Cellular uptake of CPX-351 by scavenger receptor class B type 1-mediated nonendocytic pathway.

The proper uptake of drugs in liposome formulations into target cells markedly impacts therapeutic efficacy. The protein corona (PC), formed by the adsorption of serum proteins onto the liposome surface, binds to specific surface receptors of target cells, influencing the uptake pathway. We investigated the uptake pathway into leukemia cells based on PC analysis of CPX-351, a liposome containing cytarabine and daunorubicin in a fixed 5:1 synergistic molar ratio. The PC of CPX-351 mixed with fetal bovine serum was analyzed by nanoflow liquid chromatography-tandem mass spectrometry. CPX-351 uptake in HL-60, K562, and THP-1 leukemia cell lines was measured by flow cytometry using daunorubicin fluorescence. The major components of CPX-351 PC include apolipoproteins A-I and A-II, which bind to scavenger receptor class B type 1 (SR-BI), a nonendocytic pathway that takes up only liposome contents. SR-BI was expressed in each cell, and its expression correlated with CPX-351 uptake. The uptake was significantly decreased by the inhibition of clathrin-mediated endocytosis and macropinocytosis. Additionally, blocks lipid transport-1 (BLT-1), a selective inhibitor of SR-BI, decreased the uptake; however, high-dose BLT-1 addition significantly increased the uptake, which was more strongly inhibited by macropinocytosis suppression compared with clathrin-mediated endocytosis. BLT-1 enhances the binding of SR-BI to liposomes in a dose-dependent manner. These findings indicate that the enhancement of binding between SR-BI and CPX-351 activates different pathways, such as macropinocytosis, distinct from CPX-351 alone. SR-BI may be a biomarker for CPX-351 therapy, and the combination of CPX-351 with high-dose BLT-1 may augment therapeutic efficacy.

Hematopoiesis in the spleen after engraftment in unrelated cord blood transplantation evaluated by 18F-FLT PET imaging.

Cord blood is an important donor source for allogeneic hematopoietic stem cell transplantation (allo-HSCT), with its unique composition and quality of hematopoietic cells. The proliferation site and potency of infused hematopoietic stem cells in humans may vary between stem cell sources. We investigated this possibility in a prospective, exploratory study to assess hematopoietic dynamics using the radiopharmaceutical 3'-deoxy-3'-18F-fluorothymidine (18F-FLT), a thymidine analog used in positron emission tomography imaging, before allo-HSCT and on days 50 and 180 after allo-HSCT. We evaluated 11 patients with hematological malignancies who underwent allo-HSCT [five with peripheral blood stem cell transplantation (PBSCT) and six with unrelated cord blood transplantation (UCBT)]. Before allo-HSCT, 18F-FLT uptake did not differ between the two groups. At day 50, 18F-FLT uptake in the spleen was significantly greater in the UCBT group than in the PBSCT group (p = 0.0043), with no difference in whole-body bone marrow. At day 180, the differences in spleen uptake had diminished, and there were no differences between groups in whole-body bone marrow or the spleen, except for the sternum. The persistence of splenic hematopoiesis after engraftment in the UCBT group may reflect the complex systemic homing and proliferation mechanisms of cord blood hematopoietic cells.

Poor outcome of allogeneic transplantation for therapy-related acute myeloid leukemia induced by prior chemoradiotherapy.

