Acute Promyelocytic Leukemia Group Research Articles

Human Leukocyte Antigen-DR and Cluster Designation 34: Double-negative Acute Myeloid Leukemias – Our Experience in Clinical Setting

Abstract Introduction: Dual negativity for cluster designation (CD) 34 and human leukocyte antigen (HLA)-DR antigen in leukemia panel is an important finding in clinical practice. The combination of this finding though seen classically in acute promyelocytic leukemia (APL) is not specific to it but can be seen in many other myeloid leukemias like the ones associated with nucleophosmin 1 (NPM1) or FMS-related tyrosine kinase 3 gene-internal tandem duplication (FLT3-ITD) abnormalities. It is important to identify APL from non-APL leukemia as treatment and prognosis vary. Aims and Objectives: We analyzed CD 34 and HLA-DR dual-negative acute myeloid leukemia (AML) cases presented to us over 2.5 years (26 cases) and segregated them into APL and non-APL groups to study their morphological/flow cytometric and cytogenetic profile and correlation with treatment response. Materials and Methods: It was a prospective study including all newly diagnosed AMLs showing CD 34 and HLA-DR dual negativity in flow cytometry profile. Cases in which complete information/cytogenetics/molecular profile were not available, were excluded from the study. The patients were followed up till the end of induction to look for morphological response to induction therapy. The clinical and treatment records were pulled out from the patient database after ethical committee clearance. Results: A total of 139 new AML cases were encountered during the study period out of which 28 (20%) were found to be dual negative for CD34 and HLA-DR. The non-APL group showed higher mean age, TLC at baseline, variable morphology, and more number of aberrant expression on flow cytometry profile. No significant difference was noted in terms of gender, presence of hepatosplenomegaly, DIC as complication, or percentage of blasts/blasts equivalent at baseline. Our study found that while all APL patients had PML-RARA, the associated molecular abnormalities were much lesser as compared to the non-APL group which showed a variety of abnormalities such as NPM1, FLT3, RAS mutation, and mutations involving epigenetic modifiers. The response rate to induction therapy was significantly lower in the non-APL group as compared to the APL group. Conclusion: The non-APL myeloid leukemia which is dual negative is commonly found to be associated with cup-shaped morphology, NPM, or FLT3-ITD mutation along with other abnormalities. These patients were older in age, showed higher TLC and higher blast counts, associated with poorer response to induction therapy as compared to the APL group.

Outcomes of Acute Myeloid Leukemia (AML) in Adolescents and Young Adults (AYAs) Compared to Adults in a Referral Center from Lower Myanmar

Introduction Acute myeloid leukemia (AML) is the second most common form of haematological malignancies with high prevalence among all age groups in Myanmar. However, there are very limited data particularly related to AML in adolescents and young adults (AYAs). To fill the gap in AML data from resource-constraint countries and to compare the treatment outcomes of AYAs (15-39 years) with adults (40 years and above), a hospital-based, prospective study was conducted between January 2019 to October 2021, on the cases of AML treated at the North Okkalapa General and Teaching Hospital, one of three referral centers of Myanmar. Methods All cases of AML other than acute promyelocytic leukemia (APL) received two courses of induction containing daunorubicin and cytarabine followed by three courses of consolidation with high dose cytarabine. Treatment of APL included differentiation agents (all-trans-retinoeic acid and arsenic trioxide) based induction with addition of daunorubicin and cytarabine in high-risk cases until remission followed by chemotherapy free consolidation and maintenance up to two years. Patients were followed up for a minimum of one year and overall survival (OS) was calculated using the Kaplan-Meier method. Results A total of 140 including 81 (57.9%) AYAs and 59 (42.1%) adults with newly diagnosed de-novo AML were treated during 34-months period. Median age of AYA AML was 22 years (range-13-39 years) whereas that of adult AML was 54 years (range-40-76 years). There was no gender difference (49.2% versus 50.7%, for male and female). Among AML subtypes, M4 was the commonest subtype (28.5%) and APL, M3 (22.8%) was the second most prevalent AML followed by M2 (18.5%) and M5 (10.7%) subtypes. Cytogenetic data was available in 37 of 108 (34.2 %) non-APL cases with 16.2 %, 67.6% and 16.2 % respectively had good, intermediate, and high-risk cytogenetics. Of 108 non-APL including 61 (56.5%) AYAs and 47 (43.5%) adults, 46 (42.6%) died within one week or during induction and remaining 62 (57.4%) achieved remission at the end of induction. Among 32 APL (20 AYAs and 12 adults), mortality rate was 21.9% due to early death (12.5%) and induction death (9.4%) with only 78% achieved remission after induction. There was no statistically significant difference between the remission rates of AYAs and adults, in both APL (75.0% versus 83.3%, respectively, p=0.68) and non-APL groups (60.65% versus 53.2% respectively, p=0.43). During follow-up, 29 (20.7 %) were lost to follow-up while 6 non-APL AML (5 AYAs and 1 adult, 5.6%) relapsed within one year with 18 of 32 APL (56.3%) and 32 of 108 non-APL AML (29.6%) remained alive at one year. Two-year cumulative survival for AYAs compared to adults was 47% vs 42% respectively for non-APL AML (p=0.42) and 74% vs 83% for APL (p=0.608) with no statistically significant difference between two age groups. Conclusion In this resource limited setting, although having higher proportion of younger population and better prognostic types like APL, remission rate and survival was still low due to higher number of early and induction deaths which could be improved by early diagnosis and better supportive care.

Interplay between hypertriglyceridemia and acute promyelocytic leukemia mediated by the cooperation of peroxisome proliferator-activated receptor-α with the PML/RAR α fusion protein on super-enhancers.

