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Background: We recently reported results of the prospective, open‐label HOVON‐100 trial in 334 adult patients with acute lymphoblastic leukemia (ALL) randomized to first‐line treatment with or without clofarabine (CLO). No improvement of event‐free survival (EFS) was observed, while a higher proportion of patients receiving CLO obtained minimal residual disease (MRD) negativity. Aim: In order to investigate the effects of CLO in more depth, two multi‐state models were developed to identify why CLO did not show a long‐term survival benefit despite more MRD‐negativity. Methods: The first model evaluated the effect of CLO on going off‐protocol (not due to refractory disease/relapse, completion or death) as a proxy of severe treatment‐related toxicity, while the second model evaluated the effect of CLO on obtaining MRD negativity. The subsequent impact of these intermediate events on death or relapsed/refractory disease was assessed in both models. Results: Overall, patients receiving CLO went off‐protocol more frequently than control patients (35/168 [21%] vs. 18/166 [11%], p = 0.019; HR 2.00 [1.13–3.52], p = 0.02), especially during maintenance (13/44 [30%] vs. 6/56 [11%]; HR 2.85 [95%CI 1.08–7.50], p = 0.035). Going off‐protocol was, however, not associated with more relapse or death. Patients in the CLO arm showed a trend towards an increased rate of MRD‐negativity compared with control patients (HR MRD‐negativity: 1.35 [0.95–1.91], p = 0.10), which did not translate into a significant survival benefit. Conclusion: We conclude that the intermediate states, i.e., going off‐protocol and MRD‐negativity, were affected by adding CLO, but these transitions were not associated with subsequent survival estimates, suggesting relatively modest antileukemic activity in ALL. [ABSTRACT FROM AUTHOR]

Management of patients with chronic lymphocytic leukemia (CLL) is changing due to considerable advances in the therapeutic armamentarium, and new therapies will possibly continue to emerge in the near future. Therefore, the CLL working group of the Dutch-Belgium Haemato-Oncology Cooperative Group for Adults in the Netherlands (HOVON) necessitated revising the Dutch CLL guidelines. The current guideline is based on the expert opinion of the HOVON CLL working group members and focusses on well-designed clinical trials taking into account efficacy with special emphasis on toxicity, treatment duration and treatment intensity. This article provides recommendations on diagnosis, treatment strategies in front-line and relapsed setting and provides supportive care measurements during novel-based therapies as well as for infectious CLL-related complications. The recommendations presented here are intended to provide guidance for the management of CLL patients in the Netherlands, and take into account the availability of treatment strategies at the time of this publication. [ABSTRACT FROM AUTHOR]

Results from registry studies suggest that harnessing Natural Killer (NK) cell reactivity mediated through Killer cell Immunoglobulin-like Receptors (KIR) could reduce the risk of relapse after allogeneic Hematopoietic Cell Transplantation (HCT). Several competing models have been developed to classify donors as KIR-advantageous or disadvantageous. Basically, these models differ by grouping donors based on distinct KIR–KIR–ligand combinations or by haplotype motif assignment. This study aimed to validate different models for unrelated donor selection for patients with Myelodysplatic Syndromes (MDS) or secondary Acute Myeloid Leukemia (sAML). In a joint retrospective study of the European Society for Blood and Marrow Transplantation (EBMT) and the Center for International Blood and Marrow Transplant Research (CIBMTR) registry data from 1704 patients with secondary AML or MDS were analysed. The cohort consisted mainly of older patients (median age 61 years) with high risk disease who had received chemotherapy-based reduced intensity conditioning and anti-thymocyte globulin prior to allogeneic HCT from well-matched unrelated stem cell donors. The impact of the predictors on Overall Survival (OS) and relapse incidence was tested in Cox regression models adjusted for patient age, a modified disease risk index, performance status, donor age, HLA-match, sex-match, CMV-match, conditioning intensity, type of T-cell depletion and graft type. KIR genes were typed using high-resolution amplicon-based next generation sequencing. In univariable and multivariable analyses none of the models predicted OS and the risk of relapse consistently. Our results do not support the hypothesis that optimizing NK-mediated alloreactivity is possible by KIR-genotype informed selection of HLA-matched unrelated donors. However, in the context of allogeneic transplantation, NK-cell biology is complex and only partly understood. KIR-genes are highly diverse and current assignment of haplotype motifs based on the presence or absence of selected KIR genes is over-simplistic. As a consequence, further research is highly warranted and should integrate cutting edge knowledge on KIR genetics, and NK-cell biology into future studies focused on homogeneous groups of patients and treatment modalities. [ABSTRACT FROM AUTHOR]

