The Role of Nucleophosmin 1 (NPM1) Mutation in the Diagnosis and Management of Myeloid Neoplasms

Nucleophosmin (NPM1) is a multifunctional protein with both proliferative and growth-suppressive roles in the cell. In humans, NPM1 is involved in tumorigenesis via chromosomal translocations, deletions, or mutation. Acute myeloid leukemia (AML) with mutated NPM1, a distinct diagnostic entity by the current WHO Classification of myeloid neoplasm, represents the most common diagnostic subtype in AML and is associated with a favorable prognosis. The persistence of NPM1 mutation in AML at relapse makes this mutation an ideal target for minimal measurable disease (MRD) detection. The clinical implication of this is far-reaching because NPM1-mutated AML is currently classified as being of standard risk, with the best treatment strategy (transplantation versus chemotherapy) yet undefined. Myeloid neoplasms with NPM1 mutations and <20% blasts are characterized by an aggressive clinical course and a rapid progression to AML. The pathological classification of these cases remains controversial. Future studies will determine whether NPM1 gene mutation may be sufficient for diagnosing NPM1-mutated AML independent of the blast count. This review aims to summarize the role of NPM1 in normal cells and in human cancer and discusses its current role in clinical management of AML and related myeloid neoplasms.

T-MDS Is a Distinct Clinical and Pathological Entity Characterized By Better Survival Compared to t-AML

Introduction: Therapy-related myeloid neoplasm (t-MN) includes acute myeloid leukemia (AML), myelodysplastic syndrome (MDS), and myelodysplastic/myeloproliferative neoplasms (MDS/MPN) that occur as a complication of DNA-damaging therapies. The World Health Organization recommends considering t-MN as a single entity. Whether t-MDS and t-AML have distinct characteristics and outcomes is not known. The aim of this study was to compare clinicopathological characteristics and outcomes of t-MDS and t-AML. Methods: All patients diagnosed with t-MN based on the World Health Organization criteria were identified. Bone marrow biopsies, cytogenetic, and next-generation sequencing (NGS) were obtained at the treating physician's discretion. Pathogenic/likely pathogenic variants (PV) were called based on the standard criteria. Overall survival (OS) was calculated from the time of t-MN diagnosis until the last follow up using Kaplan-Meier analysis using Wilcoxon test. For survival analysis comparing chemotherapy to best supportive care (BSC) only, patients were censored at the time of allogeneic stem cell transplant (SCT). Multivariate analysis was performed using Cox proportional hazard method and corrected using false discovery rate (FDR). Statistical analysis was performed using JMP (v14.1, SAS Institute) and significance was defined as P&lt;0.05. Results: We identified 554 patients, of which 180 (32.4%), 365 (65.8%), and 9 (1.6%) presented as t-AML, t-MDS, and t-MDS/MPN respectively. t-MDS/MPN patients were excluded from further analysis due to a small number. Clinical and laboratory characteristics of the t-AML and t-MDS cohorts is shown in Table 1. t-AML patients were significantly more anemic and thrombocytopenic at presentation. As expected, t-AML had a higher peripheral blood and BM blast count. There was no difference in proportion of patients with chromosomal abnormalities, though a statistically significantly higher proportion of t-MDS patients had chromosome 5 abnormality, 5q deletion, monosomy 5, chromosome 7 abnormality, monosomy 7 compared to t-AML patients. On other hand, 11q23 (mixed lineage leukemia, MLL) rearrangement was more common in t-AML compared to t-MDS (9.3% vs. 2.8%, P=0.005). A higher proportion of t-MDS patients had PV detected by NGS compared to t-AML (92.9% vs. 85.6%, P=0.038). A higher proportion of t-MDS patients had PV in TP53 (37.6% vs. 21.4%, P=0.004) and ASXL1 (23% vs. 11.7%, P=0.016) genes; whereas a higher proportion of t-AML patients had PV in RAS (18.9% vs. 9.1%, P=0.013) and WT1 (8.1% vs. 2.9%, P=0.05) genes. One hundred twenty-eight (35%) of 365 t-MDS patients progressed to t-AML. The presence of any chromosomal abnormality at t-MDS diagnosis predicted a higher risk of transformation to t-AML (χ 2 3.9, P=0.03). t-AML patients had a significantly shorter OS compared to t-MDS (9.2 vs. 19.7 months, P&lt;0.0001, Figure A). This difference persisted when stratified by no disease modifying therapies (BSC only) 2 vs. 17 months (P&lt;0.0001, Figure B), as well as among those who received at least one line of chemotherapy (14 vs. 24.6 months, P&lt;0.001). Finally, a higher proportion of patients with t-AML underwent SCT and there was a trend towards improved survival for t-AML patients (vs. t-MDS 52.9 vs. 20.7 months, P=0.07) from the time of transplant. Multivariate analysis for OS performed to control for all the variables that were different at presentation (except for blast count), showed that t-MDS (as opposed to t-AML) phenotype at diagnosis, and undergoing SCT were independent predictors of improved survival (Table 2). Conclusion: t-MDS and t-AML have distinct clinical, cytogenetic, and genetic features at presentation. In the absence of disease modifying therapies, t-AML is a more aggressive phenotype, consistently associated with a shorter survival. Even after controlling adverse risk features, t-AML phenotype had a shorter survival compared to t-MDS. Figure 1 Figure 1. Disclosures Litzow: AbbVie: Research Funding; Astellas: Research Funding; Amgen: Research Funding; Actinium: Research Funding; Pluristem: Research Funding; Jazz: Other: Advisory Board; Omeros: Other: Advisory Board; Biosight: Other: Data monitoring committee. Hiwase: Novartis: Membership on an entity's Board of Directors or advisory committees; AbbVie: Membership on an entity's Board of Directors or advisory committees.

