Cytogenetic Groups Research Articles

PB2094 A SINGLE CENTRE EXPERIENCE WITH AZACITIDINE FOR MDS, AML AND CMML IN RELATION TO CYTOGENETIC RISK AND PERFORMANCE STATUS

Background:Azacitidine is a hypomethylating agent which is used in the treatment of myelodysplastic syndromes (MDS), acute myeloid leukaemia (AML) and chronic myelomonocytic leukaemia (CMML). In the AZA‐001 trial, azacitidine altered the natural history of patients with higher‐risk MDS (Fenaux et al., Lancet 2009) by significantly improving overall survival (OS) compared to conventional care regimens (24.5 months vs 15.0 months) and in particular improved OS in the poor risk cytogenetics group (17.4 months vs 6 months) which led to its NICE approval in 2011.Aims:We report a single centre experience over 4 years of using azacitidine in the licensed NICE indications and compared results to the published data.MethodsWe retrospectively reviewed patients with MDS, AML and CMML who received azacitidine at Ipswich Hospital NHS Trust between November 2014 and November 2018. Data was collected on demographics, disease characteristics, treatment, blood and platelet transfusion response, disease progression and cause of deathResults:Thirty‐nine patients met the NICE criteria for treatment and were included in the analysis, irrespective of the number of cycles received. Median age was 72.2 years. Male: Female ratio was 2:1. Median number of cycles was 9 (range from 1‐43). 51% of patients had a diagnosis of MDS, 31% AML and 18% CMML. 25.6% had poor risk cytogenetics as per the IPSS criteria. Median percentage of blasts on bone marrow aspirate was 15.7%. Causes of death were either disease progression or sepsis with only one death unrelated to the underlying condition (lung cancer). Median Kaplan‐Meier OS for all groups from the start of treatment with azacitidine was 18 months, with MDS patients OS of 22 months compared to 18 months for AML and 13 months for CMML (p = 0.22). There was a significant difference noted in the group who had poor risk (IPSS) cytogenetics versus other cytogenetic risks, with a median OS of 8 months and 20 months respectively (p = 0.002). A significant difference was also seen in the median OS based on performance status (PS), with an OS of 7 months, 20 months and not yet reached for PS 2, 1 and 0 respectively (p = 0.005).Summary/Conclusion:In the AZA‐001 trial median OS on azacitidine was 24 months vs. 18 months seen in our cohort. The AZA‐001 trial also showed improved OS for poor risk cytogenetics at 17.4 months vs. only 8 months seen in our experience. Although our data does support an overall improvement in median OS for all groups, our data showed less impressive results, with a 6 months less survival advantage in all groups and 9 months less OS in the poor cytogenetic group as compared to the trial data. As previously shown, we observed that the most significant factors in predicting OS were cytogenetic risks and PS. Interestingly, a large real world registry collection in Canada of 1101 patients on azacitidine over 6 years only showed a median OS of 12 months for all groups which further highlights the difference we often see between real world patients and trial data.

PB1901 IBRUTINIB, SINGLE AGENT BTK INHIBITOR, FOR RELAPSED/REFRACTORY (R/R) CHRONIC LYMPHOCYTIC LEUKEMIA: A REAL‐WORLD EXPERIENCE FROM RETE EMATOLOGICA PUGLIESE (REP).

Background:Ibrutinib has showed to improve Progression Free Survival (PFS) and Overall Survival (OS) in patients with Chronic Lymphocytic Leukemia (CLL) maintaining a good tolerability profile. Moreover a good tolerability profile was showed in previously published data.Aims:Within the Rete Ematologica Pugliese (REP) seven hematologic centers verified the safety and the efficacy of Ibrutinib as a single agent treatment. Response rate, PFS and OS have been evaluated in all treated patients and in poor cytogenetic risk groups.Methods:One hundred twenty‐two patients from seven hematologic centers of REP were enrolled in the study. Ibrutinib was administred as salvage therapy across different lines as reported: 2nd line n = 75 (61%) (BR n = 48, FCR n = 24, other n = 3); 3rd line n = 35 (28,7%); 4th line n = 12 (8,2%). All patients received Ibrutinib 420 mg once daily until progression or unacceptable toxicity. PFS, OS and Overall Response Rate (ORR) were calculated. Kaplan Meier method was used to estimate PFS/OS and differences in survival times between groups were assessed with a log‐rank test.Results:Patients have a median age of 65 years (range: 28‐84), 50% of them had more than 65 yrs. Cytogenetic FISH was performed in 66% of patients (n = 80). No abnormalities were found in 31% of patients (n = 25): while del17p, del13q, del11q and trisomy12 were found in n = 33, n = 13, n = 3 and n = 6 of patients, respectively. Unmutated and mutated IgVH status was performed in 73 patients (60%); of these, 46(63%) patients had unmutated and 27 (37%) had mutated IgVH.Overall, ORR was achieved in 94 patients (77%) (complete response [CR] was reached in 10%) of patients). In the subgroup having a del17p ORR was achieved in 21 (61%) patients. Median of follow up time is 17 months (range 1‐45). The estimated PFS at 30 months was 66,7% from the entire study population. Patients with del17p displayed a median PFS of 39 months while it was not reached in patients having no history of cytogenetic abnormalities (Figure 2). Median OS was not reached from all treated patients and the estimated OS at 30 months was 72.7%, while no difference in terms of OS was found when patients with and without del17p were compared (81.7% vs 90.2%), (overall logrank p = 0.807) (Figure 4).Out of all treated patients, 47% of them showed the following adverse events (AEs) with grade ≥3: neutropenia (16%), hypertension (12%), atrial fibrillation (3%), anemia (3%), diarrhea (2%).Summary/Conclusion:In REP real‐world experience, treatment for R/R CLL patients with Ibrutinib as a single agent demonstred to be effective across negative and positive cytogenetic groups and to be well tolerated. AES did not result in treatment interruptions in the most of cases. In fact, over a median follow up of 17 months, 80% of patients remain on Ibrutinib‐treatment. Clearly, these results will require longer follow up time to be further confirmed.image

Allogeneic stem cell transplantation using HLA-matched donors for acute myeloid leukemia with deletion 5q or monosomy 5: a study from the Acute Leukemia Working Party of the EBMT.

