Impact of Different Fludarabine Doses in the Fludarabine-Based Conditioning Regimen for Unrelated Bone Marrow Transplantation.

The purine analog fludarabine (Flu) plays a central role in reduced-intensity conditioning and myeloablative reduced-toxicity conditioning regimens because of limited nonhematologic toxicities. Few reports assess the impact of different dose of Flu on the clinical outcomes and the Flu doses vary across reports. To compare the effect of Flu dose, the clinical outcomes of patients who received Flu and busulfan (FB; n = 1647) or melphalan (Flu with melphalan (FM); n = 1162) conditioning for unrelated bone marrow transplantation were retrospectively analyzed using Japanese nationwide registry data. In the FB group, high-dose Flu (180 mg/m2; HFB) and low-dose Flu (150/125 mg/m2; LFB) were given to 1334 and 313 patients, respectively. The 3-year overall survival (OS) rates were significantly higher in the HFB group than in the LFB group (49.5% versus 39.2%, P < .001). In the HFB and LFB groups, the cumulative incidences were 30.4% and 36.6% (P = .058) for 3-year relapse and 25.1% and 28.1% (P = .24) for 3-year nonrelapse mortality (NRM), respectively. In the multivariate analysis for OS and relapse, Flu dose was identified as an independent prognostic factor (hazard ratio: 0.83, P = .03; hazard ratio: 0.80, P = .043). In the FM group, high-dose Flu (180 mg/m2; HFM) and low-dose Flu (150/125 mg/m2; LFM) were given to 118 and 1044 patients, respectively. The OS, relapse, and NRM after 3 years did not differ significantly between the HFM and LFM groups (48.3% versus 48.8%, P = .92; 23.7% versus 27.2%, P = .55; 31.9% versus 30.8%, P = .67). These findings suggest that high-dose Flu was associated with favorable outcomes in the FB group but not in the FM group.

Impact of stem cell selection between bone marrow and peripheral blood stem cells for unrelated hematopoietic stem cell transplantation for hematologic malignancies: on behalf of the Donor/Source Working Group of the Japanese Society for Transplantation and Cellular Therapy.

BACKGROUND AIMS: This study aimed to comprehensively assess the impact of stem cell selection between bone marrow (BM) and peripheral blood (PB) in unrelated hematopoietic stem cell transplantation (HSCT) for hematological malignancies. Our objective was to identify specific factors associated with better transplant outcomes. METHODS: A retrospective analysis was conducted using data from the Japanese HSCT registry. Inclusion criteria were patients aged 0-70 years who underwent their first unrelated HSCT with BM or PB, with an 8/8 or 7/8 allele HLA match for hematological malignancies between 2010 and 2020. RESULTS: Among 10 295 patients, no significant difference was observed in overall survival, relapse, graft-versus-host disease (GVHD)-free, relapse-free survival (GRFS) or non-relapse mortality between the groups. Patients who received PB showed no clear difference in acute GVHD but had a greater rate of chronic GVHD, resulting in poor chronic GVHD-free, relapse-free survival (CRFS). Subgroup analyses highlighted the importance of patient-specific factors in source selection. Patients with non-Hodgkin lymphoma and a greater hematopoietic cell transplantation-comorbidity index showed better CRFS and GRFS when BM was the preferred source. Similar trends were observed among patients with standard-risk disease for CRFS. However, no such trends were evident among patients aged 0-24 years, indicating that both sources are viable choices for young patients. CONCLUSIONS: This real-world retrospective analysis showed similar basic outcomes for BM and PB in an unrelated setting. The results support that BM may still be preferred over PB, especially when the long-term quality of life is a major concern. A consideration of individual factors can further optimize transplant success. Further research is warranted to explore the long-term implications of stem cell source selection.

Outcomes of allogeneic hematopoietic stem cell transplantation for relapsed or refractory diffuse large B-cell lymphoma.