Blinatumomab and Inotuzumab for the Treatment of Multiply Relapsed Acute Lymphoblastic Leukemia: A Real-Life Campus ALL Study

Blinatumomab (Blina) and inotuzumab (InO) have improved the outcome of relapsed/refractory B-lymphoblastic leukemia (R/R B-ALL). However, many patients (pts) relapse after these treatments and little is known on their outcomes after recurrence and re-treatment with subsequent immunotherapy. We hereby describe the clinical characteristics and outcome of 71 pts with R/R B-ALL treated with both Blina and InO in any sequence - Blina/InO or InO/Blina - at different disease recurrences. At diagnosis, the median age was 34 years (15-64) and the male/female ratio was 1.6. Sixteen pts (22%) were Ph+ ALL, 3 (4%) were t(4;11)+ and 9 (13%) carried a complex karyotypes. ECOG PS was 0-1 in 66 pts (93%). At the time of the first immunotherapy, pts had received a median of 2 previous lines of treatment (1-8). All Ph- pts received intensive chemotherapy front-line; Ph+ pts received TKIs and steroids in 13 cases and intensive chemotherapy plus TKIs in 3 cases. Blina was the first salvage treatment (Blino/InO sequence) in 57 pts (80%) and InO (InO/Blina sequence) in 14 (20%). Twenty-seven pts (38%) had underwent a previous allogeneic hematopoietic stem cell transplantation (HSCT). At the start of Blina as first immunotherapy, the median bone marrow (BM) blast count was 40% (0-100%); at the start of InO as first immunotherapy, the median BM blast count was 64% (2-90%). An extramedullary involvement was present in 5 patients (9%) in the Blina/InO group and in 1 patients (7%) in the InO/Blina group. During immunotherapy, the median number of lumbar punctures was 2 (0-9). A median of 2 cycles were administered for both Blina (range 1-9) and Ino (range 1-4). In the Blina/InO group, after Blina a G3/4 toxicity occurred in 15 cases (26%): non-hematologic in 12 cases (21%), neurologic in 6 (8%). Infections occurred in 17 pts (30%). In the InO/Blina group, after InO a G3/4 toxicity occurred in 3 pts (21%), with extra-hematologic toxicity in 2 cases (14%, liver toxicity 1 case). Infections occurred in 4 cases (28%). In the Blina/InO group, after Blina 36 pts (63%) achieved a complete remission (CR), with a negative minimal residual disease (MRD) in 24 (42%) pts; after InO, a CR was re-achieved in 47 pts (82.4%), with 34 (59.6%) being MRD-. In the InO/Blina group, after InO a CR was reached in 13 cases (93%), with 6 pts (42.8%) being MRD-; after Blina, a CR was re-achieved in 6 pts (42.8%), with 3 (21.4%) being MRD-. This salvage immunotherapy strategy represented a bridge to alloHSCT for 26 pts (37%). From the first immunotherapy, in the Blina/InO group, the median overall survival (OS) was 19 months and after InO 6.3 months (OS in MRD- vs MRD+, p ns). Disease free survival (DFS) after Blina was 7.4 months (11.6 vs 2.7 months in MRD- vs MRD+ pts, p .03) and after InO it was 5.4 months (MRD- vs MRD+ pts, p ns). In the InO/Blina group, the median OS was 9.4 months and after Blina 4.6 months (7.5 vs 2.8 months in MRD- vs MRD+ pts, p .02). DFS after InO was 5.1 months (MRD- vs MRD+ pts, p ns) and after Blina it was 1.5 months (8.7 vs 2.5 gg in MRD- vs MRD+ pts, p .02). OS and DFS in MRD- pts after Blina was significantly better, both in the Blina/InO and the InO/Blina groups. With a median follow-up of 16.5 months from the start of immunotherapy and 33.8 months from initial diagnosis, 24 pts (34%) are alive and 16 (22%) are alive in CR. Four patients (6%) died in CR due to veno-occlusive disease during HSCT after InO treatment. Interestingly, OS and DFS from the first immunotherapy was better in pts with a previous alloHSCT (median survival 24.2 vs 13 months, p=.0135). AlloHSCT after second immunotherapy was associated with a better OS and DFS (OS 9.8 and DFS 7.2 months vs 7.8 and 4.4 months, p ns). Our real-life study in R/R B-cell ALL pts with multiple previous lines of treatment demonstrates the feasibility and efficacy of a sequential immunotherapy strategy in terms of MRD response, DFS and OS, and as a bridge to HSCT. SM and PC: equal contributors Disclosures Papayannidis: Janssen: Honoraria; Astellas: Honoraria; AbbVie: Honoraria; Amgen: Honoraria; Pfizer: Honoraria; Novartis: Honoraria. Curti: Jazz Pharma: Membership on an entity's Board of Directors or advisory committees; Pfizer: Membership on an entity's Board of Directors or advisory committees; Novartis: Membership on an entity's Board of Directors or advisory committees; Abbvie: Membership on an entity's Board of Directors or advisory committees. Chiaretti: amgen: Consultancy; pfizer: Consultancy; novartis: Consultancy; Incyte: Consultancy. Forghieri: Jannsen: Membership on an entity's Board of Directors or advisory committees; Novartis: Speakers Bureau; Jazz: Honoraria. Bonifacio: Bristol Myers Squibb: Honoraria; Amgen: Honoraria; Novartis: Honoraria; Pfizer: Honoraria. Cerrano: Janssen: Honoraria; Insight: Honoraria; Jazz: Honoraria. Fracchiolla: Gilead: Honoraria, Speakers Bureau; Abbvie: Honoraria, Membership on an entity's Board of Directors or advisory committees; Amgen: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Pfizer: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau.

Prediction of Complete Remission and Survival in Acute Myeloid Leukemia Using Supervised Machine Learning