Patients with newly diagnosed acute promyelocytic leukemia (APL) are often obese or overweight, accompanied by metabolic disorders, such as dyslipidemia. However, the link between dyslipidemia and leukemia is obscure. Here, we conducted a retrospective study containing 1,412 cases (319 newly diagnosed APL patients, 393 newly diagnosed non-APL acute myeloid leukemia patients, and 700 non-tumor controls) and found that APL patients had higher triglyceride levels than non- APL and control groups. Using clinical data, we revealed that hypertriglyceridemia served as a risk factor for early death in APL patients, and there was a positive correlation between triglyceride levels and leukocyte counts. RNA sequencing analysis of APL patients having high or normal triglyceride levels highlighted the contribution of peroxisome proliferatoractivated receptor-α (PPARα), a crucial regulator of cell metabolism and a transcription factor involved in cancer development. The genome-wide chromatin occupancy of PPARα revealed that PPARα co-existed with PML/RARα within the super-enhancer regions to promote cell proliferation. PPARα knockdown affected the expression of target genes responsible for APL proliferation, including FLT3, and functionally inhibited the proliferation of APL cells. Moreover, in vivo results in mice having high fat diet-induced high triglyceride levels supported the connection between high triglyceride levels and the leukemic burden, as well as the involvement of PPARα-mediated-FLT3 activation in the proliferation of APL cells. Our findings shed light on the association between APL proliferation and high triglyceride levels and provide a genetic link to PPARα-mediated hyperlipidemia in APL.

Low specificity of HLA-DR expression for diagnosis of acute promyelocytic leukemia

Contemporary therapy of acute promyelocytic leukemia (APL) is based on the use of all-trans retinoic acid, which is effective against tumor cells harboring RARa gene rearrangements (most common – t(15;17)(q24;q21)/PML::RARa). In several studies, it was suggested to use typical immunophenotypic features of APL (HLA-DR-negativity, etc) for prediction of RARa rearrangements presence. In this study, we aimed to evaluate the range of genetic aberrations that could be found in the HLA-DR-negative acute myeloid leukemia (AML). Our study was approved by the Independent Ethics Committee of the Dmitry Rogachev National Medical Research Center of Pediatric Hematology, Oncology and Immunology. Among studied 806 pediatric AML patients, HLA-DR-negativity was found in 253 cases. Only in 45.4% of them t(15;17)(q24;q21)/PML::RARa was found, while in remaining 54.6% normal karyotype or other genetic aberrations without RARa involvement. Frequency of the most common immunophenotypic features of APL, such as total CD117, CD33 and MPO expression with the lack of CD34, was higher in patients with t(15;17)(q24;q21)/PML::RARa, although only two thirds of APL cases were found to have all these signs. Moreover, the percentage of cells positive or negative for mentioned antigens varied significantly in APL group. Thus we can conclude, that all “typical” immunophenotypic characteristics of APL including HLA-DR-negativity, are very unspecific and cannot be used for reliable prediction of presence of t(15;17)(q24;q21)/PML::RARa.

Profiling FLT3 Mutations in Mexican Acute Myeloid Leukemia Pediatric Patients: Impact on Overall Survival.

Background: Acute myeloid leukemia (AML) is the second most frequent leukemia in childhood. The FLT3 gene participates in hematopoietic stem cell proliferation. FLT3 mutations are recurrent in AML and influence prognosis. In Mexican pediatric AML patients, FLT3 mutational profile, and their clinical impact have not been evaluated.Aim of the study: This study aimed to identify the profile of FLT3 mutations in pediatric patients with de novo AML and to assess their possible influence on overall survival (OS) and other clinical features.Methods: Massive parallel target sequencing of FLT3 was performed in 80 patients.Results: FLT3 mutations [internal tandem duplication (ITD) or tyrosine kinase domain (TKD)] were identified in 24% of them. OS was significantly lower in FLT3POS cases than in FLT3NEG (p = 0.03). The average OS for FLT3POS was 1.2 vs. 2.2 years in FLT3NEG. There were no significant differences in the children's sex, age, percentage of blasts in bone marrow aspirate, or white blood cell count in peripheral blood at diagnosis between both groups. No differences were identified stratifying by the mutational load (high > 0.4) or type of mutation. The negative effect of FLT3 mutations was also observed in patients with acute promyelocytic leukemia (APL).Conclusions: FLT3 mutational profile is described in Mexican pediatric AML patients for the first time. Mutated FLT3 negatively impacts the outcome of AML patients, even considering the APL group. The clinical benefit from treatment with tyrosine kinase inhibitors in the FLT3POS pediatric patients needs to be assessed in clinical trials. FLT3 testing may contribute to better risk stratification in our pediatric AML patients.

Safety of gemtuzumab ozogamicin as monotherapy or combination therapy in an expanded-access protocol for patients with relapsed or refractory acute myeloid leukemia

Gemtuzumab ozogamicin (GO) remained available to US clinicians through an open-label expanded-access protocol (NCT02312037) until GO was reapproved. Patients were aged ≥3 months with relapsed/refractory (R/R) acute myeloid leukemia (AML), high-risk myelodysplastic syndrome, or acute promyelocytic leukemia (APL), and had exhausted other treatment options. Three hundred and thirty one patients received GO as monotherapy for R/R AML (n = 139), combination therapy for R/R AML (n = 183), or treatment for R/R APL (n = 9). Corresponding treatment discontinuations occurred in 68, 39, and 33% of patients. All-causality grade 5 AEs occurred in 52, 22, and 22% of patients in the monotherapy, combination, and APL groups, respectively. Corresponding grades 3 and 4 treatment-related AEs were reported in 60, 55 and 78% of patients. Hepatotoxicity occurred in five patients: veno-occlusive disease (n = 4) and drug-induced liver injury (n = 1). GO was generally well tolerated in patients with R/R AML or APL. Most frequent treatment-related grade ≥3 AEs were hematologic AEs.Clinicaltrials.gov identifier: NCT02312037

Jak-Stat Signaling Pathway Related Gene Expressions and Blood Biochemical indicators in Acute Promyelocytic Leukemia

Jak-Stat Signaling Pathway Related Gene Expressions and Blood Biochemical indicators in Acute Promyelocytic Leukemia

Clinical Profile of Acute Myeloid Leukemia in North India and Utility of Nontransplant Measures in its Management

