Update of the M. D. Anderson Cancer Center experience with hyper-CVAD and rituximab for the treatment of mantle cell and Burkitt-type lymphomas

Efficacy of chemotherapy protocols for hematological malignancies: H-CVAD versus GELA/BURKIMAB/PETHEMA LAL

The hyper-CVAD/methotrexate-cytarabine (H-CVAD/ MTX-AraC) chemotherapy protocol has been one of the standard treatments for hematological malignancies, such as mantle cell lymphoma (MCL), Burkitt lymphoma (BL), and B-cell and T-cell acute lymphoblastic leukemia. Because results of this therapy are poor, it has been progressively replaced with new specific regimens with better efficacy profiles (GELA protocol for MCL, BURKIMAB for BL, and PETHEMA for B-cell and T-cell acute lymphoblastic leukemia [ALL]). The objective of this study was to analyze the response rates and survival of these therapeutic regimens. This retrospective and descriptive observational study of 81 patients compared 42 patients treated with hyper-CVAD/methotrexate-cytarabine (group A) with 39 patients treated with GELA/BURKIMAB/PETHEMA (group B). More patients in group B than in group A completed the treatment (89.7% vs. 47.6%, p < 0.001). In group A, 14.3% did not complete treatment because of death compared with 7.7% in group B, and 29% in group A had cycle delays versus 6.7% in group B (p < 0.001). In group A, 78.6% of group A achieved a complete response (CR) compared with 94.9% of group B (p = 0.050). Disease-free survival (DFS) and overall survival (OS) were significantly higher in group B (p < 0.001 in both cases). Data for current therapeutic protocols have indicated superior efficacy, with higher complete response rates, as well as better disease-free survival and overall survival results. This article provides the best results in terms of the efficacy of treatment of four hematological malignancies (MCL, BL, B-cell ALL, and T-cell ALL) with the most current specific therapeutic regimens (GELA for MCL, BURKIMAB for BL, and PETHEMA for B-cell ALL and T-cell ALL) with respect to a classic general protocol (H-CVAD/MTX-AraC for all four). These results may represent a great advance in the treatment of these blood cancers, achieving an important long-term benefit for these hematological patients.

Comparison in safety of chemotherapy protocols for blood cancers: toxicity of H-CVAD versus GELA/BURKIMAB/PETHEMA LAL

Background and objective

The Hyper-CVAD/Methotrexate-Cytarabine (H-CVAD/MTX-AraC) chemotherapy protocol has been one of the standard treatments for blood cancers, such as Mantle cell lymphoma (MCL), Burkitt’s lymphoma (BL) and B-cell and T-cell acute lymphoblastic leukaemia (ALL). Due to high toxicity, it has been progressively replaced with new specific regimens with a better safety profile (GELA protocol for MCL, BURKIMAB for BL and PETHEMA for B-cell and T-cell ALL). The objective of this study is to analyse the toxicity and infectious complications of these therapeutic regimens, as well as the event free survival (EFS).

Patients and methods

This is a retrospective and descriptive observational study of 81 patients, comparing 42 patients treated with H-CVAD/MTX-AraC (group A) versus 39 patients treated with GELA/BURKIMAB/PETHEMA (group B).

Results

All patients in group A developed pancytopenia, but in group B 74.4% neutropenia, 51.3% thrombocytopenia and 69.2% anaemia. The total number of infections in group A was higher than in group B: 154 versus 48, 3.67 versus 1.23 per patient and 0.59 versus 0.25 per cycle. Likewise, febrile neutropenia happened: 106 versus 21 cases, 2.52 versus 0.52 per patient and 0.41 versus 0.11 per cycle. EVS is higher in group B: 33% versus 79% (2-year), and 24% versus 69% (5-year).

Conclusions

Current therapeutic protocols have shown higher EFS due to better safety profile, with less haematological, neurological and haemorrhagic toxicity, as well as lower rates of infectious complications.