Achievement of complete remission (CR) signifies a crucial milestone in the therapy of acute myeloid leukemia (AML) while refractory disease is associated with dismal outcomes. Hence, accurately identifying patients at risk is essential to tailor treatment concepts individually to disease biology. Machine Learning (ML) is a branch of computer science that can process large data sets for a plethora of purposes. The underlying mechanism does not necessarily begin with a manually drafted hypothesis model. Rather the ML algorithms can detect patterns in pre-processed data and derive abstract information. We used ML to predict CR and 2-year overall survival (OS) in a large multi-center cohort of 1383 AML patients who received intensive induction therapy using clinical, laboratory, cytogenetic and molecular genetic data. To enable a customizable and reusable technological approach and achieve optimal results, we designed a data-driven platform with an embedded, automated ML pipeline integrating state-of-the-art software technology for data management and ML models. The platform consists of five scalable modules for data import and modelling, data transformation, model refinement, machine learning algorithms, feature support and performance feedback that are executed in an iterative manner to approach step-wisely the optimal configuration. To reduce dimensionality and the the risk of overfitting, dynamic feature selection was used, i.e. features were selected according to their support by feature selection algorithms. To be included in an ML model, a feature had to pass a pre-determined threshold of overall predictive power determined by summing the normalized scores of the feature selection algorithms. Features below the threshold were automatically excluded from the ML models for the respective iteration. In that way, features of high redundancy or low entropy were automatically filtered out. Our classification algorithms were completely agnostic of pre-existing risk classifications and autonomously selected predictive features both including established markers of favorable or adverse risk as well as identifying markers of so-far controversial relevance. De novo AML, extramedullary AML, double-mutated (dm) CEBPA, mutations of CEBPA-bZIP, NPM1, FLT3-ITD, ASXL1, RUNX1, SF3B1, IKZF1, TP53, U2AF1, t(8;21), inv(16)/t(16;16), del5/del5q, del17, normal or complex karyotypes, age and hemoglobin at initial diagnosis were statistically significant markers predictive of CR while t(8;21), del5/del5q, inv(16)/t(16;16), del17, dm CEBPA, CEBPA-bZIP, NPM1, FLT3-ITD , DNMT3A, SF3B1, U2AF1, TP53, age, white blood cell count, peripheral blast count, serum LDH and Hb at initial diagnosis as well as extramedullary manifestations were predictive for 2-year OS. For prediction of CR and 2-year OS, AUROCs ranged between 0.77 - 0.86 and 0.63 - 0.74, respectively. We provide a method to automatically select predictive features from different data types, cope with gaps and redundancies, apply and optimize different ML models, and evaluate optimal