Is hematopoietic cell transplantation still a valid option for mantle cell lymphoma in first remission in the chemoimmunotherapy-era?

SOHO State of the Art Updates and Next Questions: Treatment Evolution of Mantle Cell Lymphoma: Navigating the Different Entities and Biological Heterogeneity of Mantle Cell Lymphoma in 2024

Progress in mantle cell lymphoma (MCL) has led to significant improvement in outcomes of patients even in the real world (RW) setting albeit to a lesser degree. In parallel to the demonstration of benefit using combination therapy with rituximab plus high-dose cytarabine (R-AraC) as well as dose intensive therapy-autologous stem cell transplantation (DIT-ASCT) consolidation and maintenance, it became clear over the last 2 decades that MCL is a highly heterogenous disease at the molecular level, explaining differences observed in clinical behavior and response to therapy. While clinical prognostic factors and models have helped stratify patients with distinct outcomes, they failed to help guide therapy. The identification of molecular high-risk (HR) features, in particular, but not only, p53 aberrations (including mutations and deletions [del]), as well as complex karyotype (CK), has allowed to identify subsets of patients with poorer outcomes (median overall survival [OS] <2 years) regardless of conventional therapies used. The constant pattern of relapse seen in MCL has fueled sustained and productive efforts, with 7 novel agents approved in the United States (US), showing high and durable efficacy even in HR and chemo-refractory patients and likely curing a subset of patients in the relapsed or refractory (R/R) setting. Progress in diagnostics, in particular next-generation sequencing (NGS), which is accessible in routine practice nowadays, can help recognize patients with HR features, well beyond MIPI or Ki-67 prognostication, although the impact on decision making is still unclear. The era of integrating novel agents into our prior standard of care (SOC) has begun with a confirmed benefit, for example, ibrutinib (Ib) in the TRIANGLE study, defining the first new potential SOC in younger patients in over 30 years. Expanding on novel agents, either in combination, sequentially or to replace chemotherapy altogether, using biological doublets or triplets has led to a median progression-free survival (PFS) in excess of 72 months, certainly competitive with prior SOC and will continue to reshape the management of MCL patients. Achieving minimal residual disease negative (MRD-ve) status is becoming a new endpoint in MCL, and customizing maintenance and/or de-escalation/consolidation strategies is within reach, although it will require prospective, built-in MRD-based approaches, with the goal of eliminating subclinical disease and not simply delaying time to relapse. Taking into account the biological diversity of MCL is now feasible in routine clinical practice and has already helped recognize what not to do for HR patients (i.e., avoid intensive induction chemotherapy and/or ASCT for p53 mutated patients) as well as identify promising novel options. Ongoing and future work will help expand on these dedicated approaches, to further improve the management and outcomes of all MCL patients.

Is myeloablative dose intensity necessary in allogeneic hematopoietic cell transplantation for lymphomas?

The advent of novel immunotherapy and tyrosine kinase inhibitors has ushered a new era in the treatment of Hodgkin and non-Hodgkin lymphomas. Allogeneic hematopoietic cell transplantation remains, however, a vital component in the management and potential cure of lymphomas, especially in the relapsed setting. Considering the biological and clinical heterogeneity of various subtypes of lymphomas, the optimal intensity of conditioning regimens remains controversial. Reduced intensity conditioning regimens have broadened applicability of the procedure to older and frail patients. Observational studies suggest that although reduced intensity allografting is associated with higher risk of relapse, overall survival is comparable and in some cases even better, than observed with myeloablative regimens. Here, we review the available published data pertaining to allogeneic hematopoietic cell transplantation using reduced intensity or myeloablative conditioning for various lymphoma histologies. Owing to the lack of randomized prospective trials, recommendations are mainly based on registry and single-institution studies. Special emphasis must be given to implementing strategies to prevent relapse when using reduced intensity regimens. Identifying particular patients who may benefit from myeloablative regimens in lymphomas remains to be better defined.

