Phase 1 study of tazemetostat in Japanese patients with relapsed or refractory B-cell lymphoma.

BACKGROUND: Tazemetostat is a selective and orally available inhibitor of enhancer of zeste homolog 2 (EZH2), a histone methyltransferase and epigenetic regulator of cellular differentiation programs. We carried out a phase I study of tazemetostat in Japanese patients with relapsed or refractory B-cell non-Hodgkin-type lymphoma (B-NHL) to evaluate its tolerability, safety, pharmacokinetics, and preliminary antitumor activity. METHODS: Tazemetostat was given orally at a single dose of 800 mg on the first day and 800 mg twice daily (BID: total 1600 mg/d) on following days in a 28-day/cycle manner. Tazemetostat dose-limiting toxicity (DLT) was evaluated up to the end of the first treatment cycle. Archival tumor tissues were analyzed for hotspot EZH2 mutations. RESULTS: As of 15 January 2018, seven patients (four follicular lymphoma [FL] and three diffuse large B-cell lymphoma [DLBCL]) were enrolled. The median age was 73 (range, 59-85) years, and the median number of prior chemotherapy regimens was three (range, one to five). No DLT was observed (one patient was not evaluable due to early disease progression). The common treatment-related adverse events (AEs) were thrombocytopenia and dysgeusia (three patients each; 42.9%). No treatment-related serious AEs were observed. The objective response rate was 57% (4/7 patients), including responses in three of four patients with FL and one of three patients with DLBCL. An EZH2 mutation was detected in one patient with FL responding to treatment. CONCLUSIONS: Tazemetostat at 800 mg BID showed an acceptable safety profile and promising antitumor activity in Japanese patients with relapsed or refractory B-NHL.

Phase II study of E7777 in Japanese patients with relapsed/refractory peripheral and cutaneous T-cell lymphoma.

E7777 is a recombinant cytotoxic fusion protein composed of the diphtheria toxin fragments A and B and human interleukin-2. It shares an amino acid sequence with denileukin diftitox, but has improved purity and an increased percentage of active monomer. We undertook a multicenter, single-arm phase II study of E7777 in patients with relapsed or refractory peripheral T-cell lymphoma (PTCL) and cutaneous T-cell lymphoma (CTCL) to evaluate its efficacy, safety, pharmacokinetics, and immunogenicity. A total of 37 patients were enrolled, of which 17 and 19 patients had PTCL and CTCL, respectively, and one patient with another type of lymphoma (extranodal natural killer/T-cell lymphoma, nasal type), diagnosed by the Central Pathological Diagnosis Committee. Among the 36 patients with PTCL and CTCL, objective response rate based on the independent review was 36% (41% and 31%, respectively). The median progression-free survival was 3.1 months (2.1 months in PTCL and 4.2 months in CTCL). The common adverse events (AEs) observed were increased aspartate aminotransferase (AST) / alanine aminotransferase (ALT), hypoalbuminemia, lymphopenia, and pyrexia. Our results indicated that a 9 µg/kg/d dose of E7777 shows efficacy and a manageable safety profile in Japanese patients with relapsed or refractory PTCL and CTCL, with clinical activity observed across the range of CD25 expression. The common AEs were manageable, but increase in ALT / AST, hypoalbuminemia, and capillary leak syndrome should be carefully managed during the treatment.

Clinical outcome of Epstein-Barr virus-positive diffuse large B-cell lymphoma of the elderly in the rituximab era.