configurations in a scalable and reusable ML platform. In a proof-of-concept manner, our algorithms utilize both established markers of favorable or adverse risk and also provide further evidence for the roles of U2AF1, IKZF1, SF3B1, DNMT3A and bZIP mutations of CEBPA in AML risk prediction. Our study serves as a fundament for prospective validation and data-driven ML-guided risk assessment in AML at initial diagnosis for the individual patient. Image caption: Patient features were automatically selected by machine learning to predict complete remission (CR) and 2-year overall survival (OS) after intensive induction therapy. Based on a continuous feature support metric with a predefined cut-off of 0.5 (determined by optimal classification performance), 27 and 25 features were automatically selected for prediction of CR (A) and 2-year OS (C), respectively. For each of these features predicted by machine learning, odds ratios and 95% confidence intervals (CI) were calculated for CR (B) and 2 year OS (D). BMB: bone marrow blast count; FLT3h/low: FLT3-ITD ratio, h=high&gt;0.5; Hb: hemoglobin; karyotype, c: complex aberrant karyotype (≥ 3 aberrations); karyotype, n: normal karyotype (no aberrations); LDH: lactate dehydrogenase; PBB: peripheral blood blast count; PLT: platelet count; WBC: white blood cell count. Figure 1 Figure 1. Disclosures Schetelig: Roche: Honoraria, Other: lecture fees; Novartis: Honoraria, Other: lecture fees; BMS: Honoraria, Other: lecture fees; Abbvie: Honoraria, Other: lecture fees; AstraZeneca: Honoraria, Other: lecture fees; Gilead: Honoraria, Other: lecture fees; Janssen: Honoraria, Other: lecture fees . Platzbecker: Janssen: Honoraria; Celgene/BMS: Honoraria; AbbVie: Honoraria; Novartis: Honoraria; Takeda: Honoraria; Geron: Honoraria. Müller-Tidow: Pfizer: Research Funding; Janssen: Consultancy, Research Funding; Bioline: Research Funding. Baldus: Celgene/BMS: Honoraria; Amgen: Honoraria; Novartis: Honoraria; Jazz: Honoraria. Krause: Siemens: Research Funding; Takeda: Honoraria; Pfizer: Honoraria; art-tempi: Honoraria; Kosmas: Honoraria; Gilead: Other: travel support; Abbvie: Other: travel support. Haenel: Bayer Vital: Honoraria; Jazz: Consultancy, Honoraria; GSK: Consultancy; Takeda: Consultancy, Honoraria; Novartis: Consultancy, Honoraria; Roche: Consultancy, Honoraria; Amgen: Consultancy; Celgene: Consultancy, Honoraria. Schliemann: Philogen S.p.A.: Consultancy, Honoraria, Research Funding; Abbvie: Consultancy, Other: travel grants; Astellas: Consultancy; AstraZeneca: Consultancy; Boehringer-Ingelheim: Research Funding; BMS: Consultancy, Other: travel grants; Jazz Pharmaceuticals: Consultancy, Research Funding; Novartis: Consultancy; Roche: Consultancy; Pfizer: Consultancy. Middeke: Roche: Consultancy, Honoraria; Janssen: Consultancy, Honoraria, Research Funding; Abbvie: Consultancy, Honoraria; Pfizer: Consultancy, Honoraria; Jazz: Consultancy; Astellas: Consultancy, Honoraria; Sanofi: Honoraria, Research Funding; Novartis: Consultancy; Gilead: Consultancy; Glycostem: Consultancy; UCB: Honoraria.

