Mechanisms of action and resistance in histone methylation-targeted therapy.

Epigenomes enable the rectification of disordered cancer gene expression, thereby providing new targets for pharmacological interventions. The clinical utility of targeting histone H3 lysine trimethylation (H3K27me3) as an epigenetic hallmark has been demonstrated1-7. However, in actual therapeutic settings, the mechanism by which H3K27me3-targeting therapies exert their effects and the response of tumour cells remain unclear. Here we show the potency and mechanisms of action and resistance of the EZH1-EZH2 dual inhibitor valemetostat in clinical trials of patients with adult T cell leukaemia/lymphoma. Administration of valemetostat reduced tumour size and demonstrated durable clinical response in aggressive lymphomas with multiple genetic mutations. Integrative single-cell analyses showed that valemetostat abolishes the highly condensed chromatin structure formed by the plastic H3K27me3 and neutralizes multiple gene loci, including tumour suppressor genes. Nevertheless, subsequent long-term treatment encounters the emergence of resistant clones with reconstructed aggregate chromatin that closely resemble the pre-dose state. Acquired mutations at the PRC2-compound interface result in the propagation of clones with increased H3K27me3 expression. In patients free of PRC2 mutations, TET2 mutation or elevated DNMT3A expression causes similar chromatin recondensation through de novo DNA methylation in the H3K27me3-associated regions. We identified subpopulations with distinct metabolic and gene translation characteristics implicated in primary susceptibility until the acquisition of the heritable (epi)mutations. Targeting epigenetic drivers and chromatin homeostasis may provide opportunities for further sustained epigenetic cancer therapies.

Development and evaluation of a rapid one-step high sensitivity real-time quantitative PCR system for minor BCR-ABL (e1a2) test in Philadelphia-positive acute lymphoblastic leukemia (Ph+ ALL).

OBJECTIVE: Minimal residual disease assessment of BCR-ABL messenger ribonucleic acid levels is crucial in Philadelphia chromosome-positive acute lymphoblastic leukemia for prognosis and treatment planning. However, accurately quantifying minor BCR-ABL transcripts, which comprise 70% of Philadelphia chromosome-positive acute lymphoblastic leukemia cases, lacks a national-approved method. METHODS: We developed the "Otsuka" minor BCR-ABLmessenger ribonucleic acid assay kit with exceptional precision (0.00151%). Minor BCR-ABL messenger ribonucleic acid levels were analyzed in 175 adults, 36 children with acute lymphoblastic leukemia and 25 healthy individuals to evaluate the kit's performance. RESULTS: The "Otsuka" kit showed high concordance with a commonly used chimeric gene screening method, indicating reliable detection of positive cases. Quantitative results demonstrated a robust correlation with both a laboratory-developed test and a diagnostic research product. The "Otsuka" kit performs comparably or even surpass to conventional products, providing valuable insights into Philadelphia chromosome-positive acute lymphoblastic leukemia pathology. CONCLUSIONS: The 'Otsuka" minor BCR-ABL messenger ribonucleic acid assay kit exhibits excellent performance in quantifying minor BCR-ABL transcripts in Philadelphia chromosome-positive acute lymphoblastic leukemia patients. Our results align well with established screening methods and show a strong correlation with laboratory-developed tests and diagnostic research products. The "Otsuka" kit holds great promise as a valuable tool for understanding Philadelphia chromosome-positive acute lymphoblastic leukemia pathology and guiding effective treatment strategies.

An update on the developments in the treatment of adult T-cell leukemia-lymphoma: current knowledge and future perspective.