Diffuse large B-cell lymphoma (DLBCL) is the most common subtype of malignant lymphoma. The incidence of Epstein-Barr virus (EBV)-positive DLBCL in Asian and Latin American countries ranges from 8 to 10%. The prognosis of patients with EBV-positive DLBCL is controversial. To compare the clinical outcome of EBV-positive and EBV-negative patients with DLBCL in the rituximab era, we analyzed 239 patients with de novo DLBCL diagnosed between January 2007 and December 2011. The presence of EBV in lymphoma cells was detected using EBV-encoded RNA in situ hybridization, and it was found that 18 (6.9%) of 260 patients with diagnosed DLBCL tested positive. Among the 260 cases, 216 cases were treated with rituximab plus chemotherapy, as were 8 EBV-positive DLBCL patients. The median overall survival and progression-free survival times in patients with EBV-positive DLBCL were 8.7 months and 6.8 months, respectively. The median overall survival and progression-free survival could not be determined in EBV-negative DLBCL patients (P = 0.0002, P < 0.0001, respectively). The outcome of patients with EBV-positive DLBCL remains poor, even in the rituximab era.

Impact of previous anthracycline therapy in patients with acute myeloid leukemia receiving venetoclax.

Venetoclax (VEN) combination regimens are now recognized as effective against acute myeloid leukemia (AML). However, the prognosis of patients who do not attain a composite complete response (cCR) is extremely poor, and clinical determinants of response remain unknown. Medical records of 57 patients with AML treated with VEN combination regimens from April 2021 to March 2022 at six institutions were retrospectively analyzed. The primary endpoint was cCR, complete remission, or complete remission with incomplete hematologic recovery after one cycle of VEN combination regimen. Five patients had previously relapsed after allogeneic hematopoietic stem cell transplantation (allo-SCT). The treatment regimen was azacitidine-VEN in 48 patients (84%) and low-dose cytarabine-VEN in 9 patients (16%). Thirty patients (53%) achieved cCR after one cycle of a VEN regimen. In univariate analysis, the number of prior chemotherapy regimens, post-allo-SCT relapse, and cytogenetic risk category were associated with a decreased likelihood of achieving cCR. In multivariate analysis, second-line chemotherapy remained a significant predictor of response. Patients who received anthracycline immediately before the VEN regimen had a higher cCR rate than patients who did not receive anthracycline. In this study, prior chemotherapy/allo-SCT and cytogenetic risk were associated with VEN treatment outcomes.

Association of promyelocytic leukemia protein with expression of IL-6 and resistance to treatment in multiple myeloma.

BACKGROUND/AIMS: Promyelocytic leukemia protein (PML) was originally identified as a tumor suppressor but has been recently shown to have the ability to control stem cell function in multiple tissues including malignancies. This study aimed to evaluate the biological and clinical significance of PML in multiple myeloma (MM). METHODS: We knocked down PML in myeloma cells with a lentiviral vector expressing microRNA to target PML, which were used for in vitro analyses. We also evaluated the association between PML expression in the bone marrow and patients' clinical parameters. RESULTS: The expression of IL-6 was decreased in myeloma cells with knocked-down PML expression. Immunohistochemical study showed that the PML expression level varied widely in the bone marrow of 48 MM patients, and that IL-6 expression correlated with PML expression in these patients. In addition, MM with high PML expression at diagnosis showed a poor prognosis regarding the 2-year survival, and PML and IL-6 positivity increased with the progression of disease in 13 sequentially analyzed cases. CONCLUSIONS: These results suggest that PML expression was positively associated with IL-6 expression in patients and was also related to tumor development and resistance to treatment in MM.

Successful Treatment of Therapy-related Acute Promyelocytic Leukemia with All-trans-retinoic acid Following Epirubicin for Hepatocellular Carcinoma and Docetaxel and Pembrolizumab Therapies for Lung Carcinoma: A Triple Malignancy Case.

A 69-year-old man was referred to the hematology department for the evaluation of pancytopenia. He had been treated with radiation and epirubicin for hepatocellular carcinoma, and with docetaxel and pembrolizumab for lung adenocarcinoma. Bone marrow smears exhibited markedly increased promyelocytes, and polymerase chain reaction (PCR) study demonstrated chimeric fusion genes of PML-RARA. He was diagnosed with therapy-related acute promyelocytic leukemia (t-APL) and treated with all trans-retinoic acid (ATRA). After 30 days of ATRA treatment, complete hematological response was achieved. To the best of our knowledge, this case represents the first description of successfully treated t-APL diagnosed after treatment with pembrolizumab.

