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

The addition of bortezomib to rituximab, high-dose cytarabine and dexamethasone in relapsed or refractory mantle cell lymphoma-a randomized, open-label phase III trial of the European mantle cell lymphoma network

The therapy of relapsed or refractory (r/r) mantle cell lymphoma (MCL) patients remains a major clinical challenge to date. We conducted a randomized, open-label, parallel-group phase-III trial hypothesizing superior efficacy of rituximab, high-dose cytarabine and dexamethasone with bortezomib (R-HAD + B) versus without (R-HAD) in r/r MCL ineligible for or relapsed after autologous stem cell transplant (ASCT). Primary endpoint was time to treatment failure (TTF), secondary endpoints included response rates, progression free survival, overall survival, and safety. In total, 128 of 175 planned patients were randomized to R-HAD + B (n = 64) or R-HAD (n = 64). Median TTF was 12 vs. 2.6 months (p = 0.045, MIPI-adjusted HR 0.69; 95%CI 0.47-1.02). Overall and complete response rates were 63 vs. 45% (p = 0.049) and 42 vs. 19% (p = 0.0062). A significant treatment effect was seen in the subgroup of patients >65 years (aHR 0.48, 0.29-0.79) and without previous ASCT (aHR 0.52, 0.28-0.96). Toxicity was mostly hematological and attributable to the chemotherapeutic backbone. Grade ≥3 leukocytopenia and lymphocytopenia were more common in R-HAD + B without differences in severe infections between both arms. Bortezomib in combination with chemotherapy can be effective in r/r MCL and should be evaluated further as a therapeutic option, especially if therapy with BTK inhibitors is not an option. Trial registration: NCT01449344.

Novel treatment for mantle cell lymphoma - impact of BTK inhibitors and beyond

Mantle cell lymphoma (MCL) primarily affects older adults, accounting for 3-10% of all non-Hodgkin lymphoma (NHL) in western countries. The disease course of MCL is heterogenous; driven by clinical, cytogenetics, and molecular features that shape differences in outcomes, including proliferation index, MIPI scores, and mutational profile such as TP53 aberration. The advent of novel agents has fundamentally evolved the treatment landscape for MCL with treatment strategies that can now be more effectively tailored based on both patient- and disease-specific factors. In this review, we discuss the major classes of novel agents used for the treatment of MCL, focusing on efficacy and notable toxicities of BTK inhibitors. We further examine effective novel combination regimens and, lastly, discuss future directions for the evolution of targeted approaches for the treatment of MCL.

Recent advances in genomics and therapeutics in mantle cell lymphoma

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

Up-Front ASCT Overcomes the Survival Benefit Provided by HDAC-Based Induction Regimens in Mantle Cell Lymphoma: Data from a Real-Life and Long-Term Cohort

BACKGROUND

Mantle cell lymphoma (MCL) is a rare malignancy with heterogeneous behavior. Despite the therapeutic advances recently achieved, MCL remains incurable. Currently, the standard of care for young and fit patients involves induction immunochemotherapy followed by up-front autologous stem cell transplantation (ASCT). However, the role of more intensive induction regimens, such as those based on high doses of cytarabine (HDAC), remains controversial in the management of ASCT-eligible patients.

METHODS

This retrospective, observational, and single-center study involved 165 MCL patients treated at the largest oncology center in Latin America from 2010 to 2022. We aimed to assess outcomes, determine survival predictors, and compare responses between different primary therapeutic strategies, with a focus on assessing the impact of HDAC-based regimens on outcomes in ASCT-eligible patients.

RESULTS

The median age at diagnosis was 65 years (38-89 years), and 73.9% were male. More than 90% of the cases had a classic nodal form (cnMCL), 76.4% had BM infiltration, and 56.4% presented splenomegaly. Bulky ≥ 7 cm, B-symptoms, ECOG ≥ 2, and advanced-stage III/IV were observed in 32.7%, 64.8%, 32.1%, and 95.8%, respectively. Sixty-four percent of patients were categorized as having high-risk MIPI. With a median follow-up of 71.1 months, the estimated 2-year OS and EFS were 64.1% and 31.8%, respectively. Patients treated with (R)-HDAC-based regimens had a higher ORR (85.9% vs. 65.7%, p = 0.007) compared to those receiving (R)-CHOP, as well as lower POD-24 rates (61.9% vs. 80.4%, p = 0.043) and lower mortality (43.9% vs. 68.6%, p = 0.004). However, intensified induction regimens with (R)-HDAC were not associated with a real OS benefit in MCL patients undergoing up-front consolidation with ASCT (2-year OS: 88.7% vs. 78.8%, p = 0.289). Up-front ASCT was independently associated with increased OS (p < 0.001), EFS (p = 0.005), and lower POD-24 rates (p < 0.001) in MCL. Additionally, CNS infiltration, TLS, hypoalbuminemia, and the absence of remission after induction were predictors of poor OS.

CONCLUSIONS

In the largest Latin American cohort of MCL patients, we confirmed the OS benefit promoted by up-front consolidation with ASCT in young and fit patients, regardless of the intensity of the immunochemotherapy regimen used in the pre-ASCT induction. Although HDAC-based regimens were not associated with an unequivocal increase in OS for ASCT-eligible patients, it was associated with higher ORR and lower rates of early relapses for the whole cohort.

Real-world treatment and outcome patterns of patients with mantle cell lymphoma in China: A large, multicenter retrospective analysis

BACKGROUND

Mantle cell lymphoma (MCL) is an uncommon heterogeneous subtype of B cell non-Hodgkin lymphoma, and clinical features in MCL appear regional characteristics. MCL treatment opinions are not uniform between countries or regions within Asia and China, and Asian patient-specific data for MCL treatment are fewer. The study aims to explore the clinical characteristics, treatment patterns and prognosis of MCL patients in China.

METHODS

A total of 805 patients diagnosed with MCL between April 1999 and December 2019 at 19 comprehensive hospitals in China were included in this retrospective analysis. Kaplan-Meier method coupled with the log-rank test was used for univariate analysis, and COX proportional hazards model was used for multivariate analysis (MVA). p < 0.05 was consided statistically significant. All outputs were produced using R version 4.1.0.

RESULTS

The median age of the cohort was 60.0 years with a male-to-female ratio of 3.36:1. Five-year progression-free survival (PFS) and overall survival (OS) rates were 30.9% and 65.0%, respectively. High-intermediate/high-risk group according to MIPI-c, without high-dose cytarabine, lack of Auto-SCT as consolidation and maintenance treatment and SD/PD in initial treatment remained statistically relevant to poor PFS on MVA, and ki67 ≥50%, B symptoms, high-intermediate/high risk group according to MIPI-c, without high-dose cytarabine, lack of maintenance treatment, SD/PD in initial treatment and relapse/refractory state were independently associated with poorer OS on MVA.

CONCLUSIONS

First-line high dose cytarabine exposure, auto-SCT as consolidation therapy obtained survival benefits in Chinese population. Our study further confirmed the value of maintenance treatment and explored the application of new drug treatment and bendamustine in R/R MCL patients.