Allogeneic hematopoietic stem cell transplantation (allo-HSCT) is a currative treatment modality for diffuse large B-cell lymphoma (DLBCL) because of the intrinsic graft-versus-lymphoma effect. However, limited information is available regarding which patients with relapsed or refractory DLBCL are likely to benefit from allo-HSCT. We retrospectively analyzed data from 1268 DLBCL patients who received allo-HSCT. The overall survival and progression-free survival (PFS) rates were 30.3% and 21.6% at 3 years, respectively. Multivariate analysis revealed that stable or progressive disease at transplantation, male patient, poorer performance status at transplantation, and shorter intervals from previous transplantation were associated independently with a lower PFS. Four prognostic factors were used to construct a prognostic index for PFS, predicting 3-year PFS of 55.4%, 43.7%, 20.4% and 6.6%, respectively. The prognostic model predicted relapse rates following allo-HSCT accordingly (P < 0.0001), whereas did not predict transplantation-related mortality (P = 0.249). The prognostic index can identify a subgroup of DLBCL patients who benefit from allo-HSCT and it is worthwhile to evaluate whether this model is also applicable to patients undergoing allo-HSCT in cases of relapse after chimeric antigen receptor engineered T-cell therapy, although the application of allo-HSCT has been declining with the increase of novel immunotherapies.

Allogeneic hematopoietic cell transplantation for patients with acute myeloid leukemia not in remission.

Allogeneic hematopoietic cell transplantation (HCT) is the last option for long-term survival for patients with chemotherapy-refractory acute myeloid leukemia (AML). By using the Japanese nationwide registry data, we analyzed 6927 adults with AML having undergone first allogeneic HCT while not in complete remission (CR) between 2001 and 2020. The 5-year overall survival (OS), relapse, and non-relapse mortality (NRM) rates were 23%, 53%, and 27%, respectively. Multivariate analysis identified several factors predictive of OS mainly through their effects on relapse (cytogenetics, percentage of blasts in the peripheral blood, and transplantation year) and NRM (age, sex, and performance status). As regards disease status, relapsed disease was associated with a higher risk of overall mortality than primary induction failure (PIF). The shorter duration of the first CR increased the risks of relapse and overall mortality for the relapsed group, and the longer time from diagnosis to transplantation did so for the PIF group. Our experience compiled over the past two decades demonstrated that >20% of patients still enjoy long-term survival with allogeneic HCT performed during non-CR and identified those less likely to benefit from allogeneic HCT. Future efforts are needed to reduce the risk of posttransplant relapse in these patients.

Long-term effectiveness and safety of high dose chemotherapy followed by autologous stem cell transplantation in daily practice in patients with diffuse large B-cell lymphoma.

We retrospectively evaluated long-term outcomes of high dose chemotherapy followed by autologous stem cell transplant (HDC/ASCT) in patients with diffuse large B-cell lymphoma (DLBCL). Between 2004 and 2020, 46 DLBCL patients received HDC/ASCT in our institution, including 12 patients (26.1%), who received as an upfront setting (UFS). At a median follow-up time of 69 months (range, 2-169 months), the 5-year progression-free survival (PFS) rates were 82.5% (95%CI, 46.1-95.3%) in the UFS, and 57.8% (95%CI, 38.1-73.2%) in the relapsed or refractory (R/R) patients (n=34), respectively. The 5-year PFS rates were 62.3% (95%CI, 34.0-81.3%) in primary resistant (n=13) or early relapsing (within 1 year from the initial diagnosis) patients (n=4), and 53.3% (95%CI, 25.9-74.6%) in those relapsing >1 year after the initial diagnosis (n=17), with no statistically significant difference (p=0.498). In R/R patients, multivariate analysis showed that the remission status before HDC/ASCT was an independent poor prognostic factor for progression-free survival (hazard ratio [HR], 17.0; 95%CI, 3.35-86.6; p=0.000630) and high-risk category in the international prognostic index for OS (HR, 9.39; 95%CI, 1.71-51.6; p=0.0100). The incidence of non-relapse mortality by 5 years, and 10 years were 12.2%, and 15.2%, respectively. Eleven patients (23.9%) developed second malignancies, which was the most frequent late complication after HDC/ASCT, with 5-year, and 10-year cumulative incidence of 16.9%, 22.5%, respectively. In conclusion, HDC/ASCT is effective for chemo-sensitive R/R DLBCL regardless of the timing and lines of therapy. However, careful observation is required, considering the long-term complications such as secondary malignancies.

Chlorpromazine cooperatively induces apoptosis with tyrosine kinase inhibitors in EGFR-mutated lung cancer cell lines and restores the sensitivity to gefitinib in T790M-harboring resistant cells.