Therapy-related acute myeloid leukemia (t-AML) is a therapeutic challenge as a late complication of chemotherapy (CHT) and/or radiotherapy (RT) for primary malignancy. Allogeneic hematopoietic stem cell transplantation (allo-HSCT) presents itself as a curative approach. To establish the optimal allo-HSCT strategy for t-AML, we evaluated the relationship between characteristics of primary malignancy and allo-HSCT outcomes. Patients with t-AML or de novo acute myeloid leukemia (AML) who underwent first allo-HSCT in Japan from 2011 to 2018 were identified using a nationwide database. The detailed background of t-AML was obtained by additional questionnaires. Multivariate analysis and propensity score matching (PSM) analysis were performed to detect the prognostic factors associated with t-AML and compare outcomes with de novo AML. We analyzed 285 t-AML and 6761 de novo AML patients. In patients with t-AML, receiving both CHT and RT for primary malignancy was an independent poor-risk factor for relapse and overall survival (OS) (hazard ratio (HR) 1.62; p = 0.029 and HR 1.65; p = 0.009, reference: CHT alone group), whereas other primary malignancy-related factors had no effect on the outcome. Compared to the CHT alone group, complex karyotypes were significantly increased in the CHT + RT group (86.1% vs. 57.5%, p = 0.007). In the PSM cohort, t-AML patients with prior CHT and RT had significantly worse 3-year OS than those with de novo AML (25.2% and 42.7%; p = 0.009). Our results suggest that prior CHT and RT for primary malignancy may be associated with increased relapse and worse OS of allo-HSCT in t-AML.

MALDI-TOFMS-oriented early definitive therapy improves the optimal use of antibiotics for Enterococcus spp. bloodstream infection.

Enterococci is one of a major cause of bloodstream infection (BSI). Because of its intrinsic drug-resistant nature, empiric antibiotic treatment tends to be inappropriate. We conducted a single-center retrospective cohort study to evaluate the impact of Matrix-assisted laser desorption and ionization time-of-flight mass spectrometry (MALDI-TOFMS) on the improvement of early antibiotic treatment for enterococcal infection. We also investigated the 28-day mortality, length of hospitalization and duration of antibiotic treatment for enterococcal bacteremia. A total of 173 BSI episodes (172 patients) between June 2012 and June 2019 were enrolled. Patients were divided into 2 groups before (n = 82) and after (n = 91) the implementation of MALDI-TOFMS (Control group and MALDI-TOF group, respectively). Almost an equal number of Enterococcus faecalis and Enterococcus faecium cases were identified in each group (51.2% and 48.8%, and 47.3% and 52.7% in each group). By implementing MALDI-TOFMS, the time to definitive antibiotic treatment was significantly improved (median 3 vs 1 days, p < 0.001). The 28-day mortality (29.3% vs 26.4%, p = 0.63) and length of hospitalization (median 16 vs 19 days, p = 0.58) were not significantly different. The duration of antibiotic treatment did not significantly differ between the two groups (median 11 vs 11 days, p = 0.78), but the duration was often shorter in older patients (>74 years old) in MALDI-TOF group, excluding those in the terminal phase of malignancy. By implementing MALDI-TOFMS, the time to definitive antibiotic treatment was significantly shortened. Although associated outcomes did not significantly differ, the duration of antibiotic treatment may be shortened.

Clinical outcomes of gemtuzumab ozogamicin for relapsed acute myeloid leukemia: single-institution experience.

We retrospectively evaluated the clinical efficacy and toxicity of gemtuzumab ozogamicin (GO) in patients with relapsed acute myeloid leukemia (AML). Nineteen patients (median 70 years) received GO (9 mg/m2, days 1 and 15) as salvage therapy in our institution between 2006 and 2017. The primary endpoint was the response rate. The secondary endpoint was the occurrence of adverse events. Thirteen patients had de novo AML, and 6 patients had secondary AML. Most of the patients had received salvage treatments more than once prior to GO. Six patients responded to the treatment (31.6%) with 3 complete remissions (15.8%). Five patients had stable disease, and 8 patients did not show any response. GO was more efficacious among the patients with fewer numbers of prior salvage treatments. CD33 positivity of leukemic cells was higher in responders than in nonresponders. Peripheral WT1 mRNA levels mostly decreased over time in the responders. The adverse event most commonly seen was febrile neutropenia (84%). No patient presented with veno-occlusive disease. Three patients died by day 30 (mortality rate 15.8%), one due to acute respiratory distress syndrome and the other two due to sepsis. GO remains an effective salvage treatment.

[Leukemic pulmonary infiltration diagnosed by sputum Giemsa-staining].

