Epidemiological, clinical and therapeutic profiles of mantle cell lymphoma cared for in a Moroccan center: a review of 14 cases.

Mantle cell lymphoma (MCL) accounts for 3-10% of non-Hodgkin's lymphomas (NHL). We identified 14 patients with mantle cell lymphoma, with an average number of 3.5 new cases/year. A male predominance was observed with a sex ratio equal to 6. The average age of our patients was 64.4±14.1 years, with an average diagnostic delay of 6.57 months. Regarding the clinical presentation, adenopathy was the most reported physical sign (78.6%) followed by B symptoms (57.1%). Disseminated stages were the most frequent in our series: stages IV (78.5%) and III (7.1%) versus stages I (0%) and II (7.1%). The extra-ganglionic localizations observed were hepatic 5 cases (31.1%), pulmonary 04 cases (25%), medullary 4 cases (25%), pleural 2 cases (12.5%) and prostate 1 case (6.2%). All diagnosed cases are mantle cell lymphomas, of which 12 cases (85.7%) are classical and 2 cases (14.3%) indolent. The high-risk group is, according to international prognostic index (MIPI) MCL prognostic score, the most represented in our series: 0-3 = 6 cases (42.9%), 6-11 = 8 cases (57.1%). The therapeutic protocol chosen 1st line: 9 patients treated with R-DHAP, three with R-CHOP, one with DHAOX and one with R-CVP. Second line: two patients treated with R-DHAP, one after R-CHOP and the other after R-CVP. Two patients received autologous hematopoietic stem cell transplant at the end of the treatment. The evolution was marked by the death of 7 patients, 3 lost to follow-up and 4 still followed. Additionally, the study highlights characteristics and treatment patterns of mantle cell lymphoma, emphasizing its predominance in males, delayed diagnosis, frequent dissemination, and high-risk classification, with chemotherapy as the primary treatment modality and a challenging prognosis contributing to a comprehensive understanding of mantle cell lymphoma presentation and management.

[Progressive necrotizing xanthogranuloma in both eyes: a case report].

A 55-year-old male patient presenting with 6 months of bilateral difficulty in eye opening was referred to the ophthalmology department. Upon examination, multiple yellowish tumor-like plaques and nodules were observed on the eyelids and chest of the patient, accompanied by keratitis and iridocyclitis. Histopathological examination of the skin lesions on the chest revealed dermal xanthomatous granulomas with progressive necrosis. Bone marrow biopsy showed mantle cell lymphoma. Based on the medical history, the diagnosis of progressive necrotizing xanthogranuloma with mantle cell lymphoma was confirmed. After 6 months of treatment with bendamustine combined with rituximab, there was partial alleviation of ocular symptoms in the patient.

SOX11 is a novel binding partner and endogenous inhibitor of SAMHD1 ara-CTPase activity in mantle cell lymphoma.

The sterile alpha motif and histidine-aspartate (HD) domain containing protein 1 (SAMHD1) is a deoxynucleoside triphosphate triphosphohydrolase with ara-CTPase activity that confers cytarabine (ara-C) resistance in several haematological malignancies. Targeting SAMHD1's ara-CTPase activity has recently been demonstrated to enhance ara-C efficacy in acute myeloid leukemia. Here, we identify the transcription factor SRY-related HMG-box containing protein 11 (SOX11) as a novel direct binding partner and first known endogenous inhibitor of SAMHD1. SOX11 is aberrantly expressed not only in mantle cell lymphoma (MCL), but also in some Burkitt lymphomas. Co-immunoprecipitation of SOX11 followed by mass spectrometry in MCL cell lines identified SAMHD1 as the top SOX11 interaction partner which was validated by proximity ligation assay. In vitro, SAMHD1 bound to the HMG box of SOX11 with low-micromolar affinity. In situ crosslinking studies further indicated that SOX11-SAMHD1 binding resulted in a reduced tetramerization of SAMHD1. Functionally, expression of SOX11 inhibited SAMHD1 ara-CTPase activity in a dose-dependent manner resulting in ara-C sensitization in cell lines and in a SOX11-inducible mouse model of MCL. In SOX11-negative MCL, SOX11-mediated ara-CTPase inhibition could be mimicked by adding the recently identified SAMHD1 inhibitor hydroxyurea. Taken together, our results identify SOX11 as a novel SAMHD1 interaction partner and its first known endogenous inhibitor with potentially important implications for clinical therapy stratification.