Overcoming Tyrosine Kinase Inhibitor Resistance in Transformed Cell Harboring SEPT9-ABL1 Chimeric Fusion Protein.

Hematological malignancies harboring various ABL1 fusions are expected to be sensitive to tyrosine kinase inhibitors (TKIs), similar to those with BCR-ABL1. However, SEPT9-ABL1 exhibits TKI resistance both in vitro and in vivo. SEPT9-ABL1 has the same ABL1 region as seen in BCR-ABL1 but no point mutation in its kinase domain, which is one of the main mechanisms underlying TKI resistance in the leukemic cells harboring BCR-ABL1. The purpose of this study was to reveal the mechanism underlying TKI resistance induced by SEPT9-ABL1. We focused on the TP53 status because TKI-induced apoptosis in BCR-ABL1-positive cells is achieved through TP53. Mouse TP53 homologue TRP53 was downregulated and less phosphorylated in the cells expressing SEPT9-ABL1 than in those with BCR-ABL1, resulting in the prevention of apoptosis induced by TKIs. The CRM1 inhibitor KPT-330 accumulated nuclear TRP53 and NFKB1A (also known as IκBα), which is thought to capture TRP53 in the cytoplasm, and induced apoptosis in the hematopoietic cells expressing SEPT9-ABL1. In addition, the combination treatment of KPT-330 and imatinib, which induced the marked nuclear accumulation of PP2A and SET, reactivated PP2A through its dephosphorylation and inhibited SET expression, resulting in the effective induction of the apoptosis in the cells expressing SEPT9-ABL1. The combination treatment with KPT-330 and imatinib successfully reduced the subcutaneous masses expressing SEPT9-ABL1 and extended the survival of the mice intraperitoneally transplanted with SEPT9-ABL1-expressing cells. These results show that therapy with CRM1 inhibitors may be effective for overcoming TKI resistance induced by SEPT9-ABL1.

Primary CNS post-transplant lymphoproliferative disorder following haploidentical HSCT using post-transplant high-dose cyclophosphamide.

Neurological complications after hematopoietic stem cell transplantation (HSCT) are frequently life-threatening, and their clinical management can be highly challenging. In the case of central nervous system lesions post-HSCT, a definitive diagnosis is often difficult to reach because many different causative and contributing conditions may be present, including bacterial, fungal, or viral infections; original disease relapse; and post-transplant lymphoproliferative disorder (PTLD). Here, we report a case of a 32-year-old male patient with Philadelphia chromosomepositive acute lymphoid leukemia who underwent three HSCTs and was then diagnosed with primary central nervous system (PCNS) PTLD by brain biopsy. The third HSCT was a haplo-identical peripheral blood stem cell transplantation from his mother, with post-transplant high-dose cyclophosphamide and tacrolimus used as graft-versus-host disease prophylaxis. Four months after the HSCT, multiple small ring lesions were detected in the parabasal ganglia of the patient's brain during magnetic resonance imaging. A lesion biopsy indicated Epstein-Barr virus (EBV)-positive, diffuse large B-cell lymphoma. Because the patient had no evidence of systemic lymphadenopathy, we diagnosed him with PCNS-PTLD. There was no EBV DNA in this patient's cerebrospinal fluid. The diagnosis of PCNS-PTLD by EBV DNA polymerase chain reaction is difficult and highlights the importance of a brain biopsy to diagnose PCNS-PTLD, especially in cases showing no EBV DNA in the cerebrospinal fluid. Although a rare condition, it is essential to locate and analyze cases of PCNS-PTLD after HSCT to establish the optimal strategy for treatment or prophylaxis.

A Case of Composite Lymphoma with Extranodal NK/T-cell Lymphoma, Nasal-type and Diffuse Large B-cell Lymphoma.

