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

Mantle cell lymphoma characterized by numerous diffuse polypoid lesions along the entire digestive tract: A case report

Primary mantle cell lymphoma (MCL) in the gastrointestinal tract is rare, accounting for 4-9% of all reported cases of gastrointestinal non-Hodgkin lymphoma. Furthermore, involvement of the entire gastrointestinal tract in MCL is rare. The present report describes an example of MCL characterized by numerous diffuse polypoid lesions along the whole digestive tract. In particular, there was a focus on the endoscopic presentation of the digestive tract. The patient initially received a treatment regimen of rituximab combined with cyclophosphamide, doxorubicin, vincristine and prednisone. After two cycles of treatment, the regimen was changed to rituximab combined with etoposide, oxaliplatin and ifosfamide, with the addition of ibrutinib capsules. Patients with MCL have a poor prognosis; however, complete response can be achieved after treatment.

Mantle Cell Lymphoma Under the Scope of Personalized Medicine: Perspective and Directions

Mantle cell lymphoma (MCL) is a rare, incurable non-Hodgkin's lymphoma characterized by naive B cells infiltrating the lymphoid follicle's mantle zone. A key feature of MCL is the cytogenetic abnormality t(11;14) (q13:q14), found in 95% of cases, leading to Cyclin D1 overexpression resulting in uncontrolled cell cycle progression and genetic instability. Occasionally, Cyclin D2 or D3 overexpression can substitute for Cyclin D1, causing similar effects. The transcription factor SOX11 is a hallmark of classical Cyclin D1-positive MCL and also in cases without the typical t(11;14) abnormality, making it an important diagnostic marker. MCL's development necessitates secondary genetic changes, including mutations in the ATM, TP53, and NOTCH1 genes, with the TP53 mutation being the only genetic biomarker with established clinical prognostic value. The Mantle Cell Lymphoma International Prognostic Index (MIPI) score, which considers age, performance status, serum LDH levels, and leukocyte count, stratifies patients into risk groups. Histologic variants of MCL, such as classic, blastoid, and pleomorphic, offer additional prognostic information. Recent research highlights new mutations potentially tied to specific populations among MCL patients, suggesting the benefit of personalized management for better predicting outcomes like progression-free survival. This approach could lead to more effective, risk-adapted treatment strategies. However, challenges remain in patient stratification and in developing new therapeutic targets for MCL. This review synthesizes current knowledge on genetic mutations in MCL and their impact on prognosis. It aims to explore the prognostic value of genetic markers related to population traits, emphasizing the importance of tailored molecular medicine in MCL.

Primary adrenal mantle cell lymphoma mimicking a non-functional retroperitoneal paraganglioma

Key Clinical Message

Patients presenting with abdominal pain and retroperitoneal mass in radiographic images may be in the early stages of primary adrenal mantle cell lymphoma, which requires histological studies for a definite diagnosis.

Abstract

This report presents a 37-year-old woman complaining of ambiguous abdominal pain, with imaging findings revealing a retroperitoneal abdominal mass on the left side of the aorta, and a possible diagnosis of non-functional retroperitoneal paraganglioma. Total laparoscopic excision was performed. Surprisingly, histological examinations revealed features in favor of mantle cell lymphoma.

Targeting DNMT3A-mediated oxidative phosphorylation to overcome ibrutinib resistance in mantle cell lymphoma

The use of Bruton tyrosine kinase (BTK) inhibitors such as ibrutinib achieves a remarkable clinical response in mantle cell lymphoma (MCL). Acquired drug resistance, however, is significant and affects long-term survival of MCL patients. Here, we demonstrate that DNA methyltransferase 3A (DNMT3A) is involved in ibrutinib resistance. We find that DNMT3A expression is upregulated upon ibrutinib treatment in ibrutinib-resistant MCL cells. Genetic and pharmacological analyses reveal that DNMT3A mediates ibrutinib resistance independent of its DNA-methylation function. Mechanistically, DNMT3A induces the expression of MYC target genes through interaction with the transcription factors MEF2B and MYC, thus mediating metabolic reprogramming to oxidative phosphorylation (OXPHOS). Targeting DNMT3A with low-dose decitabine inhibits the growth of ibrutinib-resistant lymphoma cells both in vitro and in a patient-derived xenograft mouse model. These findings suggest that targeting DNMT3A-mediated metabolic reprogramming to OXPHOS with decitabine provides a potential therapeutic strategy to overcome ibrutinib resistance in relapsed/refractory MCL.

NSD family proteins: Rising stars as therapeutic targets

Epigenetic modifications, including DNA methylation and histone post-translational modifications, intricately regulate gene expression patterns by influencing DNA accessibility and chromatin structure in higher organisms. These modifications are heritable, are independent of primary DNA sequences, undergo dynamic changes during development and differentiation, and are frequently disrupted in human diseases. The reversibility of epigenetic modifications makes them promising targets for therapeutic intervention and drugs targeting epigenetic regulators (e.g., tazemetostat, targeting the H3K27 methyltransferase EZH2) have been applied in clinical therapy for multiple cancers. The NSD family of H3K36 methyltransferase enzymes-including NSD1 (KMT3B), NSD2 (MMSET/WHSC1), and NSD3 (WHSC1L1)-are now receiving drug development attention, with the exciting advent of an NSD2 inhibitor (KTX-1001) advancing to Phase I clinical trials for relapsed or refractory multiple myeloma. NSD proteins recognize and catalyze methylation of histone lysine marks, thereby regulating chromatin integrity and gene expression. Multiple studies have implicated NSD proteins in human disease, noting impacts from translocations, aberrant expression, and various dysfunctional somatic mutations. Here, we review the biological functions of NSD proteins, epigenetic cooperation related to NSD proteins, and the accumulating evidence linking these proteins to developmental disorders and tumorigenesis, while additionally considering prospects for the development of innovative epigenetic therapies.

Clinical features of neurotoxicity after CD19 CAR T-cell therapy in mantle cell lymphoma

ABSTRACT

CD19 chimeric antigen receptor (CAR) T-cell therapy has proven highly effective for treating relapsed/refractory mantle cell lymphoma (MCL). However, immune effector cell-associated neurotoxicity syndrome (ICANS) remains a significant concern. This study aimed to evaluate the clinical, radiological, and laboratory correlatives associated with ICANS development after CD19 CAR T-cell therapy in patients with MCL. All patients (N = 26) who received standard-of-care brexucabtagene autoleucel until July 2022 at our institution were evaluated. Laboratory and radiographic correlatives including brain magnetic resonance imaging (MRI) and electroencephalogram (EEG) were evaluated to determine the clinical impact of ICANS. Seventeen (65%) patients experienced ICANS after treatment, with a median onset on day 6. Ten (38%) patients experienced severe (grade ≥3) ICANS. All patients with ICANS had antecedent cytokine release syndrome (CRS), but no correlation was observed between ICANS severity and CRS grade. Overall, 92% of EEGs revealed interictal changes; no patients experienced frank seizures because of ICANS. In total, 86% of patients with severe ICANS with postinfusion brain MRIs demonstrated acute neuroimaging findings not seen on pretreatment MRI. Severe ICANS was also associated with higher rates of cytopenia, coagulopathy, increased cumulative steroid exposure, and prolonged hospitalization. However, severe ICANS did not affect treatment outcomes of patients with MCL. Severe ICANS is frequently associated with a range of postinfusion brain MRI changes and abnormal EEG findings. Longer hospitalization was observed in patients with severe ICANS, especially those with abnormal acute MRI or EEG findings, but there was no discernible impact on overall treatment response and survival.

The influence of marital status at diagnosis on survival of adult patients with mantle cell lymphoma

PURPOSE

Marital status has been reported to influence the survival outcomes of various cancers, but its impact on patients with mantle cell lymphoma (MCL) remains unclear. This study aimed to assess the influence of marital status at diagnosis on overall survival (OS) and cancer-specific survival (CSS) in patients with MCL.

