HLA haploidentical stem cell transplantation from HLA homozygous donors to HLA heterozygous donors may have lower survival rates than haploidentical transplantation from HLA heterozygous donors to HLA heterozygous donors: a retrospective nationwide analysis.

In HLA haploidentical stem cell transplantation, patients and donors usually share one HLA haplotype and have one different HLA haplotype (hetero-to-hetero). However, there are rare cases of transplantation from HLA homozygous donors to heterozygous recipients (homo-to-hetero), resulting in mismatches only in the graft-versus-host direction. We previously reported that homo-to-hetero transplants have a lower survival rate in a mouse model than hetero-to-hetero transplants due to stronger graft-versus-host disease (GVHD) but inferior graft-versus-leukemia effect. To examine whether homo-to-hetero transplant effects also occur in humans, we retrospectively compared the results of 59 homo-to-hetero and 4,539 hetero-to-hetero cases in the Japanese transplant registry data. The results showed no statistical difference between the homo-to-hetero and hetero-to-hetero groups in the cumulative incidences of neutrophil engraftment (83.1% vs 89.0%), acute GVHD II-IV (36.8% vs 38.8%), III-IV (16.8% vs 17.4%), chronic GVHD (32.7% vs 30.7%), relapse (52.9% vs 49.0%), and non-relapse mortality (31.6% vs 28.2%). In contrast, overall survival was significantly lower in the homo-to-hetero group than in the hetero-to-hetero group (12.6% vs 26.2%, p = 0.0308). The inferior effect of homo-to-hetero transplantation on overall survival remained significant in multivariate analyses.

Immunoreactivity to WT1 peptide vaccine is associated with prognosis in elderly patients with acute myeloid leukemia: follow-up study of randomized phase II trial of OCV-501, an HLA class II-binding WT1 polypeptide.

We previously conducted a randomized phase II trial of OCV-501, a WT1 peptide presented by helper T cells, in elderly AML (acute myeloid leukemia) patients in first remission, indicating no difference in 2-year disease-free survival (DSF) between the OCV-501 and placebo groups. Here, we analyzed 5-year outcome and biomarkers. Five-year DFS was 36.0% in the OCV-501 group (N = 52) and 33.7% in the placebo group (N = 53), with no significant difference (p = 0.74). The peripheral WT1 mRNA levels were marginally suppressed in the OCV-501 group compared with the placebo group. Enhanced anti-OCV-501 IgG response by the 25th week was an independent favorable prognostic factor. Anti-OCV-501 IFNγ responses were less frequent than the IgG reactions. These findings suggest that host immunoreactivity has a significant impact on the prognosis of AML and that further improvement of the WT1 peptide vaccine is needed.

Allogeneic Hematopoietic Cell Transplantation for Patients with Relapsed Acute Promyelocytic Leukemia.

Although autologous hematopoietic cell transplantation (HCT) is an established therapy for patients with relapsed acute promyelocytic leukemia (APL) after returning to complete remission (CR), the role of allogeneic HCT remains unclear for treating relapsed APL. This study aimed to investigate allogeneic HCT outcomes in patients with relapsed APL, focusing particularly on those who underwent transplantation in non-CR and those who had relapsed after prior autologous HCT. We retrospectively analyzed Japanese nationwide transplantation registry data of patients with relapsed APL age ≥16 years who underwent allogeneic HCT between 2006 and 2020. A total of 195 patients were eligible for this analysis, including 69 who underwent transplantation in non-CR and 55 who relapsed after prior autologous HCT. The median duration of follow-up for survivors was 5.4 years. Multivariate analysis revealed that both non-CR at transplantation (hazard ratio [HR], 1.74; 95% confidence interval [CI], 1.12 to 2.71; P = .014) and prior autologous HCT (HR, 2.10; 95% CI, 1.28 to 3.44; P = .013) were associated with higher risks of overall mortality. The 5-year overall survival (OS) rates for patients who underwent transplantation in CR and non-CR were 58% and 39%, respectively (P = .085), if they did not have a history of prior autologous HCT. In the patients who had relapsed after prior autologous HCT, the 5-year OS rate was 47% for those who underwent allogeneic HCT in CR and 6% for those who did so in non-CR (P = .001). Allogeneic HCT still provides an opportunity for long-term survival for certain patients with relapsed APL for whom autologous HCT is unlikely to be effective. The dismal outcome of those with prior autologous HCT who underwent allogeneic HCT in non-CR poses a significant therapeutic challenge.