Adult T-cell leukemia-lymphoma is defined as peripheral T-cell lymphoma caused by the human T-cell leukemia virus type I. Adult T-cell leukemia-lymphoma is classified into indolent (favorable chronic or smoldering) or aggressive (acute, lymphoma or unfavorable chronic) types. This review discusses the therapeutic developments for patients with adult T-cell leukemia-lymphoma and unmet issues in treating adult T-cell leukemia-lymphoma. For indolent adult T-cell leukemia-lymphoma, a watchful waiting strategy is recommended until the disease progresses to aggressive adult T-cell leukemia-lymphoma. For aggressive adult T-cell leukemia-lymphoma, multi-agent chemotherapy with or without allogeneic hematopoietic stem cell transplantation has been recommended. However, many patients with adult T-cell leukemia-lymphoma relapse, and their prognosis is poor. Recently, novel agents, including mogamulizumab, lenalidomide, brentuximab vedotin, tucidinostat and valemetostat, have been approved for patients with relapsed or refractory aggressive adult T-cell leukemia-lymphoma, and the combination of mogamulizumab with multi-agent chemotherapy or brentuximab vedotin with cyclophosphamide, doxorubicin and prednisone has been approved for patients with untreated aggressive adult T-cell leukemia-lymphoma in Japan. Importantly, the aging of patients with adult T-cell leukemia-lymphoma has recently been reported, and no standard of care for elderly patients with adult T-cell leukemia-lymphoma has been established. New evidence must be obtained from prospective clinical trials to improve the prognosis of patients with adult T-cell leukemia-lymphoma.

Mortality and risk of progression to adult T cell leukemia/lymphoma in HTLV-1-associated myelopathy/tropical spastic paraparesis.

Human T cell leukemia virus 1 (HTLV-1) causes the functionally debilitating disease HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP) as well as adult T cell leukemia lymphoma (ATLL). Although there were concerns that the mortality of HAM/TSP could be affected by the development of ATLL, prospective evidence was lacking in this area. In this 5-y prospective cohort study, we determined the mortality, prevalence, and incidence of ATLL in 527 HAM/TSP patients. The standard mortality ratio of HAM/TSP patients was 2.25, and ATLL was one of the major causes of death (5/33 deaths). ATLL prevalence and incidence in these patients were 3.0% and 3.81 per 1,000 person-y, respectively. To identify patients at a high risk of developing ATLL, flow cytometry, Southern blotting, and targeted sequencing data were analyzed in a separate cohort of 218 HAM/TSP patients. In 17% of the HAM/TSP patients, we identified an increase in T cells positive for cell adhesion molecule 1 (CADM1), a marker for ATLL and HTLV-1-infected cells. Genomic analysis revealed that somatic mutations of HTLV-1-infected cells were seen in 90% of these cases and 11% of them had dominant clone and developed ATLL in the longitudinal observation. In this study, we were able to demonstrate the increased mortality in patients with HAM/TSP and a significant effect of ATLL on their prognosis. Having dominant clonal expansion of HTLV-1-infected cells with ATLL-associated somatic mutations may be important characteristics of patients with HAM/TSP who are at an increased risk of developing ATLL.

Clinical significance of the immunoglobulin G heavy-chain repertoire in peripheral blood mononuclear cells of adult T-cell leukaemia-lymphoma patients receiving mogamulizumab.

'Monitoring of immune responses following mogamulizumab-containing treatment in patients with adult T-cell leukaemia-lymphoma (ATL)' (MIMOGA) is a multicentre prospective clinical study (UMIN000008696). In the MIMOGA study, we found that a lower percentage of CD2- CD19+ B cells in peripheral blood mononuclear cells (PBMC) was a significant unfavourable prognostic factor for overall survival (OS). Accordingly, we then analysed the immunoglobulin G (IgG) heavy-chain repertoire in PBMC by high-throughput sequencing. Of the 101 patients enrolled in the MIMOGA study, for 81 a sufficient amount of PBMC RNA was available for repertoire sequencing analysis. Peripheral IgG B cells in patients with ATL had a restricted repertoire relative to those in healthy individuals. There was a significant positive correlation between the Shannon-Weaver diversity index (SWDI) for the IgG repertoire and proportions of B cells in the PBMC of the patients. Multivariate analysis identified two variables significantly affecting OS: a higher serum soluble interleukin-2 receptor level, and a lower SWDI for the IgG repertoire [hazard ratio, 2·124; 95% confidence interval, 1·114-4·049; n = 44]. The present study documents the importance of humoral immune responses in patients receiving mogamulizumab-containing treatment. Further investigation of strategies to enhance humoral immune responses in patients with ATL is warranted.

[Successful treatment of myelodysplastic syndromes complicated by myeloid sarcoma with haploidentical allogeneic hematopoietic stem cell transplantation using post-transplant cyclophosphamide].

