ALBERT

Description: In patients with multiple myeloma (MM), risk stratification by chromosomal abnormalities may enable a more rational selection of therapeutic approaches. In the present study, we analyzed the prognostic value of 12 chromosomal abnormalities in a series of 354 MM patients treated within the HOVON-65/GMMG-HD4 trial. Because of the 2-arm design of the study, we were able to analyze the effect of a bortezomib-based treatment before and after autologous stem cell transplantation (arm B) compared with standard treatment without bortezomib (arm A). For allanalyzed chromosomal aberrations, progression-free survival (PFS) and overall survival (OS) were at least equal or superior in the bortezomib arm compared with the standard arm. Strikingly, patients with del(17p13) benefited the most from the bortezomib-containing treatment: the median PFS in arm A was 12.0 months and in arm B it was 26.2 months (P = .024); the 3 year-OS for arm A was 17% and for arm B it was 69% (P = .028). After multivariate analysis, del(17p13) was an independent predictor for PFS (P 〈 .0001) and OS (P 〈 .0001) in arm A, whereas no statistically significant effect on PFS (P = .28) or OS (P = .12) was seen in arm B. In conclusion, the adverse impact of del(17p13) on PFS and OS could be significantly reduced by bortezomib-based treatment, suggesting that long-term administration of bortezomib should be recommended for patients carrying del(17p13). This trial is registered at the International Standard Randomised Controlled Trial Number Register as ISRCTN64455289.

Description: Tumor necrosis factor (TNF)-alpha has been identified as a major inducer of colony stimulating factor (CSF)-secretion by human vascular endothelial cells and fibroblasts. In the present study we assessed the capacity of TNFs to induce release of CSF-1 from highly purified peripheral blood monocyte preparations. Whereas monocytes do not accumulate CSF-1 messenger (m)RNA constitutively and consequently do not produce CSF-1 protein, CSF-1 mRNA and protein secretion became detectable, when monocytes were cultured in the presence of TNF-alpha, that was synergistically enhanced by interferon-gamma (IFN-gamma). However, under identical experimental conditions TNF-beta failed to induce monocyte CSF-1 synthesis. Cultures of monocytes in the presence of TNF-beta before addition of TNF-alpha abolished the CSF-1 inducing capacity of TNF-alpha, suggesting that TNF-beta may act as antagonist to TNF-alpha for CSF-1 production. These data point out a previously unrecognized function of TNF-alpha to modulate CSF-1 release by monocytes and demonstrate disparate biological properties of different TNF species in hematopoiesis.

Description: Abstract 3287 Poster Board III-1 Blast crisis (BC) in CML in the imatinib era is a rare event with 1–3% of newly diagnosed BC patients per year in the IRIS study, but prognosis, once BC has occurred, remains poor. Historical and recent studies with imatinib and second generation tyrosine kinase inhibitors (TKI) reported a median survival time of 7–10 months and two year survival probabilities of

