MEN1112/OBT357, an Anti Bst1/CD157 Humanized Antibody Inducing Acute Myelogenous Leukemia (AML) Blast Depletion in an Autologous Ex Vivo Assay: A Potential New Targeted Therapy for AML

Blood ◽  
2015 ◽  
Vol 126 (23) ◽  
pp. 788-788
Author(s):  
Adriano Venditti ◽  
Francesco Buccisano ◽  
Luca Maurillo ◽  
Maria Ilaria Del Principe ◽  
Andrea Coppola ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Acute Myeloid Leukemia ◽  
Peripheral Blood ◽  
Myeloid Leukemia ◽  
Ex Vivo ◽  
Myelogenous Leukemia ◽  
Monocytic Differentiation ◽  
Healthy Donors ◽  
Ex Vivo Assay ◽  
Acute Myeloid

Abstract Acute myeloid leukemia (AML) is a disease with a poor outcome and novel approaches are needed to improve survival and decrease toxicity of current therapies. Bst1/CD157 is a protein belonging to the ADP-ribosyl-cyclase family expressed on monocytes and neutrophils. This antigen was shown to be also expressed in peripheral blood (PB) and bone marrow (BM) blasts of acute myeloid leukemia (AML) patients either at primary diagnosis or at relapse(1,2,3). MEN1112/OBT357 is a humanized, de-fucosylated antibody targeting Bst1/CD157 with high affinity and developed to generate antibody dependent cell-mediated cytotoxicity (ADCC) response against AML blasts. Peripheral blood (PB) and bone marrow (BM) samples of 38 AML patients (29 at diagnosis, 6 at relapse, 3 resistant), have been analyzed for the expression of Bst1/CD157 on AML blast cells by fluorescence-activated cell sorting (FACS) using a PE conjugated form of MEN1112/OBT357. Bst1/CD157 expression has been confirmed in 91% and 96% of PB and BM AML samples, respectively. Furthermore, statistical analysis demonstrated that monocyte-oriented blasts are characterized by a brighter expression of Bst1/CD157 compared to blasts of non-monocytic lineage. The efficacy of MEN1112/OBT357 in depleting AML blasts was evaluated through FACS analysis in an autologous ex vivo assay performed on whole blood. The assay was set up using blood from healthy donors exposed to 10 μg/ml Rituximab for 18 hours to induce B cell depletion. In the same conditions, the ability of 10 μg/ml MEN1112/OBT357 to induce blasts depletion was tested.In whole PB,MEN1112/OBT357 was able to deplete AML blasts in 15/32 evaluable cases (46%). In BM, MEN1112/OBT357 induced blast depletion in 9/24 evaluable cases (36%). Interestingly, higher depletion rate was observed in relapse/refractory patients. When CD16A-158Phe/Val polymorphisms were analyzed utilizing a sequence based typing (SBT) assay, it was demonstrated that AML blast depletion was independent by FcRg polymorphism. Furthermore, no significant shedding of Bst1/CD157 antigen was observed in sera from AML patients, compared to the sera from patients with other hematologic diseases or healthy donors. In summary, we confirmed the frequent expression of Bst1/CD157 on blasts from AML patients, with the brightest pattern of positivity observed in cases belonging to monocytic differentiation lineage. MEN1112/OBT357 also induced a promising ADCC against AML blasts in an autologous setting, which is independent from FcR g phenotype. Since in vivo the exposure of AML blasts to MEN1112/OBT357 largely exceeds the incubation time of the depletion assay, we expect a further improvement of its anti-leukemic effect in the clinical setting. Based on these results, a phase I study in patients with relapsed or refractory AML has been initiated in December 2014. Disclosures Bellarosa: Menarini Ricerche: Employment. Bressan:Menarini Ricerche: Employment. Wilson:Oxford Biotherapeutics: Employment. Manzini:Menarini Ricerche: Employment. Capriati:Menarini Ricerche SpA: Employment. Simonelli:Menarini Ricerche SpA: Employment. Binaschi:Menarini Ricerche: Employment.

Detection of Nucleophosmin Gene Mutations in Plasma from Patients with Acute Myeloid Leukemia: Clinical Significance and Implications.

Blood ◽  
2007 ◽  
Vol 110 (11) ◽  
pp. 2855-2855
Author(s):  
Wanlong Ma ◽  
Xi Zhang ◽  
Iman Jilani ◽  
Farhad Ravandi ◽  
Elihu Estey ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Acute Myeloid Leukemia ◽  
Peripheral Blood ◽  
Myeloid Leukemia ◽  
Gene Mutations ◽  
Leukemic Cells ◽  
Striking Difference ◽  
Plasma Dna ◽  
Npm1 Mutation ◽  
Acute Myeloid