A 54-year-old man with acute myeloid leukemia (AML) underwent allogeneic bone marrow transplantation from a human leukocyte antigen-matched unrelated donor in nonremission status. Bone marrow aspiration performed on day 14 showed that the patient had achieved complete remission; however, he relapsed on day 28. The patient developed a wet cough, and chest computed tomography performed on day 27 revealed pneumonia. Because pneumonia developed along with the leukemic relapse, we suspected that it was due to pulmonary leukemic infiltration (PLI). Giemsa-stained sputum showed some blast cells and fluorescence in situ hybridization indicated that the patient had monosomy 7, which was also detected in bone marrow blasts. Though we prescribed hydroxycarbamide and decreased tacrolimus rapidly, AML progressed and led to the patient's death on day 45. Histopathological findings of the autopsy performed the next day showed diffuse alveolar damage in both lungs. The blast cells were packed in blood vessels of alveolar septa and were also seen in alveoli. PLI was diagnosed pathologically. In conclusion, our case demonstrates that Giemsa stain of sputum is useful in quick diagnosis of PLI without invasive examination.

The stability of initial tacrolimus concentration following allogeneic hematopoietic stem cell transplantation reduces the risk of acute GVHD.

BACKGROUND: Early tacrolimus (TAC) concentrations correlate with the risk of acute graft-versus-host disease (aGVHD); however, whether the variability of early TAC concentrations after allo-HSCT governs the occurrence of aGVHD remains unknown. Here, we evaluate the correlation between the intrapatient variability (IPV) of initial TAC concentrations and the development of aGVHD. METHODS: We retrospectively assessed 202 patients who underwent allo-HSCT and received standard GVHD prophylaxis by continuous intravenous (iv) infusion of TAC and iv methotrexate. IPV was calculated by using the % coefficient of variation in the initial 4 weeks. RESULTS: With median follow-up duration of 20.7 months, 24 patients were diagnosed with grades II-IV aGVHD. Overall survival (OS) and relapse at 12 months after allo-HSCT were 70.6% (95% confidence interval [CI], 63.7%-76.4%) and 18.9% (95% CI, 13.0%-24.4%), respectively. When IPV was categorized into two groups (high: ≥9.5%; low: <9.5%), the cumulative incidence of grades II-IV aGVHD was greater in the IPV-high group at week 3 (odds ratio: 4.15; 95% CI, 1.37%-12.6%, P = .01). No significant differences were observed in OS and relapse between the two groups. CONCLUSION: We concluded that adjusting early TAC concentration stable may reduce aGVHD after allo-HSCT without affecting the relapse rate.

Prediction of clinical outcome by controlling nutritional status (CONUT) before allogeneic hematopoietic stem cell transplantation in myeloid malignancies.

Malnutrition before allogeneic hematopoietic cell transplantation (allo-HCT) is associated with poor clinical outcomes. Herein, we evaluated the predictive value of controlling nutritional status (CONUT) in patients undergoing allo-HCT for myeloid malignancies. We retrospectively analyzed 200 patients with myeloid malignancies who underwent allo-HCT for the first time. We evaluated CONUT before the initiation of conditioning and compared malnourished patients (poor CONUT, n = 56) with non-malnourished patients (normal CONUT, n = 144). The cumulative incidence of non-relapse mortality within 100 days (early NRM) was significantly higher in the poor CONUT group than in the normal CONUT group [21.4% (95% CI: 11.8-33.0%) vs. 9.7% (95% CI: 5.6-15.2%); P = 0.025]. In multivariate analysis, poor CONUT was an independent and significant risk factor for early NRM [HR: 2.2 (95% CI: 1.0-4.7); P = 0.048]. The overall 1-year survival rate was significantly lower in the poor CONUT group than in the normal CONUT group [53.3% (95% CI: 39.4-65.4%) vs. 71.0% (95% CI: 62.7-77.7%); P = 0.005]. These findings suggest that CONUT before allo-HCT is a useful predictor of poor outcomes in patients with myeloid malignancies.

