Owing to the more recent positive results with the anti-CD33 immunotoxin gemtuzumab ozogamicin, therapy against acute myeloid leukemias (AMLs) targeting CD33 holds many promises. Here, CD33 and CD123 ...expression on AML blasts was studied by flow cytometry in a cohort of 319 patients with detailed information on French-American-British/World Health Organization (FAB/WHO) classification, cytogenetics and molecular aberrations. AMLs of 87.8% express CD33 and would therefore be targetable with anti-CD33 therapies. Additionally, 9.4% of AMLs express CD123 without concomitant CD33 expression. Thus, nearly all AMLs could be either targeted via CD33 or CD123. Simultaneous presence of both antigens was observed in 69.5% of patients. Most importantly, even AMLs with adverse cytogenetics express CD33 and CD123 levels comparable to those with favorable and intermediate subtypes. Some patient groups with unfavorable alterations, such as FMS-related tyrosine kinase 3-internal tandem duplication (FLT3-ITD) mutations, high FLT3-ITD mutant/wild-type ratios and monosomy 5 are even characterized by high expression of CD33 and CD123. In addition, blasts of patients with mutant nucleophosmin (NPM1) revealed significantly higher CD33 and CD123 expression pointing toward the possibility of minimal residual disease-guided interventions in mutated NPM1-positive AMLs. These results stimulate the development of novel concepts to redirect immune effector cells toward CD33- and CD123-expressing blasts using bi-specific antibodies or engineered T cells expressing chimeric antigen receptors.
This study evaluated azacitidine as treatment of minimal residual disease (MRD) determined by a sensitive donor chimerism analysis of CD34(+) blood cells to pre-empt relapse in patients with CD34(+) ...myelodysplastic syndromes (MDS) or acute myeloid leukemia (AML) after allogeneic hematopoietic stem cell transplantation (HSCT). At a median of 169 days after HSCT, 20/59 prospectively screened patients experienced a decrease of CD34(+) donor chimerism to <80% and received four azacitidine cycles (75 mg/m(2)/day for 7 days) while in complete hematologic remission. A total of 16 patients (80%) responded with either increasing CD34(+) donor chimerism to ≥80% (n=10; 50%) or stabilization (n=6; 30%) in the absence of relapse. Stabilized patients and those with a later drop of CD34(+) donor chimerism to <80% after initial response were eligible for subsequent azacitidine cycles. A total of 11 patients (55%) received a median of 4 (range, 1-11) additional cycles. Eventually, hematologic relapse occurred in 13 patients (65%), but was delayed until a median of 231 days (range, 56-558) after initial decrease of CD34(+) donor chimerism to <80%. In conclusion, pre-emptive azacitidine treatment has an acceptable safety profile and can substantially prevent or delay hematologic relapse in patients with MDS or AML and MRD after allogeneic HSCT.
The adoptive transfer of CD19-specific chimeric antigen receptor engineered T cells (CAR T cells) resulted in encouraging clinical trials in indolent B-cell malignancies. However, they also show the ...limitations of this fascinating technology: CAR T cells can lead to even life-threatening off-tumor, on-target side effects if CAR T cells crossreact with healthy tissues. Here, we describe a novel modular universal CAR platform technology termed UniCAR that reduces the risk of on-target side effects by a rapid and reversible control of CAR T-cell reactivity. The UniCAR system consists of two components: (1) a CAR for an inert manipulation of T cells and (2) specific targeting modules (TMs) for redirecting UniCAR T cells in an individualized time- and target-dependent manner. UniCAR T cells can be armed against different tumor targets simply by replacement of the respective TM for (1) targeting more than one antigen simultaneously or subsequently to enhance efficacy and (2) reducing the risk for development of antigen-loss tumor variants under treatment. Here we provide 'proof of concept' for retargeting of UniCAR T cells to CD33- and/or CD123-positive acute myeloid leukemia blasts in vitro and in vivo.