Abstract Nucleotides insertion in the nucleophosphamin (NPM1) gene has been reported in about one third of patients with acute myeloid leukemia (AML). Multiple studies showed that the presence of NPM1 mutations associated with better outcome in patients with AML. Studies reported to date have analyzed leukemic cells obtained from bone marrow or peripheral blood. We tested for mutations in the NPM1 gene using peripheral blood plasma and compared results with clinical outcome from a single institution. Analyzing plasma from 98 newly diagnosed patient with AML showed NPM1 mutation in 24 (23%) of patient while only one (4%) of 28 previously untreated patients with myelodysplastic syndrome (MDS) showed NPM1 mutation. Compared with peripheral blood cells, 2 (8%) of the 24 positive patients were negative by cells; none were positive by cells and negative by plasma. Most of the mutations detected (45%) were in patients with FAB classification M2, M4 and M5. In addition to the reported 4 bp insertion, we also detected 4 bp deletion in one patient in cells and plasma. Patients with NPM1 mutation had a significantly higher white blood cell count (P = 0.0009) and a higher blast count in peripheral blood (P = 0.002) and in bone marrow (P = 0.002). Blasts in patients with NPM1 mutant expressed lower levels of HLA-DR (P = 0.005), CD13 (P = 0.02) and CD34 (P < 0.0001), but higher CD33 levels (P = 0.0004). Patients with NPM1 mutation appear to have better chance of responding to standard therapy (P = 0.06). Event free survival of patients with NPM1 mutation was longer (P = 0.056) than in patients with intermediate cytogenetic abnormalities. The most striking difference in survival was in patients who required >35 days to respond to therapy (Figure). Survival was significantly longer in patients with NPM1 mutation requiring >35 days to respond (P = 0.027). This data not only support that NPM1 plays a significant role in the biology and clinical behavior of AML, but also show that plasma DNA is enriched with leukemia-specific DNA and is a reliable source for testing. Figure Figure

Mesenchimal Stroma Cells From Patients with Myelodysplastic Syndrome and Acute Myeloid Leukemia Show Distinct Cytogenetic and DNA-Mutation Data as Compared with Bone Marrow Leukemic Blasts.

Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 4697-4697
Author(s):  
Olga Blau ◽  
Wolf-Karsten Hofmann ◽  
Claudia D Baldus ◽  
Gundula Thiel ◽  
Florian Nolte ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Acute Myeloid Leukemia ◽  
Myeloid Leukemia ◽  
Conflicts Of Interest ◽  
Control Analysis ◽  
Npm1 Mutation ◽  
Dna Mutation ◽  
Healthy Donors ◽  
Acute Myeloid

Abstract Abstract 4697 Bone marrow mesenchymal stroma cells (BMSC) are key components of the hematopoietic microenvironment. BMSC from patients with acute myeloid leukemia (AML) and myelodisplasic syndrome (MDS) display functional and quantitative alterations. To gain insight into these questions, we carried out cytogenetic analyses, FISH, FLT3 and NPM1 mutation examinations of both hematopoietic (HC) and BMSC derived from 53 AML and 54 MDS patients and 35 healthy donors after in vitro culture expansion. Clonal chromosomal aberrations were detectable in BMSC of 12% of patients. Using FISH we have assume that cytogenetic markers in BMSC were always distinct as the aberrations in HC from the same individual. 17% and 12% of AML patients showed FLT3 and NPM1 mutations in HC, respectively. In BMSC, we could not detect mutations of NPM1 and FLT3, independent from the mutation status of HC. For control analysis, BMSC cultures from 35 healthy donors were prepared under the same conditions. BMSC from healthy donors did show normal diploid karyotypes and absence of specific DNA-mutations of NPM1 and FLT3. Our data indicate that BMSC from MDS and AML patients are not a part of malignant clone and characterized by genetic aberrations. Lack of aberrations as detected in HC and appearance of novel clonal rearrangements in BMSC may suggest enhanced genetic susceptibility and potential involvement of BMSC in the pathogenesis of MDS and AML. Disclosures: No relevant conflicts of interest to declare.

Targeted Intravenous Busulfan and Fludarabine Allogeneic Transplantation Conditioning in Acute Myeloid Leukemia.

Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 2290-2290
Author(s):  
Joseph A. Pidala ◽  
Jongphil Kim ◽  
Claudio Anasetti ◽  
Melissa Alsina ◽  
Ernesto Ayala ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Overall Survival ◽  
Acute Myeloid Leukemia ◽  
Myeloid Leukemia ◽  
Research Funding ◽  
Large Series ◽  
Myelogenous Leukemia ◽  
Secondary Aml ◽  
Relapsed Disease ◽  
Acute Myeloid