Clinical and Molecular Characteristics Associated with Vitamin C Deficiency in Myeloid Malignancies; Real World Data from a Prospective Cohort

Background: Vitamin C is an essential water-soluble vitamin required for many redox reactions in our body and its deficiency causes scurvy, a well characterized disease with multiple hematological manifestations. Studies dating back to 1950's demonstrated that patients with myeloid neoplasms tend to have lower plasma levels of vitamin C than healthy controls. Recent studies have shown that as much as 80% of patients with hematological malignancies in a cohort from Denmark had low vitamin C levels. Myeloid neoplasms tend to harbor mutations in epigenetic regulators which play a role in DNA methylation. One such mutation commonly seen in myeloid neoplasms and clonal hematopoiesis of indeterminate potential (CHIP) is TET2 for which vitamin C serves as a cofactor. There is a scarcity of clinical data on patients with low vitamin C level in myeloid neoplasms. Our study investigated the rates of vitamin C deficiency and the disease clinical and genomic characteristics associated with it at our center. Methods: We retrospectively collected data from a prospectively maintained list of patients treated for myeloid neoplasms at a large tertiary cancer center on whom vitamin C levels where serially collected during the study period. We obtained multiple baseline characteristics at the time of diagnosis including cytogenetic and molecular mutational data. Baseline characteristics were defined using descriptive statistics. Categorical variables were compared using a Fisher's exact test and continuous variables were analyzed using Mann Whitney U test for statistical significance. Institutional review board approval was obtained for the study. Statistical analysis was done using R Studio version 1.4.1717. Results: A total of 50 patients with myeloid neoplasms were identified with vitamin C levels available at least once during the study period. Nine (18%) patients had a low vitamin C level (LOW) defined as less than 0.4 mg/dl as per the Mayo lab testing with a reference range between 0.4 to 2.0 mg/dl. Baseline characteristics of patients with low vitamin C level and patients with normal vitamin C level (NORMAL) are shown in Table 1. The median vitamin C level in the LOW group was 0.2 mg/dl and NORMAL group was 1 mg/dl (p &lt;0.001). The median age at diagnosis for patients in the LOW cohort was 64 years compared to 72 years for patients with normal vitamin C level (p = 0.015). Twenty-two (53.6%) of patients were female in the NORMAL cohort while six patients (66.7%) were females in the LOW cohort (p=NS). In the vitamin C LOW group only 55% of the patients were white compared to 83% in the NORMAL group (p = 0.093). The majority of patients in the Vit C LOW group had acute myeloid leukemia (AML) 44.5%, compared to 9.8% in the group with normal vitamin C levels (p = 0.03). Median white blood cell count, platelet counts, peripheral blast count and bone marrow blast count were not statistically significant amongst the 2 groups. Majority of patients in both groups 56.1% (NORMAL) vs 77.8% (LOW) had normal cytogenetics at the time of diagnosis (p = 0.284). There was a higher tendency to harbor ASXL1 and IDH2 mutation in the cohort with LOW levels 44.5% (p = 0.09) and 22.2% (p value = 0.143) compared to 17% and 4.8% respectively in the NORMAL cohort. Conclusions: Our analysis of the baseline characteristics of patients with myeloid neoplasms with vitamin C levels reveals interesting findings including a lower age at diagnosis for patients with low vitamin C levels and higher proportion of patients with acute myeloid leukemia compared to the cohort with normal levels. We also noted a higher tendency for occurrence of certain molecular mutations including ASXL1 and IDH2 among the patients with low vitamin C level. With recent papers implicating the role of ASXL1 in leukaemogenesis these findings suggest the hypothesis that vitamin C deficiency could accelerate clonal evolution with a higher tendency to transform into acute leukemia at a lower age. Further multi-institutional studies are needed to understand the relevance of low vitamin C level in myeloid neoplasms and the role of therapeutic vitamin C supplementation to retard leukaemogenesis. Figure 1 Figure 1. Disclosures Patel: Celgene-BMS: Membership on an entity's Board of Directors or advisory committees; Agios: Membership on an entity's Board of Directors or advisory committees; PVI: Honoraria. Awan: Cardinal Health: Consultancy; Abbvie: Consultancy; Merck: Consultancy; Beigene: Consultancy; Johnson and Johnson: Consultancy; Astrazeneca: Consultancy; BMS: Consultancy; Janssen: Consultancy; Genentech: Consultancy; Dava Oncology: Consultancy; Verastem: Consultancy; ADCT therapeutics: Consultancy; Incyte: Consultancy; MEI Pharma: Consultancy; Karyopharm: Consultancy; Kite pharma: Consultancy; Celgene: Consultancy; Gilead sciences: Consultancy; Pharmacyclics: Consultancy. Anderson: Celgene, BMS, Janssen, GSK, Karyopharm, Oncopeptides, Amgen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding. Madanat: Blue Print Pharmaceutical: Honoraria; Stem line pharmaceutical: Honoraria; Onc Live: Honoraria; Geron Pharmaceutical: Consultancy.

Impact of p53 Disruption on AML & HR-MDS Treatment out-Come. a Single Centre Experience