Deletion 5q or monosomy 5 (-5/5q-) in acute myeloid leukemia (AML) is a common high-risk feature that is referred to allogeneic stem cell transplantation. However, -5/5q- is frequently associated with other high-risk cytogenetic aberrations such as complex karyotype, monosomal karyotype, monosomy 7 (-7), or 17p abnormalities (abn (17p)), the significance of which is unknown. In order to address this question, we studied adult patients with AML harboring -5/5q- having their first allogeneic transplantation between 2000 and 2015. Five hundred and one patients with -5/5q- have been analyzed. Three hundred and thirty-eight patients (67%) were in first remission and 142 (28%) had an active disease at time of allogeneic transplantation. The 2-year probabilities of overall survival and leukemia-free survival were 27% and 20%, respectively. The 2-year probability of treatment-related mortality was 20%. We identified four different cytogenetic groups according to additional abnormalities with prognostic impact: -5/5q- without complex karyotype, monosomal karyotype or abn(17p), -5/5q- within a complex karyotype, -5/5q- within a monosomal karyotype and the combination of -5/5q- with abn(17p). In multivariate analysis, factors associated with worse overall survival and leukemia-free survival across the four groups were active disease, age, monosomal karyotype, and abn(17p). The presence of -5/5q- without monosomal karyotype or abn(17p) was associated with a significantly better survival rate while -5/5q- in conjunction with monosomal karyotype or abn(17p) translated into a worse outcome. The patients harboring the combination of -5/5q- with abn(17p) showed very limited benefit from allogeneic transplantation.

Real World Efficacy and Safety Results of Ixazomib Lenalidomide and Dexamethasone Combination in Relapsed/Refractory Multiple Myeloma: Data Collected from the Hungarian Ixazomib Named Patient Program

Ixazomib-Revlimid-Dexamethasone is an all-oral treatment protocol for multiple myeloma with a manageable tolerability profile which was available through a named patient program for Hungarian patients from December 2015 to April 2017. We analyzed the clinical characteristics and survival of 77 patients treated at 7 centers within this program. The majority of patients responded, we found complete response in 9, very good partial response in 8, partial response in 32, minor response or stable disease in 13 and progressive disease in 11 patients. Progression free survival was 11.4 months. There was a trend of longer progression free survival in those with 1 vs. >1 prior treatment, with equally good effectivity in standard risk and high risk cytogenetic groups. The adverse events were usually mild, none leading to permanent drug interruptions. There were 5 fatalities: 3 infections and 2 pulmonary embolisms. Our real word data support the use of Ixazomib-Revlimid-Dexamethasone as a highly effective and well tolerated oral treatment protocol for relapsed myeloma.

The MRD-Negativity Rate Measured By Flow Cytometry after the 1st and the 2nd Induction Course Among CR AML Patients from Different Cytogenetic Subgroups Does Not Differ Though the Morphological CR Achievement Does

Background. The recent ELN recommendations (2017) have introduced new criteria of response in AML - complete remission with MRD-negativity (CR/MRD-neg). It's a well-known fact that AML with different cytogenetics has different chemosensitivity, and so - CR rate in patients with favorable, intermediate or poor cytogenetic markers substantially differs. MRD negativity corresponds to more favorable long-term results in CR patients, but it's not clear whether the MRD-negativity rate is the same in favorable, intermediate or poor risk AML pts. As it is still poorly understood whether the high risk AML patients need classical «7+3» induction, we introduced a new approach for this cohort of patients - prolonged low-dose cytostatic exposure after hypomethylating priming.Aim. To evaluate the MRD-negativity in CR AML patients from different cytogenetic subgroups after the first classical non-intensive induction: «7+3», «Aza+7+3», «Aza-Ida-Ara-C», and the second induction differed by intensity.Materials and patients. 83 AML patients with a median age of 37 y.o. (17-59), m/f 31/52, after achieving CR (69 pts) were included in the MRD study in the National Research Center for Hematology. From March 2016 till Dec 2017, 49 pts disregarding cytogenetic risk were treated with «7+3» as the first induction course (Dauno 60 mg/m2 1-3 days, Ara-C 100 mg/m2 bid 1-7 days). The second induction course for these pts was «7+3» with continuous Ara-C infusion (200 mg/m2 1-7 days). Since Dec 2017 till July 2018 in all patients epigenetic priming with 3 days of Azacitidine (75 mg/m2) was applied additionally in order to obtain the cytogenetic results prior to cytostatic exposure. All patients were tested by molecular markers (FLT3, CEBPa, mNPM1) but this data did not influence the treatment choice. 8 pts from favorable/intermediate cytogenetic risk group after Aza-prephase have got «7+3» (Dauno 60 mg/m2 4-6 days, Ara-C 200 mg/m2 by continuous infusion, 4-10 days), and 13 pts from poor cytogenetic risk group (complex, -7,-5, inv3, monosomy) after Aza-priming received prolonged low-dose schedule (Ida 3 mg/m2 4-10 days, Ara-C 10 mg/m2 bid sc 4-17 days). The second induction course for favorable/intermediate risk group was FLAG-Ida, for poor risk group - the same as the 1st induction. MRD testing was performed by 6-color flow cуtometry with FACS Canto II (BD) machine after 1st and 2nd chemotherapy courses. The rate of MRD-negativity was calculated among CR patients.Results. Totally among 83 patients CR was achieved in 83%, early death was registered in 6% and refractory AML was diagnosed in 11%. The induction and MRD testing results after the 1st and the 2nd induction course according to prognostic group and treatment arm are demonstrated in the Table.1. Morphological CR rate differs substantially in patients from favorable/intermediate and poor risk by any treatment approach (p=0,04). The prolonged low-dose induction with Aza-prephase induced the same numbers of CRs as the classical «7+3»: 69% vs 46% (p=0,42). Epigenetic priming provided identical MRD-negative CRs in all treatment and cytogenetic groups: 75% vs 62% in favorable/intermediate risk group (p=0,29), 67% vs 50% in poor risk (p=0,62). The second intensive induction with Flag-Ida in favorable/intermediate risk group did not increase the portion of MRD-neg CR pts in comparison with «7+3»: 88% vs 71% (р=0,14). Early relapse rate through all groups showed comparable results.Conclusion. Though the morphological CR achievement is highly influenced by cytogenetic subgroup in AML, the MRD-negativity rate among CR pts by flow cytometry after the 1st and the 2nd induction course is similar. The de-intensification of induction for poor risk group did not lead to the deterioration of therapy efficacy and provided the same rate of MRD-negativity. The 2nd intensified induction after «7+3» did not increase the MRD-negativity in CR pts. [Display omitted] DisclosuresNo relevant conflicts of interest to declare.