Using post-transplant cyclophosphamide (PTCy-haplo), haploidentical allogeneic hematopoietic stem cell transplantation has shown a surge in popularity in recent years. There are, however, only a few reports of PTCy-haplo being used to treat myelodysplastic syndromes (MDS) that have been complicated by myeloid sarcoma (MS). An immuno-suppressive therapy was given to a 25-year-old man who was diagnosed with low-risk MDS in September 2007. After an ileocecal ulcer biopsy that revealed MS in July 2019, a chromosomal analysis of the bone marrow cells in August 2019 revealed loss of chromosome 7, which is associated with poor prognosis. Because the patient lacked an HLA-matched sibling donor, he underwent PTCy-haplo in December 2019. On day 33, complete remission and donor chimerism was achieved. Ileocecal ulcer scarring was discovered by a colonoscopy on day 54. Grade I cutaneous acute graft-versus-host disease was discovered approximately on day 30 and treated with topical steroids. PTCy-haplo may be an effective treatment for MS.

[Warm autoimmune hemolytic anemia accompanied by metachronous double primary cancer].

In about half of the cases, autoimmune hemolytic anemia (AIHA) is secondary to an underlying disease, often due to paraneoplastic syndromes. Recently, the number of patients developing metachronous multiple primary malignant tumors (MPMTs) has been increasing due to the aging of the population and the longer survival times of those with malignant tumors. A 78-year-old woman was diagnosed with sigmoid colon cancer in May 2017 and with warm AIHA in October 2017. She received prednisolone for her warm AIHA treatment, which relieved her anemia symptoms. In January 2020, she had a warm AIHA relapse and received PSL again. In May 2020, she was diagnosed with peritonitis due to a small intestinal perforation and underwent laparoscopic partial resection of the small intestine. Subsequently, she was diagnosed with diffuse large B-cell lymphoma. It is important to consider the possibility of MPMTs and perform the appropriate examinations to determine whether malignant tumors are present in patients with a history of malignant tumors and a long history of AIHA relapse.

Circulating cell-free DNA in the peripheral blood plasma of patients is an informative biomarker for multiple myeloma relapse.

BACKGROUND: Multiple myeloma (MM) is an incurable hematological malignancy. Despite the introduction of several novel drugs, most patients relapse. Biomarkers to identify the early signs of relapse will make it possible to adjust the therapeutic strategy before the disease worsens. Although understanding genetic changes is important for the treatment of MM, currently known biomarkers of relapse, including serum free-light chains and monoclonal paraproteins, are not associated with genetic changes. METHODS: We therefore performed a multicenter study to examine the usefulness of circulating cell-free DNA (cfDNA) present in the peripheral blood (PB) plasma of patients as a biomarker for MM relapse. RESULTS: We identified several driver mutations by combined analysis of next-generation sequencing and existing databases of candidate oncogenes. Furthermore, relapse was detected more sensitively by monitoring the circulating cfDNA with these driver mutations than by conventional serum free-light chain examination. CONCLUSION: These results suggest the potential utility of cfDNA in the PB plasma of patients as a relevant early biomarker for MM relapse.

[Cooccurrence of classic Hodgkin lymphoma and multiple myeloma].

Although classic Hodgkin's lymphoma (CHL) sometimes develops after treatment for multiple myeloma (MM), simultaneous diagnosis of both malignancies is extremely rare without previous treatment history. Here we describe a case of a 54-year-old female who complained of left cervical lymphadenopathy. Biopsy specimen from the left cervical lymph node revealed mixed-cellularity CHL. Bone marrow aspirate comprised 10.3% plasma cells. She was diagnosed with MM due to involved: uninvolved serum free light chain ratio of >100. She achieved complete response for CHL after 4 cycles of doxorubicin, bleomycin, vinblastine, and dacarbazine chemotherapy along with 30 Gy of involved-field radiotherapy. Three years later, bortezomib, lenalidomide, and dexamethasone (VRd-lite) therapy was initiated for MM. Severe neutropenia during her 1st cycle prompted a dosage reduction of lenalidomide and bortezomib. Partial response was achieved after 4 cycles of VRd-lite followed by high-dose melphalan/autologous stem cell transplantation. No severe adverse events were recorded. This was followed by 4 cycles of carfilzomib, lenalidomide, and dexamethasone therapy, which resulted in complete remission. As the number of elderly people increases, multiple myeloma patients with previous history of other malignancies would increase. Our case has shown that VRd-lite therapy may be suitable for those patients.

