Advances in Molecular Biology and Targeted Therapy of Mantle Cell Lymphoma

Real-world effectiveness and safety of ibrutinib in relapsed/refractory mantle cell lymphoma in Japan: post-marketing surveillance

Efficacy and safety data for ibrutinib in Japanese patients with relapsed/refractory (R/R) mantle cell lymphoma (MCL) were limited at the time of its approval in Japan. All-case post-marketing surveillance was conducted in Japanese R/R MCL patients who began ibrutinib treatment between December 2016 and December 2017, and patients were followed until 30 June 2020. In the effectiveness analysis set (n = 202), the overall response rate was 59.9%, 52-week progression-free survival was 47.5%, and overall survival was 69.3%. Safety was assessed in 248 patients (median age 74.0 years). When ibrutinib treatment was started, patients had received a median of three prior lines of therapy. The overall incidence of adverse events (AE) was 74.6%, and AE frequency and severity grade distribution were similar between patients with 1 versus more than 1 prior line of therapy. The most common AE was platelet count decreased (all grades; 10.4%), similarly to previous observations in patients with R/R chronic lymphocytic leukemia/small lymphocytic lymphoma. Five patients (2.0%) developed atrial fibrillation. The effectiveness and safety of ibrutinib were consistent with its known profile at approval in Japan. These results suggest that ibrutinib is effective and safe in Japanese R/R MCL patients in routine clinical practice.

Comprehensive FISH testing using FFPE tissue microarray of primary lymph node tissue identifies secondary cytogenetic abnormalities in Mantle Cell Lymphoma

INTRODUCTION

Mantle Cell Lymphoma (MCL), is characterised by the reciprocal translocation t(11;14) resulting in CCND1-IGH gene fusion and subsequent upregulation of the CCND1 gene. Rearrangements of MYC and losses of CDKN2A and TP53 have been identified as biomarkers informing prognostic and potentially therapeutic information however these are not routinely assessed in MCL investigation. We aimed to identify additional cytogenetic changes using fluorescence in situ hybridisation (FISH) on formalin fixed paraffin embedded (FFPE) primary lymph node tissue microarrays in a cohort of 28 patients diagnosed with MCL between 2004 and 2019. FISH results were compared with corresponding immunohistochemistry (IHC) biomarkers to determine if IHC was a reliable screening tool to direct FISH testing.

METHOD

FFPE lymph node tissue samples were constructed into tissue microarrays (TMA) which were stained with 7 immunohistochemical biomarkers: Cyclin D1, c-Myc, p16, ATM, p53, Bcl-6 and Bcl-2. The same TMAs were hybridised with FISH probes for the corresponding genes; CCND1-IGH, MYC, CDKN2A, ATM, TP53, BCL6 and BCL2. FISH and the corresponding IHC biomarkers were analysed to determine if secondary cytogenetic changes could be identified and if IHC could be used as a reliable, inexpensive predictor of FISH abnormalities to potentially direct FISH testing.

RESULTS

CCND1-IGH fusion was detected in 27/28 (96%) of samples. Additional cytogenetic changes were identified by FISH in 15/28 (54%) of samples. Two additional abnormalities were detected in 2/28 (7%) samples. Cyclin D1 IHC overexpression was an excellent predictor of CCND1-IGH fusion. MYC and ATM IHC were useful screening tests to direct FISH testing and identified cases with poor prognostic features including blastoid change. IHC did not show clear concordance with FISH for other biomarkers.

CONCLUSION

FISH using FFPE primary lymph node tissue can detect secondary cytogenetic abnormalities in patients with MCL which are associated with an inferior prognosis. An expanded FISH panel including MYC, CDKN2A, TP53 and ATM should be considered in cases where anomalous IHC expression or is seen for these markers or if the patient appears to have the blastoid variant of the disease.

