ALBERT

Description: NPM1 mutation (NPM1c) defines the commonest molecular subtype of AML, which is molecularly heterogeneous, with outcome influenced by the pattern of cooperating mutations. This has generated interest in molecular profiling to guide treatment approach, particularly concerning allogeneic transplantation (SCT) in first complete remission (CR1). Patients with NPM1c AML with FLT3-ITD and/or DNMT3A mutations have been associated with poorer outcome and are widely considered candidates for SCT. Conversely, those with the NPM1c/FLT3-ITDneg genotype are no longer routinely transplanted in CR1, due to their generally favorable outcome. Given the molecular heterogeneity, use of real time quantitative PCR (RT-qPCR) to detect residual leukemia (MRD) could improve outcome prediction. However, its value has been questioned by recent studies providing evidence that relapse can arise from preleukemic clones. To address these issues we analysed sequential samples from 346 patients (median age 50y, 6-81y) with NPM1c AML treated in the UK NCRI AML17 trial (median follow-up 35mo). An established RT-qPCR assay with mutation-specific primers was used, allowing MRD detection in all patients, covering 27 NPM1 mutations. Assays were confirmed to be mutant specific, with a median sensitivity of 1 in 105 (1 in 103.7-7.1). Overall 2,569 follow-up samples (902 BM, 1667 PB) were analysed (median 6 samples/pt). To determine if MRD assessment provided independent prognostic information, targeted sequencing (Haloplex, Agilent Technologies) of 51 genes was undertaken in 223 cases with available diagnostic DNA. The panel included established recurrent mutation targets in NPM1c AML and 14 genes found to be mutated in whole exome sequencing of 27 cases with differing kinetics of relapse or sustained molecular remission (CRm). For patients in documented morphological CR, early MRD assessment distinguished those at markedly differing risk of relapse and overall survival (OS). For patients with NPM1 mutant transcripts still detectable in peripheral blood (PB) following chemotherapy course 2 (30 of 194, 15%), cumulative incidence of relapse was 77% at 3 years, compared to 28% in those testing PCR negative (p