Colonic lymphomatous polyposis mantle cell lymphoma: a case report and review of literature.

INTRODUCTION: Mantle cell lymphoma is a rare lymphoma of the gastrointestinal tract that may present as multiple lymphomatous polyposis. We report a case of lymphomatous polyposis with a review of the literature. CASE REPORT: A 56-year-old man of Black ethnicity and Ivorian nationality with no relevant past medical history, consulted for a sudden onset symptoms of gastrointestinal obstruction, which evolved over 2 days. Macroscopic examination revealed the presence of multiple polyploid formations of the colonic mucosa. Histology showed diffuse lymphomatous proliferation of submucosa consisting off small lymphoid cells with a hyperchromatic crenelated nucleus, suggesting lymphomatous polyposis. Immunohistochemical examination showed expression by the tumor cells of antibodies to CD20, CD5, Bcl2, and cyclin D1. They did not express antibodies to CD10 and CD23. The Ki67 proliferation index was 25%. We have thus retained the diagnosis of mantle cell lymphomatous polyposis. CONCLUSION: Multiple lymphomatous polyposis is a rare entity characterized by the presence of numerous gastrointestinal polyploid lesions sometimes involving several segments of the gastrointestinal tract. Typical lymphoma presenting as lymphomatous polyposis is mantle cell lymphoma; although, other tumors may have this aspect.

Phase 1/2 multicenter trial of acalabrutinib in Chinese patients with relapsed/refractory mantle cell lymphoma.

Acalabrutinib studies have limited Asian participation. This phase 1/2 study (NCT03932331) assessed acalabrutinib in Chinese patients with relapsed/refractory (R/R) mantle cell lymphoma (MCL). Primary endpoint was blinded independent central review (BICR)-assessed overall response rate (ORR). Overall, 34 patients were enrolled. Most patients were men (88%); median age was 63 years and 59% had ≥3 prior treatments. Median treatment duration was 14 months (range, 1-24). Any-grade adverse events (AEs) and grade ≥3 AEs occurred in 85.3% and 44.1% of patients, respectively. AEs causing treatment discontinuation were aplastic anemia, thrombocytopenia, and gastrointestinal infection (n = 1 each). Fatal AEs occurred in 2 patients (aplastic anemia and multiple organ dysfunction syndrome [n = 1 each]). BICR-assessed ORR was 82.4% (95% confidence interval [CI]: 65.5, 93.2); 12 (35.3%) patients achieved complete response. Estimated 12-month OS was 84.5% (95% CI: 66.6, 93.3). Acalabrutinib yielded tolerable safety and high response rates in Chinese patients with R/R MCL.

Inhibition of SRC-3 as a potential therapeutic strategy for aggressive mantle cell lymphoma.