METHODS

The study utilized data from the National Cancer Institute's Surveillance, Epidemiology, and End Results (SEER)-18 databases, including 6437 eligible individuals diagnosed with MCL from 2000 to 2018. A 1:1 propensity matching method (PSM) minimized confounding factor. Univariate and multivariate analyses determined hazard ratios (HR). Stratified hazard models were developed for married and unmarried statuses across time intervals.

RESULTS

Married patients exhibited better 5-year OS and CSS rates compared to unmarried patients (54.2% vs. 39.7%, log-rank p < 0.001; 62.6% vs. 49.3%, log-rank p < 0.001). Multivariate analysis indicated that being unmarried was an independent risk factor for OS (adjusted HR 1.420, 95% CI 1.329-1.517) and CSS (adjusted HR 1.388, 95% CI 1.286-1.498). After PSM, being unmarried remained an independent risk factor for both OS and CSS. Among unmarried patients, widowed individuals exhibited the poorest survival outcomes compared to patients with other marital statuses, with 5-year OS and CSS rates of 28.5% and 41.0%, respectively. Furthermore, in the 10-year OS and CSS hazard model for widowed individuals had a significantly higher risk of mortality, with the probability of overall and cancer-specific mortality increased by 1.7-fold and 1.6-fold, respectively.

CONCLUSION

Marital status at diagnosis is an independent prognostic factor for MCL patients, with widowed individuals showing worse OS and CSS than those who are married, single, or divorced/separated. Adequate psychological and social support for widowed patients is crucial for improving outcomes in this patient population.

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.

SENP3 Promotes Mantle Cell Lymphoma Development through Regulating Wnt10a Expression

OBJECTIVE

SUMO-specific protease 3 (SENP3), a member of the SUMO-specific protease family, reverses the SUMOylation of SUMO-2/3 conjugates. Dysregulation of SENP3 has been proven to be involved in the development of various tumors. However, its role in mantle cell lymphoma (MCL), a highly aggressive lymphoma, remains unclear. This study was aimed to elucidate the effect of SENP3 in MCL.

METHODS

The expression of SENP3 in MCL cells and tissue samples was detected by RT-qPCR, Western blotting or immunohistochemistry. MCL cells with stable SENP3 knockdown were constructed using short hairpin RNAs. Cell proliferation was assessed by CCK-8 assay, and cell apoptosis was determined by flow cytometry. mRNA sequencing (mRNA-seq) was used to investigate the underlying mechanism of SENP3 knockdown on MCL development. A xenograft nude mouse model was established to evaluate the effect of SENP3 on MCL growth in vivo.

RESULTS

SENP3 was upregulated in MCL patient samples and cells. Knockdown of SENP3 in MCL cells inhibited cell proliferation and promoted cell apoptosis. Meanwhile, the canonical Wnt signaling pathway and the expression of Wnt10a were suppressed after SENP3 knockdown. Furthermore, the growth of MCL cells in vivo was significantly inhibited after SENP3 knockdown in a xenograft nude mouse model.

CONCLUSION

SENP3 participants in the development of MCL and may serve as a therapeutic target for MCL.

Resistance to PRMT5-targeted therapy in mantle cell lymphoma

ABSTRACT

Mantle cell lymphoma (MCL) is an incurable B-cell non-Hodgkin lymphoma, and patients who relapse on targeted therapies have poor prognosis. Protein arginine methyltransferase 5 (PRMT5), an enzyme essential for B-cell transformation, drives multiple oncogenic pathways and is overexpressed in MCL. Despite the antitumor activity of PRMT5 inhibition (PRT-382/PRT-808), drug resistance was observed in a patient-derived xenograft (PDX) MCL model. Decreased survival of mice engrafted with these PRMT5 inhibitor-resistant cells vs treatment-naive cells was observed (P = .005). MCL cell lines showed variable sensitivity to PRMT5 inhibition. Using PRT-382, cell lines were classified as sensitive (n = 4; 50% inhibitory concentration [IC50], 20-140 nM) or primary resistant (n = 4; 340-1650 nM). Prolonged culture of sensitive MCL lines with drug escalation produced PRMT5 inhibitor-resistant cell lines (n = 4; 200-500 nM). This resistant phenotype persisted after prolonged culture in the absence of drug and was observed with PRT-808. In the resistant PDX and cell line models, symmetric dimethylarginine reduction was achieved at the original PRMT5 inhibitor IC50, suggesting activation of alternative resistance pathways. Bulk RNA sequencing of resistant cell lines and PDX relative to sensitive or short-term-treated cells, respectively, highlighted shared upregulation of multiple pathways including mechanistic target of rapamycin kinase [mTOR] signaling (P < 10-5 and z score > 0.3 or < 0.3). Single-cell RNA sequencing analysis demonstrated a strong shift in global gene expression, with upregulation of mTOR signaling in resistant PDX MCL samples. Targeted blockade of mTORC1 with temsirolimus overcame the PRMT5 inhibitor-resistant phenotype, displayed therapeutic synergy in resistant MCL cell lines, and improved survival of a resistant PDX.

Genetic and prognostic analysis of blastoid and pleomorphic mantle cell lymphoma: a multicenter analysis in China

Blastoid or pleomorphic mantle cell lymphoma (B/P-MCL) is characterized by high invasiveness and unfavorable outcomes, which is still a challenge for treating MCL. This retrospective study was performed to comprehensively analyze the clinical, genomic characteristics and treatment options of patients with B/PMCL from multicenter in China. Data were obtained from 693 patients with B/PMCL from three centers in China between April 1999 and December 2019. Seventy-four patients with BMCL (n = 43) or PMCL (n = 31) were included in the analysis. The median age of the cohort was 60.0 years with a male-to-female ratio of 2.89:1. The 3-year progression-free survival (PFS) and overall survival (OS) rates were 44.1% and 46.0%, respectively. Mutations of TP53, ATM, NOTCH1, NOTCH2, NSD2, SMARCA4, CREBBP, KMT2D, FAT1, and TRAF2 genes were the most common genetic changes in B/P-MCL. Progression of disease within 12 months (POD12) could independently predict the poor prognosis of patients with blastoid and pleomorphic variants. Patients with POD12 carried a distinct mutation profile (TP53, SMARCA4, NSD2, NOTCH2, KMT2D, PTPRD, CREBBP, and CDKN2A mutations) compared to patients with non-POD12. First-line high-dose cytosine arabinoside exposure obtained survival benefits in these populations, and BTKi combination therapy as the front-line treatment had somewhat improvement in survival with no significant difference in the statistic. In conclusion, B/P-MCL had inferior outcomes and a distinct genomic profile. Patients with POD12 displayed a distinct mutation profile and a poor prognosis. New therapeutic drugs and clinical trials for B/P-MCL need to be further explored.

EGR1-mediated metabolic reprogramming to oxidative phosphorylation contributes to ibrutinib resistance in B-cell lymphoma

The use of Bruton tyrosine kinase inhibitors, such as ibrutinib, to block B-cell receptor signaling has achieved a remarkable clinical response in several B-cell malignancies, including mantle cell lymphoma (MCL) and diffuse large B-cell lymphoma (DLBCL). Acquired drug resistance, however, is significant and affects the long-term survival of these patients. Here, we demonstrate that the transcription factor early growth response gene 1 (EGR1) is involved in ibrutinib resistance. We found that EGR1 expression is elevated in ibrutinib-resistant activated B-cell-like subtype DLBCL and MCL cells and can be further upregulated upon ibrutinib treatment. Genetic and pharmacological analyses revealed that overexpressed EGR1 mediates ibrutinib resistance. Mechanistically, TCF4 and EGR1 self-regulation induce EGR1 overexpression that mediates metabolic reprogramming to oxidative phosphorylation (OXPHOS) through the transcriptional activation of PDP1, a phosphatase that dephosphorylates and activates the E1 component of the large pyruvate dehydrogenase complex. Therefore, EGR1-mediated PDP1 activation increases intracellular adenosine triphosphate production, leading to sufficient energy to enhance the proliferation and survival of ibrutinib-resistant lymphoma cells. Finally, we demonstrate that targeting OXPHOS with metformin or IM156, a newly developed OXPHOS inhibitor, inhibits the growth of ibrutinib-resistant lymphoma cells both in vitro and in a patient-derived xenograft mouse model. These findings suggest that targeting EGR1-mediated metabolic reprogramming to OXPHOS with metformin or IM156 provides a potential therapeutic strategy to overcome ibrutinib resistance in relapsed/refractory DLBCL or MCL.