Description: Background: Venetoclax (VEN) is a potent small molecule BH3-mimetic drug that selectively targets the prosurvival protein BCL-2 and has an emerging role for treatment in Acute Myeloid Leukaemia (AML). This ongoing Phase 1b study aims to evaluate the optimal dose, safety and efficacy of VEN in combination with modified intensive chemotherapy in fit, elderly patients with AML who have not received prior induction chemotherapy. Here we present updated data including molecular correlates of response and treatment outcomes. Methods: Eligibility: Patients were enrolled with AML (excluding APL), age ≥65 years (≥60 years if monosomal karyotype), ECOG 0-1 and adequate organ function. Prior HMA/LDAC was permitted after a 14-day washout. Treatment: 1) Dose escalation cohorts comprised VEN 50mg (Cohort A), 100mg (B), 200mg (C), 400mg (D) or 600mg (E); 2) a 7-day VEN pre-phase incorporating dose ramp-up to minimise tumour lysis risk followed by a 7-day overlap with chemotherapy (day -6 to +7); 3) attenuated induction chemotherapy with cytarabine 100mg/m2/day IVI d1-5 staggered with idarubicin 12mg/m2 IV d2-3. For patients in remission, 4 cycles of consolidation were administered, comprising 14 days of VEN (day -7 to +7) with bolus cytarabine (100mg/m2/day IV d+1-2) and idarubicin (12mg/m2 IV d+1) followed by 7 cycles of VEN monotherapy maintenance; planned to commence q28d. Antifungal azoles were avoided during VEN exposure. The first patient was enrolled 17JUL2016. Molecular studies- Next generation sequencing using a 54-gene TruSight myeloid panel was performed on baseline bone marrow samples. FLT3-ITD testing was performed by capillary electrophoresis. RT-qPCR was used to detect minimal residual disease (MRD) in NPM1-mutated cases (assay sensitivity: 10-5-10-6). Results: The data cut-off date was 13JUL2018. 44 patients were enrolled with 3 patients still in the induction cycle. Median age was 72 years (range 63-80 years; 23% ≥75 years), 66% of patients were male, 41% had secondary AML and 38% prior hypomethylating agent (HMA) exposure. Main grade ≥3 non-haematological adverse events during induction were febrile neutropenia (56%), sepsis (32%), rapid atrial fibrillation (15%), diarrhoea (12%), nausea (10%) and localised infection (10%). No clinical TLS was observed. One hematologic dose-limiting toxicity was reported in cohort E (VEN 600mg), but a maximum tolerated dose has not been reached. We observed progressive delay in platelet count recovery as patients proceeded with each cycle of therapy (median time to platelets ≥50x109/L was 25d in induction, 37d in consolidation 1 and 57d in consolidation 4). Treatment-related mortality was 7% in induction. 18/38 (47%) had ≥30% relative reduction in bone marrow (BM) blasts after 7 days of pre-phase VEN monotherapy, with no correlation between VEN dosage and the degree of BM blast reduction. Overall CR/CRi rate was 71%. CR/CRi was achieved in 95% of patients with de novo AML (vs 42% in secondary/therapy-related AML). Response rates were 88% in intermediate vs 46% in adverse cytogenetic risk AML. Responses in patients with prior HMA therapy were 43% and 84% for previously untreated patients. Molecular data were available for 41 patients. 98% had ≥1 mutation detected. (Figure 1) Responses in response-evaluable patients were most common in NPM1 mutant AML (100%; n=7), followed by RUNX1 (90%; n=11), RAS (90%; n=10) and IDH (89%; n=9). Lowest responses were observed in TP53 mutant AML (33%; n=9). NPM1 MRD assessment was performed on 6 patients, of which 5 (83%) achieved NPM1 MRD negativity. (Figure 2) Updated response, response duration and survival data will be presented, along with molecular characteristics of relapse. Conclusion: To date, VEN up to 600mg in combination with 5+2 induction chemotherapy is tolerable in fit elderly patients with AML. Initial response rates 〉80% were observed in de novo AML, as well as NPM1, RUNX1, RAS and IDH mutant AML, whereas responses were lower in patients with prior HMA exposure, adverse karyotype, secondary and TP53 mutant AML. Molecular determinants of relapse require further study. Disclosures Wei: Servier: Consultancy, Honoraria, Other: Advisory committee, Research Funding; Amgen: Honoraria, Other: Advisory committee, Research Funding; Novartis: Honoraria, Other: Advisory committee, Research Funding, Speakers Bureau; Pfizer: Honoraria, Other: Advisory committee; Celgene: Honoraria, Other: Advisory committee, Research Funding; Abbvie: Honoraria, Other: Advisory board, Research Funding, Speakers Bureau. Fong:Celgene: Other: Advisory board; Novartis: Other: Advisory board; Amgen: Research Funding; Pfizer: Other: Speaker fees. Reynolds:Novartis: Equity Ownership, Other: former employee of Novartis AG and holds stock in the company. . Roberts:Janssen: Research Funding; AbbVie: Research Funding; Genentech: Research Funding; Walter and Eliza Hall: Employment, Patents & Royalties: Employee of Walter and Eliza Hall Institute of Medical Research which receives milestone and royalty payments related to venetoclax.