Clinical efficacy and safety of first-line treatments in patients with mantle cell lymphoma: A systematic literature review

Mantle cell lymphoma (MCL) is a rare form of non-Hodgkin's lymphoma (NHL) with a median overall survival (OS) of approximately 3-5 years. Systematic literature reviews (SLRs) identified efficacy and safety data for first-line therapies, reported in randomised controlled trials (RCTs) and non-randomised interventional studies (NRISs). Nine and 20 independent studies were included in the RCT and NRISs SLRs, respectively. Differences in the regimens and patient outcomes varied according to patient age and suitability for autologous stem cell transplantation (ASCT). In elderly patients ineligible for transplant, OS ranged from 40 months to 69.6 months. In young transplant-eligible patients, OS ranged from 53 months to 152.4 months. Despite the paucity of directly comparable evidence on the efficacy and safety of MCL therapies, these SLRs highlight that MCL remains a difficult NHL subtype to treat, with short survival highlighting the unmet need for newer treatments that improve patient outcomes.

Incorporating acalabrutinib, a selective next-generation Bruton tyrosine kinase inhibitor, into clinical practice for the treatment of haematological malignancies

Greater understanding of the mechanisms involved in the disease progression of haematological malignancies has led to the introduction of novel targeted therapies with reduced toxicity compared with chemotherapy-based regimens, which has expanded the treatment options for patients with mantle cell lymphoma (MCL) and chronic lymphocytic leukaemia/small lymphocytic lymphoma (CLL/SLL). Ibrutinib is a first-in-class Bruton tyrosine kinase (BTK) inhibitor indicated for the treatment of patients with CLL/SLL or relapsed/refractory MCL. However, next-generation BTK inhibitors have been developed with improved specificity and the potential to reduce the off-target toxicity observed with ibrutinib. Acalabrutinib is a highly selective, next-generation BTK inhibitor, which was granted accelerated approval by the US Food and Drug Administration in 2017 for the treatment of adult patients with MCL who have received at least one prior therapy. In November 2019, it was also granted approval for the treatment of adult patients with CLL/SLL on the basis of two phase 3 clinical trials. This review describes the current understanding of acalabrutinib according to clinical study data for the treatment of MCL and CLL/SLL and shares recommendations from our practice on how it should be used when treating patients in the clinic, including dosing, administration and management of adverse events.

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.

Current and emerging treatment options for mantle cell lymphoma

Mantle cell lymphoma (MCL) is a B-cell non-Hodgkin lymphoma with typically aggressive behavior. The genetic signature is the chromosomal translocation t(11;14)(q13;q32) resulting in overexpression of cyclin D1. Asymptomatic newly diagnosed MCL patients with low tumor burden can be closely observed, deferring therapy to the time of disease progression. Although MCL classically responds to upfront chemotherapy, it remains incurable with standard approaches. For patients in need of frontline therapy, the initial decision is whether to proceed with an intensive treatment strategy or a non-intensive treatment strategy. In general, given the unfavorable risk-benefit profile, older MCL patients should be spared intensive strategies, while younger and fit patients can be considered for intensive strategies. The bendamustine and rituximab (BR) regimen is becoming an increasingly popular treatment option among the elderly population, with improved progression-free survival (PFS) and acceptable side-effect profile. Although rituximab maintenance after R-CHOP improves survival outcomes in elderly patients, no clinical trial to date has shown statistical significance to support the use of rituximab maintenance after BR induction in older patients. In young and fit patients with MCL, an intensive strategy to maximize the length of first remission has emerged as a worldwide standard of care. With current high-dose cytarabine-containing immunochemotherapy regimens followed by autologous stem cell transplantation, the median PFS has exceeded 7 years. In the relapsed or refractory (R/R) setting, reduced intensity conditioning allogeneic hematopoietic stem cell transplantation may offer the highest likelihood of long-term survival in young R/R MCL patients, at the cost of increased risk of non-relapse mortality and chronic graft versus host disease. Novel agents targeting activated pathways in MCL cells, such as bortezomib, lenalidamide, ibrutinib and temsirolimus are now available for the management of R/R disease.

Burkitt leukemia limited to the bone marrow has a better prognosis than Burkitt lymphoma with bone marrow involvement in adults

Burkitt lymphoma patients with bulky disease often have bone marrow involvement. However, leukemic presentation of Burkitt lymphoma in the absence of a mass (pure Burkitt leukemia; PBL) is uncommon. Both PBL and Burkitt lymphoma/leukemia, presenting with a tumor mass and marrow involvement (BLL), are considered stage IV disease, which is associated with a poor prognosis. However, there is limited information on the prognosis in adults with PBL because they have typically been included in cohorts of patients with BLL. This study identified 23 patients, which included 10 PBL and 13 BLL cases. Complex karyotypes (100%) were seen in all BLL cases compared to the PBL group (40%; p = 0.061). Patients with PBL had a significantly better 5-year overall survival of 87.5% vs only 24.3% in the BLL group (p = 0.005). The 5-year overall survival of patients with PBL treated with intensive chemotherapy is superior to those with BLL who are similarly treated.