Personalized approaches for treatment-naïve mantle cell lymphoma

INTRODUCTION

Mantle cell lymphoma (MCL) can have diverse disease presentations, which vary in aggressiveness and prognosis, and can occur in patients with varying ability to tolerate therapy. Additionally, the options for treatment of MCL have expanded rapidly in the last decade, translating to improved outcome for patients.

AREAS COVERED

We review the initial evaluation of patients with MCL, identifying disease- and patient-specific prognostic factors, along with personalized therapies for patients with MCL. Specific scenarios include indolent and limited-stage MCL, advanced-stage disease in transplant-eligible and ineligible patients, and high-risk TP53 mutant disease. Ongoing trials and future directions in MCL treatment are also highlighted.

EXPERT OPINION

Given the wide array of disease and patient presentations with MCL, a personalized therapeutic approach is needed to optimize outcomes. The best therapeutic strategy should incorporate disease prognostic factors, patient status and comorbidities, goals of care, and response to treatment.

Impact of Pre-transplant Induction Therapy on Outcomes of Patients Who Undergo Autologous Stem Cell Transplantation for Mantle Cell Lymphoma in First Complete Remission

Mantle cell lymphoma is a rare subtype of non-Hodgkin's lymphoma with poor prognosis and continue to be challenging to treat. The choice of first line induction regimen remains a topic of debate due paucity of clinical trials. We retrospectively evaluated 66 patients diagnosed with mantle cell lymphoma who achieved first complete response after induction chemotherapy followed by autologous stem cell transplant. Treatment groups were divided into low-intensity versus high-intensity regimens. Our data showed the intensity of induction regimen does not impact posttransplant outcomes of mantle cell lymphoma who underwent autologous stem cell transplant in first complete response.

Ibrutinib improves survival compared with chemotherapy in mantle cell lymphoma with central nervous system relapse

Central nervous system (CNS) relapse of mantle cell lymphoma (MCL) is a rare phenomenon with dismal prognosis, where no standard therapy exists. Since the covalent Bruton tyrosine kinase (BTK) inhibitor ibrutinib is effective in relapsed/refractory MCL and penetrates the blood-brain barrier (BBB), on behalf of Fondazione Italiana Linfomi and European Mantle Cell Lymphoma Network we performed a multicenter retrospective international study to investigate the outcomes of patients treated with ibrutinib or chemoimmunotherapy. In this observational study, we recruited patients with MCL with CNS involvement at relapse who received CNS-directed therapy between 2000 and 2019. The primary objective was to compare the overall survival (OS) of patients treated with ibrutinib or BBB crossing chemotherapy. A propensity score based on a multivariable binary regression model was applied to balance treatment cohorts. Eighty-eight patients were included. The median age at study entry was 65 years (range, 39-87), 76% were males, and the median time from lymphoma diagnosis to CNS relapse was 16 months (range, 1-122). Patients were treated with ibrutinib (n = 29, ibrutinib cohort), BBB crossing chemotherapy (ie, high-dose methotrexate ± cytarabine; n = 29, BBB cohort), or miscellaneous treatments (n = 30, other therapy cohort). Both median OS (16.8 vs 4.4 months; P = .007) and median progression-free survival (PFS) (13.1 vs 3.0 months; P = .009) were superior in the ibrutinib cohort compared with the BBB cohort. Multivariable Cox regression model revealed that ibrutinib therapeutic choice was the strongest independent favorable predictive factor for both OS (hazard ratio [HR], 6.8; 95% confidence interval [CI], 2.2-21.3; P < .001) and PFS (HR, 4.6; 95% CI, 1.7-12.5; P = .002), followed by CNS progression of disease (POD) >24 months from first MCL diagnosis (HR for death, 2.4; 95% CI, 1.1-5.3; P = .026; HR for death or progression, 2.3; 95% CI, 1.1-4.6; P = .023). The addition of intrathecal (IT) chemotherapy to systemic CNS-directed therapy was not associated with superior OS (P = .502) as the morphological variant (classical vs others, P = .118). Ibrutinib was associated with superior survival compared with BBB-penetrating chemotherapy in patients with CNS relapse of MCL and should be considered as a therapeutic option.

Stem cell transplant for mantle cell lymphoma in Taiwan

Mantle cell lymphoma (MCL) is a B-cell lymphoma featuring an aggressive course and a progressive relapsing pattern. International guidelines recommend early consolidative autologous stem cell transplant (auto-SCT) for eligible patients while reserving allogeneic SCT (allo-SCT) as therapy for refractory cases. Since data describing the implementation of transplants in the Asian population with MCL are limited, we aimed to analyze post-SCT outcomes of 99 MCL patients from the Taiwan Bone Marrow Transplant Registry database. The median age was 56 years, and 11% of the patients had blastoid variant MCL. Ninety-four patients received auto-SCT, while 13 patients received allo-SCT, eight of which received allo-SCT after failing auto-SCT. Before auto-SCT, 52% of the patients were in their first complete remission (CR1). Overall, 37 patients (39%) relapsed after auto-SCT. The median post-auto-SCT progression-free survival and overall survival (OS) were 43.6 months and not reached, respectively. Blastoid variant MCL, transplant not received in CR1, and disease progression within 12 months post-auto-SCT independently predicted inferior OS in multivariable analysis. The median post-allo-SCT OS was 74 months. Two patients (15%) died of MCL recurrence post-allo-SCT. Three patients with refractory diseases were salvaged with ibrutinib or venetoclax to allo-SCT. Treatment strategies incorporating novel agents warrant further optimization.

Evolving frontline immunochemotherapy for mantle cell lymphoma and the impact on survival outcomes

Because there have been a dvances in frontline treatment for mantle cell lymphoma (MCL) over the last 2 decades, we sought to characterize the changes in frontline treatment patterns and their association with outcomes. Patients with newly diagnosed MCL from September 2002 through June 2015 were enrolled in a prospective cohort study, and clinical characteristics, treatment, and clinical outcomes were compared between patients diagnosed from 2002 to 2009 (Era 1) compared with 2010 to 2015 (Era 2). Patient age, sex, and simplified MCL International Prognostic Index (sMIPI) score were similar between the 2 groups. In patients age 65 years or younger, there was less use of rituximab plus hyperfractionated cyclophosphamide, vincristine, doxorubicin, and dexamethasone (R-Hyper-CVAD) (16.1% vs 8.8%) but more use of rituximab plus maximum-strength cyclophosphamide, doxorubicin, vincristine, and prednisone (R-maxi-CHOP) alternating with rituximab plus high-dose cytarabine (R-HiDAC), also known as the Nordic regimen, and R-CHOP alternating with rituximab plus dexamethasone, high-dose cytarabine, and cisplatin (R-DHAP) (1.1% vs 26.4%) and less use of R-CHOP or R-CHOP-like regimens (64.5% vs 35.2%) but more use of R-bendamustine (0% vs 12.1%) in Era 2 (P < .001). These changes were associated with improved event-free survival (EFS; 5-year EFS, 34.3% vs 50.0%; P = .010) and overall survival (OS; 5-year OS, 68.8% vs 81.6%; P = .017) in Era 2. In patients older than age 65 years, there was less use of R-CHOP or R-CHOP-like therapy (39.0% vs 14.3%) and nonstandard systemic therapy (36.6% vs 13.0%) but more use of R-bendamustine (0% vs 49.4%). These changes were associated with a trend for improved EFS (5-year EFS, 25.4% vs 37.5%; P = .051) in Era 2. The shift from R-CHOP or R-CHOP-like regimens to R-bendamustine was associated with improved EFS (5-year EFS, 25.0% vs 44.6%; P = .008) in Era 2. Results from this prospective cohort study provide critical real-world evidence for improved outcomes with evolving frontline patterns of care in patients with MCL.