Purpose: The optimal dose intensity for conditioning prior to allogeneic hematopoietic stem cell transplantation (alloHSCT) for chronic lymphocytic leukemia (CLL) is unknown. Methods: We retrospectively compared outcomes of patients who received a first alloHCST after non-myeloablative (NMA) and reduced intensity conditioning (RIC). Data of 432 patients with a median age of 55 years were included, of which 86 patients underwent NMA and 346 RIC. Results: The median follow-up after alloHSCT was 4.3 years. Compared to the RIC group, more NMA patients had purine-analog-sensitive disease, were in complete remission and received matched related donor transplantation. After RIC, the probabilities for 5-year OS, EFS, CIR, and NRM were 46%, 38%, 28%, and 35% and after NMA the respective probabilities were 52%, 43%, 25%, and 32%. In multivariate analysis, remission status prior to conditioning but not RIC versus NMA conditioning had a significant impact on CIR, EFS, and OS. Conclusion: Presumed higher anti-leukemic activity of RIC versus NMA conditioning did not translate into better outcomes after alloHSCT, but better remission status prior to conditioning did. Effective pathway inhibitor-based salvage therapies combined with NMA conditioning might thus represent the most attractive contemporary approach for alloHSCT for patients with CLL. [ABSTRACT FROM AUTHOR]

In this article we explore the ethical issues raised by permitting patients to pay for participation (P4) in clinical trials, and discuss whether there are any categorical objections to this practice. We address key considerations concerning payment for participation in trials, including patient autonomy, risk/benefit and justice, taking account of two previous critiques of the ethics of P4. We conclude that such trials could be ethical under certain strict conditions, but only if other potential sources of funding have first been explored or are unavailable. [ABSTRACT FROM AUTHOR]

Background: Few studies thus far have compared head-to-head different non-myelooablative conditioning regimens for allogeneic hematopoietic cell transplantation (allo-HCT). Methods: Here, we report the results of a phase II multicenter randomized study comparing non-myeloablative allo-HCT from HLA-identical siblings (n = 54) or from 10/10 HLA-matched unrelated donors (n = 40) with either fludarabine plus 2 Gy total body irradiation (Flu-TBI arm; n = 49) or 8 Gy TLI + anti-thymocyte globulin (TLI-ATG arm; n = 45) conditioning. Results: The 180-day cumulative incidences of grade II-IV acute GVHD (primary endpoint) were 12.2% versus 8.9% in Flu-TBI and TLI-ATG patients, respectively (P = 0.5). Two-year cumulative incidences of moderate/severe chronic GVHD were 40.8% versus 17.8% in Flu-TBI and TLI-ATG patients, respectively (P = 0.017). Five Flu-TBI patients and 10 TLI-ATG patients received pre-emptive DLI for low donor chimerism levels, while 1 Flu-TBI patient and 5 TLI-ATG patients (including 2 patients given prior pre-emptive DLIs) received a second HCT for poor graft function, graft rejection, or disease progression. Four-year cumulative incidences of relapse/progression were 22% and 50% in Flu-TBI and TLI-ATG patients, respectively (P = 0.017). Four-year cumulative incidences of nonrelapse mortality were 24% and 13% in Flu-TBI and TLI-ATG patients, respectively (P = 0.5). Finally, 4-year overall (OS) and progression-free survivals (PFS) were 53% and 54%, respectively, in the Flu-TBI arm, versus 54% (P = 0.9) and 37% (P = 0.12), respectively, in the TLI-ATG arm. Conclusions: In comparison to patients included in the Flu-TBI arm, patients included in the TLI-ATG arm had lower incidence of chronic GVHD, higher incidence of relapse and similar OS. Trial registration: The study was registered on ClinicalTrial.gov (NCT00603954) and EUDRACT (2010-024297-19). [ABSTRACT FROM AUTHOR]

Mutations in Varicella zoster virus (VZV) thymidine kinase can cause resistance of VZV to Acyclovir. In stem cell transplant recipients with Acyclovir-resistant VZV disease, we demonstrate temporal as well as spatial compartmentalization of such mutations, with important implications for sampling.Background. Acyclovir resistance of varicella zoster virus (VZV) may arise in stem cell transplant (SCT) recipients with VZV disease and is usually a result of mutations in VZV thymidine kinase (TK), which is the target protein of acyclovir. Early detection of such mutations is necessary to enable timely therapy adaptation, for example, to foscarnet. We aimed to investigate whether TK mutations arise over time, and what sample types might be the most useful for this method.Methods. Spatially and temporally distinct samples from 3 SCT recipients with VZV disease unresponsive to acyclovir treatment were retrospectively investigated for the presence of TK mutations by polymerase chain reaction and sequence analysis.Results. In all 3 patients, a mutation in the VZV TK coding region was found resulting in an amino acid substitution. TK mutations were not only temporally but also spatially compartmentalized. In particular, plasma samples frequently showed wild-type TK sequences, whereas cerebrospinal fluid or skin vesicle fluid acquired on the same day contained mutant sequences.Conclusions. This study shows the importance of careful sampling for molecular diagnostics of acyclovir resistance in VZV disease. All affected body sites should be sampled and plasma samples may not be representative for the viral mutation status. [ABSTRACT FROM AUTHOR]

Besides their role in destruction of altered self-cells, NK cells have been shown to potentiate T-cell responses by interacting with DC. To take advantage of NK-DC crosstalk in therapeutic DC-based vaccination for infectious diseases and cancer, it is essential to understand the biology of this crosstalk. We aimed to elucidate the in vitro mechanisms responsible for NK-cell recruitment and activation by DC during infection. To mimic bacterial infection, DC were exposed to a membrane fraction of Klebsiella pneumoniae, which triggers TLR2/4. DC matured with these bacterial fragments can actively recruit NK cells in a CCR5-dependent manner. An additional mechanism of DC-induced NK-cell recruitment is characterized by the induction of CCR7 expression on CD56 [ABSTRACT FROM AUTHOR]