AbstractIntroduction: Acute myeloid leukemia (AML) is a clonal accumulation of myeloid precursors in body tissues, which ultimately leads to bone marrow failure. This is an 8-year prospective, observational study in which 254 patients were enrolled. Aim of the Study: To document the clinical profile of AML and differential outcome in M3 versus non-M3 phenotype and to see impact of different variables on its survival. Methods: Patients enrolled in the study were examined, evaluated, and given standard 3:7 induction protocol, and acute promyelocytic leukemia (APML) patients were given the ICAPL 2006 protocol. Results: In our study, males outnumbered females and most of our patients were in 20–60 years of age group. The better prognosis was in patients who were in the second decade of life. Total leukocyte count and platelet count had a significant impact on the survival of the a patient. Bone marrow morphology of M3 type has extremely good prognosis and was the most common FAB type seen in our study. Flow cytometric markers such as CD15, CD33, CD117, and myeloperoxidase had positivity among 90% of patients. Overall survival is around 40% in whole-study group, 87% in APML group, and 16.5% in non-M3 group. There are still unmet needs in managing the non-M3 patients in resource-constraint countries where allogenic transplant and newer drugs have the least access. For improving the outcome in M3 AML, further newer molecules such as Flt3 and PIK3 inhibitors are being used in trials. Conclusion: There are still unmet needs in managing the non-M3 patients in resource-constraint countries where allogenic transplant and newer drugs have the least access. For improving the outcome in M3 AML, further newer molecules such as Flt3 and PIK3 inhibitors are being used in trials.

Safety of Gemtuzumab Ozogamicin As Monotherapy or Combination Therapy in an Expanded-Access Protocol for Patients with Relapsed or Refractory Acute Myeloid Leukemia

Introduction: Gemtuzumab ozogamicin (GO; MylotargTM) is an antibody-drug conjugate composed of an anti-CD33 monoclonal antibody covalently linked to the potent antibiotic calicheamicin. Previous studies have shown GO is generally well tolerated and can induce durable second remissions when administered as monotherapy or in combination with chemotherapy in patients with relapsed or refractory (R/R) acute myeloid leukemia (AML). We report safety data from an expanded-access protocol (EAP) that allowed compassionate use of GO in patients with R/R AML or acute promyelocytic leukemia (APL) and no access to comparable or alternative therapy.Methods: Conducted in the United States, the GO EAP (NCT02312037) was an open-label study in patients aged ≥3 months with R/R AML (including myelodysplastic syndrome) or APL who were considered to have the potential to derive clinical benefit and had exhausted other treatment options. The protocol allowed for treatment regimens tested in clinical trial settings and reported in the Mylotarg Investigators Brochure or peer-reviewed journals. Data from these trials indicated these regimens could potentially benefit a patient with R/R AML or APL. For R/R AML patients, the regimens included GO as monotherapy or in combination with anthracyclines and/or nucleoside-analogue containing regimens or hypomethylating agents. For patients with APL, these included GO as monotherapy or in combination with all-trans retinoic acid and/or arsenic trioxide. Patients were permitted to re-enroll in treatment, and their data are summarized according to each enrollment treatment.Results: A total of 331 patients received GO either as monotherapy for R/R AML (adult [aged ≥18 years]: n=118; pediatric [aged <18 years]: n=21), combination therapy for R/R AML (adult: n=99; pediatric: n=84), or treatment for APL (adult: n=9; pediatric: n=0). Mean age in the monotherapy, combination therapy, and APL groups was 55, 32, and 57 years, respectively.The most frequently administered doses of GO in the monotherapy group were 9 mg/m2 (1 dose: n=21 [15%]; doses on ≥2 days: n=29 [21%]) and 3 mg/m2 (1 dose: n=10 [7%]; doses on ≥2 days: n=33 [24%]). Nearly all patients in the combination-therapy group received 3 mg/m2 (1 dose: n=96 [53%]; doses on ≥2 days: n=76 [42%]). GO 6 mg/m2 was the most frequently administered dose in the APL group (1 dose: n=3 [33%]; doses on ≥2 days: n=4 [44%]). Treatment was discontinued in 94 (68%), 71 (39%), and 3 (33%) patients in the monotherapy, combination-therapy, and APL groups, respectively. Common reasons for discontinuation included resistant disease (monotherapy: n=25 [18%]; combination therapy: n=16 [9%]; APL: n=1 [11%]), adverse events (AEs) not related to study drug (monotherapy: n=7 [5%]; combination therapy: n=3 [2%]; APL: n=1 [11%]), and AEs related to study drug (monotherapy: n=6 [4]%; combination therapy: n=4 [2%]; APL: n=0).All-causality grade 5 AEs were reported in 114 (34%) patients: 72 (52%), 40 (22%), and 2 (22%) in the monotherapy, combination-therapy, and APL groups, respectively. The most common grade 5 AEs (excluding disease progression and AML) were sepsis in the monotherapy group (n=7 [5%]; 4 treatment-related), respiratory failure in the combination-therapy group (n=5 [3%]; 1 treatment-related), and intracranial hemorrhage in the APL group (n=1 [11%], not treatment-related). Grade ≥3 treatment-related, treatment-emergent AEs (TEAEs) were reported for 84 (60%) patients in the monotherapy group, 102 (56%) patients in the combination-therapy group, and 7 (78%) patients in the APL group; hematologic TEAEs were most common, followed by hepatic TEAEs (Table). Possible hepatotoxicity was reported in 5 patients: 1 case each of veno-occlusive disease (VOD) and drug-induced liver injury in the monotherapy group and 2 cases of veno-occlusive liver disease (1 fatal) and 1 case of VOD in the combination-therapy group.Conclusions: GO was generally well tolerated; only a small proportion (<5%) of patients in each group discontinued treatment due to treatment-related TEAEs. The most frequent treatment-related, grade ≥3 TEAEs were hematologic. The incidence of hepatotoxicity was low across all cohorts. The results suggest GO is an important treatment option for patients with R/R AML or APL. [Display omitted] DisclosuresWang:Jazz: Speakers Bureau; Pfizer: Consultancy, Membership on an entity's Board of Directors or advisory committees; Amgen: Consultancy; Amgen: Consultancy; Jazz: Speakers Bureau; Novartis: Speakers Bureau; Pfizer: Consultancy, Membership on an entity's Board of Directors or advisory committees; Novartis: Speakers Bureau; Abbvie: Consultancy, Membership on an entity's Board of Directors or advisory committees; Abbvie: Consultancy, Membership on an entity's Board of Directors or advisory committees. Chirnomas:Pfizer Inc: Employment, Equity Ownership. Fazal:Novartis: Consultancy, Membership on an entity's Board of Directors or advisory committees; Jazz: Membership on an entity's Board of Directors or advisory committees; Pfizer: Speakers Bureau. Lin:Jazz Pharmaceuticals: Honoraria. Nand:Pfizer: Honoraria. Pierce:Pfizer Inc: Employment, Equity Ownership. Shami:JSK Therapeutics: Employment, Equity Ownership, Membership on an entity's Board of Directors or advisory committees; Lone Star Biotherapies: Equity Ownership; Baston Biologics Company: Membership on an entity's Board of Directors or advisory committees; Pfizer: Consultancy. Vermette:Pfizer: Employment, Equity Ownership. Abboud:Agios: Honoraria; Jazz: Honoraria, Speakers Bureau.