Description: Abstract 305 Chromosomal aberrations are important prognostic parameters in multiple myeloma (MM). By using interphase fluorescent in situ hybridization (FISH) on CD138-enriched plasma cells, specific changes in interphase cells can be detected, overcoming the lack of dividing cells required for conventional cytogenetics. We evaluated the association of FISH results and outcome of a subgroup of patients (pts) within the HOVON-65/GMMG-HD4 trial, a prospective, randomized phase III trial for pts with newly diagnosed MM stage II or III according to Salmon & Durie up to 65 years. Pts were randomized to receive three cycles of VAD (arm A; vincristine, adriamycin, dexamethasone) or PAD (arm B; bortezomib, adriamycin, dexamethasone). Hematopoietic stem cells were mobilized using the CAD regimen and G-CSF. All pts received one or two cycles of high dose melphalan (200 mg/m2) with autologous stem cell transplantation followed by maintenance therapy with thalidomide 50 mg daily (arm A) or bortezomib 1.3 mg/m2 once every 2 weeks (arm B), respectively, for a maximum of 2 years. Sites in Germany, the Netherlands and Belgium participated in this trial (n=833 pts). For the German pts (GMMG, n=399) FISH was performed in a single laboratory prior to start of treatment. Cytospins of CD138 purified plasma cells were subjected to FISH with two-color probe sets for the detection of numerical changes for the following chromosome regions: 1q21/8p21, 6q21/15q22, 9q34/22q11, 11q23/13q14, and 17p13/19q13, as well as for the translocations t(4;14)(p16;q32), t(11;14)(q13;q32), and t(14;16) (q32;q23). As of July 2010 data from the first consecutively enrolled 626 patients of the trial have been analyzed, including 284 GMMG pts. For this analysis, FISH results from 258 (91%) GMMG pts were available (n=131 in arm A; n=127 in arm B). Patient characteristics in the GMMG subgroup are comparable to the analyzed trial population of 626 pts. For all pts the median follow-up time from randomization was 40.3 months (mo.). The most pronounced impact on prognosis was seen for t(4;14), del17p13, and gain1q21, each significantly associated with poor prognosis with respect to progression free survival (PFS) and overall survival (OS). The strongest prognostic impact was found for del17p13. FISH analysis detected del17p13 in 9.4% of pts (A: 12.3% vs. B: 6.4%), t(4;14) in 14.8 % (16.3% vs. 13.4%), and gain 1q21 in 33.7% of pts (33.1% vs. 34.4%). When comparing pts in the two arms for PFS, we found a borderline significance for the interaction between t(4;14) and treatment arm (p=0.06), indicating that the effect of t(4;14) depends on the treatment. Pts with t(4;14) in arm A show a very poor prognosis with a median PFS time only half as long compared to patients without translocation (18 vs. 36 mo.; p=0.003). No such negative effect was observed for patients in arm B with t(4;14) (36 vs. 40 mo.; p=0.97). PAD resulted in improved 3yr-OS rates for pts with t(4;14) (A:39% vs B:76%), while 3yr-OS was 79% and 87% in pts without t(4;14). Median PFS for pts with gain 1q21 was 22 mo. (arm A) vs. 30 mo. (arm B) compared to 41 mo. in both arms for patients without gain 1q21. Pts with gain 1q21 showed a significantly better OS when treated with bortezomib (3yr-OS rates: A: 59%, B: 83%, p=0.016). Del17p13 was significantly associated with poor prognosis in both arms for OS (A: p

Description: It is well established by in vivo and in vitro studies that dendritic cells (DCs) originate from hematopoietic progenitor cells. However, the presumed intermediate of Birbeck granule (BG)+ Langerhans cells (LCs) has not been detected in cultures derived from bone marrow or peripheral blood progenitor cells (PBPCs), thus contrasting with the data obtained with cord blood. We show here that large numbers of BG+ LCs can be generated from human CD34+ PBPCs in vitro, when granulocyte-macrophage colony-stimulating factor and interleukin-4, potent promotors of LC/DC differentiation, are combined with a cocktail of early acting hematopoietic growth factors. LCs were found to emerge from CD33+CD11b+CD14-progenitor cells that they share with the monocytic lineage. During culture, these cells exhibited a sequence of dramatic morphologic changes, starting with a major increase in granularity followed by an increase in size herein exceeding that of all peripheral blood cells. At the same time, CD1a and major histocompatibility complex class II expression were upregulated and virtually all CD1a++ cells were BG+ by electron microscopy. With prolonged culture, CD1a was downregulated on a major population of cells, paralleled by a loss of BG and an increase of CD4, CD25, and CD80 expression that may correspond to the maturation of epidermal LC in vitro. However, these cells were consistently CD5- and did not exhibit changes in the CD45-isoform expression during culture. The availability of large numbers of these highly purified BG+ LCs and mature DCs allows for specific analysis of these subpopulations and provides a source of potent antigen-presenting cells from individual patients for vaccination protocols against infectious or tumor-associated antigens.

