ALBERT

Description: AMG 531 is a novel thrombopoeisis-stimulating peptibody that increases platelet production by targeting the thrombopoietin receptor. The trial described here is an ongoing, open-label, extension study of patients with immune thrombocytopenic purpura (ITP) assessing the safety and efficacy of long-term AMG 531 treatment of ITP, as well as patient-reported health-related quality of life (HRQOL). Eligible patients have completed a previous AMG 531 study in ITP. Patients previously treated with AMG 531 receive a starting dose that is the same as the final dose given in the previous study; placebo-treated patients begin the extension study with an AMG 531 dose of 1 μg/kg. The dose is skipped, decreased, maintained, or increased based on platelet count. Analysis was performed on the 36 patients (25 female, 11 male; 29 white, 6 Hispanic, 1 black) for whom complete data are currently available. The mean age is 50.0 ± 13.0 (SD) years. Most patients (83%) had a splenectomy prior to this study. HRQOL is being assessed with an ITP disease-specific measure, the ITP Patient Assessment Questionnaire (ITP-PAQ). This report describes the first use of the ITP-PAQ to measure treatment effect. The ITP-PAQ has 10 scales: 4 Physical Health (PH)—Symptoms, Fatigue, Bother, and Activity; 2 Emotional Health (EH)—Psychological and Fear; 3 Quality of Life (QOL)—Overall, Social, and Work; and 1 Women’s Reproductive Health (WRH). Each scale is scored 0 (worst)—100 (best). A planned interim analysis was conducted to evaluate changes in HRQOL from week 1 (pretreatment) to week 24. Results indicated improvement in the areas of PH-Symptoms, with a 7.9-unit increase (p=0.007), PH-Fatigue, with a 7.8-unit increase (p=0.006), PH-Bother, with a 9.4-unit increase (p=0.025), PH-Activity, with a 7.4-unit increase (p=0.032), and QOL-Work, with a 7.9-unit increase (p=0.014). An analysis of minimal clinically important difference will be conducted when the sample size is large enough to determine if statistically significant values are clinically meaningful. A comparison of HRQOL in patients with a durable platelet response (doubling of the baseline count and ≥50×109/L at 6 or more weeks during weeks 17–24 in the absence of rescue medication) versus those without a durable response showed a trend for greater improvement among the responders in all 10 scales, with significant differences for PH-Symptoms (p=0.02), PH-Bother (p=0.02), PH-Activity (p=0.01), EH-Psychological (p=0.01), and QOL-Overall (p=0.03). Individualized dosing of AMG 531 provides a unique therapeutic option for managing platelet count in ITP while improving HRQOL.

Description: To investigate the functional change of stromal cells along with differentiation, we used a differentiation-inducible mouse embryo fibroblast cell line, C3H10T1/2 (10T1/2). Stably determined preadipocyte and myoblast cell lines were established after a brief exposure of 10T1/2 cells to 5-azacytidine. These cell lines terminally differentiated into adipocytes and myotubes, respectively, under appropriate conditions. The hematopoiesis-supporting ability of each 10T1/2-derived cell line was examined by coculture with FACS-sorted murine hematopoietic stem cells (Thy-1lo c-kit+ Lin-). The number of granulocyte-macrophage progenitors (CFU-GM) was slightly reduced after 7 days of culture with parent 10T1/2 fibroblasts, whereas a marked increase in CFU-GM number was observed when the cells were cultured on preadipocytes. Mature adipocytes and myogenically determined cell lines, on the other hand, did not support CFU-GM growth. Further, Northern analysis showed that the preadipocyte cell line acquired the ability to produce a significant amount of stem cell factor (SCF), interleukin-6 (IL-6), leukemia inhibitory factor, and macrophage colony- stimulating factor mRNAs in response to IL-1 or lipopolysaccharide stimulation. Terminal adipocytic differentiation resulted in reduced ability to express these cytokine mRNAs. Similarly, highest IL-6 activity was detected in the supernatant of preadipocyte culture, whereas adipocytes did not secrete IL-6 even after IL-1 stimulation. Interestingly, hematopoiesis-nonsupporting myoblasts and myotubes also expressed abundant SCF mRNA, suggesting that SCF, per se, may not be sufficient for stem cell growth and survival. The 10T1/2-derived cell lines could provide a valuable tool to aid in the analysis of stromal cell development and the search for novel stromal factors.