Role of CD11a and CD18 in Diagnosis of Acute Promyelocytic Leukemia

Background: Acute promyelocytic leukemia (APL) is an aggressive subtype of acute myeloid leukemia (AML) that requires rapid diagnosis and early intervention. Previous studies spotted light on APL being negative for members of β2 integrin family CD11a and CD18. The aim of this work: was to study the value of absence of CD11a and CD18 molecules in screening and its relation to prognosis of APL cases. Patients and methods: This cross sectional study was conducted on seventy adult (>18 years) patients with de novo AML, recruited from National Cancer Institute, Cairo University. They were divided in to 2 groups; group 1 of APL cases (n= 35) and group 2 of AML-Non APL cases (n= 35) as a comparative group. Both groups were investigated by flow cytometry for the expression of CD11a and CD18 molecules on leukemic cells. Results: Comparison between group 1 and group 2 illustrated significant reduction in % of cells expressing CD11a (p= 0.014), CD18 (p=0.008) and % of cells co-expressing CD11a /CD18 (p=0.007) in group 1 compared to group 2. There was significant positive correlation between % of cells expressing CD18 and TLC (r=0.411, p=0.014). There was significant positive correlation between CD11a MFI and hepatomegaly (r=0.390, p=0.021) in AML-Non APL group. Regarding the output data of ROC curve for discriminative percentage of leukemic cells expressing CD11a and CD18 between APL and Non-APL groups, at cut off 78.95% and 23.5% respectively, the specificity for both was 60% and 68.6%, respectively. While sensitivity was 77.1% and 68.6%, respectively, with Area Under Curve (AUC) of 0.671 and 0.686 and p value of 0.014, and 0.008 for leukemic cells expressing CD11a and CD18, respectively. Conclusion: [1] There is significant reduction in % of cells expressing CD11a and CD18 in APL patients, but they were neither sensitive nor specific to be used as single markers in diagnosis of APL patients. [2] Positive correlation seen between the most important prognostic factor, TLC and both CD18 MFI and percentage of cells expressing CD18 could throw light on the potentiality of CD18 as a prognostic factor. [3] Significant positive correlation between CD11a MFI and hepatomegaly in Non-APL cases might suggest a role of CD11a in migration of leukemic cells.

FLT3-ITD Mutations in Egyptian Patients of Acute Myeloid Leukemia: Correlation with Cytogenetic, FAB Subgroups and Prognosis.

FLT3-ITD mutations are common in AML subgroups, particularly in Acute Promyelocytic Leukemia (APL). It infers poor prognosis in AML patients; however, its prognostic value in APL is still controversial. We aimed to assess the distribution and prognostic value of FLT3-ITD mutation within AML subgroups, focusing on APL. In NCI, Cairo University, 346 newly diagnosed AML patients were included. Morphological, immunophenotypic and cytogenetic analysis were done at presentation and fixed follow-up points with monitoring in follow up visits of patients. FLT3-ITD mutations were detected using RT-PCR. FLT3-ITD mutations were detected in 18.5% of AML patients with significant higher incidence in M3 patients (35.5%, p = 0.027) in comparison to other types. There was significant negative association between FLT3ITD mutations and CD34 expression (p = 0.026). FLT3 wild patients had a significantly better response on Day 35 than the mutant group (p = 0.046). Overall Survival (OS) of the wild group was significantly better than that of the mutant group (p = 0.003). In APL patients, OS of wild-FLT3 patients was significantly better than of those with mutant FLT3 (p = 0.018). In non-APL patients, favorable cytogenetic changes - t(8;21) and inv(16) - are more common in FLT3 wild group (12.8%) than in FLT3 mutant group (6.3%). In non-APL patients, FLT3-ITD mutation retained its adverse prognostic effect (p = 0.016). CD34 expression affected survival in both FLT3 mutant and wild groups. We conclude that FLT3-ITD mutations infer poor prognostic effects both in AML patients generally and in the APL group specifically. CD34 may have a prognostic impact in FLT3-ITD mutant patients, which is to be further investigated.

Evolving characteristics and outcome of secondary acute promyelocytic leukemia (APL): A prospective analysis by the French-Belgian-Swiss APL group.

Reports of patients with secondary acute promyelocytic leukemia (APL) have increased in recent years, particularly for those who received treatment with mitoxantrone, and retrospective studies have suggested that their characteristics and outcomes were similar to those of patients with de novo APL. The authors investigated patients with de novo and secondary APL who were included in the ongoing APL-2006 trial. Patients with secondary APL who were included in that trial also were compared with a previous retrospective cohort of patients with secondary APL. In the APL-2006 trial, 42 of 280 patients (15%) had secondary APL. Compared with the retrospective cohort, patients with secondary APL in the APL-2006 trial had a lower incidence of prior breast carcinoma (35.7% vs 57%; P = .03) and a higher incidence of prior prostate carcinoma (26.2% vs 4.7%; P < .001). Treatment of the primary tumor in the APL-2006 trial less frequently included combined radiochemotherapy (28.6% vs 47.2%; P = .044) and no mitoxantrone (0% vs 46.7%; P = .016) but more frequently included anthracyclines (53.3% vs 38.3%; P = .015). In the APL-2006 trial, patients who had secondary APL, compared with those who had de novo APL, were older (mean, 60.2 years vs 48.7 years, respectively; P < .0001) but had a similar complete response rate (97.6% vs 90.3%, respectively), cumulative incidence of relapse (0% vs 1.8%, respectively), and overall survival (92.3% vs 90.9%, respectively) at 18 months. Although the incidence of secondary APL appears to be stable over time, evolving strategies for the treatment of primary cancers have reduced its occurrence among breast cancer patients but have increased its incidence among patients with prostate cancer. The current results confirm prospectively that patients with secondary APL have characteristics and outcomes similar to those of patients with de novo APL.