Description: In a phase I study, the sequentially administered combination of recombinant human interleukin-3 (rhIL-3) and rhGM-CSF was compared with treatment with rhIL-3 alone in 15 patients with advanced tumors but normal hematopoiesis. Patients were initially treated with rhIL-3 for 15 days. After a treatment-free interval, the patients received a second 5-day cycle of rhIL-3 at an identical dosage, immediately followed by a 10-day course of rhGM-CSF, to assess the toxicity and biologic effects of this sequential rhIL-3/rhGM-CSF combination. rhIL-3 doses tested were 125, and 250 micrograms/m2, whereas rhGM-CSF was administered at a daily dosage of 250 micrograms/m2. Both cytokines were administered by subcutaneous (SC) bolus injection. rhIL-3/rhGM-CSF treatment was more effective than rhIL-3 but equally effective to each other in increasing peripheral leukocyte counts, especially neutrophilic and eosinophilic granulocyte counts. In contrast, both modes of cytokine therapy raised the platelet counts to the same degree. rhIL-3/GM-CSF treatment was more effective than rhIL-3 in increasing the number of circulating hematopoietic progenitor cells BFU- E and CFU-GM. High-dose rhIL-3, but not low-dose rhIL-3, was as effective as the rhIL-3/rhGM-CSF combinations in increasing the number of circulating CFU-GEMM. The increase in absolute neutrophil counts correlated with the increase in the number of circulating CFU-GM. Side effects, mainly fever, headache, flushing, and sweating, were generally mild, but in two patients the occurrence of chills, rigor, and dyspnea after initiation of GM-CSF treatment necessitated dose reduction and discontinuation, respectively. These results indicate that sequential treatment with rhIL-3 and rhGM-CSF is as effective as single-factor treatment with rhIL-3 in stimulating platelet counts, whereas the effect of combination therapy on neutrophil counts and circulating progenitor cells is superior.

Description: Fanconi anemia (FA) is a recessive DNA repair disorder characterized by congenital abnormalities, bone marrow failure, genomic instability, and a predisposition to malignancies. As the majority of FA patients ultimately acquires severe bone marrow failure, transplantation of stem cells from a normal donor is the only curative treatment to replace the malfunctioning hematopoietic system. Stem cell gene transfer technology aimed at re-introducing the missing gene is a potentially promising therapy, however, prolonged ex vivo culture of cells, that was utilized in clinical trials with gammaretroviruses, results in a high incidence of apoptosis and at least in mice predisposes the surviving reinfused cells to hematological malignancy. Consequently, gene delivery systems such as lentiviruses that allow a reduction in ex vivo culture time are highly desirable. Here, we constructed a lentiviral vector expressing the human FANCA cDNA and tested the ability of this construct pseudotyped with either VSVG or a modified prototype foamyvirus (FV) envelope to correct Fanca−/− stem and progenitor cells in vitro and in vivo. In order to minimize genotoxic stress due to extended in vitro manipulations, an overnight transduction protocol was utilized where in the absence of prestimulation, murine Fanca−/− bone marrow cKit+ cells were co-cultured for 16h with FANCA lentivirus on the recombinant fibronectin fragment CH296. Transduction efficiency and transfer of lentivirally expressed FANCA was confirmed functionally in vitro by improved survival of consistently approximately 60% of clonogenic progenitors in serial concentrations of mitomycin C (MMC), irregardless of the envelope that was utilized to package the vector. Transduction of fibroblasts was also associated with complete correction of MMC-induced G2/M arrest and biochemically with the restoration of FancD2 mono-ubiquitination. Finally, to functionally determine whether gene delivery by the recombinant lentivirus during such a short transduction period is sufficient to correct Fanca−/− stem cell repopulation to wild-type levels, competitive repopulation experiments were conducted as previously described. Follow-up of up to 8 months demonstrated that the functional correction were also achieved in the hematopoietic stem cell compartment as evidenced by observations that the repopulating ability of Fanca−/− stem cells transduced with the recombinant lentivirus encoding hFANCA was equivalent to that of wild-type stem cells. Importantly, despite the fact that the gene transfer efficiency into cells surviving the transduction protocol were similar for both pseudotypes, VSVG was associated with a 4-fold higher toxicity to the c-kit+ cells than the FV envelope. Thus, when target cell numbers are limited as stem cells are in FA patients, the foamyviral envelope may facilitate overall greater survival of corrected stem cells. Collectively, these data indicate that the lentiviral construct can efficiently correct FA HSCs and progenitor cells in a short transduction protocol overnight without prestimulation and that the modified foamy envelope may have less cytotoxicity than the commonly used VSVG envelope.