This phase 1b trial investigated several doses and schedules of midostaurin in combination with daunorubicin and cytarabine induction and high-dose cytarabine post-remission therapy in newly ...diagnosed patients with acute myeloid leukemia (AML). The discontinuation rate on the 50-mg twice-daily dose schedule was lower than 100 mg twice daily, and no grade 3/4 nausea or vomiting was seen. The complete remission rate for the midostaurin 50-mg twice-daily dose schedule was 80% (FMS-like tyrosine kinase 3 receptor (FLT3)-wild-type: 20 of 27 (74%), FLT3-mutant: 12 of 13 (92%)). Overall survival (OS) probabilities of patients with FLT3-mutant AML at 1 and 2 years (0.85 and 0.62, respectively) were similar to the FLT3-wild-type population (0.78 and 0.52, respectively). Midostaurin in combination with standard chemotherapy demonstrated high complete response and OS rates in newly diagnosed younger adults with AML, and was generally well tolerated at 50 mg twice daily for 14 days. A phase III prospective trial is ongoing (CALGB 10603, NCT00651261).
Patients with Ph-negative myeloproliferative neoplasms (MPN), such as polycythemia vera (PV), essential thrombocythemia (ET), and primary myelofibrosis (PMF), are at increased risk for ...thrombosis/thromboembolism and major bleeding. Due to the morbidity and mortality of these events, antiplatelet and/or anticoagulant agents are commonly employed as primary and/or secondary prophylaxis. On the other hand, disease-related bleeding complications (i.e., from esophageal varices) are common in patients with MPN. This analysis was performed to define the frequency of such events, identify risk factors, and assess antiplatelet/anticoagulant therapy in a cohort of patients with MPN.
The MPN registry of the Study Alliance Leukemia is a non-interventional prospective study including adult patients with an MPN according to WHO criteria (2008). For statistical analysis, descriptive methods and tests for significant differences as well as contingency tables were used to identify the odds of potential risk factors for vascular events.
MPN subgroups significantly differed in sex distribution, age at diagnosis, blood counts, LDH levels, JAK2V617F positivity, and spleen size (length). While most thromboembolic events occurred around the time of MPN diagnosis, one third of these events occurred after that date. Splanchnic vein thrombosis was most frequent in post-PV-MF and MPN-U patients. The chance of developing a thromboembolic event was significantly elevated if patients suffered from post-PV-MF (OR 3.43; 95% CI = 1.39-8.48) and splenomegaly (OR 1.76; 95% CI = 1.15-2.71). Significant odds for major bleeding were previous thromboembolic events (OR = 2.71; 95% CI = 1.36-5.40), splenomegaly (OR = 2.22; 95% CI 1.01-4.89), and the administration of heparin (OR = 5.64; 95% CI = 1.84-17.34). Major bleeding episodes were significantly less frequent in ET patients compared to other MPN subgroups.
Together, this report on an unselected "real-world" cohort of German MPN patients reveals important data on the prevalence, diagnosis, and treatment of thromboembolic and major bleeding complications of MPN.
Background
Outcomes for patients with acute myeloid leukaemia (AML) undergoing allogeneic stem cell transplantation (allo‐SCT) have significantly improved in recent years.
Objectives
To assess the ...incremental improvement of transplanted AML patients in the last two decades.
Methods
Patients included in this analysis were adult AML patients who underwent allo‐SCT from an HLA‐matched sibling donor (MSD) or HLA‐matched unrelated donor (MUD) in first remission. Patient outcomes were assessed between three cohorts according to the year of transplant (1993–2002, 2003–2007 and 2008–2012).
Results
The analysis comprised a total of 20 187 patients of whom 4763 were transplanted between 1993 and 2002, 5835 in 2003 and 2007, and 9589 in 2008 and 2012. In multivariate analysis, leukaemia‐free survival (LFS) rates were significantly improved in more recently transplanted patients compared to patients transplanted in 1993–2002 Hazard ratio (HR) = 0.84, confidence interval (CI) 95%, 0.77–0.92; P = 0.003, a benefit which also extended to improved overall survival (OS; HR = 0.8, CI 95%, 0.73–0.89; P < 0.0001), and decreased nonrelapse mortality (NRM) rates (HR = 0.65, CI 95%, 0.56–0.75; P < 0.0001). Subset analysis revealed that in MSD, the rates of LFS, NRM and OS significantly improved in patients in the more recent cohort with similar results also seen in MUD. Finally, the incidence of acute graft‐versus‐host disease (GVHD) was significantly reduced leading to improved GVHD‐free/relapse‐free survival (GRFS) rates in more recently transplanted patients.