The First Reported Case of Allogenic Hematopoietic Stem Cell Transplantation for CML Blast Phase (Monocytic Lineage) in the Tyrosine Kinase Inhibitor Era.

Chronic myeloid leukemia (CML) blast phase (monocytic lineage) is extremely rare. A 39-year-old Japanese man was diagnosed with CML blast phase (monocytic lineage). T315I mutation was positive, ponatinib was initially started, and then, allogenic hematopoietic stem cell transplantation (allo-HSCT) was performed. Seven days after allo-HSCT, hyper-acute graft-versus-host disease developed, and medial temporal lobe encephalitis emerged 24 days after allo-HSCT. He was alive for over 1 year after allo-HSCT. This is the first case report of HSCT for CML blast phase (monocytic lineage) in tyrosine kinase inhibitor era. Further cases should be documented for effective treatment regimen and analysis of clinical features.

Successful bridging therapy with tirabrutinib before ASCT for relapsed primary DLBCL of the CNS complicated with PBC, cirrhosis, and pancytopenia.

The optimal therapy for relapsed primary diffuse large B-cell lymphoma (DLBCL) of the central nervous system (CNS) remains unclear. We herein report a case of relapsed primary DLBCL of the CNS complicated with primary biliary cholangitis, cirrhosis, and pancytopenia that was successfully treated with bridging therapy with tirabrutinib before autologous hematopoietic stem cell transplantation (ASCT). Tirabrutinib is well tolerated and effective for relapsed primary DLBCL of the CNS with comorbidities, including cirrhosis and pancytopenia. Tirabrutinib is a promising option as bridging therapy before ASCT.

Effectiveness of hyperbaric oxygen therapy for virus-associated hemorrhagic cystitis after allogeneic hematopoietic stem cell transplantation.

Although some studies have suggested the effectiveness of hyperbaric oxygen (HBO) therapy for hemorrhagic cystitis (HC) after allogeneic hematopoietic stem cell transplantation (HSCT), the role of HBO has not been established. We compared the treatment outcomes of 8 patients with viral HC (adenovirus [ADV], n = 2; BK virus [BKV], n = 6) treated with HBO (HBO[+]) and 8 patients (ADV, n = 2; BKV, n = 6) treated with conventional therapy (HBO[-]), such as urinary catheterization and intravenous cidofovir. HBO therapy was performed at 2.1 atmospheres for 90 min/day until clinical improvement was achieved. The median number of HBO treatments was 10 (range 8-12). The median duration of HBO treatment was 19.5 days (range 10-23 days). All 8 HBO(+) patients achieved complete remission (CR) at a median of 14.5 days (range 5-25 days). Of the 8 HBO(-) patients, 5 (62.5%) obtained CR and 3 remained symptomatic for 2-6 months. The cumulative incidence of transplant-related mortality at day 100 after allogeneic HSCT was significantly higher in the HBO(-) patients than in the HBO(+) patients (14.2 vs. 0%, P < 0.05). No severe HBO-related adverse effects were observed. In conclusion, HBO is a feasible option for treating viral HC after allogeneic HSCT.

Pembrolizumab plus lenalidomide and dexamethasone in treatment-naive multiple myeloma (KEYNOTE-185): subgroup analysis in Japanese patients.