[CD20-negative diffuse large B-cell lymphoma complicated by rheumatoid arthritis].

CD20 antigen is an important marker for diagnosis of B-cell neoplasms that is highly expressed on the surface of neoplastic B lymphocytes. Patients with rheumatoid arthritis (RA) have an increased risk of developing malignant lymphoma, of which diffuse large B-cell lymphoma (DLBCL) is the most common type. We report an unusual case of CD20-negative DLBCL complicated by rheumatoid arthritis. An 81-year old female presented with a left-sided cervical tumor, enlarged tonsil, and polyarticular pain. Pathological findings of the left tonsil showed proliferation of large atypical cells with irregular shaped nuclei. Most large cells were negative for CD3 and CD20. Additionally, these cells were positive for CD79a, BCL2, and MUM1, and negative for CD10, CD138, BCL6, PAX5, EBV-ISH, HHV8, and ALK.. Therefore, she was diagnosed with CD20-negative DLBCL complicated with RA and received dose-modified CHOP that achieved partial remission. Because CD20-negative DLBCL is rare, the identification of the clinicopathological features of this disease is urgently required.

CD4+ CADM1+ cell percentage predicts disease progression in HTLV-1 carriers and indolent adult T-cell leukemia/lymphoma.

We recently took advantage of the universal expression of cell adhesion molecule 1 (CADM1) by CD4+ cells infected with HTLV-1 and the downregulation of CD7 expression that corresponds with the oncogenic stage of HTLV-1-infected cells to develop a flow cytometric system using CADM1 versus CD7 plotting of CD4+ cells. We risk-stratified HTLV-1 asymptomatic carriers (AC) and indolent adult T-cell leukemia/lymphoma (ATL) cases based on the CADM1+ percentage, in which HTLV-1-infected clones are efficiently enriched. AC and indolent ATL cases were initially classified according to their CADM1+ cell percentage. Follow-up clinical and flow cytometric data were obtained for 71 cases. In G1 (CADM1+ ≤ 10%) and G2 (10% < CADM1+ ≤ 25%) cases, no apparent clinical disease progression was observed. In G3 (25% < CADM1+ ≤ 50%) cases, five out of nine (55.5%) cases progressed from AC to smoldering-type ATL. In G4 (50% < CADM1+ ) cases, the cumulative incidence of receiving systemic chemotherapy at 3 years was 28.4%. Our results indicate that the percentage of the CD4+ CADM1+ population predicts clinical disease progression: G1 and G2 cases, including AC cases, are stable and considered to be at low risk; G3 cases, including advanced AC cases and smoldering-type ATL cases based on the Shimoyama criteria, are considered to have intermediate risk; and G4 cases, which are mainly indolent ATL cases, are unstable and at high risk of acute transformation.

A distinct subtype of Epstein-Barr virus-positive T/NK-cell lymphoproliferative disorder: adult patients with chronic active Epstein-Barr virus infection-like features.