Conclusion
Outcome of allo‐SCT for AML patients has markedly improved in the last two decades owing to decreased nonrelapse mortality and improved rates of leukaemia‐free survival resulting in significantly longer survival.
The major histocompatibility complex (MHC, called HLA in humans) is an important genetic component of the immune system. Fish, birds and mammals prefer mates with different genetic MHC code compared ...to their own, which they determine using olfactory cues. This preference increases the chances of high MHC variety in the offspring, leading to enhanced resilience against a variety of pathogens. Humans are also able to discriminate HLA related olfactory stimuli, however, it is debated whether this mechanism is of behavioural relevance. We show on a large sample (N = 508), with high-resolution typing of HLA class I/II, that HLA dissimilarity correlates with partnership, sexuality and enhances the desire to procreate. We conclude that HLA mediates mate behaviour in humans.
To evaluate prognostic factors for relapse-free survival (RFS) and overall survival (OS) and to assess the impact of different postremission therapies in adult patients with core binding factor (CBF) ...acute myeloid leukemias (AML).
Individual patient data-based meta-analysis was performed on 392 adults (median age, 42 years; range, 16 to 60 years) with CBF AML (t(8;21), n = 191; inv(16), n = 201) treated between 1993 and 2002 in prospective German AML treatment trials.
RFS was 60% and 58% and OS was 65% and 74% in the t(8;21) and inv(16) groups after 3 years, respectively. For postremission therapy, intention-to-treat analysis revealed no difference between intensive chemotherapy and autologous transplantation in the t(8;21) group and between chemotherapy, autologous, and allogeneic transplantation in the inv(16) group. In the t(8;21) group, significant prognostic variables for longer RFS and OS were lower WBC and higher platelet counts; loss of the Y chromosome in male patients was prognostic for shorter OS. In the inv(16) group, trisomy 22 was a significant prognostic variable for longer RFS. For patients who experienced relapse, second complete remission rate was significantly lower in patients with t(8;21), resulting in a significantly inferior survival duration after relapse compared with patients with inv(16).
We provide novel prognostic factors for CBF AML and show that patients with t(8;21) who experience relapse have an inferior survival duration.
According to WHO 2008 guidelines, the required percentage of cells manifesting dysplasia in the bone marrow to qualify as significant is 10% or over in one or more hematopoietic cell lineages, but ...this threshold is controversial. No 'normal' values have been established. Therefore, we investigated dyshematopoiesis in bone marrow aspirate squash preparations of 120 healthy bone marrow donors.
Bone marrow squash slides of 120 healthy unrelated bone marrow donors were examined independently by 4 experienced morphologists. Samples were taken from the first aspiration during the harvest. Bone marrow preparation and assessment were performed according to WHO recommendations and ICSH guidelines.
More than 10% dysmyelopoiesis could be detected in 46% of bone marrow aspirate squash preparations with 26% in 2 or more cell lineages and 7% in 3 cell lineages in healthy bone marrow donors. Donors under the age of 30 years exhibited more dysgranulopoietic changes and dysmegakaryopoietic changes (P<0.001) compared to the older donors. Female donors showed more dysgranulopoietic changes than male donors (P = 0.025). The concordance rate between the 4 investigators was modest in dysgranulopoiesis but poor in dyserythropoiesis and dysmegakaryopoiesis.
The poor reliability of the 10% cut off was partly related to the proximity of the current criteria to the observed cut-off mean values of the normal population. These findings question the current WHO threshold of the 10% or over necessary for the percentage of cells manifesting dysplasia to be considered significant, and suggest that either a higher threshold would be more appropriate or different thresholds should be set for each lineage.
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