Mantle cell lymphoma (MCL) has a poor prognosis and high relapse rates despite current therapies, necessitating novel treatment regimens. Inhibition of SRC-3 show effectiveness in vivo and in vitro in other B cell lymphomas. Additionally, previous studies have shown that SRC-3 is highly expressed in the lymph nodes of B cell non-Hodgkin's lymphoma patients, suggesting SRC-3 may play a role in the progression of B cell lymphoma. This study aimed to investigate novel SRC-3 inhibitors, SI-10 and SI-12, in mantle cell lymphoma. The cytotoxic effects of SI-10 and SI-12 were evaluated in vitro and demonstrated dose-dependent cytotoxicity in a panel of MCL cell lines. The in vivo efficacy of SI-10 was confirmed in two ibrutinib-resistant models: an immunocompetent disseminated A20 mouse model of B-cell lymphoma and a human PDX model of MCL. Notably, SI-10 treatment also resulted in a significant extension of survival in vivo with low toxicity in both ibrutinib-resistant murine models. We have investigated SI-10 as a novel anti-lymphoma compound via the inhibition of SRC-3 activity. These findings indicate that targeting SRC-3 should be investigated in combination with current clinical therapeutics as a novel strategy to expand the therapeutic index and to improve lymphoma outcomes.

PRMT5 activates lipid metabolic reprogramming via MYC contributing to the growth and survival of mantle cell lymphoma.

Mantle cell lymphoma (MCL) is an incurable and aggressive subtype of non-Hodgkin B-cell lymphoma. Increased lipid uptake, storage, and lipogenesis occur in a variety of cancers and contribute to rapid tumor growth. However, no data has been explored for the roles of lipid metabolism reprogramming in MCL. Here, we identified aberrant lipid metabolism reprogramming and PRMT5 as a key regulator of cholesterol and fatty acid metabolism reprogramming in MCL patients. High PRMT5 expression predicts adverse outcome prognosis in 105 patients with MCL and GEO database (GSE93291). PRMT5 deficiency resulted in proliferation defects and cell death by CRISPR/Cas9 editing. Moreover, PRMT5 inhibitors including SH3765 and EPZ015666 worked through blocking SREBP1/2 and FASN expression in MCL. Furthermore, PRMT5 was significantly associated with MYC expression in 105 MCL samples and the GEO database (GSE93291). CRISPR MYC knockout indicated PRMT5 can promote MCL outgrowth by inducing SREBP1/2 and FASN expression through the MYC pathway.

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

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

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.

TP53 mutation is frequent in mantle cell lymphoma with EZH2 expression and have dismal outcome when both are present.

Enhancer of zeste homolog 2 (EZH2) expression is found in about 40% of mantle cell lymphoma (MCL) patients, which is associated with aggressive histology, high Ki-67 proliferation rate, p53 mutant pattern and inferior overall survival (OS). We conducted 11-gene (ATM, BIRC3, CCND1, KMT2C, KMT2D, NOTCH1, NOTCH2, RB1, TP53, TRAF2 and UBR5) next generation sequencing panel to shed more light on MCL with EZH2 expression (EZH2+ MCL). EZH2+ MCL more frequently harbor TP53 mutation compared to EZH2(-) MCL (41.2% vs. 19.1%, respectively, p = 0.045). TP53 mutation and EZH2 expression demonstrated overlapping features including aggressive histology, high Ki-67 proliferation rate and p53 mutant pattern by immunohistochemistry. Comparative analysis disclosed that EZH2 expression correlates with high Ki-67 proliferation rate irrespective of TP53 mutation. Aggressive histology is associated with EZH2 expression or TP53 mutation, possibly via independent mechanisms. p53 mutant pattern is due to TP53 mutation. MCL patients with EZH2 expression or TP53 mutation show inferior outcome and when both are present, patients have dismal outcome.

B-cell receptor signaling activity identifies patients with mantle cell lymphoma at higher risk of progression.