[Therapy for Burkitt's lymphoma according to the BL-M-04 protocol: 12-year experience]

AIM

To evaluate the efficiency and toxicity of the intensive Burkitt's lymphoma (BL) therapy protocol BL-M-04.

SUBJECTS AND METHODS

A total of 70 patients diagnosed with BL, including 45 men and 25 women whose age was 15 to 62 years (median age 31 years), were followed up in 2003 to 2014. Stage I (according to S. Murphy) was diagnosed in 4 (5.7%) patients; II in 9 (12.9%), III in 25 (35.7%), IV in 11 (15.7%), and Burkitt's leukemia in 21 (30%). There were tumor involvements of the bone marrow and central nervous system in 23 (32.9%) and 15 (21.4%) patients, respectively. B symptoms were detected in 56 (80%) patients; enhanced lactate dehydrogenase (LDH) activity was found in 50 (78.1%) out of 64 patients; moreover, in 34 (56.2%) out of 64 patients, LDH activity was more than twice as high as the reference values. The median LDH activity was 2398 (238-20,300) U/I. Acute renal failure at disease onset was identified in 17 (24.2%) patients; chemotherapy was initiated in 8 patients during renal replacement therapy. The treatment was performed using the BL-M-04±R protocol (4 successive blocks of A-C-A-C±R). Six blocks of A-C-A-C-A-C with rituximab has been carried out in patients with bone marrow involvement since 2011.

RESULTS

Sixty-two (89%) patients achieved complete remission. At this time, 6 patients died from therapy complications during remission induction; 2 patients were observed to have disease progression; 3 developed disease recurrence (2 patients had early recurrence; 1 patient developed recurrence 2 years after treatment). Five-year overall survival (OS) was 85%; 5-year relapse-free survival (RFS) was 95%. The Cox multivariate regression analysis revealed that Burkitt's leukemia and bone marrow involvement were independent factors that influenced OS and RFS. The poor somatic status (3-4 ECOC scores versus 0-2 scores) proved to be statistically significant for OS rather than RFS.

CONCLUSION

Despite the optimistic results obtained by our study group, there is a need to further improve BL treatment protocols and to elaborate novel approaches to therapy particularly for older patients and patients with Burkitt's leukemia.

Clinical outcomes of a novel combination of lenalidomide and rituximab followed by stem cell transplantation for relapsed/refractory aggressive B-cell non-hodgkin lymphoma

We retrospectively compared outcomes of patients with relapsed/refractory non-Hodgkin lymphoma (NHL) who underwent stem cell transplantation (SCT) with stable disease or better following a novel combination of lenalidomide and rituximab (LR) treatment and did not undergo SCT in a phase I/II clinical trial. We retrospectively compared outcomes of patients who underwent SCT with that of patients who had stable disease or better following LR treatment and did not undergo SCT. Twenty-two patients enrolled in LR clinical trial and undergone SCT were identified, 13 with mantle cell lymphoma (MCL) and nine with large B-cell lymphoma (LBCL). All patients who underwent SCT achieved complete response. In the MCL subset, there were no significant differences between SCT and non-SCT groups except that non-SCT patients were older and had a higher mantle-cell international prognostic index score. There was no difference between SCT-group and non-SCT-group in response duration (P=0.3), progression-free survival (PFS) (P=0.304) and overall survival (OS) (P=0.87). In LBCL subgroup, there were no significant differences between two groups except that non-SCT group had a higher international prognostic index score. Patients with LBCL who underwent SCT had significantly longer response duration (P=0.001), PFS (P=0.000), and OS (P=0.003) than the non-SCT group. The novel therapeutic combination offers a bridge to SCT in patients with relapsed/refractory aggressive B-cell NHL.