Ofatumumab plus HyperCVAD/HD-MA induction leads to high rates of minimal residual disease negativity in patients with newly diagnosed mantle cell lymphoma, results of a phase 2 study

BACKGROUND

Ofatumumab is a humanized type 1 anti-CD20 monoclonal antibody. Preclinical studies show improved complement-mediated cytotoxicity (CMC) compared to rituximab in mantle cell lymphoma (MCL). This study evaluates the safety and efficacy of combining ofatumumab with HyperCVAD/MA (O-HyperCVAD) in newly diagnosed MCL.

METHODS

In this single-arm phase 2 study, 37 patients were treated with the combination of O-HyperCVAD for 4 or 6 cycles, followed by high dose chemotherapy and autologous stem cell transplant. Primary objectives were overall response rate (ORR) and complete response (CR) rate at the end of therapy. Secondary objectives included minimal residual disease (MRD) negativity, progression-free survival (PFS), and overall survival (OS).

RESULTS

Median age was 60 years; ORR was 86% and 73% achieved a CR by modified Cheson criteria. The MRD negativity rate was 78% after 2 cycles of therapy, increasing to 96% at the end of induction; median PFS and OS were 45.5 months and 56 months, respectively. Achieving a post-induction CR by both imaging and flow cytometry was associated with improved PFS and OS. Early MRD negativity (post-2 cycles) was also associated with an improved PFS but not OS. There were 3 deaths while on therapy, and grades 3 and 4 adverse events (AEs) were observed in 22% and 68% of the patients.

CONCLUSION

The addition of ofatumumab to HyperCVAD/HD-MA led to high rates of MRD negativity by flow cytometry in patients with newly diagnosed MCL. Achieving a CR post-induction by both imaging and flow cytometry is associated with improved overall survival.

Initial Treatment Patterns and Survival Outcomes of Mantle Cell Lymphoma Patients Managed at Chinese Academic Centers in the Rituximab Era: A Real-World Study

Purpose

The aim of the study was to delineate the disease characteristics, the initial treatment patterns, and survival in patients with mantle cell lymphoma (MCL) managed in the real world.

Methods

Data of 518 MCL patients from 5 major Chinese Hematology Centers in the period from 2007 to 2017 were retrospectively analyzed.

Results

The median age was 58 years. Of the patients, 88.6% had Eastern Cooperative Oncology Group Performance Status (ECOG PS) 0–1 and 80.7% had advanced-stage disease. Ki67 expression was <30% in 39.6% of the patients, and 43.2% of patients were categorized into a low-risk group based on the Mantle Cell Lymphoma International Prognostic Index (MIPI) scoring system. Overall, 73.4% of the patients received rituximab as their first-line therapy. The most commonly used chemotherapy was the CHOP-like (cyclophosphamide, hydroxydaunomycin, oncovin, and prednisone) regimen (45.2%), followed by high-dose cytarabine-containing chemotherapy (31.3%) and bendamustine (3.3%). Of the patients, 13.7% (n = 71) underwent consolidative autologous stem cell transplantation (ASCT), and 19.3% (n = 100) received novel agents containing first-line regimens. With a median follow-up time of 52 months, the 3- and 5-year overall survival (OS) rates were 73.7% and 61.4%, respectively. Age ≤60 years, ECOG PS 0–1, stages I–II, normal lactate dehydrogenase (LDH), absence of bone marrow involvement, Ki67 <30%, and lower-risk IPI/MIPI scores were significantly associated with improved OS (p < 0.05). The inclusion of rituximab improved the 5-year OS, with borderline significance (62.5% vs. 55.2%, p = 0.076). High-dose cytarabine-containing chemotherapy showed significant clinical benefit in 5-year OS (72.1% vs. 55.9%, p = 0.010). Patients with ASCT had better 5-year OS in the younger (≤60 years) age group (87.2% vs. 64.8%, p = 0.002).

Conclusion

This large retrospective dataset unequivocally confirmed the survival advantage afforded by cytarabine-containing regimen and ASCT in a first-line setting under real-world management in the rituximab era.

SAMHD1 Mutations and Expression in Mantle Cell Lymphoma Patients

SAMHD1 (sterile alpha motif domain and histidine-aspartate domain-containing protein 1) is a deoxynucleoside triphosphate triphosphohydrolase regulating innate immune and modulating DNA damage signaling. It plays an important role in the development of some tumors. SAMHD1 was also reported as a barrier to cytarabine, a common chemotherapy drug for mantle cell lymphoma (MCL), and as a biomarker of grim prognosis for acute myelocytic leukemia (AML) patients. However, SAMHD1 expression and function in MCL have not been well-defined. In the present study, we evaluated SAMHD1 expression by immunohistochemistry and its gene structure by Sanger sequencing in MCL. Our results showed that SAMHD1 was positive in 36 (62.1%) patients. Importantly, SAMHD1-positive patients were associated with lower chemotherapy response rate (p = 0.023) and shorter overall survival (p = 0.039) than SAMHD1-negative cases. These results suggest that SAMHD1 is an adverse biomarker for MCL patients, which is due to the high expression of SAMHD1 and rapid cell proliferation. These findings were confirmed in an in vitro study using the siRNA technique. Silencing the SAMHD1 gene in the MCL cell line Jeko-1 significantly decreased cell proliferation and increased cell apoptosis. The MCL cell line with SAMHD1 knockdown showed lower Ki-67 proliferation index, higher caspase-3, and higher sensitivity to cytarabine. Furthermore, for the first time, four previously unreported missense mutations (S302Y, Y432C, E449G, and R451H) in exon 8 and exon 12 of the SAMHD1 gene were discovered by sequencing. The mutations had not been found to corelate with SAMHD1 protein expression detected by immunohistochemistry. The biological functions of this mutated SAMHD1 remain to be investigated.

R-MACLO-IVAM regimen followed by maintenance therapy induces durable remissions in untreated mantle cell lymphoma - Long term follow up results

We present long-term combined results of two clinical trials implementing R-MACLO-IVAM induction followed by thalidomide or rituximab maintenance in 44 patients with untreated mantle cell lymphoma (MCL). The first 22 patients (UM-MCL1 ClinicalTrials.gov identifier NCT00450801) received maintenance with thalidomide (200 mg daily until relapse/intolerable toxicity) and a subsequent cohort of 22 patients (UM-MCL2 ClinicalTrials.gov identifier NCT00878254) received rituximab (375 mg/m² IV weekly × 4, repeated every 6 months for 3 years). Considering all 44 patients, 41 (93.2%) achieved complete response (CR), two (4.5%) partial response (PR), and one (2.3%) was not evaluated for response. With a median follow up of 7.2 years (range < 1 month to 16 years), the 5-year progression-free survival (PFS) was 55.6% (95% CI: 38.9%-69.4%) and median PFS 7.9 years (95% CI: 3.7-11 years). The 5-year OS was 83.3% (95% CI: 68.1%-91.7%) and median OS was not reached. Patients with blastic variant (n = 6) had a 5-year PFS and OS of 20.8% and 60%, respectively. Myelosuppression was the most common adverse event during immunochemotherapy. Long-term treatment-related mortality was 6.8%. Note, R-MACLO-IVAM followed by maintenance therapy is an effective regimen to induce long-term remission in MCL without need for consolidation with ASCT.