Evolving treatment patterns and improved outcomes in relapsed/refractory mantle cell lymphoma: a prospective cohort study

Over the last two decades, the frontline therapy for mantle cell lymphoma (MCL) has evolved. However, the impact of subsequent lines of therapy on survival outcomes has not been well characterized. In this study, we investigated the treatment patterns and survival outcomes in patients with relapsed/refractory (R/R) MCL treated with second-line (2 L) therapy. Adult patients with newly diagnosed MCL from 2002 to 2015 were enrolled in a prospective cohort study. Clinical characteristics, 2 L treatment details, and outcomes were compared between patients who received 2 L treatment between 2003-2009 (Era 1), 2010-2014 (Era 2), and 2015-2021 (Era 3). 2 L treatment was heterogenous in all eras, and there was a substantial shift in the pattern of 2 L therapy over time. The estimated 2-year EFS rate was 21% (95% CI, 13-35), 40% (95% CI, 30-53), and 51% (95% CI, 37-68) in Era 1-3 respectively, and the 5-year OS rate was 31% (95% CI, 21-45), 37% (95% CI, 27-50), and 67% (95% CI, 54-83) in Era 1-3, respectively. These results provide real-world evidence on evolving treatment patterns of 2 L therapy based on the era of relapse. The changes in 2 L treatment correlated with improved EFS and OS, suggesting that treatment advances are associated with improved outcomes in patients with R/R MCL.

Potentiation of apoptosis in drug-resistant mantle cell lymphoma cells by MCL-1 inhibitor involves downregulation of inhibitor of apoptosis proteins

Bruton's tyrosine kinase inhibitors (BTKi) and CAR T-cell therapy have demonstrated tremendous clinical benefits in mantle cell lymphoma (MCL) patients, but intrinsic or acquired resistance inevitably develops. In this study, we assessed the efficacy of the highly potent and selective MCL-1 inhibitor AZD5991 in various therapy-resistant MCL cell models. AZD5991 markedly induced apoptosis in these cells. In addition to liberating BAK from the antiapoptotic MCL-1/BAK complex for the subsequent apoptosis cascade, AZD5991 downregulated inhibitor of apoptosis proteins (IAPs) through a BAK-dependent mechanism to amplify the apoptotic signal. The combination of AZD5991 with venetoclax enhanced apoptosis and reduced mitochondrial oxygen consumption capacity in MCL cell lines irrespective of their BTKi or venetoclax sensitivity. This combination also dramatically inhibited tumor growth and prolonged mouse survival in two aggressive MCL patient-derived xenograft models. Mechanistically, the augmented cell lethality was accompanied by the synergistic suppression of IAPs. Supporting this notion, the IAP antagonist BV6 induced dramatic apoptosis in resistant MCL cells and sensitized the resistant MCL cells to venetoclax. Our study uncovered another unique route for MCL-1 inhibitor to trigger apoptosis, implying that the pro-apoptotic combination of IAP antagonists and apoptosis inducers could be further exploited for MCL patients with multiple therapeutic resistance.

BET in hematologic tumors: Immunity, pathogenesis, clinical trials and drug combinations

The bromodomain and extra-terminal (BET) proteins act as "readers" for lysine acetylation and facilitate the recruitment of transcriptional elongation complexes. BET protein is associated with transcriptional elongation of genes such as c-MYC and BCL-2, and is involved in the regulation of cell cycle and apoptosis. Meanwhile, BET inhibitors (BETi) have regulatory effects on immune checkpoints, immune cells, and cytokine expression. The role of BET proteins and BETi in a variety of tumors has been studied. This paper reviews the recent research progress of BET and BETi in hematologic tumors (mainly leukemia, lymphoma and multiple myeloma) from cellular level studies, animal studies, clinical trials, drug combination, etc. BETi has a promising future in hematologic tumors, and future research directions may focus on the combination with other drugs to improve the efficacy.

PRMT5 inhibition drives therapeutic vulnerability to combination treatment with BCL-2 inhibition in mantle cell lymphoma

Mantle cell lymphoma (MCL) is an incurable B-cell malignancy that comprises up to 6% of non-Hodgkin lymphomas diagnosed annually and is associated with a poor prognosis. The average overall survival of patients with MCL is 5 years, and for most patients who progress on targeted agents, survival remains at a dismal 3 to 8 months. There is a major unmet need to identify new therapeutic approaches that are well tolerated to improve treatment outcomes and quality of life. The protein arginine methyltransferase 5 (PRMT5) enzyme is overexpressed in MCL and promotes growth and survival. Inhibition of PRMT5 drives antitumor activity in MCL cell lines and preclinical murine models. PRMT5 inhibition reduced the activity of prosurvival AKT signaling, which led to the nuclear translocation of FOXO1 and modulation of its transcriptional activity. Chromatin immunoprecipitation and sequencing identified multiple proapoptotic BCL-2 family members as FOXO1-bound genomic loci. We identified BAX as a direct transcriptional target of FOXO1 and demonstrated its critical role in the synergy observed between the selective PRMT5 inhibitor, PRT382, and the BCL-2 inhibitor, venetoclax. Single-agent and combination treatments were performed in 9 MCL lines. Loewe synergy scores showed significant levels of synergy in most MCL lines tested. Preclinical, in vivo evaluation of this strategy in multiple MCL models showed therapeutic synergy with combination venetoclax/PRT382 treatment with an increased survival advantage in 2 patient-derived xenograft models (P ≤ .0001, P ≤ .0001). Our results provide mechanistic rationale for the combination of PRMT5 inhibition and venetoclax to treat patients with MCL.

Combating relapsed and refractory Mantle cell lymphoma with novel therapeutic armamentarium: Recent advances and clinical prospects

Mantle cell lymphoma (MCL) is a rare, aggressive subtype of non-Hodgkin's lymphoma (NHL), accounting for 5% of all cases. Due to its virulence factor, it is an incurable disease and keeps relapsing despite an intensive treatment regimen. Advancements in research and drug discovery have shifted the treatment strategy from conventional chemotherapy to targeted agents and immunotherapies. The establishment of the role of Bruton tyrosine kinase led to the development of ibrutinib, a first-generation BTK inhibitor, and its successors. A conditioning regimen based immunotherapeutic agent like ibritumumob, has also demonstrated a viable response with a favorable toxicity profile. Brexucabtagene Autoleucel, the only approved CAR T-cell therapy, has proven advantageous for relapsed/refractory MCL in both children and adults. This article reviews certain therapies that could help update the current approach and summarizes a few miscellaneous agents, which, seldom studied in trials, could alleviate the regression observed in traditional therapies. DATA AVAILABILITY: The datasets generated during and/or analyzed during the current study are available from the corresponding author on reasonable request.

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.

A novel CAR-T cell product targeting CD74 is an effective therapeutic approach in preclinical mantle cell lymphoma models

BACKGROUND

Mantle cell lymphoma (MCL) is a rare B-cell non-Hodgkin lymphoma subtype which remains incurable despite multimodal approach including chemoimmunotherapy followed by stem cell transplant, targeted approaches such as the BTK inhibitor ibrutinib, and CD19 chimeric antigen receptor (CAR) T cells. CD74 is a nonpolymorphic type II integral membrane glycoprotein identified as an MHC class II chaperone and a receptor for macrophage migration inhibitory factor. Our group previously reported on CD74's abundant expression in MCL and its ability to increase via pharmacological inhibition of autophagosomal degradation. Milatuzumab, a fully humanized anti-CD74 monoclonal antibody, demonstrated significant activity in preclinical lymphoma models but failed to provide meaningful benefits in clinical trials mainly due to its short half-life. We hypothesized that targeting CD74 using a CAR-T cell would provide potent and durable anti-MCL activity.