Second primary malignancies in non-Hodgkin lymphoma: epidemiology and risk factors

With the advancements in therapeutics for non-Hodgkin lymphoma (NHL), the long-term survival of patients with NHL has markedly increased. Second primary malignancies (SPMs) have become an increasingly relevant long-term concern for NHL survivors. The etiology of SPMs is multifactorial and involves multiple steps. Germline alterations, immune dysregulation, and clonal hematopoiesis contribute to the accumulation of intrinsic adverse factors, and external factors such as lifestyle; exposure to infectious factors; and late effects of radiotherapy, chemotherapy, high-dose therapy, and autologous hematopoietic stem cell transplantation further increase SPM risk. Therapy-related myeloid neoplasms (t-MNs) are a devastating complication of cytotoxic chemotherapeutic agents. However, as targeted therapies begin to replace cytotoxic chemotherapy, the incidence of t-MNs is likely to decline, particularly for indolent B-cell NHL.

Expression of PD1 and PDL1 as immune-checkpoint inhibitors in mantle cell lymphoma

BACKGROUND

Mantle cell lymphoma (MCL) has remained incurable in most patients. The expression of PD-L1 as a prognostic and predictive marker has not been fully evaluated in MCL. The current study aimed to determine PD-1/PD-L1 expression in MCL specimens and its significance as an immune check point inhibitor.

METHODS

This retrospective study was conducted on the formalin-fixed paraffin-embedded blocks of 79 confirmed MCL patients based on immunohistochemistry (IHC). The IHC method was used to stain patient samples for PD1 and PDL1. Positive PD-1/PD-L1 expression was defined as moderate to strong or memberanous or memberanous/cytoplasmic staining in at least 5% of tumor and/or 20% of associated immune cells. Tumor aggressiveness was determined based on Ki67 and variant.

RESULTS

The mean age of the patients was 60.08 ± 10.78 years old. Majority of the patients were male. The prevalence of aggressive tumor was 25%. Positive PD1 and PDL1 expression were identified in 12 (15.0%) and 3 (3.8%) of tumor cells, respectively. PD1 and PDL1 were positive in zero (0%) and 7 (8.9%) of background cells, respectively. There was no significant difference in terms of study parameters between positive and negative groups for both PD1 and PDL1 proteins. PD1 tumor cell percentage was negatively correlated with age (r = -0.254, p = 0.046).

CONCLUSION

Our results suggest that neither PD-1 nor its ligands represent relevant targets for MCL treatment. Age may impact the efficiency of immune checkpoint inhibitors and could be related to the increased incidence of MCL with age.

CircCTNNA1 is Upregulated in Mantle Cell Lymphoma and Predicts Poor Survival by Sponging miR-34a to Increase Cell Proliferation

Background

It was reported that circular RNA (circRNA) circCTNNA1 plays an oncogenic role in colorectal cancer, while its role in mantle cell lymphoma (MCL) is unknown. This study aimed to explore the role of circCTNNA1 in MCL.

Methods

Samples of B lymphocytes were collected from 56 MCL patients and 56 healthy controls. The expression of circCTNNA1 and miR-34a in these samples were determined by RT-qPCR. The direct interaction between circCTNNA1 and miR-34a in MCL cells was detected using RNA-RNA pulldown assay. Overexpression assays were performed to study the interactions between circCTNNA1 and miR-34a. Cell proliferation was assessed with BrdU assay.

Results

The results showed that circCTNNA1 was upregulated in MCL and high expression levels of circCTNNA1 predicted the poor survival of MCL patients. MiR-34a was downregulated in MCL and inversely correlated with circCTNNA1. CircCTNNA1 was predicted to interact with miR-34a, and the interaction between them was confirmed by RNA pull-down assay. Interestingly, overexpression of circCTNNA1 and miR-34a did not affect the expression of each other. Cell proliferation analysis showed that overexpression of circCTNNA1 reversed the inhibitory effects of overexpression of miR-34a on cell proliferation.

Conclusion

Upregulation of circCTNNA1 in MCL predicts poor survival of patients and it may sponge miR-34a to promote cancer cell proliferation.

Mantle cell lymphoma: A clinical review of the changing treatment paradigms with the advent of novel therapies, and an insight into Indian data

BACKGROUND

Mantle cell lymphoma (MCL) is a rare type of mature B-cell lymphoid malignancy with the pathologic hallmark of translocation t(11;14) (q13, q32), which leads to an overexpression of Cyclin D1 (CCND1). The disease is also characterized by the presence of a high number of recurrent genetic alterations, which include aberrations in several cellular pathways. MCL is a heterogeneous disease with a wide range of clinical presentations and a majority presenting with aggressive disease in advanced stages.