The characteristics of adult patients with chronic active Epstein-Barr virus infection are poorly recognized, hindering early diagnosis and an improved prognosis. We studied 54 patients with adult-onset chronic active Epstein-Barr virus infection diagnosed between 2005 and 2015. Adult onset was defined as an estimated age of onset of 15 years or older. To characterize the clinical features of these adults, we compared them to those of 75 pediatric cases (estimated age of onset <15 years). We compared the prognosis of adult-onset chronic active Epstein-Barr virus infection with that of patients with nasal-type (n=37) and non-nasal-type (n=45) extranodal NK/T-cell lymphoma. The median estimated age of onset of these lymphomas was 39 years (range, 16-86 years). Compared to patients with pediatric-onset disease, those in whom the chronic active Epstein-Barr virus infection developed in adulthood had a significantly decreased incidence of fever (P=0.005), but greater frequency of skin lesions (P<0.001). Moreover, hypersensitivity to mosquito bites and the occurrence of hydroa vacciniforme were less frequent in patients with adult-onset disease (P<0.001 and P=0.0238, respectively). Thrombocytopenia, high Epstein-Barr virus nuclear antigen antibody titer, and the presence of hemophagocytic syndrome were associated with a poor prognosis (P=0.0087, P=0.0236, and P=0.0149, respectively). Allogeneic hematopoietic stem cell transplantation may improve survival (P=0.0289). Compared to pediatric-onset chronic active Epstein-Barr virus infection and extranodal NK/T-cell lymphoma, adult-onset chronic active Epstein-Barr virus infection had a poorer prognosis (P<0.001 and P=0.0484, respectively). Chronic active Epstein-Barr virus infection can develop in a wide age range, with clinical differences between adult-onset and pediatric-onset disease. Adult-onset chronic active Epstein-Barr virus infection is a disease with a poor prognosis. Further research will be needed.

[Hypoplastic acute promyelocytic leukemia with continuous hypocellular bone marrow after remission].

An 87-year old female presented with unsteady gait and occasional subcutaneous hematomas. Blood examination findings revealed pancytopenia and mild coagulopathy. Both the histopathological evaluation of bone marrow smears and bone marrow biopsy revealed a hypocellular bone marrow. However, APL cells were observed and PML-RARA fusion gene was detected. On the basis of these findings, the patient was diagnosed with hypoplastic acute promyelocytic leukemia. She received ATRA treatment and achieved complete remission (CR) 29 days from the commencement of therapy. After the first CR, she received two courses of ATO as a consolidation therapy. Following the latter treatments, she maintained CR, but a hypoplastic bone marrow was still observed. Hypoplastic AML is defined as AML with a low bone marrow cellularity. It is clinically important to distinguish it from aplastic anemia and hypoplastic MDS. It has been suggested that both cytogenetic and morphological diagnosis are imperative to the differential diagnosis of hypocellular bone marrow.

[Successful treatment with a combination of lenalidomide and dexamethasone for cryoglobulinemia associated with multiple myeloma].

Cryoglobulinemia (Cg) in multiple myeloma (MM) is rare and no standard treatment has yet been established. Herein, we report a case of MM with Cg, successfully treated with a combination of lenalidomide and dexamethasone. A 76-year-old woman suffering from skin ulcerations, extremity pain and peripheral neuropathy was diagnosed as having IgG-kappa MM with Cg in 1992. She intermittently received conventional chemotherapy, immunosuppressant therapy and plasma exchange. Despite these treatments, Cg-related symptoms eventually became uncontrollable. She was admitted to our hospital in 2012 because of worsening skin symptoms involving both ankles. Plasmapheresis proved ineffective. Improvement of skin ulcerations and numbness was achieved with administration of lenalidomide at 25 mg daily with weekly dexamethasone, which also decreased the cryoglobulin level. The course of this patient suggests that lenalidomide plus dexamethasone is a promising treatment for MM with Cg.

[Outcome of patients with relapsed/refractory adult T-cell leukemia-lymphoma after salvage therapy].

We retrospectively analyzed 81 relapsed or refractory adult T-cell leukemia-lymphoma (ATL) patients who received salvage therapy in our institution between 2000 and 2010. These patients had received chemotherapy, radiation, or hematopoietic stem cell transplantation (HSCT) as an initial treatment, and were then given chemotherapy, radiation, HSCT, or donor lymphocyte infusion (DLI) as salvage therapy. Median survival time was 3.9 months. Of 5 long-term survivors, who survived more than 2 years after the first salvage therapy, 4 patients received HSCT or DLI, and the other was given mogamulizumab as the salvage therapy. For patients with relapsed or refractory ATL, HSCT/DLI is a promising treatment for achieving long-term survival. Mogamulizumab may be the good choice for those who are ineligible for HSCT.

Outcomes in Patients with Classic Hodgkin Lymphoma Treated with ABVD: A Single-center Retrospective Study.