The global, randomized, open-label KEYNOTE-185 study closed early after an interim analysis showed an unfavorable benefit-risk profile with pembrolizumab plus lenalidomide and low-dose dexamethasone (Rd) versus Rd alone in treatment-naive, transplant-ineligible multiple myeloma. This subgroup analysis reported outcomes in the Japanese population. Patients were randomly assigned (1:1) to pembrolizumab plus Rd or Rd alone, stratified by age and International Staging System. The primary end point was progression-free survival (PFS). Fifty-two Japanese patients were randomly assigned to pembrolizumab plus Rd (n = 27) or Rd (n = 25). The median follow-up was 7.2 months (range, 0.4-13.8). The median PFS was not reached (NR); 6-month PFS was 91.2% versus 86.2% with pembrolizumab plus Rd versus Rd [hazard ratio (HR), 0.31; 95% CI, 0.06-1.63]. The median overall survival (OS) was NR; 6-month OS was 96.2% versus 95.7% with pembrolizumab plus Rd versus Rd (HR, 0.33; 95% CI, 0.03-3.72). With pembrolizumab plus Rd versus Rd, grade 3-5 adverse events occurred in 70.4% versus 69.6% of patients; serious adverse events occurred in 40.7% versus 52.5%. Although in the Japanese subgroup of KEYNOTE-185 adding pembrolizumab to Rd did not show an unfavorable risk-benefit, the analysis is limited by short follow-up and small sample size, affecting generalizability of the results.

Rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisolone combined with high-dose methotrexate plus intrathecal chemotherapy for newly diagnosed intravascular large B-cell lymphoma (PRIMEUR-IVL): a multicentre, single-arm, phase 2 trial.

BACKGROUND: Intravascular large B-cell lymphoma (IVLBCL) is a rare disease for which there is no available standard treatment. We aimed to ascertain the safety and activity of R-CHOP (rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisolone) with high-dose methotrexate and intrathecal chemotherapy as CNS-oriented therapy for patients with previously untreated IVLBCL. METHODS: PRIMEUR-IVL is a multicentre, single-arm, phase 2 trial at 22 hospitals in Japan. Eligible patients had untreated histologically confirmed IVLBCL, were aged 20-79 years, had an Eastern Cooperative Group performance status of 0-3, and had no apparent CNS involvement at diagnosis. Patients received three cycles of R-CHOP (rituximab 375 mg/m2 intravenously on day 1 [except cycle one, which was on day 8]; cyclophosphamide 750 mg/m2, doxorubicin 50 mg/m2, and vincristine 1·4 mg/m2 [maximum 2·0 mg] intravenously on day 1 of cycle one and day 2 of cycles two and three; and prednisolone 100 mg/day orally on days 1-5 of cycle one and days 2-6 of cycles two and three) followed by two cycles of rituximab with high-dose methotrexate (3·5 g/m2 intravenously on day 2 of cycles four and five) every 2 weeks and three additional cycles of R-CHOP. Intrathecal chemotherapy (methotrexate 15 mg, cytarabine 40 mg, and prednisolone 10 mg) was administered four times during the R-CHOP phase. The primary endpoint was 2-year progression-free survival. Efficacy analyses were done in all enrolled patients; safety analyses were done in all enrolled and treated patients. The trial is registered in the UMIN Clinical Trials Registry (UMIN000005707) and the Japan Registry of Clinical Trials (jRCTs041180165); the trial is ongoing for long-term follow-up. FINDINGS: Between June 16, 2011, and July 21, 2016, 38 patients were enrolled, of whom 37 were eligible; one patient was excluded because of a history of testicular lymphoma. Median follow-up was 3·9 years (IQR 2·5-5·5). 2-year progression-free survival was 76% (95% CI 58-87). The most frequent adverse events of grade 3-4 were neutropenia and leucocytopenia, which were reported in all 38 (100%) patients. Serious adverse events were hypokalaemia, febrile neutropenia with hypotension, hypertension, and intracerebral haemorrhage (reported in one [3%] patient each). No treatment-related deaths occurred during protocol treatment. INTERPRETATION: R-CHOP combined with rituximab and high-dose methotrexate plus intrathecal chemotherapy is a safe and active treatment for patients with IVLBCL without apparent CNS involvement at diagnosis, and this regimen warrants future investigation. FUNDING: The Japan Agency for Medical Research and Development, the Center for Supporting Hematology-Oncology Trials, and the National Cancer Center.

Two unique HLA-A*0201 restricted peptides derived from cyclin E as immunotherapeutic targets in leukemia.