RECENT FINDINGS

Management of MCL is bereft with challenges due to its resistant and relapsing pattern. Despite improvements in remission durations, the disease is currently incurable with standard therapy and has a median survival of about 3-5 years. The use of small molecules like the bruton tyrosine kinase (BTK) and BCL2 inhibitors, for treating relapsed MCL has been established leading to a diminishing role for conventional chemotherapy. Combinations of small molecule inhibitors with or without chemoimmunotherapy, are showing promising results. Cellular therapy in the form of CAR-T cell therapy, has been approved recently.

CONCLUSIONS

Personalized cancer treatment and chemo-free regimens are showing promise and results from well-planned long-term studies are evolving. In India, there is a paucity of epidemiological, clinical, and research data in this field.

Cost-Effectiveness of Brexucabtagene Autoleucel versus Best Supportive Care for the Treatment of Relapsed/Refractory Mantle Cell Lymphoma following Treatment with a Bruton's Tyrosine Kinase Inhibitor in Canada

For patients with Mantle Cell Lymphoma (MCL), there is no recognized standard of care for relapsed/refractory (R/R) disease after treatment with a Bruton's tyrosine kinase inhibitor (BTKi). Brexucabtagene autoleucel (brexu-cel) represents a promising new treatment modality in MCL. We explored whether brexu-cel was cost-effective for the treatment of R/R MCL. We developed a partitioned survival mixture cure approach to model the costs and outcomes over a lifetime horizon. The clinical data were derived from the ZUMA-2 clinical trial. The costs were estimated from the publicly available Canadian databases, published oncology literature, and pan-Canadian Oncology Drug Review economic guidance reports. The health state utilities were sourced from the ibrutinib submission to the National Institute for Health and Care Excellence for R/R MCL and supplemented with values from the published oncology literature. In the base case over a lifetime horizon, brexu-cel generated an incremental 9.56 life-years and an additional 7.03 quality-adjusted life-years compared to BSC, while associated with CAD 621,933 in additional costs. The resultant incremental cost-utility ratio was CAD 88,503 per QALY gained compared with BSC. Based on this analysis, we found brexu-cel to be a cost-effective use of healthcare resources relative to BSC for treatment of adult patients with R/R MCL previously treated with a BTKi in Canada, though additional research is needed to confirm these results using longer follow-up data.

Dose escalation of subcutaneous epcoritamab in patients with relapsed or refractory B-cell non-Hodgkin lymphoma: an open-label, phase 1/2 study

BACKGROUND

Patients with relapsed or refractory B-cell non-Hodgkin lymphoma have few treatment options. We aimed to establish the safety and recommended phase 2 dose of epcoritamab, a novel bispecific antibody that targets CD3 and CD20 and induces T-cell-mediated cytotoxic activity against CD20+ malignant B cells.

METHODS

For the dose-escalation part of this phase 1/2 study, we enrolled adults (aged ≥18 years) with relapsed or refractory CD20+ B-cell non-Hodgkin lymphoma at ten sites across four countries (Denmark, the Netherlands, the UK, and Spain). Eligible patients received priming and intermediate doses followed by full doses of subcutaneous epcoritamab administered in 28-day cycles; each subsequent cohort involved escalation of the priming, intermediate, or full dose (0·0128-60 mg). The primary objectives were to determine the maximum tolerated dose and the recommended phase 2 dose. Safety, antitumour activity, pharmacokinetics, and immune biomarkers were also assessed. This study is registered with ClinicalTrials.gov, NCT03625037, with the dose-expansion part ongoing.