Rituximab is associated with improved survival in Burkitt lymphoma: a retrospective analysis from two US academic medical centers

BACKGROUND

Burkitt lymphoma (BL) is a rare, highly aggressive B-cell malignancy treated most successfully with brief-duration, high-intensity chemotherapeutic regimens. The benefit of the addition of rituximab to these regimens remains uncertain. We sought to examine the effectiveness of chemotherapy with and without rituximab in patients with BL.

METHODS

This study is a retrospective cohort study of all adult patients with BL diagnosed and treated with modern, dose-intense chemotherapeutic regimens from 1998-2008 at two tertiary care institutions. All cases were confirmed by application of WHO 2008 criteria by hematopathologists. Medical records were reviewed for patient-, disease-, and treatment- related factors as well as treatment response and survival. Factors associated with survival were analyzed using Cox proportional hazards modeling.

RESULTS

A total of 35 patients were analyzed: 18 patients received rituximab with chemotherapy (R-chemo) and 17 received chemotherapy (chemo) alone. The median age was 42 (range 20-74 years); 57% were male; 71% had Ann Arbor Stage IV disease; 33% had central nervous system involvement; 78% had an Eastern Cooperative Oncology Group (ECOG) performance status of 0-1. R-chemo was associated with significantly longer overall survival (OS) than chemo alone (5-year OS 70% and 29%, respectively, p = 0.040). On multivariate regression analysis, poor performance status and central nervous system involvement were associated with poorer survival.

CONCLUSIONS

The addition of rituximab to chemotherapy was associated with improved OS in patients with Burkitt lymphoma. Poor performance status and central nervous system involvement were prognostically significant on multivariate analysis.

New potential therapeutic approach for the treatment of B-Cell malignancies using chlorambucil/hydroxychloroquine-loaded anti-CD20 nanoparticles

Current B-cell disorder treatments take advantage of dose-intensive chemotherapy regimens and immunotherapy via use of monoclonal antibodies. Unfortunately, they may lead to insufficient tumor distribution of therapeutic agents, and often cause adverse effects on patients. In this contribution, we propose a novel therapeutic approach in which relatively high doses of Hydroxychloroquine and Chlorambucil were loaded into biodegradable nanoparticles coated with an anti-CD20 antibody. We demonstrate their ability to effectively target and internalize in tumor B-cells. Moreover, these nanoparticles were able to kill not only p53 mutated/deleted lymphoma cell lines expressing a low amount of CD20, but also circulating primary cells purified from chronic lymphocitic leukemia patients. Their safety was demonstrated in healthy mice, and their therapeutic effects in a new model of Burkitt's lymphoma. The latter serves as a prototype of an aggressive lympho-proliferative disease. In vitro and in vivo data showed the ability of anti-CD20 nanoparticles loaded with Hydroxychloroquine and Chlorambucil to increase tumor cell killing in comparison to free cytotoxic agents or Rituximab. These results shed light on the potential of anti-CD20 nanoparticles carrying Hydroxychloroquine and Chlorambucil for controlling a disseminated model of aggressive lymphoma, and lend credence to the idea of adopting this therapeutic approach for the treatment of B-cell disorders.

Impact of chemotherapy regimen and rituximab in adult Burkitt lymphoma: a retrospective population-based study from the Nordic Lymphoma Group

BACKGROUND

Standard treatment of adult Burkitt lymphoma is not defined due to the lack of randomised trials. In this situation, population-based data may represent a useful contribution in order to identify an optimal treatment strategy.

PATIENTS AND METHODS

The aims of this study were to investigate the outcome for adult HIV-negative BL with different chemotherapy regimens, and to assess possible improvement within the time frame of the study. The study population was identified through the Swedish and Danish lymphoma registries 2000-2009.

RESULTS

A total of 258 patients were identified. Since 2000, overall survival (OS) improved significantly only for younger patients (<65 years). Intensive regimens such as the Berlin-Frankfurt-Münster, hyper-fractionated cyclophosphamide, vincristine, doxorubicin, and dexamethasone (hyper-CVAD) and cyclophosphamide, vincristine, doxorubicin, methotrexate, ifosfamide, etoposide, and cytarabine (CODOX-M/IVAC) were associated with a favourable 2-year OS of 82%, 83%, and 69%, respectively. The low-intensive CHOP/CHOEP regimens achieved a 2-year OS of 38.8%, confirming their inadequacy for the treatment of BL. In a multivariate analysis, rituximab was not significantly associated with improved OS.