METHODS

We engineered a second generation anti-CD74 CAR with 4-1BB and CD3ζ signaling domains (74bbz). Through in silico and rational mutagenesis on the scFV domain, the 74bbz CAR was functionally optimized for superior antigen binding affinity, proliferative signaling, and cytotoxic activity against MCL cells in vitro and in vivo.

RESULTS

Functionally optimized 74bbz CAR-T cells (clone 42105) induced significant killing of MCL cell lines, and primary MCL patient samples including one relapse after commercial CD19 CAR-T cell therapy with direct correlation between antigen density and cytotoxicity. It significantly prolonged the survival of an animal model established in NOD-SCIDγc-/- (NSG) mice engrafted with a human MCL cell line Mino subcutaneously compared to controls. Finally, while CD74 is also expressed on normal immune cell subsets, treatment with 74bbz CAR-T cells resulted in minimal cytotoxicity against these cells both in vitro and in vivo.

CONCLUSIONS

Targeting CD74 with 74bbz CAR-T cells represents a new cell therapy to provide a potent and durable and anti-MCL activity.

High expression of NF-κB inducing kinase in the bulge region of hair follicle induces tumor

The bulge region, a reservoir of multipotent stem cells, is possibly responsible for tumorigenesis. NF-κB-inducing kinase (NIK) is a kinase involved in the activation of the noncanonical NF-κB pathway and exhibits positive staining in tumor cells. However, whether high expression of NIK can result in tumorigenesis has not been reported in published papers. By establishing Nik-coe (Nik-stopF/F crossed with Chat-cre) and Nik-soe (Nik-stopF/F crossed with Sox9-cre) mice, we found that overexpression of Nik in the bulge region of hair follicles induced hair follicle loss and tumorigenesis. Furthermore, RNA sequencing, proteomic and phosphopeptide analyses revealed that multiple cancer pathways are involved in tumor formation. Taken together, these findings indicate that constitutive activation of Nik in the bulge region induces tumorigenesis.

Drug Discovery Targeting Nuclear Receptor Binding SET Domain Protein 2 (NSD2)

Nuclear receptor binding SET domain proteins (NSDs) catalyze the mono- or dimethylation of histone 3 lysine 36 (H3K36me1 and H3K36me2), using S-adenosyl-l-methionine (SAM) as a methyl donor. As a key member of the NSD family of proteins, NSD2 plays an important role in the pathogenesis and progression of various diseases such as cancers, inflammations, and infectious diseases, serving as a promising drug target. Developing potent and specific NSD2 inhibitors may provide potential novel therapeutics. Several NSD2 inhibitors and degraders have been discovered while remaining in the early stage of drug development. Excitingly, KTX-1001, a selective NSD2 inhibitor, has entered clinical trials. In this Perspective, the structures and functions of NSD2, its roles in various human diseases, and the recent advances in drug discovery strategies targeting NSD2 have been summarized. The challenges, opportunities, and future directions for developing NSD2 inhibitors and degraders are also discussed.

Skin Involvement by Hematological Neoplasms with Blastic Morphology: Lymphoblastic Lymphoma, Blastoid Variant of Mantle Cell Lymphoma and Differential Diagnoses

Hematological neoplasms sharing a blastic morphology may involve the skin. The skin may be either the primary site of occurrence of hematological malignancies with blastic features or cutaneous lesions are the first manifestation of an underlying systemic malignancy. The assessment of skin biopsies of hematological neoplasms with blastic features poses diagnostic problems and requires expert hematopathologists considering a wide range of differential diagnoses. The precise diagnosis of diseases sharing blastic features but with different outcomes and requiring distinct therapies is essential for patient management. The present paper mainly focuses on cutaneous involvement of the blastoid variant of mantle cell lymphoma and lymphoblastic lymphoma of B-cell or T-cell origin. The relevant literature has been reviewed and the clinical aspects, pathological features, prognosis, and therapy of both blastoid mantle cell lymphoma and lymphoblastic lymphoma involving the skin are discussed. A focus on other hematological entities with blastic features, which may involve the skin, to be taken into consideration in differential diagnosis is also given.

Risk of a second cancer and infection in patients with indolent B-cell lymphoma exposed to first-line bendamustine plus rituximab: A retrospective analysis of an administrative claims database

Bendamustine has a potent immunosuppressive effect because it causes T-cell lymphopenia, which might lead to a second primary malignancy (SPM) and would increase the risk of infection. Using the Medical Data Vision administrative claims database, we compared the cumulative incidence of SPM, infections within 6 months, and overall survival (OS) among untreated patients with indolent B-cell lymphomas (iBCL) who received rituximab-based chemotherapy between 2009 and 2020. Patients with grade 3b follicular lymphoma or a previous history of malignancy were excluded. Eligible 5234 patients were assigned to three cohorts: rituximab monotherapy (N = 780), RCHOP/RCVP/RTHPCOP (doxorubicin replaced with pirarubicin) (N = 2298), or bendamustine/rituximab (BR) (N = 2156). There were 589 recorded SPMs, of which myelodysplastic syndromes were the most common (1.7%). The cumulative incidence of SPM was significantly higher in patients treated with BR than in those treated with rituximab monotherapy (p < 0.01) or RCHOP/RCVP/RTHPCOP (p < 0.0001): the 5-year cumulative incidence function was 18.1%, 12.5%, and 12.9%, respectively. In the Fine-Gray subdistribution hazards model, BR showed a significantly higher cumulative incidence of SPM than RCHOP/RCVP/RTHPCOP (subhazard ratio, 1.33; 95% confidence interval [CI], 1.10-1.61). Furthermore, in sensitivity analysis, a nested case-control study using an entire cohort showed consistent results: the SPM odds ratios (95% CI) of first-line bendamustine, bendamustine after first-line, and any-line bendamustine were 1.43 (1.14-1.78), 1.26 (0.96-1.64), and 1.33 (1.09-1.62), respectively. Regarding infections, adjusted odds ratios (95% CI) of BR compared to RCHOP/RCVP/RTHPCOP were as follows: cytomegalovirus infection, 13.7 (4.88-38.4); bacterial pneumonia, 0.63 (0.50-0.78); and pneumocystis pneumonia, 0.24 (0.11-0.53). There was no significant difference in OS between RCHOP/RCVP/RTHPCOP and BR in patients with follicular, mantle cell, marginal zone, or lymphoplasmacytic lymphomas. In conclusion, treatment strategies that consider the risk of SPM and infections after chemotherapy are warranted in patients with iBCL.

Unveiling the Prognostic Significance of BCL6+/CD10+ Mantle Cell Lymphoma: Meta-Analysis of Individual Patients and Systematic Review

Mantle cell lymphoma (MCL) is a type of non-Hodgkin lymphoma (NHL) characterized by a hallmark translocation of t (11; 14). CD10 negativity has been used to differentiate MCL from other NHL types; however, recently, there has been an increase in the number of reported cases of CD10-positive MCL. This warrants further investigation into this rarer immunophenotype and its clinical significance. BCL6, which is a master transcription factor for the regulation of cell proliferation and key oncogene in B cell lymphomagenesis, has been reported to have co-expression with CD10 in MCL. The clinical significance of this aberrant antigen expression remains unknown. We conducted a systematic review by searching four databases and selected five retrospective analyses and five case series. Two survival analyses were conducted to determine if BCL6 positivity conferred a survival difference: 1. BCL6+ vs. BCL6- MCL. 2. BCL6+/CD10+ vs. BCL6-/CD10+ MCL. Correlation analysis was conducted to determine if BCL6 positivity correlated with the Ki67 proliferation index (PI). Overall survival (OS) rates were performed by the Kaplan-Meier method and log-rank test. Our analyses revealed that BCL6+ MCL had significantly shorter overall survival (median OS: 14 months vs. 43 months; p = 0.01), BCL6+/CD10+ MCL had an inferior outcome vs. BCL6+/CD10- MCL (median OS: 20 months vs. 55 months p = 0.1828), BCL6+ MCL had significantly higher percentages of Ki67% (Ki67% difference: 24.29; p = 0.0094), and BCL6 positivity had a positive correlation with CD10+ status with an odds ratio 5.11 (2.49, 10.46; p = 0.0000286). Our analysis showed that BCL6 expression is correlated with CD10 positivity in MCL, and BCL6 expression demonstrated an inferior overall survival. The higher Ki67 PI in BCL6+ MCL compared to BCL6- MCL further supports the idea that the BCL6+ immunophenotype may have prognostic value in MCL. MCL management should consider incorporating prognostic scoring systems adjusted for BCL6 expression. Targeted therapies against BCL6 may offer potential therapeutic options for managing MCL with aberrant immunophenotypes.