Mantle cell lymphoma - advances in molecular biology, prognostication and treatment approaches

Mantle cell lymphoma (MCL) is clinically characterised by its heterogenous behaviour with courses ranging from indolent cases that do not require therapy for years to highly aggressive MCL with a very limited prognosis. A better understanding of the complex biology of MCL has already led to the approval of several innovative agents, expanding the landscape of MCL therapies and improving therapeutic options especially for refractory/relapsed (R/R) disease. Nevertheless, to further optimise MCL treatment, early identification of individual risk profile and risk-adapted, patient-tailored choice of therapeutic strategy needs to be prospectively incorporated into clinical patient management. The present review highlights recent advances in deciphering the molecular background of MCL, the definition of prognostically relevant factors and the identification of potential druggable targets and summarises current treatment recommendations for primary and R/R MCL including novel targeted therapies.

Novel Treatments for Mantle Cell Lymphoma: From Targeted Therapies to CAR T Cells

Mantle cell lymphoma is a rare B-cell non-Hodgkin's lymphoma that retains a sobering prognosis despite an extensive research effort. Mantle cell lymphoma remains incurable even with aggressive, and at times toxic, chemoimmunotherapy with early incorporation of autologous stem cell transplantation. Given this, attention has turned to the use of targeted therapies addressing dysregulation of B-cell signaling pathways. Drugs such as immunomodulatory agents, proteasome inhibitors, and Bruton's tyrosine kinase inhibitors have shown success in the relapsed/refractory population, and there is ongoing investigation into the utilization of novel Bruton's tyrosine kinase, B-cell leukemia/lymphoma-2, and spleen tyrosine kinase inhibitors alone or in combination in both the front-line and relapsed settings. Other areas of research in novel immunotherapies include investigations of bispecific T-cell engagers and antibody-drug conjugates. Most recently, chimeric antigen receptor T-cell therapy has been granted US Food and Drug Administration approval as a result of durable remissions even in high-risk patients who have classically done poorly with traditional chemoimmunotherapy. The intent of this article is to review the literature describing these selective therapies and discuss their current and future roles in the treatment of mantle cell lymphoma.

Cellular Therapies for Mantle Cell Lymphoma

Mantle cell lymphoma (MCL) is a subtype of B cell non-Hodgkin lymphoma characterized by a heterogeneous clinical presentation. Patients who demonstrate an objective response to induction therapy(ies) and are eligible for intensive therapies are offered an autologous hematopoietic cell transplant (HCT) as front-line consolidation followed by rituximab maintenance. Allogeneic HCT is an option for younger and fit patients with high-risk disease or in patients who have relapsed after autologous HCT. Recent advances in T cell engineering brought chimeric antigen receptor T cell (CAR T) therapy from the bench to the bedside, with brexucabtagene autoleucel being the first CAR T product approved by the US Food and Drug Administration for use in relapsed/refractory MCL. In this comprehensive review, we summarize the literature on available cellular therapies for MCL and present a treatment algorithm that incorporates HCT, autologous or allogeneic, and CAR T therapies.

Blastic Mantle Cell Lymphoma of the Gastroesophageal Junction: A Unique Presentation and Literature Review

Although vast, the medical literature is deficient in reports of gastroesophageal junction (GEJ) involvement of mantle cell lymphoma (MCL). We present the unique case of a 76-year-old male who presented with worsening dysphagia, weight loss, and heartburn and who was found to have blastic variant of MCL in the GEJ. He had undergone extensive workup in the past for an ulcerative, gastric/GEJ lesion, found on four separate esophagogastroduodenoscopies (EGDs) and two esophageal ultrasounds, whose biopsies were repeatedly negative for malignancy. On admission, physical examination and labs were unremarkable, but computed tomography showed an irregular mass involving the GEJ. EGD on admission showed a large friable, ulcerated lesion with heaped-up margins involving the GEJ whose biopsies showed histological and immunohistochemical (IHC) findings consistent with blastic MCL. A bone marrow biopsy showed minimal involvement (<5%) of CD5+/CD23+ B cells and was negative for both cyclin D1 and t(11;14). The biopsy of the lesion was diffusely infiltrated by atypical lymphocytes with prominent nucleoli and IHC stains positive for CD20, cyclin D1, BCL-2, and BCL-6 as well as a Ki-67 proliferative index >90%, all consistent with blastic MCL, a rare and aggressive subtype of MCL. He was started on guideline-based chemoimmunotherapy as he was not a candidate for stem cell transplantation. Repeat imaging 1 year later showed improvement of the mass, with negative endoscopic biopsies for lymphoma. This case provides additional distinct features to the various clinical presentations associated with this rare proliferative disorder, thereby enhancing the medical literature on MCL.

Cytarabine nanotherapeutics with increased stability and enhanced lymphoma uptake for tailored highly effective therapy of mantle cell lymphoma

Mantle cell lymphoma (MCL) is a rare subtype of B-cell non-Hodgkin lymphoma (B-NHL) with chronically relapsing clinical course. Implementation of cytarabine (araC) into induction and salvage regimen became standard of care for majority of MCL patients. In this study, tailored N-(2-hydroxypropyl)methacrylamide (HPMA)-based polymer nanotherapeutics containing covalently bound araC (araC co-polymers) were designed, synthesized and evaluated for their anti-lymphoma efficacy in vivo using a panel of six patient-derived lymphoma xenografts (PDX) derived from newly diagnosed and relapsed / refractory (R/R) MCL. While free araC led to temporary inhibition of growth of MCL tumors, araC co-polymers induced long-term disappearance of the engrafted lymphomas with no observed toxicity even in the case of PDX models derived from patients, who relapsed after high-dose araC-based treatments. The results provide sound preclinical rationale for the use of HPMA-based araC co-polymers in induction, salvage or palliative therapy of MCL patients.

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.

Management of Mantle Cell Lymphoma in the Era of Novel Oral Agents

Objectives: To discuss (1) recent and emerging data for pharmacological management of untreated and relapsed/refractory (R/R) mantle cell lymphoma (MCL) with agents approved in the United States, (2) important considerations for toxicity monitoring and management, and (3) preliminary data and ongoing studies for agents in MCL-specific clinical trials. Data Sources: PubMed/MEDLINE, EMBASE, Google Scholar, product labeling, National Comprehensive Cancer Network, American Cancer Society, and ClinicalTrials.gov were searched for studies published between January 1, 2017, and January 31, 2020, and key historical trials. Study Selection and Data Extraction: Relevant studies conducted in humans and selected supporting preclinical data were reviewed. Data Synthesis: MCL is a rare but usually aggressive non-Hodgkin lymphoma that most commonly affects the older population. Traditionally, the treatment of MCL has been determined based on transplant eligibility. Newer data suggest that more tolerable frontline therapy may produce outcomes similar to intensive historical induction regimens, possibly precluding fewer patients from autologous stem cell transplant and producing better long-term outcomes in transplant-ineligible patients. In the R/R setting, novel regimens are improving outcomes and changing the landscape of treatment. Relevance to Patient Care and Clinical Practice: This review summarizes and discusses recent and emerging data for management of newly diagnosed and R/R MCL; key supportive care considerations for agents are also discussed. Conclusions: Recent study results are changing management of MCL. Although these data have complicated the picture of regimen selection, increasingly effective and tolerable therapy and additional anticipated data point to a brighter future for patients with MCL.