Mantle cell lymphoma (MCL) is an incurable B-cell malignancy characterized by a high clinical variability. Therefore, there is a critical need to define parameters that identify high-risk patients for aggressive disease and therapy resistance. B-cell receptor (BCR) signaling is crucial for MCL initiation and progression and is a target for therapeutic intervention. We interrogated BCR signaling proteins (SYK, LCK, BTK, PLCγ2, p38, AKT, NF-κB p65, and STAT5) in 30 primary MCL samples using phospho-specific flow cytometry. Anti-IgM modulation induced heterogeneous BCR signaling responses among samples allowing the identification of two clusters with differential responses. The cluster with higher response was associated with shorter progression free survival (PFS) and overall survival (OS). Moreover, higher constitutive AKT activity was predictive of inferior response to the Bruton's tyrosine kinase inhibitor (BTKi) ibrutinib. Time-to-event analyses showed that MCL international prognostic index (MIPI) high-risk category and higher STAT5 response were predictors of shorter PFS and OS whilst MIPI high-risk category and high SYK response predicted shorter OS. In conclusion, we identified BCR signaling properties associated with poor clinical outcome and resistance to ibrutinib, thus highlighting the prognostic and predictive significance of BCR activity and advancing our understanding of signaling heterogeneity underlying clinical behavior of MCL.

Optical genomic mapping is a helpful tool for detecting CCND1 rearrangements in CD5-negative small B-cell lymphoma: Two cases of leukemic non-nodal mantle cell lymphoma.

Optical genome mapping (OGM) is a new DNA-based technology which provides comprehensive examination of the entire genome. We report two patients who presented with splenomegaly and leukocytosis with lymphocytosis including villous lymphocytes. Neither patient had lymphadenopathy. Bone marrow evaluation showed involvement by small B-cell lymphoma in a sinusoidal and interstitial distribution, and immunophenotypic analysis showed that the neoplastic cells were positive for B-cell markers and cyclin D1 but were negative for SOX11 and CD5. Initially, the clinicopathologic features in both patients were thought to be suspicious for hairy cell leukemia variant or splenic marginal zone lymphoma. However, OGM detected CCND1 rearrangement: t(2;11)/IGK::CCND1 in one case and t(11;14)/IGH::CCND1 in the other case. These cases illustrate the valuable role OGM can play in establishing the diagnosis of MCL. Case 1 also contributes to the paucity of literature on the rare occurrence of IGK::CCND1 in MCL.

[Efficacy and Prognosis of Chemotherapy Regimen Containing BTK Inhibitor in Treatment of Recurrent/Refractory Mantle Cell Lymphoma].

OBJECTIVE: To investigate the efficacy and prognosis of chemotherapy regimen containing Bruton's tyrosine kinase (BTK) inhibitor in the treatment of relapsed/refractory mantle cell lymphoma (R/R MCL). METHODS: The clinical data of 134 patients with R/R MCL were collected and analyzed retrospectively. The clinical characteristics of patients and effect of chemotherapy regimen on efficacy, overall survival (OS) and progression-free survival (PFS) were observed. RESULTS: The median age of the patients was 58(56-61) years old, and male to female ratio was about 2.9∶1. Patients with Ann Arbor stage III-IV accounted for 77.6%, extranodal involvement > 2 for 43.3%, bone marrow involvement for 60.4%, gastrointestinal involvement for 24.6%, and hepatosplenomegaly for 38.1%. The median follow-up time was 30 (2-103) months, overall response rate (ORR) was 41.8%, 3-year PFS was not reached, and 3-year and 5-year OS rate was 62.7% and 53.8%, respectively. The ORR of BTK inhibitor group was 56.9%, which was higher than 32.5% of non-BTK inhibitor group (P =0.006). The difference was statistically significant in PFS between the two groups (P =0.002), but was not in OS (P>0.05). The difference was statistically significant in OS between classical and special morphology (P < 0.001), but was not in PFS (P >0.05). Ki-67 was an influencing factor for OS and PFS. Multivariate analysis showed that Ki-67, B symptoms, MIPI score, and Ann Arbor stage were independent prognostic factors affecting patients' OS. The second-line treatment regimen was an independent prognostic factor affecting patients' PFS. CONCLUSIONS: The chemotherapy regimen containing BTK inhibitors can effectively improve the efficacy and prolong the PFS of R/R MCL patients. Ki-67, B symptoms, MIPI score, and Ann Arbor stage are independent prognostic factors for R/R MCL patients.

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.