Predictive factors and outcomes for ibrutinib therapy in relapsed/refractory mantle cell lymphoma-a "real world" study

Ibrutinib has demonstrated significant activity in relapsed/refractory mantle cell lymphoma (MCL) in clinical trials. However, the impact of hematopoietic cell transplantation on the outcomes of ibrutinib and the predictive factors for ibrutinib response has not been well studied. Hence, we conducted a multicenter retrospective study of MCL patients who received ibrutinib to (1) determine the overall response rate (ORR), duration of response (DOR), progression-free survival (PFS), and overall survival (OS) of ibrutinib in routine clinical practice, (2) examine characteristics predictive of response to ibrutinib therapy, and (3) describe the outcomes of patients failing ibrutinib. Ninety-seven patients met the eligibility criteria. Overall response rate and median DOR to ibrutinib were 65% and 17 months, respectively. Only lack of primary refractory disease was predictive of ibrutinib response on multivariate analysis. Twenty-nine patients received postibrutinib therapies, with an ORR of 48% and a median DOR of 3 months. The median OS and PFS for the entire group (n = 97) was 22 and 15 months, respectively. On multivariate analysis, ibrutinib response, low MCL international prognostic index, and absence of primary refractory disease were predictors of better PFS, while ibrutinib response and Eastern Cooperative Oncology Group performance status ≤1 were predictors of better OS. The median OS postibrutinib failure was 2.5 months. Our results confirm the high ORR and DOR of ibrutinib in MCL and that prior hematopoietic cell transplantation does not negatively influence ibrutinib outcomes. Survival following ibrutinib failure is poor with no specific subsequent therapy showing superior activity in this setting. As a result, for select (transplant eligible) patients, allogeneic transplant should be strongly considered soon after ibrutinib response is documented to provide durable responses.

Allogeneic hematopoietic stem cell transplantation in patients with advanced indolent lymphoproliferative disorders

BACKGROUND

The role of allogeneic hematopoietic stem cell transplantation for advanced indolent lymphoproliferative disorders remains to be established.

OBJECTIVE

This paper aims to describe the results of allogeneic hematopoietic stem cell transplantation in patients with advanced indolent lymphoproliferative disorders.

METHODS

This article reports on 29 adult patients submitted to allogeneic transplantations from 1997 to 2010.

RESULTS

Most had follicular non-Hodgkin lymphoma (n=14) or chronic lymphocytic leukemia (n=12). The median age was 44 years (range: 24-53 years) and 65% of patients were male. Only 21% had had access to rituximab and 45% to fludarabine. All had advanced disease (stage IV) with partial response or stable disease. Most underwent myeloablative conditioning n=17-59%). In this scenario, refractory disease was observed in seven (24%) patients, the 100-day mortality rate was 17% (n=5) and relapse occurred in four patients (18%). The main cause of death throughout the follow up was refractory disease in six of the 12 patients who died. Moderate and severe chronic graft-versus-host disease was frequent; about 41% of 24 patients analyzed. The overall survival rates and disease free survival at 42 months were 56.7% and 45.4%, respectively. According to Kaplan-Meyer analysis, the median time from diagnosis to transplant predicted the overall survival; however age, gender and conditioning regimen did not predict the prognosis. It was impossible to reach other conclusions because of the small sample size in this study.

CONCLUSIONS

The role of allogeneic transplantations should be re-evaluated in the era of targeted therapy.

Bortezomib for the treatment of mantle cell lymphoma: an update

Bortezomib is a first in class proteasome inhibitor, initially approved by the US Food and Drug Administration for the treatment of plasma cell myeloma. Bortezomib has been approved for the treatment of relapsed and refractory mantle cell lymphoma (MCL) and, more recently, in the upfront setting as well. Treatment algorithms for MCL have rapidly evolved over the past two decades, and the optimal regimen remains to be defined. The choice of treatment regimen is based on disease risk stratification models, the expected toxicity of antineoplastic agents, the perceived patient ability to tolerate the planned treatments and the availability of novel agents. As new drugs with novel mechanisms of action and variable toxicity profiles come into use, treatment decisions for a given patient have become increasingly complex. This article provides an overview of the evolving use of bortezomib in the rapidly changing management landscape of MCL.