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.

PAX5 aberrant expression incorporated in MIPI-SP risk scoring system exhibits additive value in mantle cell lymphoma

Mantle cell lymphoma (MCL) is a subtype of non-Hodgkin lymphoma with highly heterogeneous clinical courses. Paired-box 5 (PAX5), the regulator of B cell differentiation and growth, is abnormally expressed in several types of cancers. Herein, we explored the prognostic value of PAX5 in MCL by comprehensively analyzing the clinical features and laboratory data of 82 MCL cases. PAX5 positivity was associated with shorter overall survival (OS; p = 0.011) and was identified as an independent prognostic factor in MCL patients. The elevated β2-MG (p = 0.027) and advanced Mantle Cell Lymphoma International Prognostic Index (MIPI) score (p = 0.014) were related to positive PAX5 expression. The MIPI-SP risk scoring system was established and exhibited a superior prognostic value for OS depending on an area under the curve (AUC) of 0.770 (95% CI, 0.658-0.881) than MIPI score. Bioinformatic analysis of PAX5-related genes supported the mechanistic roles of PAX5 in MCL. This study provides insight into the potential role of PAX5 in MCL, and the novel risk scoring system MIPI-SP optimizes the risk stratification and facilitates prognosis evaluation in MCL patients. KEY MESSAGES: • Paired-box 5 positivity indicated adverse prognosis in mantle cell lymphoma patients. • Positive PAX5 expression was related to MIPI score and β2-MG in MCL patients. • MIPI-SP risk scoring system has superior prognostic value than MIPI score in MCL.

Prognostic Role of CDKN2A Deletion and p53 Expression and Association With MIPIb in Mantle Cell Lymphoma

INTRODUCTION

Mantle cell lymphoma (MCL) is a rare type of lymphoma, which despite improvements in therapies in recent decades, remains an incurable disease. There is currently no reliable marker of chemoresistance available. In this study, we investigated the prognostic role of MIPIb and the association with biological markers including SOX11, p53 expression, Ki-67, and CDKN2A.

MATERIALS AND METHODS

This retrospective study was focused on 23 patients with newly diagnosed classical MCL, treated at the University Hospital of Bari (Italy) between January 2006 and June 2019.

RESULTS

We identified a MIPIb value ≥ 5.4440 as a prognostic parameter that correlates with p53 expression and CDKN2A deletion. We also observed that patients with p53 overexpression had a significantly higher MIPIb (5.52 ± 0.53) which in 80% of patients had a value higher than 5.4440. On the other hand, CDKN2A deletion was found more frequently (75%) associated with MIPIb ≥5.4440. Only the CDKN2A deletion was associated with a higher proliferation index, with 66.7% of samples having Ki67 ≥30%. From the survival analysis we found that patients with p53 overexpression and CDKN2A deletion have a significantly worse prognosis with a median overall survival of 50 (P = .012) and 52 months (P = .018), respectively.

CONCLUSION

p53 expression and CDKN2A deletion represent a reliable pretreatment prognostic factor that identifies patients who do not benefit from currently used immunochemotherapy-based therapies and who are candidates for diversified treatments with the aim of improving prognosis. The MIPIb represents a prognostic index that correlates well with these biological alterations and can be used in clinical practice as their surrogate.

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.

CAR T-Cell therapy for the management of mantle cell lymphoma

Mantle cell lymphoma (MCL) is a subtype of Non-Hodgkin lymphoma (NHL) of mature B-cells characterized by translocation, which is typically due to excess expression of Cyclin D1. Although with the progress in our knowledge of the causes for MCL and available treatments for MCL, this cancer is still incurable. Age, male gender, rapid advancement, significant nodal involvement, elevated serum lactate dehydrogenase level, and prognostic indications including increased expression of Ki-67 and presence of TP53 mutation, are symbols of poor outcome. Advanced immunotherapy using chimeric antigen receptor (CAR)-T cells is advantageous for patients suffering from B-cell malignancies and MCL. Targeting B-cell antigens on the cell surface is a feasible approach in re-occurring (R/R) MCL because of significant responses obtained in other B-cell cancers. USFDA has approved brexucabtagene autoleucel (Tecartus, KTE-X19), a novel CAR T-cell therapy to be used in patients with MCL who have not responded to previous treatments or have relapsed. The FDA approved this new treatment depending on the outcomes of the ZUMA-2 clinical trial. Serious adverse reactions, moderate anti-tumor activity, allergen withdrawal, antigen escape, limited tumor infiltration, and trafficking are major barriers to successful CAR T-cell therapy. This review is a brief synopsis of the development of CAR T-cell therapy for MCL.

p53 directly downregulates the expression of CDC20 to exert anti-tumor activity in mantle cell lymphoma

BACKGROUND

Cell cycle dysregulation characterized by cyclin D1 overexpression is common in mantle cell lymphoma (MCL), while mitotic disorder was less studied. Cell division cycle 20 homologue (CDC20), an essential mitotic regulator, was highly expressed in various tumors. Another common abnormality in MCL is p53 inactivation. Little was known about the role of CDC20 in MCL tumorigenesis and the regulatory relationship between p53 and CDC20 in MCL.

METHODS

CDC20 expression was detected in MCL patients and MCL cell lines harboring mutant p53 (Jeko and Mino cells) and wild-type p53 (Z138 and JVM2 cells). Z138 and JVM2 cells were treated with CDC20 inhibitor apcin, p53 agonist nutlin-3a, or in combination, and then cell proliferation, cell apoptosis, cell cycle, cell migration and invasion were determined by CCK-8, flow cytometry and Transwell assays. The regulatory mechanism between p53 and CDC20 was revealed by dual-luciferase reporter gene assay and CUT&Tag technology. The anti-tumor effect, safety and tolerability of nutlin-3a and apcin were investigated in vivo in the Z138-driven xenograft tumor model.

RESULTS

CDC20 was overexpressed in MCL patients and cell lines compared with their respective controls. The typical immunohistochemical marker of MCL patients, cyclin D1, was positively correlated with CDC20 expression. CDC20 high expression indicated unfavorable clinicopathological features and poor prognosis in MCL patients. In Z138 and JVM2 cells, either apcin or nutlin-3a treatment could inhibit cell proliferation, migration and invasion, and induce cell apoptosis and cell cycle arrest. GEO analysis, RT-qPCR and WB results showed that p53 expression was negatively correlated with CDC20 expression in MCL patients, Z138 and JVM2 cells, while this relationship was not observed in p53-mutant cells. Dual-luciferase reporter gene assay and CUT&Tag assay revealed mechanistically that CDC20 was transcriptionally repressed by p53 through directly binding p53 to CDC20 promoter from - 492 to + 101 bp. Moreover, combined treatment of nutlin-3a and apcin showed better anti-tumor effect than single treatment in Z138 and JVM2 cells. Administration of nutlin-3a/apcin alone or in combination confirmed their efficacy and safety in tumor-bearing mice.

CONCLUSIONS

Our study validates the essential role of p53 and CDC20 in MCL tumorigenesis, and provides a new insight for MCL therapeutics through dual-targeting p53 and CDC20.

Treatment Outcomes and Roles of Transplantation and Maintenance Rituximab in Patients With Previously Untreated Mantle Cell Lymphoma: Results From Large Real-World Cohorts

PURPOSE

Commonly used first-line (1L) treatments for mantle cell lymphoma include high-dose cytarabine-based induction followed by autologous stem-cell transplant (ASCT) for younger patients and several chemoimmunotherapy regimens for older patients. Continuous debates exist on the role of ASCT in younger patients and maintenance rituximab (MR) after bendamustine plus rituximab (BR).