FINDINGS

Between June 26, 2018, and July 14, 2020, we enrolled 73 patients with relapsed, progressive, or refractory CD20+ mature B-cell non-Hodgkin lymphoma. 68 patients received escalating full doses (0·0128-60 mg) of subcutaneous epcoritamab. No dose-limiting toxic effects were observed, and the maximum tolerated dose was not reached; the full dose of 48 mg was identified as the recommended phase 2 dose. All 68 patients received at least one dose of epcoritamab and were included in safety analyses: common adverse events were pyrexia (47 patients [69%]), primarily associated with cytokine release syndrome (CRS; 40 [59%], all grade 1-2), and injection site reactions (32 [47%]; 31 grade 1). There were no grade 3 or higher CRS events. No discontinuations occurred due to treatment-related adverse events or treatment-related deaths. Overall response rate in patients with relapsed or refractory diffuse large B-cell lymphoma was 68% (95% CI 45-86), with 45% achieving a complete response at full doses of 12-60 mg. At 48 mg, the overall response rate was 88% (47-100), with 38% achieving a complete response. Patients with relapsed or refractory follicular lymphoma had an overall response rate of 90% (55-100), with 50% achieving a complete response at full doses of 0·76-48 mg. Epcoritamab induced robust and sustained B-cell depletion, and CD4+ and CD8+ T-cell activation and expansion, with modest increases in cytokine levels.

INTERPRETATION

Single-agent subcutaneous epcoritamab for treatment of patients with relapsed or refractory B-cell non-Hodgkin lymphoma merits investigation in ongoing phase 2 and phase 3 studies.

FUNDING

Genmab and AbbVie.

Advances in chimeric antigen receptor T-cell therapy for B-cell non-Hodgkin lymphoma

B-cell non-Hodgkin lymphoma (B-NHL) is a group of heterogeneous disease which remains incurable despite developments of standard chemotherapy regimens and new therapeutic agents in decades. Some individuals could have promising response to standard therapy while others are unresponsive to standard chemotherapy or relapse after autologous hematopoietic stem-cell transplantation (ASCT), which indicates the necessity to develop novel therapies for refractory or relapsed B-NHLs. In recent years, a novel cell therapy, chimeric antigen receptor T-cell therapy (CAR-T), was invented to overcome the limitation of traditional treatments. Patients with aggressive B-NHL are considered for CAR-T cell therapy when they have progressive lymphoma after second-line chemotherapy, relapse after ASCT, or require a third-line therapy. Clinical trials of anti-CD19 CAR-T cell therapy have manifested encouraging efficacy in refractory or relapsed B-NHL. However, adverse effects of this cellular therapy including cytokine release syndrome, neurotoxicity, tumor lysis syndrome and on-target, off-tumor toxicities should attract our enough attention despite the great anti-tumor effects of CAR-T cell therapy. Although CAR-T cell therapy has shown remarkable results in patients with B-NHL, the outcomes of patients with B-NHL were inferior to patients with acute lymphoblastic leukemia. The inferior response rate may be associated with physical barrier of lymphoma, tumor microenvironment and low quality of CAR-T cells manufactured from B-NHL patients. Besides, some patients relapsed after anti-CD19 CAR-T cell therapy, which possibly were due to limited CAR-T cells persistence, CD19 antigen escape or antigen down-regulation. Quite a few new antigen-targeted CAR-T products and new-generation CAR-T, for example, CD20-targeted CAR-T, CD79b-targeted CAR-T, CD37-targeted CAR-T, multi-antigen-targeted CAR-T, armored CAR-T and four-generation CAR-T are developing rapidly to figure out these deficiencies.

Real World Treatment Practices for Mantle Cell Lymphoma in Japan: An Observational Database Research Study (CLIMBER-DBR)