Invasive Fungal Infections in Acute Promyelocytic Leukemia Patients. Results of a Prospective Multicenter Study in Italy

OBJECTIVESAim of this prospective study was to evaluate the risk of invasive fungal infection (IFI) in patients (pts) with acute promyelocytic leukemia (APL) and to compare APL pts with patients affected by non promyelocytic acute myeloid leukemia (npAML) in order to evaluate factors potentially linked to IFI in these two subsets of acute myeloid leukemia.PATIENTS AND METHODSFrom January 2010 to April 2012 all pts with newly diagnosed AML were registered in 33 Italian participating centers. A minimum follow up of 90 days after 1st induction chemotherapy was requested for all pts. A prolonged follow up until June 2014 was made only for APL. Data were collected about age, gender, AML subtype, treatment and also about post chemotherapy risk factors for IFI (duration of neutropenia, mucosal damages, vomiting, diarrhea, presence of medical devices), antifungal prophylaxis, onset of IFI, level of certainty (possible/probable/proven), and antifungal treatment. Only for APL the survey was prolonged for at least 3 months in order to analyze if these pts have an IFI risk during other than first induction phases.RESULTS1,192 consecutive newly diagnosed adult AML pts (npAML:1,086/APL:106) were enrolled in the study.Among npAML pts, those receiving low dose chemotherapy and/or palliative treatment were excluded from the analysis; in the remaining 881 pts 214 cases (24%) of IFI were recorded.Considering APL, 3 pts were excluded from the analysis due to early death (1 pt) or bad performance status (2 pts). The remaining 103 pts received APL treatment according to local protocols: all trans retinoic acid (ATRA) plus chemotherapy (90 pts) or ATRA plus arsenic trioxide (ATO)(13 pts). Only 8 (8%) APL pts developed an IFI after the induction phase: 1 proven, 3 probable and 4 possible IFI. All cases were caused by molds. All APL were followed for a median follow up of 36 months (range 3-54). During this time only 2 other cases of IFI were observed: 1 possible IFI during consolidation at 16 weeks from APL diagnosis and 1 probable aspergillosis in a rare case of APL relapse at 132 weeks from APL diagnosis. All the IFI occurred in pts treated with ATRA plus chemotherapy.IFI was fatal in only 1 case (cerebral aspergillosis), all the other pts recovered after antifungal treatment.A comparison between npAML and APL was made in order to analyze the risk of IFI within 90 days after induction treatment among these 2 groups of patients (see table). A significantly lower number of overall IFI and systemic antifungal treatment was observed in the APL group, in spite of the fact that systemic anti mold prophylaxis was significantly less frequently utilized. Table 1Comparison between APL and npAML in induction phaseAPLnpAMLpNumber of pts103881Mean age51550.01m/f50/53448/433N.S.Performance status (WHO)0-1>1. 76 27. 284 597. <0.0001Central venous catheter52 (50%)687 (78%)<0.0001Neutropenia (<1000/mm3)103 (100%)874 (99%)N.S.Mean duration of neutropenia (<1000/mm3)23 days25 days0.1Mean duration of deep neutropenia (<500/mm3)17.5 days24 days0.04Antifungal prophylaxis94 (91%)837 (95%)N.S.Topical antifungal prophylaxis17 (17%)60 (7%)0.0005Drug in prophylaxisfluconazoleitraconazoleposaconazoleother.33 (32%)13 (12%)38 (37%)1 (1%).168 (19%)117 (13%)513 (58%)23 (3%).0.002N.S. <0.0001IFIsall casesproven/probable.8 (8%)4 (4%).214 (24%)77 (9%).0.00010.08moldsall casesproven/probable.8 (8%)4 (4%).191 (22%)55 (6%).0.0006N.S.yeastsall cases.0.23 (3%). <0.0001Antifungal treatmentMean duration11 (11%)17 days275 (31%)14 days<0.0001 N.S.Overall mortality at 30 days8 (8%)110 (12%)N.S.Mortality due to IFI at 30 days1 (1%)25 (3%)N.S.Comparing APL among them in order to identify parameters that could be correlated to IFI presentation, no significant factors were identified.DISCUSSIONIn our prospective study we specifically analyzed the incidence and the type of IFI in APL during a prolonged follow-up. Only 10 cases of IFI were documented and in most cases (6 pts) the infection was only possible. Comparing APL to npAML a lower incidence of overall IFI was observed despite less use of mold active drugs as prophylaxis. It could be attributed to the different chemotherapy (less aggressive in APL) and to lower duration of deep neutropenia. No yeast infection was observed in APL. On the basis of this study, APLs may be considered at low risk of IFI so probably the use of a mold active antifungal prophylaxis could be omitted. DisclosuresNo relevant conflicts of interest to declare.

