft-versus-leukemia in a retrovirally induced murine CML model: mechanisms of T-cell killing

The graft-versus-leukemia (GVL) effect, mediated by donor T cells, has revolutionized the treatment of leukemia. However, effective GVL remains difficult to separate from graft-versus-host disease (GVHD), and many neoplasms are GVL resistant. Murine studies aimed at solving these problems have been limited by the use of leukemia cell lines with limited homology to human leukemias and by the absence of loss-of-function leukemia variants. To address these concerns, we developed a GVL model against murine chronic-phase chronic myelogenous leukemia (mCP-CML) induced with retrovirus expressing the bcr-abl fusion cDNA, the defining genetic abnormality of chronic-phase CML (CP-CML). By generating mCP-CML in gene-deficient mice, we have studied GVL T-cell effector mechanisms. mCP-CML expression of Fas or tumor necrosis factor (TNF) receptors is not required for CD8-mediated GVL. Strikingly, maximal CD4-mediated GVL requires cognate interactions between CD4 cells and mCP-CML cells as major histocompatibility complex-negative (MHC II(-/-)) mCP-CML is relatively GVL resistant. Nevertheless, a minority of CD4 recipients cleared MHC II(-/-) mCP-CML; thus, CD4 cells can also kill indirectly. CD4 GVL did not require target Fas expression. These results suggest that CPCML's GVL sensitivity may in part be explained by the minimal requirements for T-cell killing, and GVL-resistance may be related to MHC II expression.