Description: Acute myeloid leukemia (AML) is the most common acute leukemia diagnosed in adults, characterized by significant heterogeneity in terms of biology and clinical outcome. Improvements in sequencing technologies have led to the discovery of frequent somatic mutations in epigenetic modifiers, placing epigenetic deregulation in the center of AML. Yet, the global view and the impact of this deregulation on disease characteristics are under investigation. To gain a more comprehensive understanding of epigenetic deregulation in AML, particularly the heterogeneous subset with normal karyotype (CN-AML), associated with intermediate clinical prognosis, we performed H3K27me3 profiling on CN-AML patient samples. Primary bone marrow or peripheral blood samples containing more than 80% of blasts were selected from the Institut Paoli-Calmettes Biological Resources Center inventory for the purpose of genetic and epigenetic studies. We initially analyzed 35 CN-AML samples by ChIP coupled with hybridization on oligonucleotide promoter arrays (Chip-chip) for genomic H3K27me3 distribution. Clustering analysis revealed 586 highly H3K27me3-variable genomic regions across patients corresponding to 461 genes mostly involved in chromatin organization. The heterogeneity in the H3K27me3 profile was characterized by a remarkable H3K27me3 enrichment at the chromosome 6 p22.2-22 region that encompasses 70 kbp within the major HIST1 cluster. This striking H3K27me3 enrichment was covering 11 histone genes and was partially overlapping with the focal deletion at 6p22 found in acute lymphoblastic leukemia. The HIST1 H3K27me3 enrichment profile clearly distinguished 2 groups of CN-AML patients based on their HIST1 H3K27me3 level. In order to independently extend this observation, we analyzed the H3K27me3 status by using ChIP followed by qPCR (ChIP-qPCR) at the same HIST1 genomic locations, in an independent cohort of 51 CN-AML patients. This revealed the presence of this abnormal epigenetic profile in about 50% of the patients. CN-AML samples were split in two groups, according to the median H3K27me3 enrichment levels at the HIST1 cluster genes. These two groups were analyzed for clinical and molecular characteristics. Patients with high HIST1 H3K27me3 level had a markedly higher incidence of NPM1 mutation (89% vs. 40%; p= 1.75x10-5) and a lower incidence of WT1 mutation (0% vs. 20%; p=0.028). No significant association was observed with FLT3 (ITD and TKD), IDH1/2, DNMT3A nor ASXL1 mutations. Patients with high HIST1 H3K27me3 level had a significant longer leukemia free survival at 5 years (allo-grafted patients censored, LFS-allo; 13.33 vs. 8.92 months p=0.0053). Moreover, multivariate analysis showed that HIST1 H3K27me3 status provided a more powerful prognostic indicator than the NPM1mut/FLT3-ITDneg and NPM1/FLT3-ITD genotypes. In conclusion,using epigenetic profiling, our analysis has enabled the discovery of a new epigenetic alteration that affects CN-AML and impacts prognosis. We demonstrate that the HIST1 cluster is targeted by epigenetic events that lead to high H3K27me3 level and predicts a good prognosis. This may help refine risk stratification in AML, identifying a further group of patients unlikely to benefit from allogeneic transplantation in first remission. Overall, our data provide a proof of concept that epigenetic profiling could be used to discover new biomarkers with prognostic value. Disclosures No relevant conflicts of interest to declare.

Description: Lack of progress in curing AML is likely, in part, to be due to the genetic and functional heterogeneity of AML. ~13 Tier 1 mutations occur per patient sample arrayed in 2-5 clones (CGARN, N Engl J Med, 2013). Not all AML cell populations may be equally chemosensitive; for example, leukemia-propagating leukemic stem cells (LSC) are more chemoresistant. (Ishikawa et al., Nat Biotechnol, 2007). Additionally, the impact of genetic heterogeneity on LSC function is unclear. In ~ 70% of primary human AML with 〉2% CD34+ cells, LSCs exist within both CD34+CD38- and CD34+CD38+ compartments (Taussig et al., Blood, 2008), and have progenitor-like transcriptional programmes (Goardon et al., Cancer Cell, 2011). ~30% of AML with