Immunotherapy targeting leukemia-associated antigens has shown promising results. Because of the heterogeneity of leukemia, vaccines with a single peptide have elicited only a limited immune response. Targeting several peptides together elicited peptide-specific cytotoxic T lymphocytes (CTLs) in leukemia patients, and this was associated with clinical responses. Thus, the discovery of novel antigens is essential. In the current study, we investigated cyclin E as a novel target for immunotherapy. Cyclin E1 and cyclin E2 were found to be highly expressed in hematologic malignancies, according to reverse transcription polymerase chain reaction and western blot analysis. We identified two HLA-A*0201 binding nonameric peptides, CCNE1M from cyclin E1 and CCNE2L from cyclin E2, which both elicited the peptide-specific CTLs. The peptide-specific CTLs specifically kill leukemia cells. Furthermore, CCNE1M and CCNE2L CTLs were increased in leukemia patients who underwent allogeneic hematopoietic stem cell transplantation, and this was associated with desired clinical outcomes. Our findings suggest that cyclin E1 and cyclin E2 are potential targets for immunotherapy in leukemia.

Paroxysmal nocturnal hemoglobinuria-phenotype cells predict a good response to eltrombopag in patients with refractory aplastic anemia.

To identify factors affecting responsiveness to eltrombopag (EPAG), we retrospectively analyzed 38 aplastic anemia patients treated with EPAG who were refractory (n = 29) or showed an inadequate response (n = 9) to conventional therapies. The efficacy was evaluated at 16 weeks after starting EPAG and at any given time when the best response was achieved. Hematologic responses were observed in 15 patients (39%) at week 16 and in 25 (66%) at any given time. Ten of 19 (53%) achieved transfusion independence. A univariate analysis revealed the presence of PNH-phenotype cells and the relatively higher platelet counts as associated with a good response to EPAG.

[Successful treatment with total cranial irradiation for central nervous system involvement of Langerhans cell sarcoma during chemotherapy].

Langerhans cell sarcoma (LCS) is an extremely rare neoplasm of Langerhans cell origin characterized by systemic involvement and a poor prognosis. There are, however, few reports of LCS with central nervous system involvement. We experienced a patient with LCS recurrence in the brain that appeared during systemic chemotherapy. The brains lesions eventually responded to total cranial irradiation. A 60-year-old female presented with systemic lymphadenopathy. LCS was diagnosed based on neck lymph node biopsy findings. Two cycles of ESHAP induced marked regression of her lymphadenopathy, but FDG-PET/CT scan revealed new lesions in the central nervous system and her disorientation gradually worsened. We administered 37.5 Gy of total cranial irradiation which improved her consciousness and shrank the brain tumors as demonstrated by MRI. The patient's clinical course indicates that radiation therapy may be effective for central nervous system involvement of LCS even if the lesion is resistant to systemic chemotherapy.

Paraptosis cell death induction by the thiamine analog benfotiamine in leukemia cells.

Benfotiamine is a synthetic thiamine analogue that stimulates transketolase, a cellular enzyme essential for glucose metabolism. Currently, benfotiamine is used to treat diabetic neuropathy. We recently reported that oral benfotiamine induced a temporary but remarkable recovery from acute myeloid leukemia in an elderly patient who was ineligible for standard chemotherapy due to dementia and renal failure. In the present study we present evidences that benfotiamine possess antitumor activity against leukemia cells. In a panel of nine myeloid leukemia cell lines benfotiamine impaired the viability of HL-60, NB4, K562 and KG1 cells and also inhibited the growing of primary leukemic blasts. The antitumor activity of benfotiamine is not mediated by apoptosis, necrosis or autophagy, but rather occurs though paraptosis cell death induction. Mechanistic studies revealed that benfotiamine inhibited the activity of constitutively active ERK1/2 and concomitantly increased the phosphorylation of JNK1/2 kinase in leukemic cells. In addition, benfotiamine induced the down regulation of the cell cycle regulator CDK3 which resulted in G1 cell cycle arrest in the sensitive leukemic cells. Moreover, combination index studies showed that benfotiamine enhanced the antiproliferative activities of cytarabine against leukemia cells. These findings suggest that benfotiamine has antitumor therapeutic potential.