We previously reported that the antipsychotic drug chlorpromazine (CPZ), which inhibits the formation of clathrin-coated vesicles (CCVs) essential for endocytosis and intracellular transport of receptor tyrosine kinase (RTK), inhibits the growth/survival of acute myeloid leukemia cells with mutated RTK (KIT D816V or FLT3-ITD) by perturbing the intracellular localization of these molecules. Here, we examined whether these findings are applicable to epidermal growth factor receptor (EGFR). CPZ dose-dependently inhibited the growth/survival of the non-small cell lung cancer (NSCLC) cell line, PC9 harboring an EGFR-activating (EGFR exon 19 deletion). In addition, CPZ not only suppressed the growth/survival of gefitinib (GEF)-resistant PC9ZD cells harboring T790 M, but also restored their sensitivities to GEF. Furthermore, CPZ overcame GEF resistance caused by Met amplification in HCC827GR cells. As for the mechanism of CPZ-induced growth suppression, we found that although CPZ hardly influenced the phosphorylation of EGFR, it effectively reduced the phosphorylation of ERK and AKT. When utilized in combination with trametinib (a MEK inhibitor), dabrafenib (an RAF inhibitor), and everolimus (an mTOR inhibitor), CPZ suppressed the growth of PC9ZD cells cooperatively with everolimus but not with trametinib or dabrafenib. Immunofluorescent staining revealed that EGFR shows a perinuclear pattern and was intensely colocalized with the late endosome marker, Rab11. However, after CPZ treatment, EGFR was unevenly distributed in the cells, and colocalization with the early endosome marker Rab5 and EEA1 became more apparent, indicating that CPZ disrupted the intracellular transport of EGFR. These results suggest that CPZ has therapeutic potential for NSCLC with mutated EGFR by a novel mechanism different from conventional TKIs alone or in combination with other agents.

CD34+ myeloma cells with self-renewal activities are therapy-resistant and persist as MRD in cell cycle quiescence.

Side population (SP) is known to include therapy-resistant cells in various cancers. Here, we analyzed SP using multiple myeloma (MM) samples. The SP accounted for 2.96% in MM cells from newly diagnosed MM (NDMM). CD34 was expressed in 47.8% of SP cells, but only in 2.11% of bulk MM cells. CD34+ MM cells expressed more immature cell surface markers and a gene signature than CD34- MM cells. CD34+ but not CD34- MM cells possessed clonogenic activities and showed long-term self-renewal activities in xenotransplantation assays. Similarly, whereas 2.20% of MM cells were CD34+ in NDMM (n = 38), this proportion increased to 42.6% in minimal residual disease (MRD) samples (n = 16) (p < 0.001) and to 17.7% in refractory/relapsed MM (RRMM) (n = 30) (p < 0.01). Cell cycle analysis showed that 24.7% of CD34+ MM cells from NDMM were in G0 phase while this proportion was 54.9% in MRD (p < 0.05) and 14.5% in RRMM, reflecting the expansion of MM. Together, CD34+ MM cells with long-term self-renewal activities persist as MRD in cell cycle quiescence or remain as therapy-resistant cells in RRMM, substantiating the necessity of targeting this population to improve clinical outcomes of MM.

C-type lectin-like receptor 2 specifies a functionally distinct subpopulation within phenotypically defined hematopoietic stem cell population that contribute to emergent megakaryopoiesis.

C-type lectin-like receptor 2 (CLEC-2) expressed on megakaryocytes plays important roles in megakaryopoiesis. We found that CLEC-2 was expressed in about 20% of phenotypical long-term hematopoietic stem cells (LT-HSCs), which expressed lower levels of HSC-specific genes and produced larger amounts of megakaryocyte-related molecules than CLEC-2low LT-HSCs. Although CLEC-2high LT-HSCs had immature clonogenic activity, cultured CLEC-2high LT-HSCs preferentially differentiated into megakaryocytes. CLEC-2high HSCs yielded 6.8 times more megakaryocyte progenitors (MkPs) and 6.0 times more platelets 2 weeks and 1 week after transplantation compared with CLEC-2low LT-HSCs. However, platelet yield from CLEC-2high HSCs gradually declined with the loss of MkPs, while CLEC-2low HSCs self-renewed long-term, indicating that CLEC-2high LT-HSCs mainly contribute to early megakaryopoiesis. Treatment with pI:C and LPS increased the proportion of CLEC-2high LT-HSCs within LT-HSCs. Almost all CLEC-2low LT-HSCs were in the G0 phase and barely responded to pI:C. In contrast, 54% of CLEC-2high LT-HSCs were in G0, and pI:C treatment obliged CLEC-2high LT-HSCs to enter the cell cycle and differentiate into megakaryocytes, indicating that CLEC-2high LT-HSCs are primed for cell cycle entry and rapidly yield platelets in response to inflammatory stress. In conclusion, CLEC-2high LT-HSCs appear to act as a reserve for emergent platelet production under stress conditions.