Description: Background: Acute myeloid leukaemia (AML) arises from the transformation of hematopoietic stem and progenitor cells. Targeting BCL-2 with the BH3-mimetic venetoclax (VEN) has emerged as a highly efficacious treatment option for elderly patients with AML, in combination with either low-dose ara-C (LDAC) (Wei, ASH 2017) or hypomethylating agents (HMA) (Di Nardo, Lancet Oncol 2018). Long-term survival outcomes, however, remain poor among patients with adverse risk karyotype, who often harbour mutations in the TP53 gene. Identification of more effective treatment options with TP53 independent activity represents an area of high unmet therapeutic need in AML. Methods: Panobinostat (histone deacetylase inhibitor; HDACi) was obtained from Novartis, S55746 (BCL-2 inhibitor) was obtained from Servier, and venetoclax (BCL-2 inhibitor) was obtained from Selleck Chemicals. Primary AML samples were obtained from patients providing informed consent. For in vivo experiments, NOD/Rag-/-/Il2rgtm1Wjl Tg(IL3, CSF2, KITLG) (NRG-SG3) mice were used. Dosing for S55746 was 100mg/kg daily Mon-Fri and panobinostat 10mg/kg on Mon/ Wed/ Fri. Results: A panel of 22 drugs were screened for enhanced anti-leukaemic activity in combination with BH3-mimetics targeting either BCL-2 or MCL1 against 45 primary AML patient samples. This revealed the histone deacetylase inhibitor (HDACi) panobinostat to have substantially enhanced efficacy: LC50 at 48h was reduced by 〉2 logs when combined with VEN to target BCL-2 in 13/21 (62%) or S55746 in 19/24 (79%) cases. Targeted exome sequencing revealed adverse-risk AML, including TP53 mutant cases, to be sensitive to this combination. Studies performed in factor dependent myeloid (FDM) cells, derived from gene knockout mice, demonstrated cell death from panobinostat to be Bax/Bak dependent. CRISPR/Cas9 BIM (MV4;11) and TP53 (OCI-AML3) deleted AML cell lines confirmed panobinostat-VEN activity to be independent of these pathways. Comparison of panobinostat in combination with BCL-2 targeting showed the combination to be less affected by p53 deficiency than cytotoxic (idarubicin, ara-C) + BCL2 inhibitor combinations. Patient-derived xenograft (PDX) models confirmed that this combination was tolerable and able to rapidly suppress bone marrow AML in vivo. Exploratory CyTOF and Western blot studies in MV4;11 cells showed that panobinostat +/- BCL-2 targeting markedly suppressed levels of MYC, pSTAT5 and pERK. Conclusions: Combined targeting of HDAC and BCL-2 represents a promising, chemotherapy-free, treatment option for patients with AML, including sub-groups with adverse risk genomic characteristics. The combination may have particular relevance for patients with adverse risk AML, including cases defective in functioning TP53. Figure. Figure. Disclosures Teh: The Walter and Eliza Hall Institute of Medical Research: Other: Institutional funding for venetoclax including milestone and royalty payments.. Kraus-Berthier:servier: Employment. Kloos:Servier: Employment; Novartis: Other: Partnership. Schoumacher:Servier: Employment. Gray:The Walter and Eliza Hall Institute of Medical Research: Other: Institutional funding for venetoclax including milestone and royalty payments.. Wei:Celgene: Honoraria, Other: Advisory committee, Research Funding; Novartis: Honoraria, Other: Advisory committee, Research Funding, Speakers Bureau; Amgen: Honoraria, Other: Advisory committee, Research Funding; Pfizer: Honoraria, Other: Advisory committee; Servier: Consultancy, Honoraria, Other: Advisory committee, Research Funding; Abbvie: Honoraria, Other: Advisory board, Research Funding, Speakers Bureau.

Description: Key Points CXXC5 inhibits Wnt signaling and is a candidate tumor suppressor in AML. Low CXXC5 expression is an independent prognostic factor in AML.

Description: Relapse remains the most common cause of treatment failure for patients with acute myeloid leukemia (AML) who undergo allogeneic stem cell transplantation (alloSCT), and carries a grave prognosis. Multiple studies have identified the presence of measurable residual disease (MRD) assessed by flow cytometry before alloSCT as a strong predictor of relapse, but it is not clear how these findings apply to patients who test positive in molecular MRD assays, which have far greater sensitivity. We analyzed pretransplant blood and bone marrow samples by reverse-transcription polymerase chain reaction in 107 patients with NPM1-mutant AML enrolled in the UK National Cancer Research Institute AML17 study. After a median follow-up of 4.9 years, patients with negative, low (

Description: Introduction Relapse remains the most common cause of treatment failure for patients with acute myeloid leukaemia (AML) who undergo allogeneic stem cell transplantation (SCT) and carries a grave prognosis. Multiple studies have identified the presence of minimal residual disease (MRD) prior to SCT assessed by flow cytometry (FCM) as a strong predictor of relapse: however, little is known about the impact of molecular MRD pre-SCT. Molecular techniques can provide 100-1000 fold greater sensitivity than FCM in NPM1 mutated AML allowing identification of patients with very low level MRD prior to SCT. Peri-transplant management decisions for patients with positive molecular MRD are highly challenging due to the absence of robust outcome data. Methods Between 2009-14 the NCRI AML17 study enrolled 3215 adult non-APML patients aged 16-77 eligible for intensive chemotherapy. Central screening for NPM1 mutations was positive in 861/2949 (29%); 530 patients provided serial samples for MRD monitoring. Paired blood (PB) and bone marrow aspirates (BM) were requested after each chemotherapy cycle and then quarterly; additional samples were requested pre- and post-SCT. Samples were analysed by RT-qPCR using a suite of 27 mutation-specific reverse primers. Results were only fed back to clinicians after June 2012 when patients could be treated for confirmed re-emergent or persistent molecular positivity. Post-remission treatment was determined according to the validated NCRI risk score, with poor-risk patients recommended for SCT during first complete remission (CR1). Survival analysis was performed using the logrank test. Results In total 108/530 patients received SCT (CR1 57 (52%), after molecular relapse or progression (MR) 30 (28%), CR2 21 (19%)). Five-year survival post-SCT (5y-OS) was 65% in CR1, and 54% in MR/CR2 (p=0.3). After MR 26/30 patients received chemotherapy prior to SCT. Evaluable pre-SCT PB and BM samples taken within 60 days of SCT were available for 104 and 78 patients (both available n=74). Considering PB samples, 5y-OS was 73% (median OS (mOS) not reached (NR)) for MRD-ve patients (n=74) vs. 30% (mOS 8.1 m) for any PB positivity (n=30) (p