METHODS

Retrospective data from 4,216 patients with mantle cell lymphoma in the Flatiron Health electronic record-derived deidentified database diagnosed between 2011 and 2021, mostly in US community oncology settings, were evaluated for treatment patterns and outcomes. The efficacy findings with ASCT and MR were validated in an independent cohort of 1,168 patients from 12 academic centers.

RESULTS

Among 3,614 patients with documented 1L treatment, BR was the most used. Among 1,265 patients age < 65 years, 30.5% received cytarabine-based induction and 23.5% received ASCT. There was no significant association between ASCT and real-world time to next treatment (hazard ratio [HR], 0.84; 95% CI, 0.68 to 1.03; P = .10) or overall survival (HR, 0.86; 95% CI, 0.63 to 1.18; P = .4) among ASCT-eligible patients. Among MR-eligible patients, MR after BR versus BR alone was associated with a longer real-world time to next treatment (HR, 1.96; 95% CI, 1.61 to 2.38; P < .001) and overall survival (HR, 1.51; 95% CI, 1.19 to 1.92; P < .001). The efficacy findings were consistent in the validation cohort.

CONCLUSION

In this large cohort of patients treated primarily in the US community setting, only one in four young patients received cytarabine or ASCT consolidation, suggesting the need to develop treatments that can be delivered effectively in routine clinical practice. Together with the validation cohort, data support future clinical trials exploring regimens without ASCT consolidation in young patients, whereas MR should be considered for patients after 1L BR and rituximab plus cyclophosphamide, doxorubicin, vincristine, and prednisone.

Three-Year Follow-Up of KTE-X19 in Patients With Relapsed/Refractory Mantle Cell Lymphoma, Including High-Risk Subgroups, in the ZUMA-2 Study

PURPOSE

Brexucabtagene autoleucel (KTE-X19) autologous anti-CD19 chimeric antigen receptor (CAR) T-cell therapy is approved for the treatment of relapsed/refractory mantle cell lymphoma (MCL). Outcomes after a 3-year follow-up in the pivotal ZUMA-2 study of KTE-X19 in relapsed/refractory MCL are reported, including for subgroups by prior therapy (bendamustine and type of Bruton tyrosine kinase inhibitor [BTKi]) or high-risk characteristics.

METHODS

Patients with relapsed/refractory MCL (one to five prior therapies, including prior BTKi exposure) received a single infusion of KTE-X19 (2 × 10⁶ CAR T cells/kg).

RESULTS

After a median follow-up of 35.6 months, the objective response rate among all 68 treated patients was 91% (95% CI, 81.8 to 96.7) with 68% complete responses (95% CI, 55.2 to 78.5); medians for duration of response, progression-free survival, and overall survival were 28.2 months (95% CI, 13.5 to 47.1), 25.8 months (95% CI, 9.6 to 47.6), and 46.6 months (95% CI, 24.9 to not estimable), respectively. Post hoc analyses showed that objective response rates and ongoing response rates were consistent among prespecified subgroups by prior BTKi exposure or high-risk characteristics. In an exploratory analysis, patients with prior bendamustine benefited from KTE-X19, but showed a trend toward attenuated T-cell functionality, with more impact of bendamustine given within 6 versus 12 months of leukapheresis. Late-onset toxicities were infrequent; only 3% of treatment-emergent adverse events of interest in ZUMA-2 occurred during this longer follow-up period. Translational assessments revealed associations with long-term benefits of KTE-X19 including high-peak CAR T-cell expansion in responders and the predictive value of minimal residual disease for relapse.

CONCLUSION

These data, representing the longest follow-up of CAR T-cell therapy in patients with MCL to date, suggest that KTE-X19 induced durable long-term responses with manageable safety in patients with relapsed/refractory MCL and may also benefit those with high-risk characteristics.

[Immunohistochemical and Molecular Genetic Profile of Mantle Cell Lymphoma of the Lacrimal Gland: A Case Series of an Uncommon Tumour of the Lacrimal Gland]

BACKGROUND

Mantle cell lymphomas (MCL) represent a rare subclass of Non-Hodgkin Lymphoma affecting the lacrimal gland (GL).

AIM

To extensively describe the immunohistochemical profile of GL-MCL.

MATERIAL UND METHODS

Single center, retrospective electronic records review of 3 patients with biopsy proven LG-MCL.

RESULTS

The herein presented case series of three patients comprises a focal case involving solely the lacrimal gland, a symptomatic LG-MCL manifesting as the first sign of a systemic disease as well as a case of LG-MCL presenting as a relapsed systemic lymphoma. The three patients presented positive CD19 and CD20, negative CD10 and CD23. One patient showed an uncommon negativity for CD5. The increased expression of cyclin D1 caused by the classical translocation t(11;14) (q13;q32) in the fluorescence-in-situ-hybridisation were observed in all cases. B-cell-lymphoma-2 protein (BCL-2) and transcription factor SOX-11 (SOX-11) were also overexpressed.

DISCUSSION

LG-MCL show an immunohistochemical profile corresponding to the classical profile of MCL. Overexpression of molecules for target therapies was found in all cases (CD20 for rituximab, BCL2 for Bruton-kinase-inhibitors and CD19 for CAR-T cell therapy). The removal of the GL can potentially drive to severe complications, even if aimed to confirm diagnosis. Therefore, the choice between GL-biopsy and exstirpation should be carefully evaluated, especially in cases of suspected lymphoma.

A rapid and sensitive UPLC-MS/MS method for the determination of zanubrutinib in beagle plasma and its application in pharmacokinetics

A reliable and sensitive ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method was developed for the determination of zanubrutinib in the plasma of beagle dogs. The column used was an Acquity BEH C₁₈ column (2.1 mm × 50 mm, 1.7 μm), maintained at 40°C with an injection volume of 2 μl. The gradient elution program was as follows: 0-1 min, 10-10% A; 1-1.1 min, 10-90% A; 1.1-2.1 min, 90-90% A; 2.1-2.2 min, 90-10% A; 2.2-3.0 min, 10-10% A. Mobile phase A was 0.1% formic acid, B was acetonitrile, and the total analysis time was 3 min. The mass spectrometry was performed in positive ion mode, and the scanning mode was multi-reaction monitoring mode with electrospray ionization as the ion source; m/z 472.2 → 455.01 for zanubrutinib and m/z 441.03 → 137.99 for ibrutinib (internal standard). The plasma samples were processed by protein precipitation. The standard curve showed good linearity (r²  = 0.999 8) in the range of 1.0-1,000 ng/ml (zanubrutinib) with a low limit of quantification of 1 ng/ml. Also, the intra-day and inter-day precision (RSD) was <5.88% and the accuracy (RE) ranged from -1.56 to 1.08%; the recoveries of zanubrutinib in beagle plasma ranged from 90.12 to 93.53% (RSD 1.67-6.42%) and the ME values of zanubrutinib were 98.70-101.06% (RSD 5.37-8.49%, n = 6). All values meet US Food and Drug Administration requirements. A rapid, highly selective and sensitive method for the determination of zanubrutinib concentration in plasma by UPLC-MS/MS was successfully developed. This method is suitable for pharmacokinetic studies in beagle dogs by following oral administration of zanubrutinib.

Multicolor flow cytometric assessment of Ki67 expression and its diagnostic value in mature B-cell neoplasms

Background

There is no unified standard data about the sensitivity and specificity regarding flow cytometry analysis of Ki67 expression during lymphoma diagnoses.

Objective

This evaluated the efficacy of multicolor flow cytometry (MFC) in an estimate of the proliferative activity of B-cell non-Hodgkin lymphoma by comparing the expression of Ki67 using MFC and immunohistochemicals (IHC).