Azacitidine Improves Outcome in Patients with MDS and AML with High Risk Cytogenetics - a Single Center Experience

Azacitidine is a novel hypomethylating agent shown to improve leukaemia free survival and overall survival in comparison with other modalities of treatment in MDS and AML patients. There is proven reduction in transfusion requirements by improvement in haematological parameters with continuous azacitidine use. However azacitidine benefit in high risk cytogenetics group is unclear. Recent retrospective study from GESMD and GFM registries showed that Azacitidine improves outcome in higher‐risk MDS patients with chromosome 7 abnormalities. Here we report our experience in high risk cytogenetics group including complex karyotype.Methodology:-We retrospectively reviewed patients with MDS and AML who received Azacitidine at the Heart of England NHS Foundation Trust from April 2012- January 2018. Patient's demographic data, disease characteristics, treatment, outcome and follow up data were obtained and all patients were included irrespective of the number of the cycles.Results57 patients were included in the analysis. Median age of treatment was 73.9 years. Median number of cycles was 6 (range from 1 to 43). There were 68% of MDS patients, 22.8% of AML and 8.8% of CMML2 patients in the cohort .Varying degree of performance stage was noted including ECOG 0,1 and 2 at 40.4%,43.9% and 7.7% respectively. 9 patients had monosomy 7 and 11 patients had complex karyotype (3/>3). 42.1% had high risk cytogenetics.At presentation, median Hb was 9g/dl, Neutrophil count was 0.7x109/l and platelet count was 41x109/l. Median bone marrow blast percentage was10% and median RIPSS score was 6.5. Causes of death were mainly disease progression and sepsis. 42.2% died due to disease progression and 35.1% died due to sepsis.Overall survival was not affected by age, Bone marrow median blast percentage and median neutrophil count, however, survival was affected by presenting peripheral blast percentage, cytogenetic risk group and was statistically significant (P<0.05)Overall, median progression free survival (PFS) was 19monts while median overall survival (OS) was 12 months. There was no statistically significant PFS or OS difference for patients who had varying performance stage.High risk cytogenetics group:Among high risk cytogenetics group, 21% Patients had red cell transfusion independence at 6 months, 28% had an improvement in the neutrophil count to >1x10^9/L at 6 months. 25% patients had doubling of platelet count at 3 months leading to platelet independence and 17.8% maintained platelet transfusion independence. A significant difference was noted in the group of who had high risk cytogenetic versus other cytogenetic risks with PFS of 15 and 29 months respectively, OS of 8 months and 15 months respectively. with high risk cytogenetics still had a PFS advantage with treatment.ConclusionAzacidine therapy has benefited for the patients who had advanced age AML CMML and MDS who has non high risk cytogenetic based on IPSS-R risk categorization. However, the group of patients with high risk cytogenetic considered historically very poor survival had considerable PFS and OS benefitting treatment rather than best supportive care. DisclosuresMurthy:celgene: Consultancy, Other: Travel grant for educational meeting; Abbview: Other: Travel grant for Educational meeting. Kartsios:Bayer: Consultancy, Honoraria, Speakers Bureau; BMS: Consultancy, Honoraria, Speakers Bureau; Daiichi Sankyo: Consultancy, Honoraria, Speakers Bureau; Boehringer Inglelheim: Consultancy, Honoraria, Speakers Bureau. Nikolousis:Celgene: Consultancy, Other: Travel grant for educational meetings.

Role of Measurable Residual Disease (MRD) in Redefining Complete Response (CR) in Elderly Patients with Acute Myeloid Leukemia (AML): Results from the Pethema-Flugaza Phase III Clinical Trial

Background: Incidence of AML is highest among the elderly and the general outcome is poor as compared to young patients, even those who tolerate intensive induction chemotherapy and achieve morphological CR. However, the role of MRD in redefining CR in elderly AML remains poorly investigated due to the reluctance to treat them with intensive chemotherapy, the renewed interest in low-intensity therapy such as hypomethylating agents (HMA), and the lack of molecular MRD markers in most patients.Aim: To help defining the role of MRD assessment by multidimensional flow cytometry (MFC) and therapeutic decision making in older AML patients treated with semi-intensive chemotherapy vs HMA.Methods: A total of 285 AML patients (excluding APL) with a median age of 75 were included in the phase III PETHEMA-FLUGAZA clinical trial and were randomized to receive 3 induction cycles with fludarabine and cytarabine (FLUGA) followed by 6 consolidation cycles with reduced intensity FLUGA, vs 3 induction cycles with 5-azacitidine (AZA) followed by 6 consolidation cycles with AZA. After consolidation, patients continued with the same treatment if MRD ≥0.01% or stopped if MRD <0.01%. MRD was prospectively assessed after induction and consolidation among patients in CR with or without incomplete blood count recovery, in a central laboratory blinded for clinical outcomes. At diagnosis, the EuroFlow panel for MDS/AML (first-five 8-color combinations) was used to identify leukemia-associated immunophenotypes (LAIP). Patients without a LAIP (6%) were excluded from this analysis. At CR, bone marrow samples were immunophenotyped with ≥2 8-color combinations based on previously identified maturation arrest, lineage commitment and LAIPs, maintaining markers' position from diagnosis to MRD to provide a digital fingerprint of leukemic blasts at diagnosis during MRD assessment. Over 1 million events per tube were measured for assessing MRD with an estimated sensitivity of 0.01%. The cumulative incidence of relapse (CIR) was calculated from the date of CR to the date of relapse, considering death without relapse as a competing event.Results: On intention-to-treat, 38/141 (27%) patients achieved CR after 3 cycles of FLUGA, and 31/144 (21.5%) after 3 cycles of AZA (P =.33). Among patients in CR with previously identified LAIP, 14/69 (20%) achieved a negative MRD status whereas the remaining 55 (80%) had persisting MRD: 56% with ≥0.1% MRD and 24% with 0.01%-0.09% MRD. Of note, negative MRD rates were particularly lower among AML patients with myelodysplasia-related changes as compared to other subtypes (11% vs 27%, respectively; P=.09). Regarding the effect of semi-intensive chemotherapy vs HMA on depth of response, we observed a non-significant trend toward higher MRD-negative rates among patients in CR after FLUGA vs those treated with AZA (26% vs 15%, respectively; P=.28).The 2-year CIR rates for MRD-positive and MRD-negative patients were 88% and 47%, respectively (HR, 3.3; P =.001). Of note, the CIR of patients in CR but with persistent MRD were similarly poor as compared to those in partial remission (HR, 0.82; P =.48). Furthermore, MRD-positive patients with adverse cytogenetics displayed the poorest outcome with significantly higher 2-year CIR rates than MRD-positive cases with intermediate/favorable cytogenetics (HR, 2.1; P =.008). Interestingly, among patients in CR and persistent MRD, 2-year CIR rates showed a non-significant trend towards slightly more frequent relapses in those treated with FLUGA vs AZA (91% vs 77%, respectively; HR, 1.7; P =.09). On multivariable analysis for CIR including MFC-MRD and cytogenetics, MFC-MRD (HR, 3.6; P =.001) and cytogenetics (HR, 2.0; P =.007) retained significant prognostic value. The median overall survival (OS) for MRD-positive and MRD-negative patients was 17 and 29 months, respectively (P =.04). On multivariable analyses for OS including age, WBC count, cytogenetic grouping and secondary disease, persistent MRD showed a trend for independent prognostic value (HR, 2.4; P =.07).Conclusions: This study reveals that sensitive MFC-MRD assessment supersedes CR and is an independent prognostic factor in older patients with AML, treated with semi-intensive chemotherapy or HMA. Nevertheless, the risk of relapse among the few patients with no MRD (5%) remains high after stopping treatment, and warrants innovative approaches aimed at maintaining an MRD-negative CR status. DisclosuresSan-Miguel:Janssen: Honoraria; BMS: Honoraria; Novartis: Honoraria; Celgene: Honoraria; Amgen: Honoraria; Sanofi: Honoraria; Roche: Honoraria. Montesinos:Novartis: Research Funding, Speakers Bureau; Daiichi Sankyo: Consultancy, Speakers Bureau.