Initial and Consolidation Therapy for Younger Patients with Mantle Cell Lymphoma

Mantle cell lymphoma is an incurable B-cell malignancy. Treatment of young fit patients is particularly challenging, because careful consideration should be made when building a long-term treatment strategy that would provide longer remissions and increase patients' quality of life. Most young fit patients achieve long remissions with a combination of immunochemotherapy containing rituximab and high-dose cytarabine, followed by high-dose chemotherapy and autologous stem-cell transplantation. The addition of maintenance therapy with rituximab following autologous stem-cell transplantation prolongs the time to relapse and increases overall survival. Despite an intensive approach, late relapses are common and are usually treated with novel agents.

Evaluating the Therapeutic Potential of Zanubrutinib in the Treatment of Relapsed/Refractory Mantle Cell Lymphoma: Evidence to Date

Mantle cell lymphoma (MCL) is an uncommon B-cell non-Hodgkin lymphoma characterized by an aggressive clinical course in the majority of patients. Despite recent improvements in outcomes, MCL remains incurable and a major therapeutic challenge. BTK inhibitors are the preferred treatment option for patients with relapsed/refractory MCL, including those unfit for chemotherapy or those with chemoresistant disease. In addition to ibrutinib and acalabrutinib, the FDA recently approved zanubrutinib for the treatment of patients with relapsed/refractory MCL based on the results of two Phase 2 clinical trials showing overall response rates of 85-87% with complete responses in 30-77% of patients. Compared with ibrutinib, zanubrutinib is more selective for BTK and has less off-target inhibition, which is thought to limit certain toxicities although direct comparative data are still lacking. This review article summarizes data from clinical trials of currently FDA-approved BTK inhibitors in MCL with a focus on zanubrutinib.

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.

Correlative analysis of overall survival with clinical characteristics in 127 patients with mantle cell lymphoma: a multi-institutional cohort in Taiwan

Mantle cell lymphoma (MCL) is a B-cell non-Hodgkin lymphoma often with extranodal involvement at diagnosis, and yet how this feature correlates with survival awaits elucidation. To address this issue, a correlative analysis between clinical features of 127 MCL patients and their overall survival (OS) was conducted. In this cohort, the median age at MCL diagnosis was 62 years and 81% were males. Eighty-four percent of patients were Ann Arbor stage 4, and 15% were blastoid variants. In patients with gastrointestinal MCL, approximately 40% had gastric involvement. In treatment, CHOP-based induction chemotherapy was given to 61.1% of patients. One-third of patients undertook autologous stem cell transplant (SCT), and 4.7% had allogeneic SCT. The median OS was 82 months and well-stratified in MIPI risk groups. In the multivariate analysis for OS, blastoid variants and gastric involvement were both independent risk factors whereas auto-SCT had a protective effect. Overall, this study corroborated with the current understandings and international therapeutic standards for MCL. Auto-SCT associated with a better OS while allo-SCT remained an option for blastoid variants and those who failed Auto-SCT. Interestingly, patients with gastric involvement tended to have worse survival, a finding that spawns more studies to investigate the mechanism.

Long-term results of the MCL01 phase II trial of rituximab plus HyperCVAD alternating with high-dose cytarabine and methotrexate for the initial treatment of patients with mantle cell lymphoma

Mantle cell lymphoma is a rare and incurable lymphoproliferative disorder. In the MCL01 trial, patients were treated with the R-HCVAD regimen [rituximab plus HyperCVAD (hyperfractionated cyclophosphamide, vincristine, doxorubicin, dexamethasone; R-CVAD) alternating with high-dose methotrexate and cytarabine (AM)] for four cycles followed by autologous stem cell transplantation (ASCT) for those who reached only a partial response. After a median follow-up of 10·5 years, we reported 10-year progression-free and overall survival rates of 35% and 61% respectively, with a 10-years cumulative incidence rate of second malignancies of 10·6%. Mature results of the MCL01 trial confirmed the efficacy of HyperCVAD-AM as a frontline regimen for younger patients (≤65 years).

Systematic literature review of the global burden of illness of mantle cell lymphoma

Background: Mantle cell lymphoma (MCL), a rare and aggressive disease, accounts for approximately 5% of all B-cell non-Hodgkin's lymphomas. Evidence on the burden of this disease, for patients and healthcare providers, is scarce.Methods: Four systematic literature reviews were developed to identify epidemiological, real-world clinical, economic and humanistic burden data on patients with MCL. Electronic databases searched included MEDLINE and Embase, NHS EED and Econlit.Results: Eight epidemiological studies, 19 clinical burden, 2 economic impact and 0 quality of life studies were identified. The range of standardized MCL incidence rates was 0.1-1.27/100,000. Overall survival rates of patients at 3 years differed by age at diagnosis (≤65 years: 76-81%, >65 years: 46-64%) and disease stage (stage I: 73-80%, stage IV: 48-53%). Outcomes were poorer in previously treated patients, and those with later stage or blastoid disease, and improved with more recent diagnosis/treatment. Hospitalization is a major contributor to healthcare cost and differs by therapy toxicity.Conclusions: We identified significant data gaps for many G20 countries for epidemiology, real-world clinical, economic and humanistic burden. These literature reviews demonstrate the ongoing unmet need for MCL patients globally. Future research to further understand the real-world impact of MCL is needed along with new therapeutic options to improve patient outcomes.

[Risk - adapted intensive induction therapy, autologous stem cell transplantation, and rituximab maintenance allow to reach a high 7-year survival rate in patients with mantle cell lymphoma]

Mantle cell lymphoma (MCL) is aggressive B-cell neoplasm diagnosed predominantly among older men. R-CHOP-like regimens allow to achieve high response rate, but the overall survival (OS) are disappointingly short - 3-4 years. An addition of high - dose cytarabine to the upfront therapy and autoSCT significantly improved outcomes but remain feasible largely for medically fit patients. Based on the activity and good tolerance of gemcitabine - oxaliplatin schemes in relapsed and refractory MCL patients, we developed an alternative first - line course for patients who are not eligible for R-HD-MTX-AraC.

AIM

Assess toxicity and efficacy of R-DA-EPOCH/ R-HD-MTX-AraC and R-DA-EPOCH/R-GIDIOX schemes, autoSCT and R-maintenance in untreated MCL patients.