Description: KMOE -2/05 cells, derived from a patient with acute erythremia, became benzidine-positive after the addition of cytosine arabinoside (CA). Radioimmunoassays using antihuman hemoglobin antibodies revealed an elevated amount of hemoglobin in the CA-exposed cells over that in the control cells (without CA). Isoelectric focusing of the CA-exposed cell lysate formed benzidine-positive foci in the positions of human adult Hb (HbA) and human fetal Hb (HbF). To determine the types of globin synthesized in the CA-exposed cells, globin chains internally labeled with [3H] leucine were purified by carboxy-methyl (CM)-Sephadex column chromatography, immunoadsorption by Sepharose-coupled antihuman Hb antibodies and Sephadex G-100. The labeled globin chains were finally separated by CM-cellulose chromatography in urea. Two distinct peaks of radioactivity were shown in exactly the same fractions as carrier human globin alpha- and beta-chains. These observations indicate that these KMOE -2/05 cells synthesize HbA.

Description: Recent studies have suggested that bone marrow (BM) cells can contribute to regeneration processes in various tissues. Cardiomyocytes derived from BM cells have been observed after myocardial infarction (MI), and BM-derived cells mobilized by cytokines were capable of regenerating the myocardial tissue, leading to an improvement in survival or cardiac function after MI. However, the responsible BM cells have not been fully identified. The most likely candidates for the BM-derived stem cells with the ability to regenerate myocardial tissue are hematopoietic stem cells (HSC) and mesenchymal stem cells (MSC). The aim of this study was to determine the precise origin of the BM cells mobilized by cytokines to repair infarcted myocardium. Here, we used two independent clonal studies; we transplanted genetically marked single HSC or clonal MSC into lethally-irradiated recipient mice, induced MI, treated the mice with G-CSF, and analyzed the cardiac tissues. First, we transplanted single CD34−c-kit+Sca-1+lineage− side population (CD34−KSL-SP) cells or whole BM cells from mice ubiquitously expressing enhanced green fluorescent protein (EGFP) into lethally-irradiated mice, induced myocardial infarction (MI), and treated the animals with G-CSF to mobilize stem cells to the damaged myocardium. At 8 weeks post-MI, from 100 specimens we counted only 3 EGFP+actinin+ cells in myocardium of CD34−KSL-SP cells-transplanted mice, but more than 5,000 EGFP+actinin+ cells in whole BM cell-transplanted mice, suggesting that most of EGFP+actinin+ cells derived from non-hematopoietic BM cells. These results suggested that the major population of cells mobilized from the BM and active in the regeneration of cardiomyocytes was non-hematopoietic in origin. Next, clonally purified mesenchymal stem cells, CMG cells, transfected with a pMLC2v-EGFP plasmid encoding EGFP driven by the myosin light chain promoter were transplanted directly into BM of lethally-irradiated mice, MI was induced, and they were treated with G-CSF. As a result, a number of EGFP+actinin+ cells were observed in the ischemic myocardium, indicating that CMG cells had been mobilized and differentiated into cardiomyocytes. Together, these results suggested that the vast majority of BM-derived cardiomyocytes are of mesenchymal origin.

Description: Key Points Global survival rate was 74% at a median follow-up after HSCT of 57 months. Preexisting mycobacterial infection and colitis were associated with poor HSCT outcome.

Description: We investigated the effect of interleukin-6 (IL-6) on murine megakaryocytopoiesis in a serum-free culture system. The addition of IL- 6 to a culture containing interleukin-3 (IL-3) resulted in a significant increase in the number of megakaryocyte colonies by bone marrow cells of normal mice. The megakaryocytic progenitors that survive exposure to 5-fluorouracil (5-FU) exhibited a more significant response to IL-6 and IL-3. Polyclonal anti-IL-6 antibody neutralized the stimulatory effect of IL-6 on megakaryocyte colony growth supported by IL-3. Delayed addition experiments and replating experiments of blast cell colonies showed that megakaryocytic progenitors are supported by IL-3 in the early stage of the development but require IL- 6 for their subsequent proliferation and differentiation. In addition, IL-6 increased the size of megakaryocytes in granulocyte-macrophage- megakaryocyte colonies. The combination of granulocyte colony- stimulating factor or granulocyte-macrophage colony stimulating factor with IL-3 resulted in an increase in the granulocyte-macrophage colony growth of bone marrow cells of 5-FU-treated mice or normal mice, respectively, but had little effect on the enhancement of pure and mixed megakaryocyte colony growth. These results suggest that IL-6 plays an important role in murine megakaryocytopoiesis.