Composite lymphoma (CL) is defined as the occurrence of two distinct types of lymphoma within the same patient. Most cases of CL involve Hodgkin and non-Hodgkin lymphomas or two distinct types of B-cell lymphomas; true CL is a composite B-cell and T-cell lymphoma, and is rare. We herein report a case involving concurrent extranodal NK/T-cell lymphoma, nasal-type and diffuse large B-cell lymphoma, which has not been previously reported. As the mechanisms and treatments of composite B-cell and T-cell lymphomas are unclear, further studies are required to improve the prognosis.

Correction to: Dysplastic features seen in a patient with acute myeloid leukemia harboring the KMT2A-TET1 fusion gene.

In the original publication of the article, the title was incorrectly published as "Dysplastic features seen in a patient with acute myeloid leukemia harboring the KTM2A-TET1 fusion gene". The correct title should be "Dysplastic features seen in a patient with acute myeloid leukemia harboring the KMT2A-TET1 fusion gene".

Three cases of spontaneous splenic rupture in malignant lymphoma.

Spontaneous splenic rupture is a rare but often life-threatening condition. However, there is no consensus on appropriate management for this condition, due to its rarity. Here, we report three cases of malignant lymphoma with spontaneous splenic rupture. In each case, progression of splenic bleeding was rapid and complicated by malignant lymphoma. Spontaneous splenic rupture complicated by malignant lymphoma may cause exacerbation of anemia and hypovolemic shock. When splenic rupture is indicated by abdominal pain, tachycardia, or hypotension in a patient with splenomegaly, abdominal examination should be performed immediately, and emergency transcatheter arterial embolization and/or splenectomy should be considered.

The Successful Prevention of Thromboembolism Using Rivaroxaban in a Patient with Antithrombin Deficiency during the Perioperative Period.

Antithrombin (AT) deficiency, a rare disorder of the coagulation system, is a serious risk factor for thromboembolism. Approximately 50-90% of patients with AT deficiency develop thromboembolism during their lifetime. In addition, surgery is a major risk factor for thromboembolism in these patients. We herein report the case of a 90-year-old woman with AT deficiency who was safely and successfully managed using rivaroxaban (a direct oral factor Xa inhibitor) during the perioperative period of surgery for right femur fracture. The present case illustrates the effectiveness of rivaroxaban in preventing thromboembolisms due to surgery, even in very elderly patients with antithrombin deficiency. Further investigations are needed to determine the optimal dosage of rivaroxaban.

Successful treatment with low-dose nivolumab in refractory Hodgkin lymphoma after allogeneic stem cell transplantation.

Previous studies have reported that an antibody that blocks programmed cell death 1 (PD-1) has therapeutic activity in patients with refractory/relapsed Hodgkin lymphoma (HL). However, the safety and efficacy of these agents in the post-allogeneic stem cell transplantation (allo-SCT) setting are not well known. Here, we describe a patient who was diagnosed as classical HL and treated with five regimens of chemotherapies with autologous SCT. Complete remission (CR) was not achieved following this initial treatment, so we performed allo-SCT from an HLA-matched sibling donor. Since his disease progressed at day 403 after allo-SCT, we decided to use nivolumab in the treatment of his refractory disease. To prevent the worsening of his chronic graft-versus-host disease (GVHD), we reduced the initial dose and frequency of nivolumab compared with the previous report. After four courses of 0.5 mg/kg of nivolumab every three weeks, FDG-PET imaging showed partial response (PR) to the treatment, a remarkable result. However, since the escalated dose of 2 mg/kg resulted in worsening of dyspnea and skin sclerosis, we initiated systemic administration of prednisolone and reduced nivolumab to 1 mg/kg. At the time of this report, his HL is in stable PR with three weekly administration of nivolumab and steroid controlled mild chronic GVHD.

Successful bypass surgery for esophageal carcinoma under adequate factor XIII/13 replacement therapy in a case of intractable autoimmune hemorrhaphilia due to anti-Factor XIII/13 antibodies.