Description: Abstract 2261 Poster Board II-238 Cytomegalovirus reactivation (HCMV) occurs frequently after hematopoetic stem cell transplantation and is associated with an increased treatment-related mortality. We aimed first to evaluate the cytotoxic effects of CMV on AML in vitro, and further, the clinical outcome of patients with AML with a documented CMV reactivation after transplant. First, we show that HCMV infects acute leukemia cell line Kasumi-1 (AML) and SD-1 (ALL), inhibits their proliferation and induces apoptosis almost in all cells after 14 days. HCMV further inhibits the proliferation of bone marrow progenitor cells derived from healthy volunteers as demonstrated here by the reduction of the number and size of colony forming units in methylcellulose assays. The induction of apoptosis is unusual because HCMV possesses various strategies to prevent apoptosis in infected cells in order to delay their cell death and maintain its own virus replication. Apoptosis via a caspase-dependent pathway occurred although HCMV induced a significant up-regulation of the anti-apoptotic gene cFLIP and anti-stress gene Gadd45a and simultaneously down-regulation of pro-apoptotic genes p53, Bcl-2, Gadd45γ in Kasumi-1 and SD-1 cells, showing that the anti-apoptotic mechanisms of HCMV to prevent cell death failed. Concordantly, the coapplication of the caspase-specific inhibitor zVAD.fmk to HCMV- infected Kasumi-1 cells inhibited the induction of apoptosis to a great extent. In the second part of our study we evaluated the clinical outcome of patients with AML after transplant in whom a HCMV reactivation occurred. We evaluated a homogenous group of 140 patients with AML after myeloablative conditioning, non-T cell depleted allogeneic HSCT from a HLA-identical sibling donor, and compared the clinical results to 60 patients with CML after transplant. CMV reactivation was documented by CMV-related matrix protein pp65 antigenemia test and routinely accompanied by a CMV preemptive therapy with ganciclovir. CMV reactivation in AML patients was associated with reduced risk for relapse (11.6% v 50.5%; p

Description: Introduction Epigenetic therapies with azanucleoside DNA hypomethylating agents, alone or in combination with histone deacetylase inhibitors (HDACi), show clinical activity in myelodysplastic syndromes (MDS) and acute myeloid leukemia (AML), particularly when given at non-cytotoxic doses. They are able to reactivate epigenetically silenced genes including, among others, a number of highly immunogenic proteins dubbed Cancer/testis antigens (CTAs), predominantly the CTAs located on the X chromosome. We have previously shown that decitabine can induce expression of several CTAs, including MAGEB2 and NY-ESO-1, in myeloid cells in vitro and thereby trigger an immune response (Almstedt et al., Leuk. Res. 2010). Induction of a CTA-specific cytotoxic T cell response in vivo was reported also in AML patients treated with azacitidine and sodium valproate (VPA) and correlated with clinical response (Goodyear et al., Blood 2010). To the best of our knowledge, no data have yet been reported on the effect of combination treatment with decitabine and panobinostat or sodium valproate (VPA) on CTA reactivation in myeloid leukemia. Aim We hypothesized that by combining decitabine with HDACi we could further enhance expression of CTAs in myeloid leukemia cells and thereby boost recognition of the malignant cells by the cytotoxic T lymphocytes. Methods The myeloid cell lines U937 and Kasumi-1 were treated with decitabine alone or in combination with the HDACi VPA or panobinostat applied at non-toxic concentrations (〉80% cell viability). Expression of CTAs was analyzed by RT-qPCR and Western blot after 48 hours of HDACi treatment. DNA methylation of NY-ESO-1 and MAGEB2 promoter regions was quantified by pyrosequencing. Bone marrow mononuclear cells from 19 AML patients (treated with or without VPA as add-on to decitabine in the ongoing randomized phase II DECIDER clinical trial, NCT00867672) were collected before and on day 15 of treatment, in some patients also after 2 treatment cycles. CTA mRNA expression and promoter DNA methylation were quantified as described above. Results VPA or panobinostat alone did not induce MAGEB2 or NY-ESO-1 expression in vitro. However the pretreatment of cells with decitabine prior to addition of either HDACi resulted in a synergistic dose-dependent reactivation of MAGEB2 and NY-ESO-1 on the mRNA level (confirmed for the latter on the protein level). Pyrosequencing analysis of the heavily methylated NY-ESO-1 and MAGEB2 promoters revealed, as expected, no methylation changes upon HDACi treatment, but a dose-dependent hypomethylation upon decitabine. In recently initiated in vivo studies (DECIDER trial), until now cells from 19 AML patients receiving epigenetic treatment were sequentially analyzed. Induction of MAGEB2 mRNA was observed in 9 patients (from absent to a median of 0.002 relative to GAPDH, range 0.0004-0.043), with concomitant DNA hypomethylation of the MAGEB2 promoter from median 83% pretreatment methylation (range 63%-90%) to 63% posttreatment (range 44%-74%). In 5 patients modest hypomethylation without changes in MAGEB2 expression was observed (from median pretreatment values of 89% [72%-92%] to 82% [58%-87%] posttreatment). Another 5 patients disclosed neither hypomethylation nor reexpression of MAGEB2 (results as yet blinded to treatment arm and clinical response). Conclusions Combined epigenetic treatment with the hypomethylating agent decitabine and the HDACi VPA or panobinostat synergistically induced a dose-dependent reactivation of the CTAs MAGEB2 and NY-ESO-1 in vitro, accompanied by promoter hypomethylation. First translational results of the DECIDER AML trial also indicate in vivo effects of the epigenetic treatment on CTA induction. The unmasking of CTAs to the immune system by epigenetically active drugs can increase anti-tumor immune responses, and thus has clear implications for future clinical trials combining epigenetic therapy and specific immunotherapy in myeloid neoplasia. Disclosures: No relevant conflicts of interest to declare.