Objective Classic Hodgkin lymphoma (CHL) has been regarded as a curable disease when treated appropriately, especially in younger patients, and ABVD (doxorubicin, bleomycin, vinblastine, and dacarbazine) has been regarded as the standard regimen. However, a relatively poor prognosis has been reported in older patients with CHL, and the efficacy and tolerability of the ABVD regimen has not been fully elucidated. We retrospectively investigated the outcomes in patients with CHL treated with ABVD at our institute. Methods Twenty-five patients were evaluated; 14 were ≤60 years of age, and 11 were >60 years of age (older group). Results The ABVD doses were reduced in all patients in the older group; the median average relative dose intensity was 0.58. In the older group, the 5-year overall survival (OS) and median OS were 100% and not reached, respectively, for patients with early-stage CHL and 66.7% and not reached, respectively, for those with advanced-stage CHL. No patients died of CHL, and only one treatment-related death was observed in the older group. Conclusion ABVD with dose attenuation may represent a feasible and effective strategy for the treatment of older patients with CHL in clinical practice, particularly in those with early-stage disease, although the optimal degree of attenuation remains unclear.

Chronological genome and single-cell transcriptome integration characterizes the evolutionary process of adult T cell leukemia-lymphoma.

Subclonal genetic heterogeneity and their diverse gene expression impose serious problems in understanding the behavior of cancers and contemplating therapeutic strategies. Here we develop and utilize a capture-based sequencing panel, which covers host hotspot genes and the full-length genome of human T-cell leukemia virus type-1 (HTLV-1), to investigate the clonal architecture of adult T-cell leukemia-lymphoma (ATL). For chronologically collected specimens from patients with ATL or pre-onset individuals, we integrate deep DNA sequencing and single-cell RNA sequencing to detect the somatic mutations and virus directly and characterize the transcriptional readouts in respective subclones. Characteristic genomic and transcriptomic patterns are associated with subclonal expansion and switches during the clinical timeline. Multistep mutations in the T-cell receptor (TCR), STAT3, and NOTCH pathways establish clone-specific transcriptomic abnormalities and further accelerate their proliferative potential to develop highly malignant clones, leading to disease onset and progression. Early detection and characterization of newly expanded subclones through the integrative analytical platform will be valuable for the development of an in-depth understanding of this disease.

A Phase I/II Multicenter Trial of HLA-Haploidentical PBSCT with PTCy for Aggressive Adult T Cell Leukemia/Lymphoma.

Adult T cell leukemia/lymphoma (ATL) is a highly aggressive hematologic malignancy with a very poor prognosis, and most patients with ATL are elderly. Although post-transplantation cyclophosphamide (PTCy) has yielded promising results in various diseases, available data are limited regarding its outcomes in ATL. The aim of this study was to determine the safety and efficacy of reduced-intensity peripheral blood stem cell transplantation (PBSCT) from a human leukocyte antigen (HLA)-haploidentical donor using PTCy as graft-versus-host disease (GVHD) prophylaxis. This was a prospective, multicenter phase I/II study (UMIN000021783) conducted at 16 hospitals in Japan. The primary endpoint was the probability of survival with engraftment and without grade III/IV acute GVHD at day 60 after PBSCT. The expected probability of the primary endpoint was estimated to be 60%, and the threshold probability was set at 30% on the basis of previous studies. The conditioning regimen consisted of fludarabine (30 mg/m2/d from day -7 to -2), melphalan (40 mg/m2/d on days -3 and -2), and total body irradiation (2 Gy on day -1). GVHD prophylaxis consisted of tacrolimus starting at 0.02 mg/kg/d on day -1, PTCy (50 mg/kg/d on days +3 and +5), and mycophenolate mofetil 2000 mg/d starting on day +6. Eighteen ATL patients underwent PBSCT. The probability of patients who met the primary endpoint was 89% (95% confidence interval, 65% to 99%). The cumulative incidences of grade II to IV acute GVHD, III/IV acute GVHD, and moderate-to-severe chronic GVHD were 39%, 11%, and 17%, respectively. The probabilities of overall survival were 83% at 1 year and 73% at 2 years. The cumulative incidences of non-relapse mortality and disease progression at 1 year were 11% and 28%, respectively. HLA-haploidentical PBSCT with PTCy as GVHD prophylaxis is a valid option for patients with aggressive ATL.