Introduction: Acute myeloid leukaemia (AML) is a heterogeneous disorder that arises from clonal expansion of malignant hematopoietic precursor cells. Somatic mutations of the p53 gene have been reported in 5-10% of AML, with a higher incidence therapy-related disease and elderly patients. Alteration or loss of p53 is one of the most powerful independent indicators of poor outcome. Methods: This is a retrospective analysis of AML & high risk-Myelodysplastic syndrome (HR-MDS) patients treated over the study period (2006-2020). Informed consent was obtained. Initial presentation, treatment response, and survival were analysed. Percentage of p53 expression (a surrogate marker for TP53 mutations) by immunohistochemistry (IHC) (&gt;30% cut-off) on BM trephines was analysed and its impact on treatment outcome was evaluated. Results: We identified 114 patients (AML=104 & HR-MDS=10), the median age was 70 years (Range 36-85) with male predominance (M=73 vs. F=41). The AML group included, 57 patients (50%) with Denovo AML and 47 patients (41%) with Secondary AML (MDS=27, MPN=12 / JAKII mutation =7, t-AML=8). The median age was 70 years (Range 36-85) and the median blast count was 70% (Range 25-95%). Cytogenetic analysis reports were available on 78 patients (75%)(Poor risk=40 vs. Intermediate risk=38). NPM1 (22 patients) and FLT3 mutations analysis (33 patients )were available and reported as positive in 4(18%) and 5(15%) patients respectively. The HR-MDS is defined by patients who fall into higher-risk group categories in the original or revised IPSS (N=10), the median age was 74 years (Range 63-83) with male predominance (M=7 vs. F=3). The median blast count was 15% (Range 11-18%). Cytogenetic risk prognostic subgroup results were available on 6 patients (60%), 2 patients (2%) had intermediate-risk and 4 patients (4%) had poor-risk. Ninety-nine patients (87%) were eligible for treatment, 48 patients (42%) were treated with intensive induction chemotherapy, and 51 patients (45%) received less intensive therapy (HMA / LD-Ara C). Five patients (4%) consolidated with allogeneic stem cell transplant (Allo-SCT) post-induction therapy. The remaining (15 patients) were on supportive care. Forty-one AML patients (36%) relapsed post CR1, 3 patients had Allo-SCT in CR2. Table 1 At the time of study analysis (31/01/2021), 25 patients (22%) are still alive including 23 patients (20%) with AML (Denovo AML=18 & Sec AML=5) and 2 patients (4%) with HR-MDS. The median age of the survival group was 69 years (Range 51-83). The whole study cohort median OS was 12 months. (Figure. 1) The median OS & PFS for AML patients were 15 & 13 months respectively. According to AML sub-type, t-AML associated with shortest median OS of 2.5 months (P.value 0.0190). (Figure. 2) The median OS was more favourable for intermediate-risk than the high-risk cytogenetic AML, 24 and 10 months respectively (P&lt;00016).(Figure. 