Survival after Hematopoietic Stem Cell Transplantation in an Older, Fit Cohort of Patients with Advanced Myelodysplastic Syndromes: The MDS-TAO Study

Background: The utility of reduced-intensity conditioning hematopoietic stem cell transplantation (RIC HSCT) for fit elderly patients with advanced myelodysplastic syndromes (MDS) is unclear.Methods: The MDS Transplant-Associated Outcomes Study, or “MDS-TAO,” was a prospective longitudinal observational study at the Dana-Farber/Harvard Cancer Center designed to examine survival, quality of life, and other outcomes for RIC HSCT versus non-HSCT approaches for HSCT-eligible patients with advanced MDS ages 60 to 75. All patients who met eligibility criteria were approached in the leukemia or HSCT clinics; 96% agreed to enroll. Inclusion criteria included histologically-confirmed diagnosis of MDS or CMML, and (1) therapy-related disease or (2) Int-2/high IPSS (Greenberg, Blood, 1997), or (3) non-IPSS poor-risk cytogenetics (Haase, Blood, 2007), or (4) severe cytopenia/platelet or red cell transfusion-dependence. Exclusions were (1) comorbidities that in the judgment of the treating physician precluded HSCT eligibility (2) prior donor search and (3) patient unwillingness to consider HSCT. Considering time to transplant as a time-dependent variable, hazard ratio for ultimate HSCT was estimated using Cox regression analysis controlling for age, gender, ECOG performance status, IPSS, IPSS cytogenetic risk group, and year of consent. Landmark analyses at 5 months were conducted to present estimates of overall survival for patients who were alive for at least 5 months and received HSCT versus patients who did not (landmark cohort). Subgroup analyses (e.g., molecular characteristics) are also ongoing.Results: 290 patients were enrolled between May 2011 and May 2018; 24 had less than 1.5 months of follow up after consent and were excluded from this analysis. Of the remaining 266 patients, 143 were deceased at last follow up. Baseline characteristics are presented in the table. The median follow-up time among survivors was 31 months (range 1.9, 84). 102 patients received HSCT, of whom 45 subsequently died; of the 164 patients who have not undergone HSCT, 98 have died. The median time to HSCT among those transplanted (n=102) was 4.6 months. The median follow-up for patients alive and not yet transplanted (n=66) was 24 months (range 1.9, 82). Considering time to HSCT as a time-dependent variable (n=266), the hazard ratio for death in multivariable analysis was 0.63 (95% CI 0.42-0.96, p=0.03). Poor risk IPSS cytogenetic group was the only other factor associated with mortality, HR=1.86 (95% CI 1.15-3.00, p=0.006); age, gender, ECOG performance status, IPSS, and consent year were not. Five months was chosen for the landmark analysis given it was closest to the median time to HSCT. In the landmark cohort (N=229), HSCT patients were more likely to have Int-2/high IPSS at baseline (65% vs 35% for none, p=0.0003). No other baseline characteristics were different. Figure A shows Kaplan-Meier plots for the landmark cohort, comparing 54 who received HSCT ≤ 5 months versus 175 patients who did not receive a transplant within 5 months (log rank p=0.04). Figure B shows Kaplan-Meier plots for HSCT comparing 99 patients who received HSCT at any time during follow-up versus 130 patients who did not (log rank p=0.005).Conclusion: In this large cohort of fit elderly patients with advanced MDS, a treatment strategy that included HSCT was associated with better overall survival. DisclosuresHo:Jazz Pharmaceuticals: Consultancy. DeAngelo:Incyte: Consultancy, Honoraria; Glycomimetics: Research Funding; Amgen: Consultancy; ARIAD: Consultancy, Research Funding; Blueprint Medicines: Honoraria, Research Funding; Amgen: Consultancy; Shire: Honoraria; Takeda: Honoraria; BMS: Consultancy; Blueprint Medicines: Honoraria, Research Funding; Incyte: Consultancy, Honoraria; Glycomimetics: Research Funding; ARIAD: Consultancy, Research Funding; Pfizer Inc: Consultancy, Honoraria; Novartis Pharmaceuticals Corporation: Consultancy, Honoraria; BMS: Consultancy. Antin:Jazz Pharmaceuticals: Membership on an entity's Board of Directors or advisory committees. Soiffer:Jazz Pharmaceuticals: Membership on an entity's Board of Directors or advisory committees.

Clinical Significance and Transcriptional Profiling of Persistent Minimal Residual Disease (MRD) in Multiple Myeloma (MM) Patients with Standard-Risk (SR) and High-Risk (HR) Cytogenetics

Clinical Significance and Transcriptional Profiling of Persistent Minimal Residual Disease (MRD) in Multiple Myeloma (MM) Patients with Standard-Risk (SR) and High-Risk (HR) Cytogenetics

High Dose Mitoxantrone Based “5+1” Induction Chemotherapy Regimen in Newly Diagnosed Acute Myeloid Leukemia