Description: Introduction: Treatment of acute myeloid leukemia (AML) in elderly patients remains challenging. Low-dose DNA hypomethylating agents are a therapeutic option in myelodysplastic syndromes and AML. However, the mechanism of action of hypomethylating agents and the role of induction of DNA hypomethylation in the clinical response is still unclear. To unravel the in vivoeffects of sequential cycles of decitabine, we set out to characterize methylomes of leukemic blasts, T cells (presumably not part of the malignant clone) and granulocytes before and during treatment of AML patients enrolled in the randomized phase II DECIDER clinical trial (NCT00867672). We developed a statistical model for longitudinal data analysis to identify the strongest hypomethylation response. Methods: Peripheral blood mononuclear cells (PBMC) from AML patients were collected before and during therapy (i.v. 20 mg/m2 decitabine for 5 days, with or without subsequent oral drug add-on). Leukemic blasts and T-cells were isolated using automatic magnetic sorting of cells (autoMACS) labelled with anti-human CD34, CD117 and CD3 MACS microbeads (Miltenyi Biotec), respectively. Granulocytes were isolated using dextran sedimentation. Cell type specific genome-wide DNA methylation profiles were obtained using Infinium Human Methylation 450 BeadChip arrays. Data were analyzed using R packages RnBeads applying beta mixture quantile dilation for normalization (Teschendorff et al. Bioinformatics, 29:189–196, 2013) and a modified version of NHMMfdr for multiple testing. Results: Peripheral blood blasts (median purity: 92%) were isolated from 20 patients, and T cells (median purity: 94%) from 26 patients before treatment and on days 4 and/or 8 and 15 of treatment cycle 1. From 10 patients, blasts and T cells were also collected during and/or after cycle 2. In total, until now 127 methylomes (46 blasts, 47 T cells, 34 granulocytes) were generated and used for mathematical modelling. Since the trial is still recruiting, genome-wide methylation was interpreted blinded to all clinical data including drug add-on (ATRA, valproic acid). First, the methylation dynamics of each individual CpG site described by a specified summary statistics were identified. Then, inter-probe distance and CpG annotation were incorporated to explain the dependence structure between CpG sites. In order to control the false discovery rate (FDR), we adapted a method proposed for differential DNA methylation (Kuan & Chiang, Biometrics 68: 774–783, 2012). The summary statistics for each CpG site were modelled to follow a non–homogeneous hidden Markov model. Statistical testing was validated by simulations revealing a very high discriminative power for affected CpGs even with very low methylation dynamics. Applying the model to blasts and T cells, extensive differences in the in vivomethylation changes became apparent. In blasts, 13% of CpG (59,920 CpGs of total 460,343 CpGs) showed significant DNA hypomethylation (Δβ〉0.1, FDR