Method

A total of 559 patients with non-Hodgkin B-cell lymphoma were immunophenotyped using sensitive MFC, of which 517 were newly diagnosed and 42 were transformed lymphomas. Test samples include peripheral blood, bone marrow, various body fluids, and tissues. Through MFC multi-marker accurate gating, abnormal mature B lymphocytes with restricted expression of the light chain were screened. Ki67 was added to determine the proliferation index; the positive rate of Ki67 in tumor B cells was evaluated by cell grouping and internal control. For tissue specimens, MFC and IHC analyses were performed simultaneously to assess the Ki67 proliferation index.

Results

The positive rate of Ki67 by MFC was correlated with the subtype and aggressiveness of B-cell lymphoma. Ki67 could distinguish indolent lymphomas from aggressive subtypes with a cut-off value of 21.25%, and differentiate transformation from indolent lymphoma with a cut-off value of 7.65%. The expression of Ki67 by MFC (regardless of the type of samples)was highly agreement with the Ki67 proliferative index of tissue samples assessed by pathologic immunohistochemistry. MFC showed a fairly constant negative bias in evaluating tissue or bone marrow samples, compared with IHC.

Conclusions

Ki67 is a valuable flow marker that can distinguish between indolent and aggressive types of lymphoma and assess whether indolent lymphomas are transformed. Using MFC to evaluate the positive rate of Ki67 is important in clinical settings. MFC has unique advantages in judging the aggressiveness of lymphoma in samples of bone marrow, peripheral blood, pleural and ascites, and cerebrospinal fluid. This is particularly important when tissue samples cannot be obtained, making it an important supplement for pathologic examination.

[18F]FDG-PET/CT volumetric parameters can predict outcome in untreated mantle cell lymphoma

Several studies have shown a strong predictive value for pretreatment [¹⁸F]FDG-PET/CT metabolic parameters in different lymphoma subtypes. However, few publications exist concerning the role of metabolic parameters in mantle cell lymphoma (MCL). We retrospectively investigated the prognostic value of baseline metabolic tumor volume (MTV) and lesion dissemination in untreated MCL. We compared it to currently used prognostic factors such as stage, mantle cell lymphoma international prognostic index (MIPI) and KI-67. We report that a higher baseline MTV is a risk factor for worse overall survival (OS), progression-free survival (PFS), and disease-specific survival (DSS) in univariate analysis. In multivariate analysis, MTV was significantly associated with DSS, but not with OS and PFS. We found no correlation between lesion dissemination and outcome. The MIPI score remains the strongest predictor of outcome. These results show that MTV is an important prognostic tool and can improve patient risk stratification at staging of untreated MCL.

The Therapeutic Synergy of Selinexor and Venetoclax in Mantle Cell Lymphoma Through Induction of DNA Damage and Perturbation of the DNA Damage Response

Introduction: Mantle cell lymphoma (MCL) can be stratified into blastoid and classical subtypes based on morphological features, with the former subtype having a poorer prognosis. Despite recent advances in targeted approaches, including multiple bruton tyrosine kinase inhibitors which yield impressive clinical responses and improve prognoses, MCL remains an incurable disease with frequent relapses. Additional therapeutic interventions are therefore unmet medical needs for the management of patients with MCL. Methods: Cell viability and apoptosis assays were employed to analyze the therapeutic interaction of venetoclax combined with selinexor in MCL cells. Western blot was used to investigate the potential mechanism of action for the synergy of venetoclax in combination with selinexor in MCL cells. Results: In this study, we revealed that both blastoid and classical MCL cells were vulnerable to the cytotoxic effects of selinexor, a well-established XPO1 inhibitor, manifested by loss of cell viability and induction of cell apoptosis. Moreover, our data indicated that the addition of venetoclax to selinexor showed synergistically decreased cell viabilities and increased cell deaths in blastoid and classical MCL cells compared to each single drug treatment. Either selinexor or venetoclax treatment alone decreased MCL1 expressions and increased BAX levels in MCL cells, and these effects were further enhanced by their combined regimen. Mechanistically, our findings demonstrated that induction of DNA damage and inactivation of DNA damage response were involved in the synergistic interaction of the drug combination regimen. Conclusion: Collectively, this study might provide a potential attractive therapy option for the treatment of MCL. However, the conclusion needs additional experimental validation in in vivo models and clinical evaluations are mandatory.

Unusual Presentation of Leukemic-Phase Mantle Cell Lymphoma: A Case Report

Mantle cell lymphoma (MCL) is a rare subtype of B-cell lymphoma that can present in a variety of ways, including the leukemic phase, where it can occasionally be mistaken for acute leukemia due to the unusually high or rapidly growing number of leukocytes and the presence of circulating cancer cells that are morphologically similar to leukemic blasts in myeloid or acute lymphoblastic leukemia. We present the case of an 83-year-old Yemeni woman with multiple comorbidities who presented with abdominal pain and constitutional symptoms. She was found to have diffuse lymphadenopathy on clinical and radiological assessments. Her white blood cell count at presentation was 221 × 10⁹/L with marked monocytosis (72.8%). Lymph node biopsy and bone marrow studies, including CCND1/IGH molecular studies, confirmed MCL, the pleomorphic subtype. The patient was deemed unfit for standard-of-care chemotherapy and was started on single-agent rituximab with a slow introduction to ibrutinib but succumbed to death after two weeks of ibrutinib 280 mg daily. This case serves as a reminder to keep an open mind and take into account atypical disease presentations when formulating differential diagnoses to prevent late diagnosis and any unnecessary intervention that can postpone appropriate therapy.

Survival of patients with mantle cell lymphoma in the rituximab era: Retrospective binational analysis between 2000 and 2020

Mantle cell lymphoma (MCL) is a rare peripheral B-cell lymphoma characterised by eventual relapse and progression towards a more aggressive disease biology. With the introduction of rituximab- and cytarabine-based immunochemotherapy regimens, the prognosis of the disease has changed dramatically over the last two decades. To assess the real-world survival of patients with MCL, we used a population-based cohort of 564 patients with MCL who were diagnosed and treated between 2000 and 2020. Patient data were collected from seven Finnish treatment centres and one Spanish treatment centre. For the entire patient population, we report a 2-year overall survival (OS) rate of 77%, a 5-year OS of 58%, and a 10-year OS of 32%. The estimated median OS was 80 months after diagnosis. MCL is associated with increased mortality across the entire patient population. Additionally, we assessed the survival of patients after MCL relapse with the aim of establishing a cut-off point of prognostic significance. Based on our statistical analysis of survival after the first relapse, disease progression within 24 months of the initial diagnosis should be considered as a strong indicator of poor prognosis.

Bcl-2 Family Members Bcl-xL and Bax Cooperatively Contribute to Bortezomib Resistance in Mantle Cell Lymphoma

Mantle cell lymphoma (MCL) is an aggressive non-Hodgkin lymphoma with poor prognosis, due to the inevitable development of drug resistance. Despite being the first-in-class proteasome inhibitor for relapsed/refractory MCL, resistance to bortezomib (BTZ) in MCL patients remains a major hurdle of effective therapy, and relapse following BTZ is frequent. Understanding the mechanisms underlying BTZ resistance is, therefore, important for improving the clinical outcome and developing novel therapeutic strategies. Here, we established de novo BTZ-resistant human MCL-derived cells with the highest resistance index of 300-fold compared to parental cells. We provided compelling evidence that both Bcl-xL and Bax are key mediators in determining BTZ sensitivity in MCL cells. Overexpression of antiapoptotic Bcl-xL and depletion of proapoptotic Bax cooperatively protected MCL cells against BTZ-induced apoptosis, causing acquired BTZ resistance, likely by tilting the balance of Bcl-2 family proteins toward antiapoptotic signaling. Bioinformatics analyses suggested that high BCL2L1 (encoded Bcl-xL) and low BAX were, in part, associated with poor prognosis of MCL patients, e.g., when combined with low OGT, which regulates cellular O-GlcNAcylation. Our findings support recent strategies in small molecule drug discovery co-targeting antiapoptotic Bcl-2 family proteins using BH3 mimetics and Bax using Bax activators to overcome cancer drug resistance.