CONCLUSIONS

In this population-based retrospective series of adult BL, intensive chemotherapy regimens were associated with favourable outcome. The impact of the addition of rituximab remains uncertain and warrants further investigation.

Rituximab: current status as therapy for malignant and benign hematologic disorders

Rituximab is a chimeric monoclonal antibody targeting the pan-B-cell antigen CD20 and was the first monoclonal antibody approved for clinical use in the treatment of cancer. Since its first approval by the FDA in 1997, investigators have continued to explore a variety of clinical conditions in which rituximab has proven effective with minimal toxicity. Rituximab, as monotherapy or in combination with chemotherapy, has been studied extensively in untreated and relapsed/refractory settings as both induction and maintenance therapy for the treatment of CD20-positive lymphomas and chronic lymphocytic leukemia, in addition to non-malignant hematologic disorders including autoimmune hemolytic anemia and immune thrombocytopenic purpura. Here we discuss the clinical development of rituximab with a review of the efficacy data from clinical trials and its current status in the practice of hematology and oncology.

VcR-CVAD induction chemotherapy followed by maintenance rituximab in mantle cell lymphoma: a Wisconsin Oncology Network study

Intensive chemotherapy regimens are not feasible in many adults with mantle cell lymphoma (MCL). We sought to build upon our previous experience with a non-intensive regimen, modified R-hyperCVAD chemotherapy (rituximab, cyclophosphamide, vincristine, doxorubicin, dexamethasone) with maintenance rituximab (MR), by the incorporation of bortezomib (VcR-CVAD) and the extension of MR beyond 2 years. Patients with previously untreated MCL received VcR-CVAD chemotherapy every 21 d for six cycles. Patients achieving at least a partial response to induction chemotherapy received rituximab consolidation (375 mg/m(2) × 4 weekly doses) and MR (375 mg/m(2) every 12 weeks × 20 doses). The primary end points were overall and complete response (CR), and secondary endpoints were progression-free (PFS) and overall survival (OS). Thirty patients were enrolled, with a median age of 61 years. All patients had advanced stage disease, and 60% had medium/high MCL International Prognostic Index risk factors. A CR or unconfirmed CR was achieved in 77% of patients. After a median follow-up of 42 months, the 3-year PFS and OS were 63% and 86%, respectively. The observed 3-year PFS and OS with VcR-CVAD in MCL were comparable to reported outcomes with more intensive regimens. A cooperative group trial (E1405) is attempting to replicate these promising results.

Mantle cell lymphoma international prognostic index but not pretransplantation induction regimen predicts survival for patients with mantle-cell lymphoma receiving high-dose therapy and autologous stem-cell transplantation

PURPOSE

High-dose therapy (HDT) and autologous stem-cell transplantation (ASCT) are frequently used in an attempt to improve outcome in patients with mantle-cell lymphoma (MCL); however, the importance of intensive induction regimens before transplantation is unknown.

PATIENTS AND METHODS

To address this question, we evaluated baseline characteristics, time to treatment, induction regimen, disease status at the time of transplantation, and MIPI score at diagnosis and their associations with survival in 118 consecutive patients with MCL who received HDT and ASCT at our centers.

RESULTS

The MIPI was independently associated with survival after transplantation in all 118 patients (hazard ratio [HR], 3.5; P < .001) and in the 85 patients who underwent ASCT as initial consolidation (HR, 7.2; P < .001). Overall survival rates were 93%, 60%, and 32% at 2.5 years from ASCT for all patients with low-, intermediate-, and high-risk MIPI, respectively. Low-risk MIPI scores were more common in the intensive induction group than the standard induction group in all patients (64% v 46%, respectively; P = .03) and in the initial consolidation group (66% v 45%, respectively; P = .03). After adjustment for the MIPI, an intensive induction regimen was not associated with improved survival after transplantation in all patients (HR, 0.5; P = .10), the initial consolidation group (HR, 1.1; P = .86), or patients ≤ 60 years old (HR, 0.6; P = .50). Observation of more than 3 months before initiating therapy did not yield inferior survival (HR, 2.1; P = .12) after adjustment for the MIPI in patients receiving ASCT.

CONCLUSION

An intensive induction regimen before HDT and ASCT was not associated with improved survival after adjusting for differences in MIPI scores at diagnosis.