Autoimmune hemorrhaphilia due to anti-factor XIII (FXIII) antibodies (AH13) is a life-threatening disease associated with high risk of surgical bleeding. Since AH13 occurs mainly in the elderly, patients of AH13 tend to be complicated with other life-threatening diseases that may require surgical procedures. During our nation-wide survey on AH13, supported by the Japanese Ministry of Health, Labor, and Welfare, patients with unexplained bleeding were examined for FXIII-related parameters and anti-FXIII autoantibodies. A 64-year-old man had previously been tentatively diagnosed with AH13 and received immunosuppressive therapies, as FXIII inhibitor was detected by functional cross-mixing studies. About 2 years later, he was definitively diagnosed with AH13, because our immuno-chromatographic test and enzyme-linked immuno-sorbent assay detected FXIII-bound anti-FXIII-A subunit autoantibodies. Since routine endoscopic examination revealed suspected esophageal carcinoma, a preparatory FXIII pharmacokinetic (PK) analysis was performed by infusing FXIII concentrates prior to biopsy. Consequently, biopsy of this lesion was done without bleeding complications. One month later, a second PK study was carried out before surgery, and esophageal bypass surgery was completed successfully under FXIII replacement therapy. Our experience with this case suggests that operations can be performed safely and with confidence even in patients with such life-threatening hemorrhagic diseases.

Four hepatosplenic T-cell lymphoma cases of Japanese patients.

Hepatosplenic T-cell lymphoma (HSTCL), a rare type of γδ T-cell lymphoma, is characterized by hepatosplenomegaly and cytopenias. It is associated with immunodeficiency and its age of onset is reportedly between the 20s and 30s. We herein report 4 Japanese HSTCL cases. Three of them, including an elderly case that was 74 years of age, were not at adolescence. No cases had a history of immunodeficiency. All other disease phenotypes were similar to the typical HSTCL cases. These findings suggest that there are a certain proportion of HSTCL patients who presented after middle age.

Refractory acute promyelocytic leukemia successfully treated with combination therapy of arsenic trioxide and tamibarotene: A case report.

A 40-year-old male developed refractory acute promyelocytic leukemia (APL) after various treatments including all-trans retinoic acid, tamibarotene, arsenic trioxide (As2O3), conventional chemotherapy, and autologous peripheral blood stem cell transplantation. We attempted to use both tamibarotene and As2O3 as a combination therapy, and he achieved molecular complete remission. Grade 2 prolongation of the QTc interval on the electrocardiogram was observed during the therapy. The combination therapy of As2O3 and tamibarotene may be effective and tolerable for treating refractory APL cases who have no treatment options, even when they have previously been treated with tamibarotene and As2O3 as a single agent.

Single nucleotide polymorphisms of cytarabine metabolic genes influence clinical outcome in acute myeloid leukemia patients receiving high-dose cytarabine therapy.

Cytarabine arabinoside (Ara-C) is the most important agent for treating acute myeloid leukemia (AML). Here, we genotyped 11 single nucleotide polymorphisms (SNPs) of seven Ara-C metabolism-related genes in 39 AML patients who had received high-dose Ara-C as a single-agent treatment. Univariate analysis identified three SNPs that were significantly associated with shorter time-to-relapse (TTR): CTPS rs12144160 GG compared to AA/AG, DCTD rs9990999 AG/GG compared to AA, and SLC29A1 rs693955 CC compared to AA/AC. Multivariate analysis of TTR revealed the SLC29A1 rs693955 CC genotype and first induction failure to be significantly associated with a shorter TTR. The DCTD rs9990999 AG/GG and SLC29A1 rs693955 CC genotypes were also significantly associated with shorter duration of neutropenia. The results of our study suggest that SNP analysis can be an important tool in improving drug responsiveness and enabling a better understanding of this condition and the development of tailor-made treatments for AML patients who benefit from consolidated high-dose Ara-C therapy.