ATO Metabolites in APL an MM Patients Treated According to APL and MAC/DAC Schemes

IntroductionArsenic trioxide (ATO) has been shown to be effective in the treatment of acute promyelocytic leukemia (APL) and towards multiple myeloma (MM) cells. Biologically active form of ATO is inorganic arsenic in its trivalent form (AsIII) which is metabolised in more or less active metabolites already in hours after infusion. The major arsenic excretion metabolites are methylated, namelly methylarsonic acid (MA) and dimethylarsinic acid (DMA). Despite that ATO already has an established role in APL treatment, there is still a lack of data on its metabolism especially when it is combined with other active compounds. The aim of our study was to get an insight into ATO metabolism through measurement of its metabolites in urine and total arsenic in blood during treatment according two different protocols.Patients and methodsPatients (8 APL, 12 MM) were treated by ATO (administered as 2 h intravenous infusion) during the years 2004 - 2014. APL patients were previously treated according to a standard APL EORTC protocol. In three patients ATO was started immediately after an interruption of treatment due to a differentiation syndrome and in the remaining five patients ATO was started due to relapse. ATO (0.15 mg/L) was administered for i) 50 consecutive days and prolonged for 25 days (5 days/week) after 3 weeks break or for ii) 25 consecutive days repeated after one week break.Majority of 12 MM patients was heavily pretreated, relapsed or refractory. ATO (0.25 mg/kg) infusion was followed by injection of ascorbic acid (1g). Melphalan (0.1 mg/kg) or Dexamethasone (40 mg/kg) was added in MAC or DAC scheme respectively. ATO was given in cycles (4 consecutive days followed by 3 weeks of 2 applications/week). Treatment efficacy was evaluated by measurement of a monoclonal spike except for patients with Bence-Jones type of MM who were only clinically evaluated.The urine samples were taken before ATO infusion and analysed using HPLC separation combined on-line with hydride generation and atomic fluorescence spectrometry. Arsenic species As(III) and As(V) and both methylated metabolites MA and DMA were followed. Total arsenic concentrations in serum were analysed by ICP-MS.ResultsAll APL patients have obtained a stable molecular remission. In contrast, efficacy of ATO treatment in MM patients is difficult to be evaluated due to the patients’ initial poor condition. In three MM patients effect of ATO cannot be evaluated since they deceased during the treatment. In four out of 9 remaining MM patients at least a partial remission was obtained.Differences between both groups, or better between both protocol regimens (consecutive APL or pulse DAC/MAC in MM), are also reflected in As serum levels and in the presence of ATO metabolites in urine. During the therapy the residual As serum levels in APL group were almost two times as big as those in MM group (72,33±16.79 ng/g vs. 45.13±7.2 ng/g). That means that lower daily doses of ATO preserve higher As concentrations in time than pulse therapy with higher doses.In the urine of MAC/DAC group the proportion of DMA was higher than in the patients treated according APL protocol (48.7 ± 14.6 % vs 63.2 ± 10.4%, Figure 1), while proportions of other three metabolites were lower. A higher proportion of the main active component, As(III), was present in the body of APL patients in comparison to MAC/DAC treated MM patiens (17.5 ± 7.4 % vs 8.6 ± 4.5 %; Figure 1). Differences in metabolites between both groups were statistically significant (MA: P = 0.0127; AsIII, DMA, AsIII: P < 0.0001). [Display omitted] ConclusionsAPL patients receiving ATO daily reached a sort of a steady state with a peak in As(III) concentration after i.v. infusion and gradual fall of As(III) concentration until the next day’s infusion while concentrations of other metabolites remained relatively stable. MM patients received higher ATO doses in pulses so that decrease of As(III) after initial peak ended in prolonged lower As(III) levels in between infusions.Poor response to ATO treatment in few MM patients can be attributed to their pretreatment status but also to suboptimal treatment protocol. Significantly lower residual serum As levels were observed during DAC/MAC in comparison to daily treatment according to APL protocol. Lower but more frequent doses of ATO, similar to those in APL, may be more effective in MM. DisclosuresOff Label Use: Arsenic trioxide, drug with known antimyeloma activity. It was used as salvage options in multiple myeloma pts., in whom all other conventional treatment options were exhausted. Those patients would be otherwise treated only in a paliative way. They all wrote informed consent after we discussed the issue with them.

Effect of Young Age on Outcomes in Pediatric Acute Promyelocytic Leukemia (APL): North American Intergroup Study CALGB 9710 (Alliance)

Purpose: Clinical trials in APL have generally reported similar outcomes for children and adults. However, sub-group analysis of pediatric patients treated on 2 consecutive trials of the European APL group demonstrated that children <5 years (yr) had an increased risk of relapse (Bally et al., JCO, 2012). Here we report the effect of age < 5 yr on outcome for the North American Intergroup Study C9710.Methods: Outcomes were compared among young children (age <5 yr, n=16) to those of older age (5-12 yr, n=25 and 13-18 yr, n=45) enrolled on C9710. Treatment on C9710 included induction with daunorubicin, cytarabine and ATRA followed by two consolidation cycles with daunorubicin and ATRA and maintenance for one year with ATRA +/- mercaptopurine and methotrexate. Patients of age ≥15 yr were randomized to receive or not receive two 5-week cycles of arsenic trioxide (ATO) before the chemotherapy consolidation. However, analysis in this study of young children compared to those of older age was restricted to patients who did not receive ATO.Results: Clinical remission (CR) rates were similar between the 3 age groups (age <5 yr= 88%, age 5-12 yr= 80%, age 13-18 yr= 82%; P=0.93). Overall survival (OS) Kaplan-Meier estimates were not significantly different (log rank P=0.84), and 5 yr OS rates were 77% (age <5 yr), 80% (age 5-12 yr), and 84% (age 13-18 yr). Similarly, event-free survival (EFS) Kaplan-Meier estimates were not significantly different (log rank P=0.48), and 5 yr EFS rates were 56% (age <5 yr), 47% (age 5-12 yr), and 59% (age 13-18 yr). Young children did not have a higher relapse rate (5-yr cumulative incidence of relapse by age: <5 yr=29%, 5-12 yr=49%, 13-18 yr=29%).Conclusions: Results of this intergroup trial demonstrate that ATRA administration during induction, consolidation and maintenance leads to CR rates >80% and 5 yr OS rates >75%. These results are superior to recently published results of pediatric non-APL acute myeloid leukemia and confirm results from the prior APL intergroup trial (INT0129) that demonstrated that ATRA in induction and/or maintenance significantly improved outcomes for pediatric APL (Gregory et al., Ped Blood and Cancer, 2009). Our sub-group analysis showed no association of age with outcomes in children treated with this regimen. DisclosuresOff Label Use: Daunorubicin- labeled for use in AML for adults and for pediatric ALL (not pediatric AML) Arsenic Trioxide- labeled for use in relapsed/refractory APL (not de novo APL) Mercaptopurine and Methotrexate- labeled for use in pediatric ALL (not APL).