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.

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.

Mantle cell lymphoma: Frontline and salvage therapy

Mantle cell lymphoma (MCL) is a therapeutic challenge because of its lower cure rate when compared with other lymphomas such as diffuse large cell lymphoma. The current emphasis in the treatment of newly diagnosed MCL has been on intensifying chemotherapy, but there is no consensus on the need to consolidate with autologous stem cell transplantation. These approaches, however, have not resulted in a cure. Newer strategies include the use of models to aid in tailoring therapy. Likewise, autologous stem cell consolidation does not cure relapsed disease. Because of its known graft-versus-lymphoma effect, allogeneic stem cell transplantation offers a potentially curative option for relapsed MCL. New insights into resistance pathways and new drugs created to inhibit them offer great promise in the treatment of newly diagnosed and previously treated MCL.

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

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

Rituximab for the treatment of non-Hodgkin's lymphoma and chronic lymphocytic leukaemia

Rituximab is a monoclonal antibody that is widely utilized in the treatment of a number of B-cell-derived haematological malignancies. Rituximab, in combination with chemotherapy, has significantly improved survival outcomes for patients diagnosed with follicular lymphoma (FL) and diffuse large B-cell lymphoma (DLBCL), the two most commonly diagnosed subtypes of non-Hodgkin's lymphoma. Furthermore, chemoimmunotherapy containing rituximab has led to significant increases in complete response and progression-free survival rates for patients with both previously untreated and relapsed or refractory chronic lymphocytic leukaemia (CLL). This article reviews the efficacy data from clinical trials demonstrating the significant survival benefits associated with rituximab use in the treatment of FL, DLBCL and CLL.

Prognostic impact of proliferative index determined by quantitative image analysis and the International Prognostic Index in patients with mantle cell lymphoma

Background: The proliferative index (PI) is a powerful prognostic factor in mantle cell lymphoma (MCL); however, its utility is hampered by interobserver variability. The mantle cell international prognostic index (MIPI) has been reported to have prognostic importance. In this study, we determined the prognostic value of the PI as determined by quantitative image analysis in MCL.

Patients and methods: Eighty-eight patients with adequate tissue were included in this analysis. Patients were treated with one of two treatment programs: sequential therapy with high-dose therapy consolidation or radioimmunotherapy followed by combination chemotherapy with cyclophosphamide, doxorubicin, vincristine and prednisone. Patients were divided into four groups based on PI (<10%, 10%–29.9%, 30%–49.9%, and >50%), and outcomes were analyzed.

Results: Thirty percent was identified as the optimal cut-off for PI. By univariate analysis, intensive treatment and a low PI were associated with a superior progression-free survival (PFS); only PI was associated with overall survival. By multivariate analysis, both intensive treatment and PI correlated with PFS. The MIPI had no prognostic impact.

Conclusions: PI is the most important prognostic factor in MCL. The cut-off of 30% is clinically meaningful and can be used to tailor the intensity of therapy in future clinical trials.

Mature results of the M. D. Anderson Cancer Center risk-adapted transplantation strategy in mantle cell lymphoma

In this study, we analyzed the long-term outcome of a risk-adapted transplantation strategy for mantle cell lymphoma in 121 patients enrolled in sequential transplantation protocols. Notable developments over the 17-year study period were the addition of rituximab to chemotherapy and preparative regimens and the advent of nonmyeloablative allogeneic stem cell transplantation (NST). In the autologous transplantation group (n = 86), rituximab resulted in a marked improvement in progression-free survival for patients who received a transplant in their first remission (where a plateau emerged at 3-8 years) but did not change the outcomes for patients who received a transplant beyond their first remission. In the NST group, composed entirely of patients who received a transplant beyond their first remission, durable remissions also emerged in progression-free survival at 5 to 9 years. The major determinants of disease control after NST were the use of a peripheral blood stem cell graft and donor chimerism of at least 95%, whereas the major determinant of death was immunosuppression for chronic graft-versus-host disease. Our results show that long-term disease-free survival in mantle cell lymphoma is possible after rituximab-containing autologous transplantation for patients in first remission and after NST for patients with relapsed or refractory disease.