Abstract Abstract 2290 Poster Board II-267 Reduced and intermediate intensity conditioning with allogeneic hematopoietic cell transplantation (HCT) offers promise to effectively control hematologic malignancies, while limiting treatment related toxicity and mortality (TRM). We aimed to examine the efficacy of IV targeted Busulfan and Fludarabine (IV-Bu/Flu) in a large series of adults with exclusively acute myelogenous leukemia (AML). One hundred adults (median age 48) with AML (CR1 49, CR2 25, REL1 8, REL2 1, PIF 16, untreated 1) were treated with Busulfan 130-145 mg/m2/day for four days with pharmacokinetic targeting on the final two days to achieve an area under the curve (AUC) of 5300 (+/-10%) μmol*min/L/day and Fludarabine 40mg/m2/day for 4 days, followed by transplantation of G-CSF mobilized peripheral blood stem cells (PBSC) (N=98) or unstimulated bone marrow (BM) (N=2) from allogeneic donors (MRD 38, MUD 38, MMUD 24). Acute GVHD prophylaxis consisted of tacrolimus/methotrexate (N = 77), tacrolimus/mycophenolate mofetil (N = 22), or tacrolimus/sirolimus (N = 1). Median time to neutrophil and platelet engraftment was 16 and 12 days, respectively. Non-relapse mortality was 3% at 100 days, and 15% by 1 year. The cumulative incidence of relapse was 41%. Overall survival (OS) was 59% (95% CI: 48.1 – 67.5) at 1 year, and 42% (95% CI: 30.8-53.3) at 4 years. OS at 4 years for primary AML in CR1, secondary AML in CR1, CR2, and PIF were 52.9%, 40.1%, 41.2%, and 57.5% respectively; none with relapsed disease survived to 4 years (log-rank p = 0.0014). Progression-free survival (PFS) was 53% (95% CI: 42.8 – 62.2) at 1 year, and 32.3% (95% CI: 21.8 – 43.2) at 4 years. PFS at 4 years for primary AML in CR1, secondary AML in CR1, CR2, and PIF were 44.1%, 33.4%, 33.9%, and 33.1%, respectively, while none with relapsed disease at transplant reached this endpoint (p = 0.0264). On multivariable modeling, remission status at HCT (relapsed disease HR 14.85 (95% CI: 2.12 - 104.2), p = 0.007), moderate/severe cGVHD (HR 0.281, 95% CI: 0.10 - 0.76; p = 0.013), and day 90 bone marrow (BM) chimerism ≥ 90% (HR 0.245, 95% CI: 0.08 - 0.79; p = 0.018) predicted overall survival, and day 90 BM chimerism ≥ 90% (HR of 0.18 (95% CI: 0.08 - 0.45), p = 0.0002) predicted PFS. The following were not significantly related with OS or PFS: age, cytogenetics, donor relation, number of induction cycles, aGVHD prophylaxis regimen, maximum aGVHD grade, WBC at diagnosis, time in first CR, or % BM blasts prior to transplant. Day 90 BM chimerism and cGVHD were significantly related with relapse. Maximum grade of aGVHD predicted non-relapse mortality. These data support the low TRM and efficacy of IV-Bu/Flu in a large series of exclusively AML patients, and demonstrate the impact of day 90 bone marrow chimerism as an important prognostic factor. Further efforts to mitigate relapse risk after HCT are warranted, particularly in those with advanced disease at time of transplant. Disclosures: Off Label Use: IV busulfan and fludarabine for the treatment of acute myeloid leukemia. Alsina:Ortho Biotech: Research Funding, Speakers Bureau; Millenium: Research Funding, Speakers Bureau. Field:PDL BioPharma: Research Funding. Fernandez:Otsuka: Honoraria.

EZH2 Mutations Are Associated with Low Blast Percentage in Bone Marrow and −7/Del(7q) Karyotype in De Novo Acute Myeloid Leukemia.

Blood ◽  
2012 ◽  
Vol 120 (21) ◽  
pp. 2544-2544
Author(s):  
Xiuli Wang ◽  
Haiping Dai ◽  
Qian WANG ◽  
Qinrong Wang ◽  
Yang Xu ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Acute Myeloid Leukemia ◽  
Myeloid Leukemia ◽  
De Novo ◽  
Conflicts Of Interest ◽  
Univariate Analysis ◽  
Myelogenous Leukemia ◽  
Prognostic Impact ◽  
Coding Region ◽  
Acute Myeloid

Abstract Abstract 2544 Somatic mutation of the EZH2 gene is seen in myelodisplastic syndrome, myelofibrosis, and chronic myelomonocytic leukemia patients. The prevalence and prognostic impact of somatic mutations of EZH2 in patients with acute myelogenous leukemia (AML) remains unknown. In this study, we sought to determine the incidence and clinical implications of somatic EZH2 mutations in 714 patients with de novo AML by PCR amplification of the entire coding region followed by direct bidirectional DNA sequencing. EZH2 mutations were identified in 13/714 (1.8%) of AML patients and occurred almost exclusively in males (11/13, P=0.033). In univariate analysis, the presence of EZH2 mutations was significantly associated with lower blast percentage (21–30%) in bone marrow (P=0.0001) and −7/del(7q) (P=0.025). There was no difference in the incidence of mutations in 13 genes, including ASXL1, CBL, c-KIT, DNMT3A, FLT3, IDH1, IDH2, MLL, NPM1, NRAS, RUNX1, TET2, and WT1, between patients with and without EZH2 mutations. Complete remission, event-free survival or overall survival was similar between AML patients with and without EZH2 mutation (p>0.05). These results demonstrated EZH2 mutation as a recurrent genetic abnormality associated with lower blast percentage in BM and −7/del(7q) in de novo acute myeloid leukemia. Disclosures: No relevant conflicts of interest to declare.

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