Description: Background: Invasive fungal infections (IFIs) incur significant morbidity and mortality in neutropenic patients with hematological malignancies (HEM) after chemotherapy. The risk for these infections is related to the intensity and duration of neutropenia, and varies from 2% to 40%. Mortality rates associated with documented IFIs are considerable, reportedly ranging from 30% to 60%. Empirical antifungal therapy is the standard care for neutropenic patients with HEM, who remain febrile despite broad-spectrum antibacterial treatment. Several antifungal agents including voriconazole (VRCZ) or liposomal amphotericin B (L-AMB) have been studied as empirical therapy for febrile neutropenia (FN). However, limited data are available concerning the efficacy of micafungin (MCFG) in FN patients with acute myeloid leukemia (AML). Methods: We conducted a randomized, cooperative group, open-label trial comparing MCFG (150 mg once daily) with L-AMB (2.5 mg/kg once daily) as a first-line empirical antifungal treatment for 102 hospitalized FN patients with AML (MCFG, 53; L-AMB, 49). The efficacy end point was a favorable overall response, as determined by a five-component end point according to the criteria of Walsh et al (N Engl J Med 2004; 351: 1391). Results: At the time of enrolment, there were no significant differences in the demographics or baseline characteristics between the two groups. The mean treatment duration for MCFG and L-AMB was 14.8 and 17.1 days, respectively. The efficacy rates of MCFG and L-AMB were not significantly different (58.5% vs. 44.9%, p = 0.1698*), evaluated based on: (1) successful treatment of baseline fungal infection (3/5cases (5.7%) vs. 0/1case (0%), p = 0.170*), (2) absence of breakthrough fungal infection (90.6% vs. 98.0%, p = 0.112*), (3) survival for ≥7 days after study completion (88.7% vs. 89.8%, p = 0.855*), (4) absence of premature study drug discontinuation due to poor efficacy or drug-related adverse events (67.9% vs. 75.5%, p = 0.396*), and (5) resolution of fever during neutropenia (66.0% vs. 55.1%, p = 0.258*). However, discontinuation due to drug-related adverse events occurred less frequently in the MCFG group (1.9% vs. 12.2%, p = 0.038*). In safety evaluation, adverse events of creatinine increase and hypokalemia were less often in the MCFG group than in the L-AMB group (9.4% vs. 26.5%, P=0.023*, 22.6% vs. 57.1%, P=0.0004*). *: Chi square test. Conclusions: MCFG was as effective as L-AMB, and better tolerated than L-AMB as an empirical antifungal therapy in FN patients with AML. Disclosures Ishida: Kyowa Hakko Kirin Co: Research Funding; Nippon Shinyaku Co: Research Funding; CHUGAI PHARMACEUTICAL CO: Research Funding; Astellas Pharma Inc.: Other: Astellas Pharma Inc. (Tokyo, Japan) supported this clinical study with a grant; the sponsor was not involved in the design of study, the enrollment of patients, the collection, analysis, interpretation of the data., Research Funding.

Description: Background: In vitro observations have indicated that preplatelets, which are anucleate discoid particles that can reversibly into proplatelet fragments, are one of platelet progenitos from cultured megakaryocytes (MKs) (Thon JN, et al. JBC 2010). Recently, we identified that bone marrow (BM) MKs form and release two types of platelet progenitors, using intra-vital imaging and ultra-structural analysis of mice BM (Kowata S, et al. Thrombosis and Haemostasis 2014). However, in vivo, how the platelet progenitors translate into individual platelets after leaving BM remains poorly understood. To elucidate whether platelet progenitors have an ability of conversion into individual platelets, we performed following experiments. Methods: We isolated platelet progenitors rich fraction from whole blood of enhanced green fluorescence protein (EGFP) transgenic mice by the centrifugation (100 g, 15 min) and bovine serum albumin gradient. Mature platelets were isolated from whole blood of EGFP mice by the centrrifugation (100 g, 15 min). In vivo: The freshly enriched progenitor rich fraction or mature platelets, both of which were positive for EGFP, was transfused into wild type mice. The peripheral blood was obtained and analyzed by flow cytometry continually. The EGFP positive mature platelets in platelet gate were counted. In vitro: The freshly enriched progenitor isolates were cultured in IMDM medium at 37°C. The continual change of their characteristics in the shape and size were assessed using fluorescent microscopy with high resolution. Time-lapse images of the processes were also captured. All animal procedures were approved by the Institutional Animal Care and Use Committee of Iwate Medical University. Results: The length and size of platelet progenitors were extremely varied (Fig. 1). The red, yellow, green, and dark blue segments in the bar chart indicate the platelet progenitors (5um). The frequency of platelet progenitor was 4% at normal condition (Fig. 1 graph on the left), but increased remarkably to 3-fold at recovery from acute thrombocytopenia (Fig.1 graphs in the middle). The maximum length of platelet progenitor was more than 200 µm (Fig. 1 picture in the top right). These data were consisted with the concept from our previous study of intra-vital imaging of BM MKs (Thrombosis and Haemostasis 2014). In vivo: Flow cytometric analysis showed that there was a time-dependent increase in EGFP platelet number in the gate of mature platelet, after the injection of EGFP positive platelet progenitor rich fraction. The control was carried out using EGFP positive mature platelets instead of platelet progenitors rich fraction. (mean ± SD, 0 h: 100%, 3h: 111 ± 6.8%, 6h: 105 ± 7.1% n=3, control 0 h: 100%, 3h: 101± 6.0%, 6h: 94 ± 5.2% n=3, Data were shown as % of the number of EGFP positive mature platelets at 0 h. P