Decreased expression of T-cell-associated immune markers predicts poor prognosis in patients with follicular lymphoma.

We previously examined the utility of rituximab-bendamustine (RB) in patients with follicular lymphoma (FL) exhibiting less than optimal responses to 2 cycles of the R-CHOP chemotherapy regimen. The aim of this study was to identify molecular biomarkers that can predict prognosis in RB-treated patients in the context of the prospective cohort. We first analyzed the mutational status of 410 genes in diagnostic tumor specimens by target capture and Sanger sequencing. CREBBP, KMT2D, MEF2B, BCL2, EZH2, and CARD11 were recurrently mutated as reported before, however none was predictive for progression-free survival (PFS) in the RB-treated patients (n = 34). A gene expression analysis by nCounter including 800 genes associated with carcinogenesis and/or the immune response showed that expression levels of CD8+ T-cell markers and half of the genes regulating Th1 and Th2 responses were significantly lower in progression of disease within the 24-mo (POD24) group (n = 8) than in the no POD24 group (n = 31). Collectively, we selected 10 genes (TBX21, CXCR3, CCR4, CD8A, CD8B, GZMM, FLT3LG, CD3E, EOMES, GZMK), and generated an immune infiltration score (IIS) for predicting PFS using principal component analysis, which dichotomized the RB-treated patients into immune IIShigh (n = 19) and IISlow (n = 20) groups. The 3-y PFS rate was significantly lower in the IISlow group than in the IIShigh group (50.0% [95% CI: 27.1-69.2%] vs. 84.2% [95% CI: 58.7-94.6%], P = .0237). Furthermore, the IIS was correlates with absolute lymphocyte counts at diagnosis (r = 0.460, P = .00355). These results suggest that the T-cell-associated immune markers could be useful to predict prognosis in RB-treated FL patients. (UMIN:000 013 795, jRCT:051 180 181).

The Impact of Hemodialysis and Liver Cirrhosis on the Plasma Concentrations of Tyrosine Kinase Inhibitors in a Patient with Chronic Myeloid Leukemia.

We recently treated a chronic myeloid leukemia (CML) patient with liver and renal dysfunction, who was undergoing hemodialysis (HD). He was treated with 50 mg dasatinib (DAS) once daily just before HD. The maximum plasma concentration of DAS was 227 ng/mL on a non-HD day and 46.9 ng/mL on a HD day. He was subsequently treated with 200 mg bosutinib (BOS) once daily. The plasma concentration of BOS changed from 74.5 ng/mL before HD to 58.8 ng/mL after HD. Our results indicate that close monitoring of the plasma tyrosine kinase inhibitor concentrations should be considered in CML patients with organ impairment.

Tumour-immune microenvironment in duodenal-type follicular lymphoma.

Despite duodenal-type follicular lymphoma (DTFL) being morphologically, immunophenotypically and genetically indistinguishable from nodal FL (nFL), this entity typically shows a significantly better prognosis. Here, we analysed the tumour immune microenvironments of diagnostic specimens from patients with DTFL (n = 30), limited-stage FL (LSFL; n = 19) and advanced-stage FL (ASFL; n = 31). The mean number of CD8+ tumour-infiltrating lymphocytes (TILs) in the neoplastic follicles was higher in DTFL (1,827/mm2 ) than in LSFL (1,150/mm2 ) and ASFL (1,188/mm2 ) (P = 0·002, P = 0·002, respectively). In addition, CD8+ PD1-  T cells with non-exhausting phenotype were more abundant in the peripheral blood (PB) of DTFL than in LSFL and ASFL, indicating that DTFL may exhibit a better and longer-lasting T cell-mediated immune response. Moreover, whereas FOXP3+ CTLA-4+ effector regulatory T cells (eTregs) were rarely observed in the neoplastic follicles of DTFL (mean: 12/mm2 ), they were more abundant in LSFL (78/mm2 ) and ASFL (109/mm2 ) (P = 2·80 × 10-5 , P = 4·74 × 10-8 , respectively), and the numbers of eTregs correlated inversely with those of CD8+ TILs (r = -0267; P = 0·018). Furthermore, DTFL showed significantly fewer circulating FOXP3hi CD45RA- CD25hi eTregs (0·146%) than ASFL (0·497%) and healthy controls (0·639%) (P = 0·0003, P = 6·79 × 10-7 , respectively). These results suggest that the augmented anti-tumour immune reactions may contribute to a better prognosis on DTFL.