Critical Serum-Selenium Levels in APL and MM Patients during ATO-Treatment (According to APL and MAC/DAC Schemes)

IntroductionArsenic trioxide (As2O3; ATO; Trisenox®) is an antineoplastic chemotherapeutic agent used for the treatment of acute promyelocytic leukemia (APL) and experimentally also for other malignancies including multiple myeloma (MM). As the therapeutic doses are rather high, and arsenic-selenium interactions well-known (arsenic complexation by selenium with subsequent excretion by bile), we assume that arsenic interferes in the selenium (Se) metabolism during the treatment. As selenium deficiency (<40 ng Se/g) can be detrimental in many ways, the aim of our study was to follow serum-selenium levels in APL and MM patients during ATO treatment.PatientsOver a period of 10 years, 20 patients (8 APL, 12 MM) were treated by ATO (administered as 2-h intravenous infusions). APL patients were previously treated according to a standard APL EORTC protocol. In 3 patients the ATO was started immediately after an interruption of treatment due to a differentiation syndrome and in the remaining 5 patients ATO was started due to relapse. ATO (0.15 mg/L) was administered for i) 50 consecutive days and prolonged for 25 days (5 days/week) after a 3-weeks break or for ii) 25 consecutive days repeated after a 1-week break.The majority of 12 MM patients was heavily pretreated, relapsed or refractory. ATO (0.25 mg/kg) infusion was followed by injection of ascorbic acid (1 g); Melphalan (0.1 mg/kg) and Dexamethasone (40 mg/kg) were added according to a MAC and DAC scheme, respectively. ATO was given in cycles (4 consecutive days followed by 3 weeks of 2 applications/week). Treatment efficacy was evaluated by measurement of a monoclonal spike, except for patients with a Bence-Jones type of MM who were only clinically evaluated.Sampling and analytical methodsThe urine and blood samples were taken before ATO infusion and total selenium was analyzed using inductively coupled plasma mass spectrometry (ICP-MS).ResultsAll APL patients reached a stable molecular remission. In contrast, the efficacy of the ATO treatment in MM patients was difficult to evaluate due to the patients’ poor initial condition. In 3 MM patients the effect of ATO could not be evaluated since they deceased during the treatment. In 4 out of 9 remaining MM patients at least a partial remission occurred. Differences between both groups were also reflected in selenium-serum levels at the beginning and during the therapy. The average selenium-serum level of the APL group at the beginning of the treatment was in the range of the general population and almost two times higher than the average of the MM group (88.4 ± 17.8 ng/g, n = 5 vs. 54.6 ± 18.8 ng/g, n =10; Figure 1A). During the ATO treatment the serum-selenium levels fell significantly in both groups – final levels for APL patients were mostly around 50 ng/g and for MM patients below 40 ng/g (Figure 1B). In the urine of all patients a diminished selenium-excretion was observed during treatment.ConclusionsAlmost all APL patients receiving ATO daily responded well to the treatment while the positive treatment-response of MM patients was limited, possibly due to their pretreatment status and/or a suboptimal treatment protocol. Low serum-selenium levels (<40 ng/ml) are frequently related to a compromised immune system. Hence, low initial selenium levels and even lower final selenium levels in MM patients may increase their vulnerability to infections and ATO side-effects. [Display omitted] [Display omitted] DisclosuresOff Label Use: Arsenic trioxide, drug with known antimyeloma activity. It was used as salvage options in multiple myeloma pts., in whom all other conventional treatment options were exhausted. Those patients would be otherwise treated only in a paliative way. They all wrote informed consent after we discussed the issue with them.

Application of bone marrow samples for discrimination of acute promyelocytic leukemia from other types of acute leukemia using the routine automated hematology analyzer

Unreported parameters produced by automated blood cell counter, particularly large unstained cells (LUC) and delta neutrophil index (DNI), indicated the presence of immature and possibly abnormal cell populations in white blood cell population. The purpose of this study was to investigate the laboratory performance for discrimination of acute promyelocytic leukemia (APL) cells from other types of leukemia cells and clinical value of LUC and DNI parameters in bone marrow (BM) samples of patients with acute leukemia. A total of 73 BM samples of patients with various type of acute leukemia were analyzed. LUC and DNI parameters were determined by an automated hematology analyzer (ADVIA 120; Siemens Healthcare Diagnostics, New York, NY, USA). Statistical analysis was performed using Kruskal-Wallis and Mann-Whitney U methods. Receiver operating characteristic curve (ROC) analysis, survival analysis, and Cox proportional hazard model were used to evaluate the clinical implication. There were significant differences (P<0.05) between APL group and other group in the DNI and LUC values except for DNI between APL group and non-APL myeloid leukemia group. The area under curve of LUC was larger than that of DNI from the ROC analysis for discrimination between APL group and other group. High LUC value was associated with the increased risk of adverse outcomes and the worse overall survival in patients with acute leukemia. Delta neutrophil index and LUC in BM showed discriminating power of APL cells from other leukemia cells.