Mantle cell lymphoma (MCL) accounts for approximately 3% of all cases of malignant lymphoma in Japan. The CLIMBER-DBR (Treatment practices and patient burden in chronic lymphocytic leukemia and mantle cell lymphoma patients in the real world: An observational database research in Japan) study examined the clinical characteristics, treatment patterns, and healthcare resource utilization of MCL in a real-world clinical setting in Japan. Using the Japanese Medical Data Vision database, we extracted data for 1130 patients with MCL (ICD-10 code C83.1) registered between March 1, 2013 and February 28, 2018. The date of first MCL diagnosis was taken as the index date. The mean (standard deviation) age, body weight, and modified Charlson Comorbidity Index were 71.4 (10.9) years, 58.3 (11.7) kg, and 1.9 (1.6), respectively, and 24.6% were ≤65 years old. The median follow-up period was 654 days (first–third quartile 290.5–1049 days). A total of 802 patients (71.0%) underwent first-line treatment. The most common first-line treatment was bendamustine/rituximab (BR; 27.8%), followed by rituximab/cyclophosphamide/doxorubicin/vincristine/prednisolone (R-CHOP; 15.6%) and rituximab/tetrahydropyranyl-adriamycin/cyclophosphamide/vincristine/prednisolone (R-THP-COP; 6.5%). The median (95% confidence interval) times to initial (first-line), second-line, and third-line treatments were 45 (36–62), 687 (624–734), and 1188 (1099–1444) days, respectively. Treatment practices for MCL in Japan are consistent with trends observed in Western countries. Our study can serve as a benchmark to assess future MCL treatments in Japan.

Targeted genomic investigations in a population-based cohort of mantle cell lymphoma reveal novel clinically relevant targets

Mantle cell lymphoma (MCL) is an aggressive B-cell neoplasm that follows a heterogeneous clinical course. Recurrent mutations have been described, but their applicability in the clinical setting is currently limited. The main reasons are challenges in the sequencing of DNA retrieved from formalin-fixed tissue commonly used for tissue collection in clinical biobanks. In this study, we sequenced 77 samples from a population-based de novo MCL cohort to investigate the utility of targeted sequencing in guiding personalized treatment approaches. Tumors were genetically variable, and a similar genetic landscape as previous studies using non-formalin fixed samples was identified, with recurrent mutations including ATM, KMT2D, and TP53. Novel alterations that can be considered actionable and/or indicative of treatment response were also identified. Our approach shows the potential benefits of using target sequencing of formalin fixed samples to facilitate treatment selection and individualized clinical decisions in MCL.

Quantitative In Vivo Monitoring of Hypoxia and Vascularization of Patient-Derived Murine Xenografts of Mantle Cell Lymphoma Using Photoacoustic and Ultrasound Imaging

Tumor oxygenation and vascularization are important parameters that determine the aggressiveness of the tumor and its resistance to cancer therapies. We introduce dual-modality ultrasound and photoacoustic imaging (US-PAI) for the direct, non-invasive real-time in vivo evaluation of oxygenation and vascularization of patient-derived xenografts (PDXs) of B-cell mantle cell lymphomas. The different optical properties of oxyhemoglobin and deoxyhemoglobin make it possible to determine oxygen saturation (sO₂) in tissues using PAI. High-frequency color Doppler imaging enables the visualization of blood flow with high resolution. Tumor oxygenation and vascularization were studied in vivo during the growth of three different subcutaneously implanted patient-derived xenograft (PDX) lymphomas (VFN-M1, VFN-M2 and VFN-M5 R1). Similar values of sO₂ (sO₂ Vital), determined from US-PAI volumetric analysis, were obtained in small and large VFN-M1 tumors ranging from 37.9 ± 2.2 to 40.5 ± 6.0 sO₂ Vital (%) and 37.5 ± 4.0 to 35.7 ± 4.6 sO₂ Vital (%) for small and large VFN-M2 PDXs. In contrast, the higher sO₂ Vital values ranging from 57.1 ± 4.8 to 40.8 ± 5.7 sO₂ Vital (%) (small to large) of VFN-M5 R1 tumors corresponds with the higher aggressiveness of that PDX model. The different tumor percentage vascularization (assessed as micro-vessel areas) of VFN-M1, VFN-M2 and VFN-M5 R1 obtained by color Doppler (2.8 ± 0.1%, 3.8 ± 0.8% and 10.3 ± 2.7%) in large-stage tumors clearly corresponds with their diverse growth and aggressiveness. The data obtained by color Doppler were validated by histology. In conclusion, US-PAI rapidly and accurately provided relevant and reproducible information on tissue oxygenation in PDX tumors in real time without the need for a contrast agent.

High-Risk Mantle Cell Lymphoma in the Era of Novel Agents

PURPOSE OF REVIEW

Mantle cell lymphoma (MCL) is a heterogenous disease with a variety of morphologic and genetic features, some of which are associated with high risk disease. Here we critically analyze the current state of the understanding of MCL's biology and its implications in therapy, with a focus on chemotherapy-free and targeted therapy regimens.