Bortezomib in patients with relapsed or refractory mantle cell lymphoma: updated time-to-event analyses of the multicenter phase 2 PINNACLE study

BACKGROUND

We previously reported results of the phase 2, multicenter PINNACLE study, which confirmed the substantial single-agent activity of bortezomib in patients with relapsed or refractory mantle cell lymphoma (MCL).

MATERIALS AND METHODS

We report updated time-to-event data, in all patients and by response to treatment, after extended follow-up (median 26.4 months).

RESULTS

Median time to progression (TTP) was 6.7 months. Median time to next therapy (TTNT) was 7.4 months. Median overall survival (OS) was 23.5 months. In responding patients, median TTP was 12.4 months, median duration of response (DOR) was 9.2 months, median TTNT was 14.3 months, and median OS was 35.4 months. Patients achieving complete response had heterogeneous disease characteristics; among these patients, median TTP and DOR were not reached, and median OS was 36.0 months. One-year survival rate was 69% overall and 91% in responding patients. Median OS from diagnosis was 61.1 months, after median follow-up of 63.7 months. Activity was seen in patients with refractory disease and patients relapsing following high-intensity treatment. Toxicity was generally manageable.

CONCLUSIONS

Single-agent bortezomib is associated with lengthy responses and notable survival in patients with relapsed or refractory MCL, with considerable TTP and TTNT in responding patients, suggesting substantial clinical benefit.

Mantle cell lymphoma cells express high levels of CXCR4, CXCR5, and VLA-4 (CD49d): importance for interactions with the stromal microenvironment and specific targeting

Mantle cell lymphoma (MCL) is characterized by an early, widespread dissemination and residual disease after conventional treatment, but the mechanisms responsible for lymphoma cell motility and drug resistance are largely unknown. There is growing evidence suggesting that chemokine receptors and adhesion molecules are critical for malignant B-cell trafficking and homing to supportive tissue microenvironments, where they receive survival and drug resistance signals. Therefore, we examined chemokine receptor and adhesion molecule expression and function in MCL cells and their importance for migration and adhesion to marrow stromal cells (MSCs). We found that MCL cells display high levels of functional CXCR4 and CXCR5 chemokine receptors and VLA-4 adhesion molecules. We also report that MCL cells adhere and spontaneously migrate beneath MSCs in a CXCR4- and VLA-4-dependent fashion (pseudoemperipolesis). Moreover, we demonstrate that MSCs confer drug resistance to MCL cells, particularly to MCL cells that migrate beneath MSC. To target MCL-MSC interactions, we tested Plerixafor, a CXCR4 antagonist, and natalizumab, a VLA-4 antibody. Both agents blocked functional responses to the respective ligands and inhibited adhesive interactions between MCL cells and MSCs. These findings provide a rationale to further investigate the therapeutic potential of these drugs in MCL.

Prognostic significance of CD20 expression in adults with de novo precursor B-lineage acute lymphoblastic leukemia

Immunophenotypic classification of acute lymphoblastic leukemia (ALL) has well-recognized prognostic implications. The significance of CD20 expression has been evaluated in childhood precursor B-lineage ALL with conflicting results. We retrospectively analyzed the influence of CD20 expression on outcome in 253 adults with de novo precursor B-lineage ALL treated with either conventional (VAD/CVAD) or intensive (hyper-CVAD) frontline chemotherapy regimens in the pre-rituximab era. Overall, CD20 positivity of at least 20% was associated with lower 3-year rates of complete remission duration (CRD; 20% vs 55%, P < .001) and overall survival (OS; 27% vs 40%, p = .03). In the CD20 negative subset, the 3-year rates for CRD (58% vs 42%, p = .04) and OS (60% vs 28%, P < .001) were superior for hyper-CVAD compared with VAD/CVAD; rates were particularly favorable for the CD20 negative younger age group (68% and 85%, respectively). In contrast, 3-year CRD and OS rates were uniformly poor for the CD20-positive group regardless of therapy (27% or less). Multivariate analysis for event-free survival identified older age, leukocyte count higher than 30 x 10(9)/L, presence of Philadelphia chromosome, high systemic risk classification, and CD20 positivity as independent predictors of worse outcome. In conclusion, CD20 expression in de novo adult precursor B-lineage ALL appears to be associated with a poor prognosis. Incorporation of monoclonal antibodies directed against CD20 into frontline chemotherapy regimens warrants investigation.