Description: Introduction: ITP is a serious, chronic platelet production/destruction disorder frequently treated with CS (with a 50–70% response rate). While CS-associated adverse events are known to impair health-related quality of life, other disease complications have not been well studied in ITP patients (pts). Methods: A retrospective claims analysis used the PharMetrics Integrated Medical and Pharmaceutical Database (diagnosis, treatment, and claims data from 〉45 million managed care pts) to compare risks of disease complications in ITP pts (primary thrombocytopenia, ICD-9=287.3 [n=2454; 618 used CS; 1,836 did not]) and age- and gender-matched non-ITP controls (n= 21,196; 2,861 used CS; 18,335 did not) enrolled from July 2000 to December 2003. Incidence (new events during study period/persons exposed to risk) of osteoporosis, diabetes mellitus (DM), fractures, anxiety/depression, hepatitis C, myocardial infarction (MI), gastrointestinal (GI) bleeds, hypertension (HTN), obesity, atrial fibrillation, pancreatitis, cataracts, and stroke were compared between the 2 cohorts through December 2004. Descriptive statistics and univariate and multivariate logistic regression models assessed CS use by 4 measures (number of treatments, average daily dose, days of therapy, continuous duration). Clinical complexity was measured by the Charlson Comorbidity Index. Results: The most common events in ITP pts were HTN, anxiety/depression, DM, osteoporosis, obesity, cataracts, and MI (range, 26 [MI] to 237 [HTN] per 1,000 patient-years). These events were common but less frequent in non-ITP pts. ITP pts had significantly more CS use than non-ITP pts (by 4 treatment measures; all P4 CS doses had increased risks of most events (greatest for DM, obesity, and MI; less for osteoporosis, HTN, and depression). Event risk in non-ITP pts did not increase significantly with number of CS prescriptions. Each additional day of CS therapy was associated with a 0.5% increase in risk of osteoporosis, HTN, DM, and anxiety/depression in ITP pts. Osteoporosis, DM, and HTN were more than twice as likely to develop in ITP pts receiving ≥60 days of CS therapy vs those treated for

Description: Lenalidomide (Len), an immunomodulatory drug, has significant clinical activity in patients with relapsed and refractory multiple myeloma (MM), and it is usually administered at a dose of 25 mg daily. For Len to exert its therapeutic effects with minimum adverse effects, it is important to determine the most suitable dosage on the basis of the physiques and body surface area (BSA) of patients. We investigated the relationship between pharmacokinetic variability of this drug and its toxicity and therapeutic efficacy. The institutional review boards and ethics committees at both participating centers approved the study protocol and all patients provided written informed consent. Thirteen Japanese patients with relapsed and refractory MM were enrolled in this study. They were treated with Len at 10-25 mg for 21 days every 4 weeks. The dose of Len administered to patients with renal dysfunction was reduced according to consensus statements on the optimal use of Len. Dexamethasone at 8-40 mg weekly was added to each drug cycle. Peripheral blood was collected three hours after Len administration in the first cycle and the plasma concentration of Len was evaluated using high performance liquid chromatography. Response and progression were assessed according to the International Myeloma Working Group criteria and the severity of adverse events was graded according to the Common Terminology Criteria for Adverse Events (CTCAE) Version 4.0. The median values of age (years) and estimated creatinine clearance (eCLcr, mL/min) of the 13 enrolled patients (male to female ratio=5:8) were 69 and 66.3, respectively. The number of patients in stages I, II, and III or the unknown stage of the International Staging System were 8, 1, 2, and 2, respectively. The number of the patients who achieved the best responses during three cycles of treatment were one (7.7%) in complete response, four (30.8%) in partial response, and eight (61.5%) in stable disease. The percentage of hematological adverse events (Grade 3/4) was 38.5% and no non-hematological events (Grade 3/4) were observed. The Len concentration ranged from 172.5 ng/mL to 555.6 ng/mL with a median concentration of 341.8 ng/mL. eCLcr values did not correlate with Len concentrations, but significantly correlated with C/D ratios (p