RECENT FINDINGS

Mantle cell lymphoma (MCL) is a rare subtype of non-Hodgkin's lymphoma, defined by a hallmark chromosomal translocation t(11;14) which leads to constitutive expression of cyclin D1. Recent discoveries in the biology of MCL have identified a number of factors, including TP53 mutations and complex karyotype, that lead to unresponsiveness to traditional chemoimmunotherapy and poor outcomes. Bruton tyrosine kinase inhibitors, BH3-mimetics and other novel agents thwart survival of the neoplastic B-cells in a manner independent of high-risk mutations and have shown promising activity in relapsed/refractory MCL. These therapies are being investigated in the frontline setting, while optimal responses to chemotherapy-free regimens, particularly in high-risk disease, might require combination approaches. High-risk MCL does not respond well to chemoimmunotherapy. Targeted agents are highly active in the relapsed refractory setting and show promise in high-risk disease. Novel approaches may soon replace the current standard of care in both relapsed and frontline settings.

Immune-Checkpoint Inhibitors in B-Cell Lymphoma

Simple Summary

Immune-based treatment strategies, which include immune checkpoint inhibition, have recently become a new frontier for the treatment of B-cell-derived lymphoma. Whereas checkpoint inhibition has given oncologists and patients hope in specific lymphoma subtypes like Hodgkin lymphoma, other entities do not benefit from such promising agents. Understanding the factors that determine the efficacy and safety of checkpoint inhibition in different lymphoma subtypes can lead to improved therapeutic strategies, including combinations with various chemotherapies, biologics and/or different immunologic agents with manageable safety profiles.

Abstract

For years, immunotherapy has been considered a viable and attractive treatment option for patients with cancer. Among the immunotherapy arsenal, the targeting of intratumoral immune cells by immune-checkpoint inhibitory agents has recently revolutionised the treatment of several subtypes of tumours. These approaches, aimed at restoring an effective antitumour immunity, rapidly reached the market thanks to the simultaneous identification of inhibitory signals that dampen an effective antitumor response in a large variety of neoplastic cells and the clinical development of monoclonal antibodies targeting checkpoint receptors. Leading therapies in solid tumours are mainly focused on the cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) and programmed death 1 (PD-1) pathways. These approaches have found a promising testing ground in both Hodgkin lymphoma and non-Hodgkin lymphoma, mainly because, in these diseases, the malignant cells interact with the immune system and commonly provide signals that regulate immune function. Although several trials have already demonstrated evidence of therapeutic activity with some checkpoint inhibitors in lymphoma, many of the immunologic lessons learned from solid tumours may not directly translate to lymphoid malignancies. In this sense, the mechanisms of effective antitumor responses are different between the different lymphoma subtypes, while the reasons for this substantial difference remain partially unknown. This review will discuss the current advances of immune-checkpoint blockade therapies in B-cell lymphoma and build a projection of how the field may evolve in the near future. In particular, we will analyse the current strategies being evaluated both preclinically and clinically, with the aim of fostering the use of immune-checkpoint inhibitors in lymphoma, including combination approaches with chemotherapeutics, biological agents and/or different immunologic therapies.

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.

Unusual location of recurrent mantle cell lymphoma on fluorodeoxyglucose-positron emission tomography despite complete metabolic resolution of previous sites of disease

This case report presents a patient with recurrent pleomorphic mantle cell lymphoma (MCL), which is a relatively rare but aggressive type of lymphoma. A positron emission tomography/computed tomography scan performed to assess treatment response demonstrated a complete metabolic response in the sites of primary disease while also revealing new subcutaneous lesions, which were biopsy-proven recurrent disease. This case illustrates the importance of the different biological behavior of MCL, whereby new sites of metabolically active lesions can represent recurrent disease, even though there is a complete metabolic response at sites of primary disease.