Adenovirus pneumonia presenting with nodular shadows on chest X-ray in two unrelated allogeneic bone marrow transplant recipients.

Adenoviruses are increasingly recognized as important pathogens following allogeneic stem cell transplantation. We herein report two cases of disseminated adenovirus infection that presented with nodular shadows on chest X-ray after allogeneic bone marrow transplantation from unrelated donors. Both patients died of respiratory failure. Autopsies revealed adenovirus infection of multiple organs. Adenovirus infection should be suspected when nodular lung lesions of unknown origin appear in allogeneic stem cell transplant recipients.

Detection of minimal residual disease in patients with multiple myeloma using clonotype-specific PCR primers designed from DNA extracted from archival bone marrow slides.

Polymerase chain reaction (PCR)-negative molecular complete remission (mCR) can be induced by stem cell transplantation in some patients with multiple myeloma (MM) and is associated with long-term progression-free survival (PFS). The detection of molecular minimal residual disease (MRD), however, requires fresh or frozen materials for designing clone-specific primers, which are not always readily available. In this study, we used DNA extracted from archival bone marrow (BM) slides for PCR to detect MRD in 50 patients with MM who received various induction therapies and autologous peripheral blood stem cell transplantation (ASCT). Clonotype-specific immunoglobulin (Ig) H PCR primers were prepared for 32 of 50 cases (64%) using BM slides, and for 9 of 14 cases (64%) using fresh BM cells. DNA in peripheral blood stem cell autografts of the 22 patients who achieved at least a partial response after ASCT was subjected to PCR to amplify clonotype-specific rearranged IgH gene sequences. The median PFS of the eight patients with MRD-positive autografts was 18 months, whereas that of 14 patients with MRD-negative autografts was not reached at a median follow-up of 27 months (p = 0.012). Post-ASCT PFS of the four patients who achieved mCR was 100% at a median follow-up of 47 months. These results indicate that archival BM slides can serve as a source of DNA for preparing clonotype-specific primers for MRD monitoring in patients with MM whose cryopreserved myeloma cells are not available for DNA preparation. Our results also suggest that patients with MM who received MRD-negative autografts and achieved mCR have a long PFS.

In vivo T-cell depletion with alemtuzumab in allogeneic hematopoietic stem cell transplantation: Combined results of two studies on aplastic anemia and HLA-mismatched haploidentical transplantation.

We evaluated the efficacy of in vivo T-cell depletion with alemtuzumab in two prospective studies according to the International Conference on Harmonisation (ICH)-Good Clinical Practice (ICH-GCP) guidelines; one was for patients with aplastic anemia (AA study) and the other was for patients who were undergoing hematopoietic stem cell transplantation (HSCT) from a 2- or 3-antigen-mismatched haploidentical donor (MM study). The final dose of alemtuzumab in these studies was 0.16 mg/kg/day for 6 days. At this dose, all of the 12 and 11 patients in the AA and MM studies, respectively, achieved initial engraftment and the incidences of Grade II-IV acute graft-versus-host disease (GVHD) were 0% and 18%. While cytomegalovirus (CMV) frequently reactivated, none of the patients developed fatal CMV disease. Transplantation-related mortality within 1 year after HSCT was observed in only two and one patients, respectively. The numbers of CD4+ and CD8+ T-cells and T-cell receptor rearrangement excision circles remained low within 1 year after HSCT. These findings suggest that the use of alemtuzumab at this dose in a conditioning regimen enables safe allogeneic HSCT even from a 2- or 3-antigen-mismatched donor. However, the use of a lower dose of alemtuzumab should be explored in future studies to accelerate immune recovery after HSCT.

Late response to low-dose imatinib in patients with chronic phase chronic myeloid leukemia.