Description: Recent major advances in understanding the molecular basis of acute myeloid leukemia (AML) provide a double-edged sword. Although defining the topology and key features of the molecular landscape are fundamental to development of novel treatment approaches and provide opportunities for greater individualization of therapy, confirmation of the genetic complexity presents a huge challenge to successful translation into routine clinical practice. It is now clear that many genes are recurrently mutated in AML; moreover, individual leukemias harbor multiple mutations and are potentially composed of subclones with differing mutational composition, rendering each patient’s AML genetically unique. In order to make sense of the overwhelming mutational data and capitalize on this clinically, it is important to identify (1) critical AML-defining molecular abnormalities that distinguish biological disease entities; (2) mutations, typically arising in subclones, that may influence prognosis but are unlikely to be ideal therapeutic targets; (3) mutations associated with preleukemic clones; and (4) mutations that have been robustly shown to confer independent prognostic information or are therapeutically relevant. The reward of identifying AML-defining molecular lesions present in all leukemic populations (including subclones) has been exemplified by acute promyelocytic leukemia, where successful targeting of the underlying PML-RARα oncoprotein has eliminated the need for chemotherapy for disease cure. Despite the molecular heterogeneity and recognizing that treatment options for other forms of AML are limited, this review will consider the scope for using novel molecular information to improve diagnosis, identify subsets of patients eligible for targeted therapies, refine outcome prediction, and track treatment response.

Description: Background:The small molecule BCL-2 inhibitor Venetoclax (VEN) has emerged as a promising frontline therapy in combination with low dose cytarabine (LDAC) or hypomethylating agents in older patients with acute myeloid leukemia (AML)(DiNardo et al, Lancet Oncol 2018, Blood 2019; Wei et al,JCO 2019). The anti-leukemic activity of single agent VEN as monotherapy in newly diagnosed AML is unknown. This information would be useful for studies considering VEN as a maintenance therapy. We have previously presented preliminary outcomes from a phase 1b/2 study: Chemotherapy and Venetoclax in Elderly AML Trial (CAVEAT), which incorporated a 7-day single agent VEN run-in phase prior to combination with chemotherapy (Wei et al, ASH 2018). The study procedures incorporated a bone marrow assessment performed at study screening and on day 8, prior to commencement of chemotherapy (Figure 1A). This allowed us to explore the single agent activity of venetoclax on bone marrow blasts in treatment naïve patients with AML and to assess molecular dynamics of response. Methods:The CAVEAT trial included 51 de novo or secondary patients with AML aged ≥65 years and considered fit for intensive chemotherapy. The study enrolled patients to 5 VEN dose cohorts (50-100-200-400-600mg). VEN was administered on days 1-14 during induction. Chemotherapy commenced on day 8, with a 7-day VEN monotherapy pre-phase. Molecular studies:a 54-gene myeloid NGS panel (Illumina TruSight) and MassARRAY MALDI-TOF mass spectrometry was performed on DNA extracted from bone marrow aspirates. FLT3-ITD testing was by fragment analysis, PCR and capillary electrophoresis. Minimal residual disease (MRD) testing was performed by digital droplet PCR for IDH mutations (assay sensitivity: 10-4-10-5). Results: A total of 46 patients had paired BM assessments at screening and on day 8 for comparison. A ≥50% relative reduction in BM blasts was recorded in 13/46 (28%) patients. Figure 1B shows the relative BM blast reduction stratified by molecular subgroups. Patients with NPM1(n=9) or IDH2 (n=8) mutation achieved greater BM blast reductions (median of 56% and 55%, respectively) than IDH1 (n=6), TP53 (n=10) or FLT3-ITD (n=5) mutant cases (median of 37%, 17% and 7%, respectively). Three NPM1 mutant cases with