Genetic heterogeneity and prognostic impact of recurrent ANK2 and TP53 mutations in mantle cell lymphoma: a multi-centre cohort study

The molecular features of mantle cell lymphoma (MCL), including its increased incidence, and complex therapies have not been investigated in detail, particularly in East Asian populations. In this study, we performed targeted panel sequencing (TPS) and whole-exome sequencing (WES) to investigate the genetic alterations in Korean MCL patients. We obtained a total of 53 samples from MCL patients from five Korean university hospitals between 2009 and 2016. We identified the recurrently mutated genes such as SYNE1, ATM, KMT2D, CARD11, ANK2, KMT2C, and TP53, which included some known drivers of MCL. The mutational profiles of our cohort indicated genetic heterogeneity. The significantly enriched pathways were mainly involved in gene expression, cell cycle, and programmed cell death. Multivariate analysis revealed that ANK2 mutations impacted the unfavourable overall survival (hazard ratio [HR] 3.126; P = 0.032). Furthermore, TP53 mutations were related to worse progression-free survival (HR 7.813; P = 0.043). Among the recurrently mutated genes with more than 15.0% frequency, discrepancies were found in only 5 genes from 4 patients, suggesting comparability of the TPS to WES in practical laboratory settings. We provide the unbiased genetic landscape that might contribute to MCL pathogenesis and recurrent genes conferring unfavourable outcomes.

Concurrent TP53 and CDKN2A Gene Aberrations in Newly Diagnosed Mantle Cell Lymphoma Correlate with Chemoresistance and Call for Innovative Upfront Therapy

Mantle cell lymphoma (MCL) is a subtype of B-cell lymphoma with a large number of recurrent cytogenetic/molecular aberrations. Approximately 5–10% of patients do not respond to frontline immunochemotherapy. Despite many useful prognostic indexes, a reliable marker of chemoresistance is not available. We evaluated the prognostic impact of seven recurrent gene aberrations including tumor suppressor protein P53 (TP53) and cyclin dependent kinase inhibitor 2A (CDKN2A) in the cohort of 126 newly diagnosed consecutive MCL patients with bone marrow involvement ≥5% using fluorescent in-situ hybridization (FISH) and next-generation sequencing (NGS). In contrast to TP53, no pathologic mutations of CDKN2A were detected by NGS. CDKN2A deletions were found exclusively in the context of other gene aberrations suggesting it represents a later event (after translocation t(11;14) and aberrations of TP53, or ataxia telangiectasia mutated (ATM)). Concurrent deletion of CDKN2A and aberration of TP53 (deletion and/or mutation) represented the most significant predictor of short EFS (median 3 months) and OS (median 10 months). Concurrent aberration of TP53 and CDKN2A is a new, simple, and relevant index of chemoresistance in MCL. Patients with concurrent aberration of TP53 and CDKN2A should be offered innovative anti-lymphoma therapy and upfront consolidation with allogeneic stem cell transplantation.

PD-1, PD-L1 and PD-L2 Expression in Mantle Cell Lymphoma and Healthy Population

Cell surface expression of PD-1, PD-L1 and PD-L2 immune checkpoints on B and T cells obtained from patients with mantle cell lymphoma shows ambiguous results across many studies and creates obstacles for the implementation of immune checkpoint inhibitors into the therapy of mantle cell lymphoma. Using multiparameter flow cytometry we analysed surface expression of PD-1, PD-L1 and PD-L2 molecules on B and T cells of 31 newly diagnosed mantle cell lymphomas and compared it with the results of 26 newly diagnosed chronic lymphocytic leukaemias and 20 healthy volunteers. To gain insight into the age-dependent changes of surface expression of these immune checkpoints, flow cytometric subanalysis of 30 healthy volunteers of 25-93 years of age was conducted. Overall, we demonstrated weak surface expression of PD-1, PD-L1 and PD-L2 on B and T cells of mantle cell lymphoma patients (< 10 % when compared to healthy individuals). A significant age-dependent increase in the expression of PD-1 and its ligand PD-L2 was observed in healthy volunteers. Our results suggest that neither PD-1 nor its ligands represent relevant druggable targets for the therapy of mantle cell lymphoma. The observed age-dependent changes in healthy population could impact efficiency of immune checkpoint inhibitors and could be at least partly connected with increased incidence of cancer with age.