Higher Peak Tacrolimus Concentrations after Allogeneic Hematopoietic Stem Cell Transplantation Increase the Risk of Endothelial Cell Damage Complications.

Noninfectious transplantation-related complications (TRCs) such as graft-versus-host disease (GVHD) and endothelial cell damage (TRC-EC) are critical after allogeneic hematopoietic stem cell transplantation. Tacrolimus (TAC) is used to control GVHD. Hypertension and renal failure are common adverse events after TAC treatment. Higher blood concentrations of TAC would be expected to reduce the risk of GVHD but may increase TRC-EC. TRC-EC often develops in patients with GVHD; thus, it is difficult to clinically determine the proper intensity of immunosuppression. We therefore evaluated the impact of weekly mean/peak TAC blood concentrations (PTCs) on TRC-EC occurrence and prognosis. Patients (N = 295) who received TAC as a GVHD prophylaxis at our institute from 2009 to 2016 were eligible for this retrospective study. Forty-three patients were diagnosed with TRC-EC: 8 with sinusoidal obstructive syndrome, 28 with transplant-associated microangiopathy, and 7 with idiopathic pneumonia syndrome. The cumulative incidence of TRC-EC at 12 months was 13.8% (95% confidence interval [CI] 10.1% to 18.1%). After multivariate analysis high PTCs during days 22 to 28 (hazard ratio [HR] 2.47; 95% CI, 1.37 to 4.45; P < .01) and grades II to IV acute GVHD (HR, 5.61; 95% CI, 2.99 to 10.53; P < .01) were associated with TRC-EC occurrence. The probability of overall survival (OS) at 12 months was 67.7% (95% CI, 61.7% to 73.0%). After multivariate analysis TRC-EC diagnosis (HR, 2.47, 95% CI, 1.59 to 3.83; P < .01) and high-risk disease (HR, 1.75; 95% CI, 1.17 to 2.61; P < .01) were significantly associated with poor OS. In conclusion, higher PTC during days 22 to 28 increased the risk of TRC-EC. TRC-EC development was associated with poor OS.

3A Comparison between R-THP-COP and R-CHOP Regimens for the Treatment of Diffuse Large B-cell Lymphoma in Old Patients: A Single-institution Analysis.

Objective We retrospectively compared the clinical efficacy and toxicity of rituximab (R)-THP-COP (pirarubicin, cyclophosphamide, vincristine, and prednisolone) with that of R-CHOP (rituximab, adriamicin, cyclophosphamide, vincristine, and prednisolone) in previously untreated old patients with diffuse large B-cell lymphoma (DLBCL). Patients and Methods Patients admitted to our institution between 2004 and 2013 were examined. The patients received either R (375 mg/m2, day 1)-THP-COP (pirarubicin 50 mg/m2 day 1, cyclophosphamide 750 mg/m2 day 1, vincristine 1.4 mg/m2 day 1, and prednisolone 100 mg day 1-5) or R-CHOP (adriamicin 50 mg/m2 day 1, cyclophosphamide 750 mg/m2 day 1, vincristine 1.4 mg/m2 day 1, and prednisolone 100 mg day 1-5). The doses of chemotherapeutic agents were adjusted depending on the patient's age and associated complications. The treatment was performed for 6 to 8 cycles. Results Among 74 patients with DLBCL (median 76, range 65-90 years; male 39, female 35), 29 received R-THP-COP, while 45 received R-CHOP. The overall response rates were 94.6% (complete response 86.4%, partial response 8.1%). The 2-year overall and progression-free survival rates were 77.6% and 68.5% for the R-THP-COP regimen and 79.2% and 78.9% for R-CHOP, respectively. No significant differences were found between these two regimens regarding the clinical efficacies. The most frequent adverse event was neutropenia (72.4% for the R-THP-COP regimen, 88.9% for the R-CHOP regimen). The cardiac function as evaluated by ejection fraction values was not impaired in either regimen. Conclusion R-THP-COP was effective and safe as an alternative to R-CHOP.