3) The HR-MDS group median OS was 22 months. One hundred and four patient's BM trephines (91%) were available and screened for p53 IHC expression (AML= 96 & HR-MDS =8). Eight samples (8%) showed p53 over-expression, all these samples with underlying AML diagnosis. The remaining 96 samples (92%) were negative for high p53 expression. The majority of p53 over-expressed AML harboured complex cytogenetics, 4 patients with Sec AML, 3 patients with Denovo AML, and 1 patient with t-AML. Most of the patients (5 patients) in this sub-set had a refractory disease to induction therapy, of whom 2 patients (25%) had Allo-SCT consolidation in CR2. Only one patient (12%) is still alive in this sub-group. The median OS & PFS in p53 wild-type AML cohort was 16 & 13 months respectively, which compared favourably to 12 & 8 months in those with p53 disruptions. The P. values were 0.134 & 0.193, respectively. The impact of the p53 alterations was more pronounced on the AML sub-group treated with intensive chemotherapy (42%), the median OS & PFS in wild-type p53 AML were 24 & 20 months, while in p53 disrupted cohort were 12 & 10 months respectively (P= 0.030)(95%CI of ratio 0.1755 to 1.425) & (P=0.049)( 95%CI of ratio 0.7015 to 5.702).(Figure.4) Conclusion: In this study we demonstrated the potential role for p53 expression by IHC, which is readily available in routine practice, in assessing AML prognosis. Our real-life data confirms the dismal prognosis of p53 alterations in this disease. Participation in clinical trials based on genetic risk stratification is warranted. Figure 1 Figure 1. Disclosures No relevant conflicts of interest to declare.

Chemotherapy-Responsive Acute Myeloid Leukemia in a Veiled Chameleon (Chamaeleo calyptratus)

A 4-year-old captive-bred male veiled chameleon (Chamaeleo calyptratus) presented with anorexia, weight loss, and stomatitis. Complete blood count revealed pancytopenia and a marked leukocytosis (197 x103/µL) composed of blast cells (195 x103/µL) that had oval to irregular nuclei with finely stippled chromatin and occasional nucleoli. The diagnosis was acute leukemia of presumptive myeloid origin. Treatment with prednisone (1.5 mg/kg once daily orally) and cytosine arabinoside (300 mg/m2 subcutaneously) was initiated. Post-treatment hematologic analysis revealed decreased blast count (88.5 x103/µL) and improved mentation. Additional doses of cytosine arabinoside were given two and three weeks after the initial diagnosis with marked improvement in circulating blast concentration (15.3 x103/µL). During the course of treatment, which included the chemotherapeutics, fluid therapy, and oral supportive care, the chameleon’s weight increased 32.5% (199 g to 295 g). Unfortunately, the animal died 33 days after presentation. Histopathologic evaluation revealed hypocellular bone marrow with rare blast-like cells within vessels and mycotic granulomatous hepatitis with intralesional hyphae and fructiferous bodies. The blast cells expressed Iba1 but not CD3, CD79a, or lysozyme, suggesting a myeloid origin. Cell morphology further reinforced an acute myeloid leukemia. The authors surmised that the chameleon was responding to treatment, but ultimately succumbed to the mycotic hepatitis. This report describes the first case of acute myeloid leukemia with response to chemotherapeutic intervention in a veiled chameleon.