IntroductionIn acute myeloid leukemia (AML), dose intensification of “7+3” has not produced improved outcomes. At our center, we evaluated an intensive “5+1” regimen of high dose mitoxantrone (HDM) with high dose cytarabine (HiDAC) in all newly diagnosed AML patients. We present here our experience of this regimen at our institution.Patients and MethodsThe treatment regimen included bolus HiDAC at 3000 mg/m2 over three hours on days 1 to 5 and HDM 80 mg/m2 once on the second day immediately after the completion of cytarabine infusion. A total of 101 consecutive patients were treated from January 2009 to March 2013 with this regimen. There were twelve exceptions to the regimen dosages, where patients received a lower dose of 60 mg/m2 of mitoxantrone due to their significant comorbidities. The mean doses of mitoxantrone and Cytarabine administered for the whole cohort was 76 mg/m2 and 2844 mg/m2/day respectively. Patients who achieved CR were further consolidated by HiDAC chemotherapy cycles (1-4) and/or hypomethylating agent q28 day cycles. Patients with intermediate/adverse risk group were evaluated and considered for allogeneic transplant. Survival rates were calculated by the Kaplan-Meier method.ResultsThe median age was 65 years (range 18-90). The total number of patients in the age group <60, 60-69 and ≥70 were 30(29.7%), 35(34.6%) and 36(35.6%) respectively. Patients in favorable, intermediate and adverse cytogenetics group as per European Leukemia Net(ELN)-AML 2017 criteria were 16(15.8%), 40(39.6%) and 41(40.5%) respectively. 33 patients had secondary AML (therapy-related AML, AML with antecedent MDS or CMML, or de novo AML with MDS related cytogenetics abnormalities). The overall complete response (CR) was 76.2% (77/101). 22% (23/101) were either primary refractory or had partial responses. The CR rates in patients <60, 60-69 and ≥70 age groups were similar at 80% (24/30), 74.2% (26/35) and 77.1% (27/35) respectively. The de-novo AML patients had higher CR 83.5%(56/67) compared to secondary AML 63.6%(21/33), p=0.04. The 4 and 8-week mortality in our cohort was 3/101 (2.9%) and 7/99 (7%) respectively. Median follow-up among survivors was 62 months (range 1-109 months). The median overall survival (OS) stratified by age group < 60, 60-69 and >=70 years were 56, 31 and 9 months respectively (log-rank, p=0.02). The median overall survival in patients with secondary AML was 9 months versus 43 months in de-novo AML patients. Sixty patients underwent transplant during consolidation, 47 (46.5%) were allogeneic and 13 (12.8%) autologous. 51.7% (45/84) of patients with intermediate/adverse cytogenetic risk groups as per ENL/AML criteria proceeded to allogeneic transplants. Among these 84 patients, the percentage of patients able to proceed to transplant in age groups <60, 60-69 and ≥70 years were 75% (18/24), 60.7 % (17/28) and 31.2% (10/32) respectively.ConclusionIn conclusion, HDM based chemotherapy regimen produces high CR rates, is well tolerated and more patients can undergo curative post-remission therapy including stem cell transplant. Together with the low number of toxic deaths this induction regimen warrants further investigation. [Display omitted] DisclosuresRaffel:Magenta Therapeutics: Employment, Equity Ownership.

A Precision Medicine Heirarchical Classification Developed Using Variant Allele Frequency (VAF) for Treatment of Older Patients (Pts) with Acute Myeloid Leukemia (AML): Alliance Clinical Trials in Oncology (Alliance) Historical Patient Control

A Precision Medicine Heirarchical Classification Developed Using Variant Allele Frequency (VAF) for Treatment of Older Patients (Pts) with Acute Myeloid Leukemia (AML): Alliance Clinical Trials in Oncology (Alliance) Historical Patient Control

Genetic Characterization of B-Cell Prolymphocytic Leukemia (B-PLL): A Hierarchical Prognostic Model Involving MYC and TP53 Abnormalities. on Behalf of the Groupe Francophone De Cytogenetique Hematologique (GFCH) and the French Innovative Leukemia Organization (FILO) Group

B-PLL is defined by the presence of prolymphocytes in peripheral blood exceeding 55% of lymphoid cells. The diagnosis, mainly based on clinical and morphological data, can be difficult because of overlap with other B-cell malignancies. Because of the rarity of the disease, only case reports and small series describe its cytogenetic features. Few prognostic markers have been identified in this aggressive leukemia usually resistant to standard chemo-immuno therapy. We report here the cytogenetic and molecular findings in a large series of B-PLL. We also studied the in vitro response to novel targeted drugs on primary B-PLL cells.The study included 34 cases with a diagnosis of B-PLL validated by morphological review performed by three independent expert cytologists. The diagnosis of mantle cell lymphoma was excluded by karyotype (K) and FISH using CCND1, CCND2 and CCND3 probes. Median age at diagnosis was 72 years [46-88]. K was complex (≥3 abnormalities) in 73%, and highly complex (HCK≥5) in 45%. Combining K and FISH data, the most frequent chromosomal aberrations were: translocation targeting the MYC gene [t(MYC)] (21/34, 62%), 17p deletion including TP53 gene (13/34, 38%), trisomy 18/18q (10/33, 30%), 13q14 deletion (10/34, 29%), trisomy 3 (8/33, 24%), trisomy 12 (8/34, 24%) and 8p deletion (7/31, 23%). Whole-Exome Sequencing analysis of paired tumor-control DNA was performed in 16 patients. The most frequently mutated genes were TP53(6/16, 38%), associated with del17p in all, MYD88 (n=4), BCOR (n=4), MYC (n=3), SF3B1 (n=3), FAT1 (n=3), SETD2 (n=2), CHD2 (n=2), CXCR4 (n=2), BCLAF1 (n=2) and NFASC (n=2). Distribution of the chromosomal aberrations is shown in Fig 1. The main group of patients (21/34, 62%) had a t(MYC) that was associated with a higher % of prolymphocytes (86 vs 76, p=0.03), CD38 expression (90% vs 15%,p<0.001), and a lower K complexity (HCK≥5 : 20% vs 85%, p=0.0004). Mutations in MYC and in genes involved in RNA metabolism and chromatin remodeling were almost exclusively observed with t(MYC). Principal component analysis of gene expression data in 12 cases analyzed by RNA-Seq showed that the 7 patients with t(MYC) clustered together. These results suggest that t(MYC) form a homogeneous subgroup of B-PLL. A second group with MYC gain (5/34, 15%), was associated with HCK≥5 (100% vs 36%, p=0,01) and trisomy 3 (80% vs 14%, p=0,008). Altogether, 26/34 patients (76%) had a MYC activation, translocation or gain, that were mutually exclusive.The median overall survival (OS) for the entire cohort was 126 months with a median follow-up time of 47 months [ 0.2-141]. We found MYC activation (translocation or gain) to be associated with a shorter OS (p=0.03). Regarding MYC and del17p, we identified 3 distinct cytogenetic prognostic groups, with significant differences in OS (p=0.0006) (Fig 2). The patients without MYC activation had the lower risk (n=8, median not reached). Patients with a MYC activation without del17p had an intermediate risk (n=18, 125 months). The highest risk group corresponded to patients with both MYC and TP53 aberrations (n=7, 11 months).We performed drug response profiling on primary B-PLL cells using the ATP-based CellTiter Glo kit (Promega) (n=5). We observed that after 48h of exposure to increased doses, response was heterogeneous, with a majority of samples resistant to fludarabine (n=3), ibrutinib (n=3), idelalisib (n=4), venetoclax (n=3) and OTX015 (n=4). Annexin/PI assays using flow cytometry showed that the induced cell death could be increased by combination of ibrutinib or venetoclax with OTX015 or JQ1, two BET protein inhibitors that target MYC signaling (n=1/2).In summary, B-PLL have complex and highly complex K, a high frequency of MYC activation by translocation or gain, frequent 17p deletion, and frequent mutations in MYC, TP53, BCOR, and MYD88 genes. We identified 3 prognostic subgroups according to MYC and 17p status. Patients with MYC activation + 17p deletion have the shorter OS, and should be considered as a high-risk “double-hit” subgroup. Our results show that cytogenetic analysis is a useful diagnostic tool in B-PLL that improves prognostic stratification. We recommend to perform K and FISH (MYC and TP53) analyses systematically when a B-PLL is suspected. Our in vitro data suggest that drugs targeting the BCR and BCL2 in combination with MYC inhibition may be a therapeutic option in some patients. DisclosuresBaseggio:Takeda Oncology: Honoraria.