MATERIALS AND METHODS

47 untreated MCL patients from 6 centers were enrolled in prospective study between April 2008 and September 2013. All patients have stage II-V; ECOG 0-3; median age 55 years (29-64); Male/Female 76%/24%. MIPIb: 28% low, 33% intermediate and 39% high risk. Following 1st R-EPOCH patients were assigned to receive either R-DA-EPOCH/ R-HD-MTX-AraC or R-DA-EPOCH/ R-GIDIOX regimen. In the absence of renal failure, hematological toxicity grade 4 more than 3 days and severe infections patients received R-HD-MTX-AraC scheme (R 375 mg/m2 Day 0, Methotrexate 1000 mg/m2/24 hours Day 1, AraC 3000 mg/m2 q 12 hrs Days 2-3). Patients who had at least one of these complications received R-GIDIOX scheme (R 375 mg/m2 day 0, gemcitabine 800 mg/m2 days 1 and 4, ifosfamide 1000 mg/m2 days 1-5, dexamethasone 10 mg/m2 IV days 1-5, irinotecan 100 mg/m2 day 3, oxaliplatin 120 mg/m2 day 2). Subsequently these courses were alternating with R-DA-EPOCH in each arm of the protocol. Depending on the time of achieving CR patients received 6 or 8 courses, unless they progressed on therapy. Those patients who achieved PR/CR/CRu underwent autoSCT (BEAM-R). Post - transplant R-maintenance was administered for 3 years (R - 375 mg/m2 every 3 months).

RESULTS

29/47 patients were treated on R-HD-MTX-AraC arm (median 50 years; MIPIb: 35.7% low, 28.6% intermediate, 35.7% high risk) and 18/47 patients were on R-GIDIOX arm (median 60 years; MIPIb: 16.7% low, 38.9% intermediate, 44.4% high risk). In R-HD-MTX-AraC arm CR rate was 96.5%. In R-GIDIOX arm OR and CR rates were 94.4% and 77.7% respectively. Main hematological toxicity of R-GIDIOX was leukopenia gr. 4 occurred in 74.1%. With median follow - up of 76 months, the estimated 7-years OS and EFS in R-HD-MTX-AraC arm are 76% and 57% respectively. In R-GIDIOX arm the estimated 7-years OS and EFS are 59% and 44%, respectively. There are no statistical differences in EFS (p=0.47) and OS (p=0.06) between two arms.

CONCLUSIONS

The use of a risk - adapted strategy allowed 95.7% of patients achieve PR/CR/CRu, performed autoSCT and begun R-maintenance therapy with rituximab. None of the patients needed a premature discontinuation of therapy because of unacceptable toxicity. The performance of autoSCT and R-maintenance apparently allowed to partially offset differences in the intensity of induction therapy and to maintain comparable results of therapy in both induction arms.

The Minimal Residual Disease in Non-Hodgkin's Lymphomas: From the Laboratory to the Clinical Practice

Minimal residual disease (MRD) in non-Hodgkin's lymphomas (NHLs) still represents matter of interest and debate: indeed, the new available treatments offer higher rates of complete responses and MRD negativity than in the past, with a positive impact on the long-term survival. Furthermore, the introduction of more sensitive and accurate molecular techniques, such as digital PCR (ddPCR) and the next generation sequencing techniques (NGS), increased the possibility of identifying molecular targets to be followed after therapy (such as rearrangement of immunoglobulins, fusion genes, or mutations). This review focused on how molecular biology can help to detect MRD in different types of NHLs and how MRD can change the clinical practice in 2019. In follicular lymphoma (FL), contamination of the grafts and molecular disease persistence after transplantation represent a negative prognostic factors. The combination of Rituximab or Obinutuzumab with Bendamustine seems to be the most effective way to clear MRD in FL patients receiving chemo-immunotherapy (further studies are in progress), and also ⁹⁰Yttrium-Ibritumomab-Tiuxetan offers a deep clearance of molecular disease. Finally, molecular MRD can further stratify PET-negative cases, with subjects both PET- and MRD-negative presenting the best outcome. In aggressive lymphomas, MRD has a relevant prognostic power and can represent the platform for immunotherapy (such as CAR-T). In diffuse large B-cell lymphoma (DLBCL), the assessment of MRD in the plasma (where cell-free DNA and exosomes circulate) seems to be more predictive than the bone marrow analysis or peripheral blood mononuclear cells. Finally, NGS technologies could be more useful than the classical "patient allele-specific PCR" because they can identify any possible clone emerging during the treatment or follow-up, even if different from that identified at diagnosis, thus predicting relapse. After all, the present available molecular approaches can move MRD from the bench side to the clinical practice.

Mantle cell lymphoma: 2019 update on the diagnosis, pathogenesis, prognostication, and management

Unprecedented advances in our understanding of the pathobiology, prognostication, and therapeutic options in mantle cell lymphoma (MCL) have taken place in the last few years. Heterogeneity in the clinical course of MCL-indolent vs aggressive-is further delineated by a correlation with the mutational status of the variable region of immunoglobulin heavy chain, methylation status, and SOX-11 expression. Cyclin-D1 negative MCL, in situ MCL neoplasia, and impact of the karyotype on prognosis are distinguished. Apart from Ki-67% and morphology pattern (classic vs blastoid/pleomorphic), the proliferation gene signature has helped to further refine prognostication. Studies focusing on mutational dynamics and clonal evolution on Bruton's tyrosine kinase (BTK) inhibitors (ibrutinib, acalabrutinib) and/or Bcl2 antagonists (venetoclax) have further clarified the prognostic impact of somatic mutations in TP53, BIRC3, CDKN2A, MAP3K14, NOTCH2, NSD2, and SMARCA4 genes. In therapy, long-term follow-up on chemo-immunotherapy studies has demonstrated durable remissions in some patients; however, long-term toxicities, especially from second cancers, are a serious concern with chemotherapy. The therapeutic options in MCL are constantly evolving, with dramatic responses from nonchemotherapeutic agents (ibrutinib, acalabrutinib, and venetoclax). Chimeric antigen receptor therapy and combinations of nonchemotherapeutic agents are actively being studied and our focus is shifting toward making the treatment of MCL chemotherapy-free. Still, MCL remains incurable. The following aspects of MCL continue to pose a challenge: disease transformation, role of the cytokine-microenvironmental milieu, incorporation of positron emission tomography-computerized tomography imaging, minimal residual disease in the prognosis, circulating tumor DNA testing for clonal evolution, predicting resistance to BTK inhibitors, and optimal management of patients who progress on BTK/Bcl2 inhibitors. Next-generation clinical trials should incorporate nonchemotherapeutic agents and personalize the treatment based upon the genomic profile of individual patient. Recent advances in the field of MCL are reviewed.

Efficacy of the novel CDK7 inhibitor QS1189 in mantle cell lymphoma

Mantle cell lymphoma (MCL) is typically an aggressive and rare form of non-Hodgkin lymphoma (NHL) with a poor prognosis despite recent advances in immunochemotherapy and targeted therapeutics against NHL. New therapeutic agents are needed for MCL. In this study, we generated a potent inhibitor of cyclin-dependent kinase 7 (CDK7), designated QS1189, and confirmed its anti-cancer effects towards MCL and other lymphomas. QS1189 was highly selective for CDK7 and showed potent anticancer effects in MCL compared to other targeted therapeutic agents, such as ibrutinib and venetoclax. Consistent with a conventional CDK7 inhibitor, QS1189 treatment significantly decreased phosphorylation of the carboxyl-terminal domain of RNA polymerase II and transcription-associated genes. QS1189 induced cell cycle arrest at the G2/M phase and apoptosis. Interestingly, QS1189 overcame the acquired resistance to venetoclax, which is mediated by Bcl-xL. Similarly, QS1189 showed potent tumour cell growth inhibition of various lymphomas. Thus, CDK7 might be a suitable therapeutic target for inhibiting lymphoma, and QS1189 is a promising therapeutic option for various lymphomas and cells with acquired resistance to targeted therapy.