Association Of FLT3 Mutations With Unfavorable Factors In AML and APL Patients

BackgroundMutations in the fms-like tyrosine kinase 3 (FLT3) gene have been considered to predict a poor prognosis in acute myeloid leukemia (AML). Internal tandem duplication (ITD) of the FLT3 is one of the most frequent mutations activating aberrant signal-transduction in AML. The impact of D835 point mutations in tyrosine kinase domain (TKD) on prognosis is less clear. AimsCharacterization of AML and APL (acute promyelocytic leukemia) patients with FLT3 mutations. MethodsFLT3 status in bone marrow samples of adult patients (pts) with AML (63 pts) (m\\28; f\\35; median 53 yrs, 19-73 yrs) and APL (14 pts) (m\\3; f\\11; median 43 yrs, 25-62 yrs) at diagnosis was examined. Genomic PCR amplification of ITD and TKD containing regions of the FLT3 gene was performed. The TKD amplicon product was restricted with the EcoRV enzyme. Results were detected by gel electrophoresis. ResultsFLT3\\ITD was found in 8 AML pts (12.7%) and in 5 APL pts (35.7%), p=0.053 (Fisher Exact test). FLT3\\TKD was found in 4 AML pts (6.4%) and in 1 APL pt (7.1%).In AML group there were 1 pt with t(6;9) in FLT3\\ITD+ subgroup and 1 pt with inv16 in FLT3\\TKD+. There were 1 pt with t(6;11), 1 with dupMLL, 3 with t(8;21), 7 with inv16 in AML pts without FLT3 mutations (FLT3-). There were no significant differences in sex, age, WT1 expression at diagnosis between AML pts with FLT3\\ITD, FLT3\\TKD and without FLT3 mutations. But the presence of FLT3 mutations was related to high peripheral white blood cell (WBC) count in AML pts at diagnosis. The median value (m) of WBC was 49.2 x109\\L (range 2.75-191) in FLT3\\ITD+; m= 81 x109\\L (range 7.2-153) in FLT3\\TKD+; m= 5.4 x109\\L (range 0.2-230) in FLT3-. The differences are statistically significant between subgroups with FLT3\\ITD+ and FLT3- (p<0.05, Mann–Whitney U test); FLT3\\ITD+TKD and FLT3- (p<0.01, Mann–Whitney U test). In FLT3\\ITD+TKD subgroup 66.7% of pts had WBC over 30 x109\\L, whereas in subgroup without FLT3 mutations only 23.4% of pts had the same unfavorable factor, p=0.012 (Fisher Exact test).In APL group the t(15;17) translocation was detected in 11 pts. 3 pts were without PML\\RARa, NPM1\\RARa, PLZF\\RARa fusions. One FLT3\\TKD+ pt had bcr1 PML breakpoint. In FLT3\\ITD+ subgroup 4 pts (80%) had bcr3 PML breakpoint, whereas in FLT3- subgroup only 1 pt (12.5%) had bcr3, p=0.032 (Fisher Exact test). In FLT3\\ITD+ subgroup all pts had WBC >10 x109\\L; moreover, 3 pts (60%) had two unfavorable factors in combination (WBC >10 x109\\L plus platelet count < 40 x109\\L) at diagnosis, and in FLT3- subgroup nobody had the same combination, p=0.035, (Fisher Exact test). Out of 5 pts with FLT3\\ITD 2 ones had death in induction, 1 pt had late molecular remission, 1 had molecular persistence and 1 pt without RARa fusion had failure in WT1 reduction after induction (under 2 log). One FLT3\\TKD+ pt had the early relapse. SummaryThe results confirm previous reports. FLT3\\ITD mutations are seen more frequently in APL than in other subtypes of AML. FLT3 mutations in AML have association with such unfavorable prognostic factor as high WBC count at diagnosis. FLT3\\ITD in APL associates with bcr3 and with combination of high WBC count plus low platelet count. The presence of FLT3 mutations is related to unfavorable events in APL pts. Disclosures:No relevant conflicts of interest to declare.

Use of flow cytometry in acute promyelocytic leukemia.

7075 Background: Acute promyelocytic leukemia (APL) is a highly curable disease, with the majority of failures related to hemorrhagic complications. Hence, rapid diagnosis and early initiation of therapy can drastically prevent these complications and reduce mortality. The current diagnostic strategy utilizing fluorescent in situ hybridization (FISH) is often time-consuming and not readily available in some institutions. This is a review of our institutional experience with the use flow cytometry for diagnosis of APL. Methods: All cases with t(15;17) by FISH and karyotype between 2006 and 2012 were identified. A second group of consecutive cases of non-M3 acute myeloid leukemia (AML) and negative FISH and karyotype for t(15;17) was used for comparison. A total of 21 APL and 42 non-M3 AML cases were analyzed. Results: Both groups were comparable in regard to age, gender, white blood cell count, hemoglobin, blast count and lactate dehydrogenase level. The APL group had significantly higher prevalence of thrombocytopenia, disseminated intravascular coagulation and clinical bleeding at time of admission. Expression of CD11c was lacking in 92.3% (12/13) of APL and 14.6% (6/41) of non-M3 AML cases (p&lt;0.0001). CD34 expression was lacking in 68.4% (13/19) of APL and 42.9% (18/42) of non-M3 AML cases (p=0.06). HLA-DR expression was lacking in 88.9% (16/18) of APL and 9.5% (4/42) of non-M3 AML cases (p&lt;0.0001). Given that APL prevalence is 5% among all AML cases, lack of expression of CD11c, CD34 and HLA-DR have negative predictive values (NPVs) of 99.5%, 97.1% and 9933%, respectively. Among various immunophenotypic profiles, lack of expression of CD11c had the highest NPV (99.5%, p&lt;0.0001) and simultaneous lack of expression of CD11c and HLA-DR had the highest specificity (95.1%, p&lt;0.0001). Conclusions: Expression of CD11c reliably excludes the diagnosis of APL in the majority of AML cases. Flow cytometry has the potential of replacing FISH as the initial test to prompt initiating therapy in APL patients.

Late Relapse of Acute Promyelocytic Leukemia: Literature Review and Results of Seven Years of Clinical and Laboratory Follow-Up of a Korean Patient

Among patients with acute promyelocytic leukemia (APL), 10% to 30% experience relapse. Most relapses occur within 2 years; only a few, known as late relapses, occur 4 years after achievement of the first complete remission (CR). We present a rare case of an ethnic Asian patient with APL who experienced late relapse, which has been continuously monitored by reverse transcription polymerase chain reaction (RT-PCR) for long-term molecular remission. Recently, the European APL Group published 2 large-scale studies related to laterelapse APL; however, only 2 Asian cases of late-relapse APL had previously been documented in the literature. We consider this case to be the first report of a patient with late-relapse APL in South Korea and believe that future studies of late-relapse APL for Asian and other ethnic groups are necessary.