Chemotherapy Treatment Doesn't Beneficiate to a Group of Elderly AML Patients with Absence of Complex Karyotype and Circulating Blasts

IntroductionAlthough the median age at diagnosis of acute myeloid leukemia (AML) is 67 years, with approximately one third of patients aged 75 years or older, limited treatment options are available for the elderly. There is no standard of care for older patients with AML unfit for intensive chemotherapy. In this case, despite specific treatment such as low-dose cytarabine (LDA) and 5 azacytidine (5AZA), outcome remains extremely poor, without cure (Thomas X, Current Treat Options Oncol 2017, 18(1):2). The goal of our study is to establish a prognostic model of survival in order to identify whether the absence of specific treatment may not be harmful in a subset of patients.Patients and MethodsThe French Hauts-de-France AML observatory is a population-based database reporting AML cases diagnosed and supported in 9 Hospital Centers from the French region Haut-de-France. From January 2008 to December 2016, 572 patients older than 75 years were included in the observatory. Among them 324 patients received best supportive care (BSC) alone, 142 hypomethylating agents, 82 low doses aracytine, and 24 other treatments. As a general consensus accepted in all participating centers, BSC was proposed in unfit patients, after performance status and comprehensive geriatric assessment according to results of a preliminary fast geriatric assessment oncodage G8 (Bellera CA, Ann Oncol 2012, 23(8):2166-72). Clinical data were collected in each center. The study was conducted according to the Declaration of Helsinki and was approved by the Human Research Committee of Lille and the internal review board of the Lille University Hospital Tumor Bank (certification NF 96900-2014/65453-1).ResultsIn the BSC group, median age at diagnosis was 82 years (interquartile range [IQR] 78-86). Median WBC count was 7.3 x10^3/mL (IQR 2.18-42.5) with a median peripheral blood blasts percentage of 21% (IQR 6-59.5). Median bone marrow blasts was 51% (IQR 30-75). Karyotype was available for 181 patients. Two patients were in the favorable, 111 patients (61%) were in the intermediate, 68 patients (38%) were in the unfavorable cytogenetics group and 58 patients (32%) had a complex karyotype.For the BSC group, median survival was 3.2 months (IC 2.3- 4) with a 18% 12-months survival estimate.In univariate Cox models, WBC count (p<0.0001), circulating blasts percentage (P=0.0001), bone marrow blasts percentage (P=0.0001) and complex karyotype (p= 0.05) were predictive of a shorter survival. Neither age nor unfavorable karyotype retained prognostic value.Multivariate analysis selected two independent covariates namely circulating blasts percentage without identifiable cutoff (p=0.0002), and complex karyotype (p=0.05). Prediction of risk according to this proportional hazard model showed that patients at lowest risk could be defined by the absence of both complex karyotype and circulating blasts. The survival of this subgroup of unfit patients who received BSC (7% of patients, median 16 months) was not significantly different from the survival of fit patients with the same characteristics (absence of both complex karyotype and circulating blast) who received 5AZA or LDA (median survival of 26.6 months, p=0.07) (Figure 1.).Remaining patients (with complex karyotype or circulating blast), of the BSC cohort had a shorter survival than patients treated with 5AZA or LDA (3.7 months vs 13 months, p<0.0001).ConclusionIn a population of elderly AML patients (> 75 years), 18% are alive at 12 months without any chemotherapy. Our results indicate that the absence of chemotherapy may not be detrimental in a small subset of unfit patients identified by the absence of both complex karyotype and circulating blasts. However further studies are mandatory for characterizing most of patients alive at 12 months with BSC.Figure 1. Survival of patients with both complex karyotype and circulating blasts [Display omitted] DisclosuresNo relevant conflicts of interest to declare.

The VLA-4 Integrin Is Constitutively Activated in a Subset of CD49d-Expressing CLL: A Relationship with the Autonomous BCR-Mediated Signaling?