Imatinib was the first BCR-ABL tyrosine kinase inhibitor to become clinically available. In this study, we retrospectively evaluated the long-term efficacy of low-dose imatinib (final maintenance dose <300 mg per day) due to intolerance, in comparison to optimal-dose imatinib (≥300 mg per day) in patients with Philadelphia chromosome-positive chronic myeloid leukemia in the chronic phase. The Kaplan-Meier estimates of the median time to complete cytogenetic response, major molecular response, and complete molecular response were longer for 31 patients receiving low-dose imatinib (360, 1360, and 1420 days, respectively) than 74 patients receiving optimal-dose imatinib (170, 420, and 720 days, respectively). However, the differences in response shrank over time and progression-free survival were comparable between the two groups. These findings suggest that long-term treatment with low-dose imatinib is an acceptable alternative for patients with intolerance to the optimal dose.

An Epstein-Barr virus-associated leukemic lymphoma in a patient treated with rabbit antithymocyte globulin and cyclosporine for hepatitis-associated aplastic anemia.

Lymphoproliferative disorders (LPDs) are generally caused by uncontrolled B-cell proliferation induced by the Epstein-Barr virus (EBV) in the setting of impaired EBV-specific T-cell immunity, particularly when there is pharmacological immunosuppression including antithymocyte globulin. We herein present an unusual case of EBV associated with LPD (EBV-LPD) in which LPD occurred 3 weeks after the use of rabbit antithymocyte globulin administered for severe hepatitis-associated aplastic anemia; the patient died of fulminant leukemic lymphoma 5 days after the onset. We also review the pertinent literature on EBV-LPD after immunosuppressive therapy and document the efficacy of EBV viral load monitoring and the need for preemptive therapy.

Pulmonary T-cell lymphoma with pulmonary arterial hypertension.

We report on a 73-year-old man with systemic lymphadenopathy and chest computed tomography (CT) findings of bilateral diffuse ground-glass opacities and interlobular septal thickening. He also had pulmonary arterial hypertension (PAH). Several lymph node biopsies were attempted, without a definitive diagnosis. A thoracoscopic lung biopsy was performed, and the specimen was diagnosed as peripheral T-cell lymphoma, not otherwise specified (PTCL-NOS). Lymphoma cells had invaded lung vessels, resulting in PAH. We should include pulmonary lymphoma in the differential diagnosis of patients with PAH and chest CT findings of diffuse ground-glass opacities and interlobular septal thickening.

Mycophenolic acid inhibits natural killer cell proliferation and cytotoxic function: a possible disadvantage of including mycophenolate mofetil in the graft-versus-host disease prophylaxis regimen.

To determine how immunosuppressant agents used for graft-versus-host disease (GVHD) prophylaxis affect natural killer (NK) cells, we examined the effects of cyclosporine (CSP), tacrolimus (TAC), mycophenolic acid (MPA, an active form of mycophenolate mofetil), and methotrexate (MTX) on the proliferation and cytotoxicity of NK cells. The proliferation of NK cells from healthy individuals in the presence of interleukin (IL)-2 and IL-15 was suppressed to 51% ± 16% of that of the controls with CSP, to 31% ± 19% with TAC, to 14% ± 6% with MPA, and to 87% ± 18% with MTX. Both CSP and TAC increased the proportion of CD16(-)CD56(bright) cells, a NK cell subset capable of secreting high amount of cytokines, and also enhanced NKp30 expression, whereas MPA markedly decreased the proportion of CD16(-)CD56(bright) cells and reduced the expression of all activating NK cell receptors, including NKG2D, NKp30, NKp44, and NKp46. MPA also reduced the cytotoxicity against K562 cells from 61% ± 15% to 17% ± 7% and that against Daudi cells from 44% ± 4% to 4% ± 4%, whereas the other 3 drugs did not diminish these cytotoxicities. The inhibition of NK cell proliferation and cytotoxicity against leukemic cell lines by MPA was partially abolished by the inclusion of guanosine in the culture. Similar to the effect of MPA on T cells, MPA inhibited the down-regulation of p27 on NK cells induced by the incubation of NK cells in the presence of IL-2. These results suggest that MPA is a potent inhibitor of NK cells, and that its inclusion in the GVHD prophylaxis regimen might diminish the graft-versus-leukemia effect of NK cells.