Simplified MIPI-B prognostic stratification method can predict the outcome well-retrospective analysis of clinical characteristics and management of newly-diagnosed mantle cell lymphoma patients from China

Mantle cell lymphoma (MCL) is an invasive B-cell lymphoma with significant individual differences. Currently, MCL international prognostic index (MIPI) score and tumor cell proliferation index Ki-67 have been proved to be the most important prognostic factors. But the prognostic effect of these factors in Asian population is uncertain. This study aimed to analyze the disease characteristics and prognostic factors of Chinese MCL patients.A total of 83 cases of newly-diagnosed MCL patients diagnosed by the Department of Pathology of our hospital between January 1, 2011, and May 31, 2016, were enrolled. The disease characteristics, treatment effects, and outcomes of the patients were collected and analyzed.According to our analysis, MCL cases accounted for 6.2% of non-Hodgkin lymphoma (NHL) cases and mainly occurred in elderly males. But the proportion of patients at stage IV by Ann Arbor staging system and high-risk group by simplified-MIPI (s-MIPI) were significantly lower than that among European patients. Immunochemotherapy containing rituximab was significantly more effective than chemotherapy (overall response rate, [ORR]: 88.5% vs 65.2%, P = .021) and significantly prolonged patient survival (progression free survival [PFS]: 45.5 m vs 16.2 m, P = .001; overall survival [OS]: 58.3 m vs 22.8 m, P = .001). The multivariate analysis showed that the B symptoms, s-MIPI and administration of immunochemotherapy were independent prognostic factors that affected PFS and OS of the patients. s-MIPI and B symptom make up s-MIPI-B stratification method, by which patients in low-risk group of s-MIPI without B symptom were classified as low-risk, patients in high-risk group of s-MIPI and patients in low-risk group of s-MIPI with B symptom as high-risk, the rest as middle-risk. 3-year PFS of the 3 groups were 74.9%, 43.4% and 16.1%, respectively (P = .001). 3-year OS were 84.4%, 62.2%, 27.6% (P <.001).Chinese MCL was male predominance. We have a minor proportion of late-stage and high-risk patients compared to European patients. Immunochemotherapy was proved to significantly improve the prognosis of MCL patients. B symptoms, s-MIPI, and administration of rituximab independently influenced the outcome. s-MIPI-B prognostic stratification method may better predict the prognosis of Asian MCL patients. Still, further confirmation in larger populations is needed.

Frontline Treatment for Older Patients with Mantle Cell Lymphoma

The natural history of mantle cell lymphoma (MCL) undergoing chemotherapy is a cyclical pattern of remission followed by recurrence of disease due to acquired chemotherapy resistance. The median age of the occurrence of MCL is 65 years, so half of the newly diagnosed MCL patients are considered "elderly." The tolerance to long-term chemotherapy in elderly patients is decreased; hence, the response to frontline therapy used is of paramount importance. We hope that our review may guide clinicians in treating such populations in a more personalized and evidence-based manner.In the older patients with risk variables, frontline treatment is determined according to different body status of fit, unfit or compromised, and frail. In the fit patients, the pursuit of remission and prolongation of survival might currently justify the use of more intense and toxic therapies. For unfit or compromised older patients, disease control needs to be prioritized, maintaining a balance between the benefits and toxicities of the treatment. For frail patients, tolerance of treatment and minimizing myelotoxicity should be the primary focus. "Chemotherapy-free" regimens are likely to be considered as the first-line strategy for this population. On the other hand, in the older MCL population without risk variables, observation or "watch and wait" can prevent overtreatment. Furthermore, more clinical trials and research studies on novel agents and targeted therapies need to be translated into the general population to provide optimal treatment and to guide personalized treatment. IMPLICATIONS FOR PRACTICE: This review emphasizes the importance of frontline therapies for older MCL patients. MCL patients commonly experience a cyclical pattern of remission followed by recurrence of disease due to acquired chemotherapy resistance. As a special population, elderly patients have various comorbidities and decreased organ function, which may reduce the chances of undergoing treatment for recurrent disease. Thus, this older population of patients with MCL should be treated separately and exceptionally. So far, systematic reviews with regard to frontline treatment for older patients with MCL have not been encountered, but the hope is that this review may guide clinicians in treating such populations in a more personalized and evidence-based manner.

Update on mantle cell lymphoma

Mantle cell lymphoma (MCL) is a rare subtype of non-Hodgkin lymphoma that is most commonly treated with combination chemo-immunotherapy at diagnosis because of the poor prognosis. More indolent presentations have been described including patients who can defer initial therapy without adverse impact on survival. The 2016 World Health Organization updated classification describes 2 major subtypes, classical and leukemic nonnodal MCL, each with unique molecular features and clinical presentations. Although there is no standard of care for MCL, aggressive chemo-immunotherapy regimens containing rituximab and cytarabine, followed by consolidation with autologous stem cell transplantation and maintenance rituximab, are the most used approach in young fit patients, and chemo-immunotherapy, followed by rituximab maintenance, is most commonly used in older patients. Despite the improvement in response durations with currently available therapies, patients will inevitably relapse. A number of targeted therapies are approved in the relapsed setting and are now under evaluation in combination with standard frontline therapy. Although the approval of ibrutinib changed the landscape of therapy for relapsed MCL, prognosis remains poor after progression on ibrutinib supporting the development of ibrutinib combinations to prolong response duration as well as the development of other novel agents for ibrutinib refractory disease. With ibrutinib being incorporated into initial therapy regimens, new options will be needed at relapse. Prognostic markers, such as minimal residual disease, have been shown to correlate independently with outcomes along with predicting relapse, with the potential to guide therapeutic decisions. The future treatment of MCL therapy will need to incorporate therapy based on risk-stratification and nonchemotherapeutic approaches.

Toward a Risk-Tailored Therapeutic Policy in Mantle Cell Lymphoma

PURPOSE OF REVIEW

Mantle cell lymphoma (MCL) prognosis is strictly related to the characteristics of the disease, which can range from very indolent cases to highly aggressive and refractory ones. Here we will review the current knowledge on MCL biomarkers.