Outcomes of both abbreviated hyper-CVAD induction followed by autologous hematopoietic cell transplantation and conventional chemotherapy for mantle cell lymphoma: a 10-year single-centre experience with literature review

We retrospectively evaluated consecutive patients diagnosed with Mantle cell lymphoma (MCL) between 01 January 2000 and 31 December 2009. Eighty eight patients with MCL were included in the analysis of whom 46 (52%) received abbreviated Hyper‐CVAD (a total of two cycles; with addition of Rituximab since 2005) with an intention of proceeding to autologous hematopoietic cell transplantation (auto‐HCT), with a median age of 58 years. Response rate to induction at auto‐HCT time was 89% and complete response was 61%. Forty four patients received an auto‐HCT with a 5‐year progression‐free survival (PFS) and overall survival (OS) were 31.2% and 62.5%, respectively. There were 42 nontransplant eligible patients with a median age of 72 years, and 5‐year PFS and OS were 0.0% and 39.9%, respectively. The median survival and PFS in the auto‐HCT eligible group were 68 and 33 months, compared to 32 and 12 months in nontransplant eligible group, without a plateauing of the survival curves in either group. Treatment‐related mortality in the auto‐HCT eligible group was 10.9% (n = 5); two patients died during R‐Hyper‐CVAD and 3 (6.8%) experienced transplant‐related mortality. An abbreviated R‐Hyper‐CVAD‐based induction strategy followed by consolidative auto‐HCT is feasible and provides moderate potential of long‐term survival. Further research to define risk‐adapted strategies; to optimize disease control, is required.

Are we a step forward with targeted agents in resolving the enigma of mantle cell lymphoma?

Mantle cell lymphoma has been recognized as a distinct entity from the other non-Hodgkin lymphomas in middle 1990's. It carries a worst prognosis among all mature B-cell malignancies. Cyclin D1 and recently SOX11 are the hallmarks for this disease. Even if it is highly responsive to induction treatment, it remains incurable, since it inevitably relapses. Highly aggressive approaches with stem cell transplantation can shift the survival curve for a bit, but even so the overall survival is not significantly improved in most of the cases. Small portion of patients with this heterogeneous disease have an indolent course with long-term survival. Conventional immunochemotherapy has reached its maximal possibilities, so novel target agents are absolutely warranted. The large number of ongoing early phase trials demonstrated promising results, especially emphasizing agents that target B-cell receptor. They are mostly investigated in relapsed/refractory disease, while front-line approaches with those agents need to be explored in future times.

Outcomes of autologous or allogeneic stem cell transplantation for non-Hodgkin lymphoma

Transplant outcomes of autologous or allogeneic stem cell transplantation (SCT) have not been elucidated as a single cohort in non-Hodgkin lymphoma (NHL). We analyzed the outcomes of 270 adult recipients receiving autologous (auto) SCT (n = 198) or allogeneic (allo) SCT (n = 72) for NHL between the years 2000 and 2010. Five-year overall survival rates for B and T cell NHL were 58% and 50%, respectively (allo-SCT 51% vs. 54% for B and T-cell NHL, and auto-SCT 60% vs. 47% for B and T cell lymphoma, respectively). In multivariate analysis, the number of chemotherapy regimens and disease status pre-SCT were independently associated with long-term outcome after SCT (for both auto- and allo-SCT). We conclude that the type of transplantation offered to patients, based on patient selection and disease-related factors, can achieve long-term survival, highlighting the importance of further improvement in disease control and reducing procedure-related mortality. The role of transplantation needs to be reevaluated in the era of targeted therapy.