Whole Transcriptome Sequencing Reveals Cancer-Related, Prognostically Significant Transcripts and Tumor-Infiltrating Immunocytes in Mantle Cell Lymphoma

Mantle cell lymphoma (MCL) is an aggressive B-cell non-Hodgkin lymphoma (NHL) subtype characterized by overexpression of CCND1 and SOX11 genes. It is generally associated with clinically poor outcomes despite recent improvements in therapeutic approaches. The genes associated with the development and prognosis of MCL are still largely unknown. Through whole transcriptome sequencing (WTS), we identified mRNAs, lncRNAs, and alternative transcripts differentially expressed in MCL cases compared with reactive tonsil B-cell subsets. CCND1, VCAM1, and VWF mRNAs, as well as MIR100HG and ROR1-AS1 lncRNAs, were among the top 10 most significantly overexpressed, oncogenesis-related transcripts. Survival analyses with each of the top upregulated transcripts showed that MCL cases with high expression of VWF mRNA and low expression of FTX lncRNA were associated with poor overall survival. Similarly, high expression of MSTRG.153013.3, an overexpressed alternative transcript, was associated with shortened MCL survival. Known tumor suppressor candidates (e.g., PI3KIP1, UBXN) were significantly downregulated in MCL cases. Top differentially expressed protein-coding genes were enriched in signaling pathways related to invasion and metastasis. Survival analyses based on the abundance of tumor-infiltrating immunocytes estimated with CIBERSORTx showed that high ratios of CD8⁺ T-cells or resting NK cells and low ratios of eosinophils are associated with poor overall survival in diagnostic MCL cases. Integrative analysis of tumor-infiltrating CD8⁺ T-cell abundance and overexpressed oncogene candidates showed that MCL cases with high ratio CD8⁺ T-cells and low expression of FTX or PCA3 can potentially predict high-risk MCL patients. WTS results were cross-validated with qRT-PCR of selected transcripts as well as linear correlation analyses. In conclusion, expression levels of oncogenesis-associated transcripts and/or the ratios of microenvironmental immunocytes in MCL tumors may be used to improve prognostication, thereby leading to better patient management and outcomes.

Repurposed Effect of 177Lu-DOTATATE in the Treatment of Mantle Cell Lymphoma

Mantle cell lymphoma (MCL) is an uncommon subcategory of non-Hodgkin lymphoma (NHL). Pathogenesis primarily includes overexpression of CCND1 and SOX11 along with other molecular aberrations. Lutetium ¹⁷⁷Lu-DOTATATE is a radiolabeled somatostatin analogue used for the treatment of gastrointestinal neuroendocrine tumors. There are no clinical data supporting the use of Lutetium ¹⁷⁷Lu-DOTATATE in the treatment of lymphoma. We describe the case of an 84-year-old man with a history of MCL and carcinoid tumor of the lung. Following progression of the carcinoid malignancy, the patient was treated with Lutetium ¹⁷⁷Lu-DOTATATE. After treatment, there was an overall improvement of the patient's MCL that was demonstrated by stable lymphadenopathy on serial CT scans and down-trend of the absolute lymphocyte count. Therefore, we hypothesize that ¹⁷⁷Lu-DOTATATE might have a role and can be repurposed for treating MCL.

Tackling Mantle Cell Lymphoma in Europe

An expert panel convened by the European Alliance for Personalized Medicine (EAPM) reflected on achievements and outstanding challenges in Europe in mantle cell lymphoma (MCL). Through the prism of member state experience, the panel noted advances in outcomes over the last decade, but highlighted issues constituting barriers to better care. The list notably included availability of newer treatments, infrastructure and funding for related testing, and shortages of relevant skills and of research support. The prospect of improvements was held to reside in closer coordination and cooperation within and between individual countries, and in changes in policy and scale of investment at both national and EU levels.

Bendamustine is safe and effective for lymphodepletion before tisagenlecleucel in patients with refractory or relapsed large B-cell lymphomas

BACKGROUND

Anti-CD19 chimeric antigen receptor T-cell immunotherapy (CAR-T) is now a standard treatment of relapsed or refractory B-cell non-Hodgkin lymphomas; however, a significant portion of patients do not respond to CAR-T and/or experience toxicities. Lymphodepleting chemotherapy is a critical component of CAR-T that enhances CAR-T-cell engraftment, expansion, cytotoxicity, and persistence. We hypothesized that the lymphodepletion regimen might affect the safety and efficacy of CAR-T.

PATIENTS AND METHODS

We compared the safety and efficacy of lymphodepletion using either fludarabine/cyclophosphamide (n = 42) or bendamustine (n = 90) before tisagenlecleucel in two cohorts of patients with relapsed or refractory large B-cell lymphomas treated consecutively at three academic institutions in the United States (University of Pennsylvania, n = 90; Oregon Health & Science University, n = 35) and Europe (University of Vienna, n = 7). Response was assessed using the Lugano 2014 criteria and toxicities were assessed by the Common Terminology Criteria for Adverse Events (CTCAE) version 5.0 and, when possible, the American Society for Transplantation and Cellular Therapy (ASTCT) consensus grading.

RESULTS

Fludarabine/cyclophosphamide led to more profound lymphocytopenia after tisagenlecleucel infusion compared with bendamustine, although the efficacy of tisagenlecleucel was similar between the two groups. We observed significant differences, however, in the frequency and severity of adverse events. In particular, patients treated with bendamustine had lower rates of cytokine release syndrome and neurotoxicity. In addition, higher rates of hematological toxicities were observed in patients receiving fludarabine/cyclophosphamide. Bendamustine-treated patients had higher nadir neutrophil counts, hemoglobin levels, and platelet counts, as well as a shorter time to blood count recovery, and received fewer platelet and red cell transfusions. Fewer episodes of infection, neutropenic fever, and post-infusion hospitalization were observed in the bendamustine cohort compared with patients receiving fludarabine/cyclophosphamide.

CONCLUSIONS

Bendamustine for lymphodepletion before tisagenlecleucel has efficacy similar to fludarabine/cyclophosphamide with reduced toxicities, including cytokine release syndrome, neurotoxicity, infectious and hematological toxicities, as well as reduced hospital utilization.

Clinicopathologic Features and Treatment of CD10-Positive Mantle Cell Lymphoma: A Case Report and Review of Literature

Mantle cell lymphoma (MCL) is a rare and aggressive non-Hodgkin’s B cell lymphoma characterized by the translocation t(11;14) (q13;32) and overexpression of CCND1. MCL is immunophenotypically identified as CD20⁺, CD5⁺, CyclinD1+, CD43⁺, CD10⁻, BCL6⁻, and CD23⁻. It is often distinguished from B cell lymphomas of germinal center cell origin by the absence of CD10 expression. Here we report the unique clinicopathologic features of a patient with CD10⁺ MCL with gastrointestinal involvement and review current literature identifying this unique immunophenotype.

Molecular determinants of outcomes in relapsed or refractory mantle cell lymphoma treated with ibrutinib or temsirolimus in the MCL3001 (RAY) trial

Mantle cell lymphoma (MCL) is a rare, incurable lymphoma subtype characterized by heterogeneous outcomes. To better understand the clinical behavior and response to treatment, predictive biomarkers are needed. Using residual archived material from patients enrolled in the MCL3001 (RAY) study, we performed detailed analyses of gene expression and targeted genetic sequencing. This phase III clinical trial randomized patients with relapsed or refractory MCL to treatment with either ibrutinib or temsirolimus. We confirmed the prognostic capability of the gene expression proliferation assay MCL35 in this cohort treated with novel agents; it outperformed the simplified MCL International Prognostic Index in discriminating patients with different outcomes. Regardless of treatment arm, our data demonstrated that this assay captures the risk conferred by known biological factors, including increased MYC expression, blastoid morphology, aberrations of TP53, and truncated CCND1 3' untranslated region. We showed the negative impact of BIRC3 mutations/deletions on outcomes in this cohort and identified that deletion of chromosome 8p23.3 also negatively impacts survival. Restricted to patients with deletions/alterations in TP53, ibrutinib appeared to abrogate the deleterious impact on outcome. These data illustrate the potential to perform a molecular analysis of predictive biomarkers on routine patient samples that can meaningfully inform clinical practice.