RECENT FINDINGS

Biomarker-informed diagnosis is essential for differentiating MCL from other mature B cell tumors. Diagnosis of MCL relies on the identification of the t(11;14) translocation by FISH or the consequently aberrant expression of cyclin D1 by immunohistochemistry. For the few cases staining negative for cyclin D1, SOX11 may help to define the diagnosis. Prognostic biomarkers have been proposed to stratify MCL patients, including baseline clinical aspects (leukemic non-nodal presentation, in situ presentation, Mantle cell International Prognostic Index-MIPI), pathological aspects (blastoid morphology, Ki-67 proliferation index, SOX11 expression), genetic aspects (immunoglobulin gene mutation status, TP53 deletion or mutation, CDKN2A deletion), and depth of response after treatment (PET imaging, molecular minimal residual disease). Such tools are increasingly used as a guide for therapeutic decisions. Watchful waiting approach is recommended for patients harboring favorable clinico-biological features, such as leukemic non-nodal presentation, low MIPI score, non-blastoid disease, low Ki-67 proliferation rate, mutated immunoglobulin genes, and the lack of SOX11 expression. For patients in need of frontline therapy, the decision of whether to undertake intensive regimens is based upon patient's age and comorbidities. Central nervous system prophylaxis is recommended for cases showing blastoid morphology. The duration of remission is tightly correlated to the depth of response. With the aim of achieving a longer duration of remission and survival, younger patients may pursue more intensive regimens incorporating high-dose cytarabine, followed by myeloablative consolidation chemotherapy, autologous stem cell transplantation, and rituximab maintenance. Older patients could, on the other hand, benefit from lower intensity immunochemotherapy followed or not by a maintenance therapy depending on which frontline regimen is used. Despite the identification of several potential useful biomarkers that may inform the treatment decisions and the design of clinical trials, the treatment choice remains nowadays determined by the patient age and fitness rather than by the individual patient characteristics. Tailoring therapy toward a risk-adapted strategy to accommodate the wide spectrum of disease is an urgent challenge, and clinical trials may explore the feasibility of a biomarker-defined therapeutic policy.

R-High-CHOP/CHASER/LEED with autologous stem cell transplantation in newly diagnosed mantle cell lymphoma: JCOG0406 STUDY

Although induction immunochemotherapy including high‐dose cytarabine and rituximab followed by high‐dose chemotherapy (HDC) with autologous stem cell transplantation (ASCT) is recommended for younger patients (≤65 years old) with untreated mantle cell lymphoma (MCL), no standard induction and HDC regimen has been established. We conducted a phase II study of induction immunochemotherapy of R‐High‐CHOP/CHASER followed by HDC of LEED with ASCT in younger patients with untreated advanced MCL. Eligibility criteria included untreated MCL, stage II bulky to IV, and age 20‐65 years. Patients received 1 cycle of R‐High‐CHOP followed by 3 cycles of CHASER every 3 weeks. Peripheral blood stem cells (PBSC) were harvested during CHASER. LEED with ASCT was delivered to patients who responded to R‐High‐CHOP/CHASER. Primary endpoint was 2‐year progression‐free survival (PFS). From June 2008 to June 2012, 45 patients (median age 59 years; range 38‐65 years) were enrolled. PBSC were successfully harvested from 36 of 43 patients. Thirty‐five patients completed ASCT. Two‐year PFS was 77% (80% CI 68‐84), which met the primary endpoint. Five‐year PFS and overall survival were 52% (95% CI 34‐68%) and 71% (95% CI 51‐84%), respectively. Overall response and complete response rates after induction immunochemotherapy were 96% and 82%, respectively. The most common grade 4 toxicities were hematological. In younger patients with untreated MCL, R‐High‐CHOP/CHASER/LEED with ASCT showed high efficacy and acceptable toxicity, and it can now be considered a standard treatment option.

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

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

Current trials for frontline therapy of mantle cell lymphoma

Mantle cell lymphoma (MCL) is a rare and incurable subtype of non-Hodgkin's lymphoma that generally affects older individuals. However, the use of high-dose therapy and autologous stem cell transplant has improved significantly the prognosis of this hematological malignancy, but at the cost of increased toxicities, such as acute toxic death and secondary malignancies. But thanks to a rising understanding of the biology of MCL, the explosion of specifically targeted new efficacious agents, immunotherapy agents, and cellular therapies in the frontline setting, the prognosis of MCL is expected to improve dramatically.The initial treatment of MCL is currently not standardized and the therapeutic landscape of MCL is rapidly evolving. This review provides an extensive overview of the current frontline therapy trials for MCL and presents the results of innovative regimen, including some integrating novel agents and desintensified chemotherapy.

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

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

Efficacy of Standard Dose R-CHOP Alternating With R-HDAC Followed by Autologous Hematopoietic Cell Transplantation as Initial Therapy of Mantle Cell Lymphoma, a Single-Institution Experience

BACKGROUND

Young fit patients with mantle cell lymphoma (MCL) are commonly treated with induction chemotherapy followed by high-dose chemotherapy and autologous hematopoietic cell transplantation (AHCT). Induction regimens with modifications of R-CHOP (rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone) and/or incorporation of high-dose cytarabine (HDAC) appear more effective than R-CHOP alone.

PATIENTS AND METHODS

We adopted a modification of the Nordic protocol using standard, rather than higher dose R-CHOP, alternating with HDAC (rituximab plus HDAC), for 3 cycles each or, for patients already treated with R-CHOP alone before referral for AHCT, an additional 2 cycles of rituximab plus HDAC. We herein report our experience with 28 patients treated with this regimen who proceeded to AHCT, and compare their outcomes with patients treated with either standard-dose R-CHOP (n = 38) or R-HCVAD/MA (cyclophosphamide, vincristine, doxorubicin, dexamethasone alternating with methotrexate, and cytarabine; n = 21), before AHCT.

RESULTS

With a median follow-up duration of 26 months, our data show that this modification of the Nordic regimen is a highly effective pre-AHCT first-line therapy for MCL (3-year progression-free and overall survival rates of 69% and 75%, respectively).

CONCLUSION

By using a less intense induction, this regimen can serve as a platform for combined use of novel agents, with less risk of additive toxicity.

VcR-CVAD Induction Chemotherapy Followed by Maintenance Rituximab Produces Durable Remissions in Mantle Cell Lymphoma: A Wisconsin Oncology Network Study

INTRODUCTION

VcR-CVAD was developed as an intermediate-intensity induction regimen with maintenance rituximab (MR) to improve remission durations after first-line therapy for mantle cell lymphoma (MCL) in older and younger patients with MCL.

PATIENTS AND METHODS

Patients with previously untreated MCL received VcR-CVAD induction chemotherapy for 6 cycles (21-day cycles). Patients achieving at least a partial response received rituximab consolidation (375 mg/m² × 4 weekly doses) and MR (375 mg/m² every 12 weeks × 20 doses). The primary endpoints were overall and complete response (CR), and the secondary endpoints were progression-free survival (PFS) and overall survival (OS). Thirty patients were enrolled, with a median age of 61 years. There was an even distribution of patients < 60 years and ≥ 60 years. Mantle cell lymphoma international prognostic index medium- or high-risk disease was present in 60%. The overall response rate observed was 90% (77% CR/unconfirmed CR). After a median follow-up of 7.8 years, the 6-year PFS and OS were 53% and 70%, respectively. There was no difference in 6-year PFS or OS between the younger (age < 60 years) and older (age ≥ 60 years) subgroups. In a univariate analysis, lactate dehydrogenase, when analyzed for interaction with age, had a significant effect on PFS outcomes at 6 years. There were no pretreatment variables determined to have a significant effect on OS outcomes at 6 years.

CONCLUSIONS

Long-term outcomes with VcR-CVAD are comparable with more intensive inductions and consolidation approaches. MCL is biologically heterogeneous, and durable remission can be achieved with intermediate intensity therapy. MR appears to contribute to these excellent outcomes.