Simple Summary: Natural killer (NK) cells are potent killers of tumor cells. Many tumors, including breast cancers, develop mechanisms to suppress anti-tumor immune responses, requiring the development of strategies to overcome suppression. Here, we tested a combination therapy that aims to (1) enhance NK cell activation and (2) reduce NK cell inhibition mediated by suppressive factors in tumors or in the tumor microenvironment. We cultured cell lines under hypoxia to mimic the tumor microenvironment or used patient-derived breast cancer cells that were primed by the patient's tumor environment. Our results demonstrated that cytokine-activated NK cells remained active under hypoxia and that tumor-targeting antibodies enhanced the NK cell anti-breast cancer response. Moreover, we observed that NK cell suppression by inhibitory ligands on the tumor cells can be reduced by the selection of NK cell donors with NK receptors that are incompatible with these ligands. Collectively, we present two powerful strategies to enhance the NK cell responses against breast cancer. Natural killer (NK)-cell-based immunotherapies are an attractive treatment option for cancer. We previously showed that alloreactive mouse NK cells cured mice of 4T1 breast cancer. However, the tumor microenvironment can inhibit immune responses, and these suppressive factors must be overcome to unfold the NK cells' full anti-tumor potential. Here, we investigated the combination of antibody-dependent cellular cytotoxicity (ADDC) and the selection of KIR-HLA-ligand mismatched NK cells to enhance NK cell anti-breast cancer responses in clinically relevant settings. Donor-derived and IL-2-activated NK cells were co-cultured with patient-derived breast cancer cells or cell lines MCF7 or SKBR3 together with the anti-HER2 antibody trastuzumab. NK cells mediated anti-breast cancer cytotoxicity under normoxic and hypoxic conditions. Under both conditions, trastuzumab vigorously enhanced NK cell degranulation (CD107a) against HER2-overexpressing SKBR3 cells, but we observed a discrepancy between highly degranulating NK cells and a rather modest increase in cytotoxicity of SKBR3. Against patient-derived breast cancer cells, the anti-tumor efficacy was rather limited, and HLA class I expression seemed to contribute to inhibited NK cell functionality. KIR-ligand-mismatched NK cells degranulated stronger compared to the matched NK cells, further highlighting the role of HLA. In summary, trastuzumab and KIR-ligand-mismatched NK cells could be two strategies to potently enhance NK cell responses to breast cancer. [ABSTRACT FROM AUTHOR]

A 39-year-old man presented with a rapidly growing unilateral painless nodule on the right cheek. Histopathological examination and peripheral blood analysis both showed a population of T-cell large granular lymphocytes, which were CDI+, CD2+, CD5+, CD7+ and CD16+, with expression of cutaneous lymphocyte-associated antigen. Further laboratory examination revealed severe neutropaenia, relative lymphocytosis and a clonally rearranged T-cell receptor. The cutaneous manifestation of T-cell large granular lymphocytic leukaemia is very rare. In this particular patient, however, it was instrumental in establishing the diagnosis and may have been enabled by the expression of cutaneous lymphocyte-associated antigen on the cell surface. [ABSTRACT FROM AUTHOR]

Allogeneic stem cell transplantation (ASCT) from related or unrelated donors may cure patients with myelodysplastic syndromes (MDS), a heterogeneous group of clonal stem cell disorders. We analysed 384 elderly patients (55-69 years) with advanced MDS who received either ASCT (n=247) and were reported to The European Group for Blood and Marrow Transplantation (EBMT) or a non –transplant approach (n=137) reported to the Düsseldorf registry. Besides an attempt to answer the question of „comparison“, the purpose of this work is to explain the difficulties in comparing a non-transplant with a transplant cohort, when death before transplant is likely but unknown and the selection of patients for transplant is based on assumptions. It shows which methods are almost always biased and that even the most sophisticated approaches crucially rely on clinical assumptions. Using the most appropriate model for our data, we derive an overall univariate non-significant survival disadvantage for the transplant cohort (HR: 1.29, p = 0.11). We show that such an “average” hazard ratio is however misleading due to non-proportionality of the hazards reflecting early treatment related mortality, the occurring of which is logically correlated with the interval between diagnosis and transplant creating a disproportional drop in the (reconstructed) survival curve of the transplanted patients. Also in multivariate analysis (correcting for age > 60 (HR: 1.4, p = 0.02) and abnormal cytogenetics (HR: 1.46, p = 0.01)), transplantation seems to be worse (HR: 1.39, p = 0.05) but only in the (incorrect but commonly applied) model without time varying covariates. The long term (time depending) hazard ratio is shown to be virtually 1 and overall survival is virtually identical in both groups. Nonetheless no conclusion can be reached from a clinical point of view without assumptions which are by their very nature untestable unless all patients would be followed from diagnosis. [ABSTRACT FROM AUTHOR]