Allogeneic Stem Cell Transplantation for MDS

Myelodysplastic syndromes are clonal disorders with morphological dysplasia, a variable degree of cytopenia and a risk of transformation to acute myeloid leukemia. Prognosis is very variable and is defined by blast count, cytopenia, cytogenetics and more recently by somatic mutations, with IPSS or revised IPSS score being the most widely used to assess disease risk. HSCT remains the only curative treatment to date, with high-risk patients obtaining the biggest benefit. However, NRM should be carefully assessed before indicating the transplant in this usually old population, where organ toxicity and comorbid conditions are to be considered. Multi-domain assessment tools, such as CGA (comprehensive geriatric assessment) and EBMT score, are useful in this context and might guide physician decisions regarding the transplant. Indeed, with the development of reduced intensity conditioning regimens, the number of patient candidates for an HSCT has increased. Regarding pre-transplant treatment, patients with a blast excess > 10% might be treated with HMAs or chemotherapy, although there are no randomized trials confirming the benefit of this approach, even when achieving a complete response. Concerning donor choice, matched sibling donors continue to be the first option, although matched unrelated donors, and more recently haploidentical donors, have proven to be valid options and should be offered in the absence of a related donor. Relapse remains the main cause of transplantation failure. MRD assessment and pre-emptive or prophylactic use of HMA or other targeted inhibitors with or without DLI are accepted strategies to reduce relapse risk, but the prognosis in this context remains dismal, and is the subject for several ongoing clinical protocols.

Immunoexpression of CD34, CD117, and p53 in Hypocellular Bone Marrow Disorders

Objectives Hypocellular bone marrow (BM) disorders comprise heterogeneous entities associated with peripheral cytopenias and decreased production of hematopoietic cells in BM. This study was undertaken to analyze immunohistochemical expression of CD34, CD117, and p53 in morphologically diagnosed patients of hypocellular BM (aplastic anemia [AA], hypocellular myelodysplastic syndrome [h-MDS], and hypocellular acute myeloid leukemia [h-AML]). Materials and Methods BM specimens were obtained from patients presenting with pancytopenia/bicytopenia. On 30 patients diagnosed as hypocellular BM, immunohistochemistry (IHC) for CD34, CD117, and p53 was performed. Results BM cellularity was < 30% in all (100%) patients. Blast count was increased in h-MDS and h-AML. Features of dysplasia were noted in six (20%) patients. Out of these, three patients were diagnosed as h-MDS having bilineage/trilineage dysplasia, and the other three patients were of AA (11.5% patients) displaying only dyserythropoiesis. On IHC, percentage of BM CD34+ cells was increased in h-MDS+ h-AML (3.87 ± 0.86) as compared with AA (0.19 ± 0.15) and controls (0.81 ± 0.21), p = 0.01. Percentage of BM p53+ cells was also increased in h-MDS+ h-AML (2.9 ± 2.07) as compared with AA and controls, which did not show any p53+ cells, p = 0.0. No statistically significant difference was observed in the expression of CD117 in h-MDS+ h-AML (4.95 ± 3.40) compared with AA (4.49 ± 1.07), p = 0.99. Conclusion The study demonstrates the usefulness of CD34 and p53 immunoexpression as an important ancillary method in distinguishing various hypocellular BM disorders, especially h-MDS and AA. However, the role of CD117 remains unclear and needs to be evaluated further by larger studies.