Immunemodulatory Effects of 5-Azacitidin Through Expansion of Functional Regulatory T Cells on Paraneoplastic Inflammation Associated With Myelodysplastic Syndromes: A Case Report.

Myelodysplastic syndrome (MDS) is a heterogeneous group of clonal disorders of hematopoietic stem cells, characterized by dysplastic hematopoiesis and dysregulated immune system resulting in various clinical conditions. Paraneoplastic inflammatory syndromes, which are well known to be associated with MDS, show response to immune-modulated therapy and often disappear during the course of hematologic management. Azacitidine (5-Aza) was shown to prolong survival of high-risk MDS patients, however, the effects of 5-Aza on paraneoplastic inflammation in MDS have yet to be elucidated. 5-Aza was administered to a 60-year-old man with MDS accompanying Sweet's syndrome at a dose of 75 mg/m2/daily subcutaneously for 7 days every 28 days. 5-Aza was not only effective in controlling systemic symptoms caused by paraneoplastic inflammation, but hematologic improvements were also observed after four cycles of the 5-Aza treatment. Immune profiling in peripheral blood before and after 5-Aza treatment revealed that the effector and naive regulatory T cells in lymphocytes drastically increased after the 5-Aza treatment, i.e., 5-Aza might induce a shift in lymphocytic populations toward immunosuppression in this patient. Our results raised the immune-mediated effect of 5-Aza on both dysplastic hematopoiesis and paraneoplastic inflammation in myelodyplastic syndromes.

[Successful treatment of secondary graft failure with donor lymphocyte infusion in a post-allogeneic stem cell transplant acute myeloid leukemia patient].

Here we report a case of secondary graft failure that was effectively treated with donor lymphocyte infusion (DLI). A 64-year-old female patient with acute myeloid leukemia obtained partial remission with azacitidine therapy and subsequently underwent unrelated allogeneic bone marrow transplantation (BMT). After confirming successful engraftment and achieving complete remission with incomplete blood count recovery, she was subsequently followed up at an outpatient clinic. A routine test performed by day 110 after BMT revealed the presence of pancytopenia. A bone marrow aspirate did not reveal any evidence of disease relapse or hemophagocytic syndrome but demonstrated hematopoietic insufficiency. Donor chimerism also declined over time; thus, the patient was diagnosed with secondary graft failure. Supportive treatment, including granulocyte-colony stimulating factor and blood transfusion, failed to improve the blood parameters. Because the patient refused a second BMT, we performed DLI on day 147 after BMT (CD3+ cells: 1.0×107/kg, single dose). Consequently, the blood cell count improved promptly and dramatically without adverse events. Following this, we discussed the case and analyzed the related literature.

HIV-negative Primary Bone Marrow Hodgkin Lymphoma Manifesting with a High Fever Associated with Hemophagocytosis as the Initial Symptom: A Case Report and Review of the Previous Literature.

A 68-year-old man was referred to our hospital due to a high fever and pancytopenia. Neither tumors nor infectious lesions were detected. Hemophagocytosis was observed on the bone marrow (BM) smear, although without abnormal cells. Prednisolone therapy was ineffective for the patient's high fever. Later on, we obtained the results of a BM biopsy indicating the presence of infiltration of atypical Reed-Sternberg cells, leading to a diagnosis of HIV-negative primary bone marrow Hodgkin lymphoma (PBMHL). However, the patient died of multiple organ failure before receiving chemotherapy. As the clinical course of PBMHL is rapid, physicians must keep in mind its possibility in similar cases.

Successful anticoagulant therapy for two pregnant PNH patients, and prospects for the eculizumab era.

Paroxysmal nocturnal hemoglobinuria (PNH) is an acquired stem cell disorder characterized by intravascular hemolysis and thrombosis. The most serious complication is thrombosis, the risk of which is augmented by the hyper-coagulable state that occurs during pregnancy; despite this risk, however, young female PNH patients often desire to have a baby. We recently experienced two successful deliveries in PNH patients, who were treated with anticoagulant therapy during their pregnancies. Meanwhile, given the potential benefit of eculizumab (Soliris), a humanized monoclonal antibody against C5, in reducing thrombosis and hemolysis, it represents a promising therapeutic option for the treatment of pregnant PNH patients in combination with, or in replacement of, anticoagulant therapy.