Introduction. In chronic lymphocytic leukemia (CLL), CD49d, the alpha chain of the heterodimer CD49d/CD29 (VLA-4), is a strong negative prognosticator, and a key player of tumor cell-microenvironment interactions. The adhesive properties of VLA-4 can be rapidly inside-out activated by signals through the B-cell receptor (BCR), thus favoring the capability of the integrin to interact with its specific ligands. In this context, VLA-4 needs to be maintained in an activated state by a continuous stream of inside-out signals from the BCR, which can be triggered by canonical antigens as well as in an autonomous antigen-independent manner, a BCR-mediated signaling recently emphasized to specifically occur in CLL cells.Aim. To investigate the constitutive VLA-4 activation state in CLL cells and to connect this still not described feature with the presence of signals from the BCR continuously activating VLA-4.Methods. Expression of the integrin alpha (CD49c, CD49d, CD49e) and beta1 (CD29) chains was analyzed by flow cytometry. The VLA-4 activation state was investigated by flow cytometry using the conformational sensitive anti-CD29 monoclonal antibody HUTS21, employed in conjunction with sources of VLA-4 ligands: either autologous plasma-containing fibronectin (FN) and soluble (s) VCAM-1 or increasing concentrations of exogenously added LDV-containing peptides as a VLA-4 specific ligand. In detail: i) HUTS21 expression was analyzed using whole blood (WB) samples from 727 CLL patients. Negative controls were obtained after plasma depletion through washing of WB samples; ii) the VLA-4 activation state expressed as receptor occupancy (RO) (J Biol Chem, 284,14337, 2009) was analyzed in sequential (t=0, day14, day 30) frozen/thawed samples from CLL patients treated in vivo with ibrutinib (IB) in real-world (n=16) and from a clinical trial (NCT02827617, n=14). BCR engagement was performed using goat F(ab′)2 anti-human IgM. ELISA assays were used to quantify FN and sVCAM-1 in plasma samples.Results. According to the 30% cutoff, CD49d was expressed in 351/727 (48%), while CD29 was expressed in 676/727 (93%), and a strong correlation between CD49d and CD29 was observed (rho=0.7, p<0.0001). Among CD49d positive CLL cases, 81/351 (23%) expressed a constitutively activated form of VLA-4 identified by >20% (arbitrary cut-off) HUTS21 expression. Notably, HUTS21 positive expression was not circumscribed to VLA-4 expressing CLL, being also detected in 64/375 (17%) CD49d-, CD49c+ and/or CD49e+ CLL, thus envisioning a role of other integrins (CD49c and CD49e) in CLL cell interactions in tissues sites. HUTS21 expression did not correlate with a definite cytogenetic group, IGHV mutational status or with a specific IGHV family and stereotype. Depletion of the plasma component from the WB samples before HUTS21 staining significantly reduced the proportion of HUTS21 positive cells compared with those measured in WB samples (p=0.001, n=11), suggesting the need of plasma-borne ligands for HUTS21 epitope exposure. Consistently, both FN (mean 350 μg/ml) and sVCAM-1 (mean 4.8 μg/ml) were detected in the plasma of CLL cases, irrespective to HUTS21 positivity. According to these observations, variable constitutive VLA-4 activation states were observed in CLL cells collected at the pre-treatment stage from patients undergoing IB treatment (VLA-4 RO ranging from 0.22 to 0.40); these values significantly decreased in CLL cells collected at day 14 (p=0.03) and day 30 (p=0.02) on IB, suggesting an IB-dependent impairment of antigen-independent (autonomous) BCR signals. The variability of the constitutive VLA-4 activation levels observed at pre-treatment was paralleled by variable VLA-4 activation levels upon BCR triggering (VLA-4 RO ranging from 0.56 to 0.65). Of note, an inverse correlation between the VLA-4 constitutive level and the extent of anti-IgM induced-VLA-4 activation was found (n=19, rho=-0.5, p=0.0093), implying a competition between antigen-independent and antigen-driven BCR signalling.Conclusion. The presence of a constitutively activated form of VLA-4 is observed in a subset of CLL which might be connected to continuous VLA-4 inside-out stimulation derived from an autonomous BCR signaling, which is currently under evaluation. DisclosuresZaja:Takeda: Honoraria; Sandoz: Honoraria; Amgen: Honoraria; Novartis: Honoraria, Research Funding; Celgene: Honoraria, Research Funding; Janssen: Honoraria; Abbvie: Honoraria.

Focal Adhesion Genes Refine the Intermediate-Risk Cytogenetic Classification of Acute Myeloid Leukemia.

In recent years, several attempts have been made to identify novel prognostic markers in patients with intermediate-risk acute myeloid leukemia (IR-AML), to implement risk-adapted strategies. The non-receptor tyrosine kinases are proteins involved in regulation of cell growth, adhesion, migration and apoptosis. They associate with metastatic dissemination in solid tumors and poor prognosis. However, their role in haematological malignancies has been scarcely studied. We hypothesized that PTK2/FAK, PTK2B/PYK2, LYN or SRC could be new prognostic markers in IR-AML. We assessed PTK2, PTK2B, LYN and SRC gene expression in a cohort of 324 patients, adults up to the age of 70, classified in the IR-AML cytogenetic group. Univariate and multivariate analyses showed that PTK2B, LYN and PTK2 gene expression are independent prognostic factors in IR-AML patients. PTK2B and LYN identify a patient subgroup with good prognosis within the cohort with non-favorable FLT3/NPM1 combined mutations. In contrast, PTK2 identifies a patient subgroup with poor prognosis within the worst prognosis cohort who display non-favorable FLT3/NPM1 combined mutations and underexpression of PTK2B or LYN. The combined use of these markers can refine the highly heterogeneous intermediate-risk subgroup of AML patients, and allow the development of risk-adapted post-remission chemotherapy protocols to improve their response to treatment.

Improved cytogenetic characterization and risk stratification of pediatric acute lymphoblastic leukemia using single nucleotide polymorphism array analysis: A single center experience of 296 cases.

Single nucleotide polymorphism array (SNP-A) analyses are increasingly being introduced in routine genetic diagnostics of acute lymphoblastic leukemia (ALL). Despite this, only few studies that have compared the diagnostic value of SNP-A with conventional chromosome banding have been published. We here report such a comparison of 296 ALL cases, the largest series to date. Only genomic imbalances >5 Mb and microdeletions targeting the BTG1, CDKN2A/B, EBF1, ERG, ETV6, IKZF1, PAX5, and RB1 genes and the pseudoautosomal region 1 (PAR1) were ascertained, in agreement with recent guidelines. Of 36 T-cell ALL cases, the karyotypes of 24 cases (67%) were revised by SNP-A analyses that either revealed additional imbalances >5 Mb or better characterized the changes found by G-banding. Of 260 B-cell precursor (BCP) ALL cases, SNP-A analyses identified additional copy number alterations, including the above-mentioned microdeletions, or better characterized the imbalances found by G-banding in 236 (91%) cases. Furthermore, the cytogenetic subtype classification of 41/260 (16%) BCP ALL cases was revised based on the SNP-A findings. Of the subtype revisions, 12/41 (29%) had clinical implications as regards risk stratifying cytogenetic groups or genotype-specific minimal residual disease stratification. We conclude that SNP-A analyses dramatically improve the cytogenetic characterization of both T-cell and BCP ALL and also provide important information pertinent to risk stratification of BCP ALL.

Wilms Tumor 1 Expression at Diagnosis Correlates With Genetic Abnormalities and Polymorphism But Is Not Independently Prognostic in Acute Myelogenous Leukemia: A Hokkaido Leukemia Net Study

BackgroundThe prognostic effect of Wilms tumor 1 (WT1) expression at the diagnosis of acute myelogenous leukemia (AML) has been controversial. The aim of the present study was to determine the correlations of WT1 expression at the diagnosis of AML with established prognostic alterations. Patients and MethodsWe analyzed diagnostic bone marrow samples from 252 patients. WT1 expression, single nucleotide polymorphism (SNP) in the WT1 gene (rs16754), and Fms-like tyrosine kinase receptor-3 internal tandem duplication (FLT3-ITD) mutation were analyzed for all patients. The nucleophosmin 1 (NPM1) mutation and CCAAT/enhancer-binding protein-α (CEBPA) double mutation were analyzed for cytogenetically normal (CN)-AML. The KIT mutation was analyzed for core-binding factor AML. ResultsWithin the cytogenetically favorable prognosis group, WT1 expression in AML with inv(16) or t(15;17) was significantly greater than that in AML with t(8;21). In cases with CN-AML, FLT3-ITD and NPM1 mutations both correlated with greater expression of WT1, and the CEBPA double mutation was related to lower WT1 expression. The existence of both FLT3-ITD and NPM1 mutations showed synergistically greater expression of WT1 in CN-AML. SNP in the WT1 gene (rs16754) was significantly associated with lower expression of WT1. The WT1 levels were not prognostic factors in the total cohort or any cytogenetic group or stratified by SNP status. ConclusionBecause WT1 expression has correlated with known prognostic factors, the prognostic effect of WT1 levels could be misunderstood depending on the distribution of the collaborative mutations in each cohort. We have concluded that the prognostic significance of WT1 at the diagnosis of AML is weak compared with the other established prognostic factors.

Usefulness of BCOR gene mutation as a prognostic factor in acute myeloid leukemia with intermediate cytogenetic prognosis

BCOR gene is a transcription regulatory factor that plays an essential role in normal hematopoiesis. The wider introduction of next-generation sequencing technology has led to reports in recent years of mutations in the BCOR gene in acute myeloid leukemia (AML), but the related clinical characteristics and prognosis are not sufficiently understood. We investigated the clinical characteristics and prognosis of 377 de novo AML cases with BCOR or BCORL1 mutation. BCOR or BCORL1 gene mutations were found in 28 cases (7.4%). Among cases aged 65 years or below that were also FLT3-ITD-negative and in the intermediate cytogenetic prognosis group, BCOR or BCORL1 gene mutations were observed in 11% of cases (12 of 111 cases), and this group had significantly lower 5-year overall survival (OS) (13.6% vs. 55.0%, P = 0.0021) and relapse-free survival (RFS) (14.3% vs. 44.5%, P = 0.0168) compared to cases without BCOR or BCORL1 gene mutations. Multivariate analysis demonstrated that BCOR mutations were an independent unfavorable prognostic factor (P = 0.0038, P = 0.0463) for both OS and RFS. In cases of AML that are FLT3-ITD-negative, aged 65 years or below, and in the intermediate cytogenetic prognosis group, which are considered to have relatively favorable prognosis, BCOR gene mutations appear to be an important prognostic factor.

The impact of clonal size on the revised international prognostic scoring system (R-IPSS) in myelodysplastic syndromes (MDS) with a single cytogenetic abnormality.

7068 Background: Cytogenetics is the backbone of the R-IPSS for MDS, contributing the most points (0 to 4) to the total scoring system. The current R-IPSS cytogenetics does not factor in the clone size or the number of abnormal metaphases. The International System for Human Cytogenetic Nomenclature (ISCN) in 2016 defined the clone by the presence of a structural rearrangement in at least 2 metaphases or 3 metaphases in case of monosomies. Methods: This is a retrospective study from the Mayo Clinic records for patients with confirmed MDS by a hematopathology review. Analysis included patients with adequate karyotyping of 20 metaphases only. Patients were divided into 3 groups (grp) based on their R-IPSS cytogenetics category (Intermediate, Poor and Very Poor). Patients with a single abnormal clone only were included. The size of the abnormal clone was calculated by dividing the number of abnormal metaphases by 20. The overall survival (OS) of each R-IPSS grp with different clonal percentage was compared to the diploid cytogenetics (DC) group. The Good and Very good R-IPSS cytogenetics were excluded. Survival estimates were calculated by Kaplan-Meier curves and log-rank testing using JMP v.13. Results: Of 1301 patients, 36.5% (n = 475) had a DC, 49% (n = 637) had an abnormal karyotype and 15% (n = 189) had no available cytogenetic results. Of those with abnormal karyotype, 58% (n = 372) had a single clone. Of those with a single clone, 70% (n = 260) had a single chromosomal abnormality. The OS of the 3 groups was statistically different and consistent with their R-IPSS score. OS was higher in the DC group (OS = 54 months, n = 474) compared to the Intermediate (OS = 30.5 months, n = 121), Poor (OS = 21.1 months, n = 49), and Very poor (OS = 8.7 months, n = 75), p < 0.005 for all grps. The clone size had no impact on overall survival above 5% when combining the 3 grps, the lowest threshold to make statistical conclusions was 10% (p = 0.01). Conclusions: The clonal percentage of any abnormality detected by conventional karyotype did not affect OS in patients with MDS that have an R-IPSS risk of intermediate or above. Therefore, any chromosomal abnormality should be included in the R-IPSS cytogenetics.

FLT3 receptor/CD135 expression by flow cytometry in acute myeloid leukemia: Relation to FLT3 gene mutations and mRNA transcripts

BackgroundAlterations of the FLT3 gene are the most frequent molecular aberrations seen at diagnosis of acute myeloid leukemia (AML). Two main types of FLT3 mutations have been the most commonly detected; internal tandem duplication (ITD) in the juxtamembrane domain and point mutation D835Y in the tyrosine kinase domain (TKD). Both classes of mutations result in constitutive activation of FLT3 receptor/CD135. AimTo assess the frequency of FLT3 gene mutations (ITD and TKD D835Y) and the flow cytometric expression of FLT3 receptor/CD135 among AML patients to define the role for FLT3 receptor expression in predicting FLT3 gene mutational status and mRNA transcript level. Subjects and methodsEighty AML patients at diagnosis and 20 control subjects were enrolled. FLT3 receptor/CD135 expression, FLT3 gene mutations, and FLT3 transcript level were evaluated by flow cytometry, conventional polymerase chain reaction (PCR), and quantitative real-time reverse-transcription PCR, respectively. Fluorescence in situ hybridization was done to stratify patients into favorable, intermediate, and poor cytogenetic risk groups. ResultsFLT3-ITD was detected in 22.5% AML patients, while none had FLT3-TKD D835Y mutation. A cut-off value of >17% was assigned to define FLT3 receptor/CD135+ cases. FLT3 receptor/CD135 and FLT3 transcripts were overexpressed in 100% AML patients; higher levels were found among AML-M5 subtype and poor cytogenetic group. AML patients harboring FLT3-ITD showed a trend for higher FLT3 receptor/CD135 expression and FLT3 transcript level than those with wild-type FLT3. FLT3 receptor/CD135 >49% was predictive for FLT3-ITD. A positive correlation was found between FLT3 receptor/CD135 expression and FLT3 transcript level. ConclusionEvaluation of FLT3 receptor/CD135 expression by flow cytometry at diagnosis of AML could constitute a predictor for the FLT3-ITD mutational status and FLT3 transcript level.