ALBERT

Description: Background: NGS of myeloid mutations is an integral part of AML clinical decision-making. There is currently no information regarding concordance between NGS panels in AML using samples from the same patient across various platforms in different diagnostic laboratories. To study this important question, we analyzed NGS of myeloid mutations in diagnostic samples from The Beat AML Master Trial (BAMT) for newly diagnosed older AML patients, and compared variant calls made between institutional laboratories enrolling the study subject with those made by Foundation Medicine (FM), the central laboratory used for treatment assignment in this precision medicine trial. Methods: We identified newly diagnosed AML patient samples (peripheral blood (PB) and/or bone marrow (BM)) from 2 lead institutions in the BAMT(Ohio State, OSU and Oregon Health and Sciences University, OHSU) that were analyzed by both the institutional and by FM from Nov 15, 2016 to Apr 15, 2019. Samples sent to both laboratories 〉3 days apart were excluded. Samples were analyzed at the institutional laboratories using their respective NGS mutational panels and by FM using the FoundationOne®Heme(FMH) NGS panel which utilizes capture based sequencing. The OSU NGS assay utilizes sequencing on Illumina MiSeq. The OHSU NGS assay employs semiconductor-based sequencing (Ion Torrent PGM platform). The variant allele frequency (VAF) sensitivity for detection for all 3 laboratories range from 1-2%. We evaluated the ability to identify mutations in 8 genes : FLT3, IDH1/ 2, NPM1, TET2, DNMT3A, WT1 and TP53 used in treatment assignment in theBAMT. A detection cutoff of 2% was used to define the presence or absence of a mutation. Overall, agreement was defined as the number of times the local and central laboratories made the same call divided by the total number of patients. Sensitivity was defined as the number of present calls made locally divided by the number of present calls made centrally, and specificity as the number of absent calls made locally divided by the number of absent calls made centrally. The overall kappa statistic, controlling for institution, provided another measure of agreement between local and central calls, where a value of 1 indicates perfect agreement. Results: 194 patient samples were identified using methods above and analyzed locally at the screening institution (125 at OSU, 69 at OHSU) and centrally at FM. Type of tissue analyzed for variants between local site and FM were 59 PB, 129 BM, and 6 with BM/PB mismatch. Overall agreement in presence/absence calls between local and central results for each of the 8 genes was over 95% (Table 1). There was perfect agreement for NPM1. The sensitivity was above 94% for all genes except TP53 (88.6%) and WT1 (63.6%). Failure to detect a mutation locally was primarily due to reporting of all TP53 variants, including variants of unknown significance (VUS) (5) by FM as agreed upon in the study protocol, detection at low levels below local site sensitivity cutoff (1), detection of variants in a portion of gene not covered at the local site(1)and possible artifact (1). For the WT1 gene, discordance in 5 samples included VUS (3) reported by FM ,a variant detected in a portion of the gene not covered at the local site(1).and difference in leukemic tissue analyzed with mutation not detected by the central laboratory on a PB sample, and present at the institutional lab on a BM sample; affecting the overall agreement and specificity but not sensitivity. Specificity was at least 98% for each of the 8 genes. Finally, most discrepancies in reported mutations in FLT3 (n=2), IDH1 (n=1), IDH2 (n=2), DNMT3A (n=4) and TET2 (n=5) were due to reporting of VUS in one laboratory and not by another. Conclusion: Detection of pathogenic myeloid mutations using orthogonal assays showed a high degree of concordance for genes used in therapeutic assignment on the BAMT.The small number of discordant results, in TP53 and WT1, were attributed to the reporting of VUS. This study illustrates the importance of quality control and standardization as NGS continues to be widely utilized in AML for clinical decision making, with a variety of platforms across multiple laboratories. Our next steps involve evaluating the differences in VAFs reported between local and central laboratories when a given mutation is identified, as well as the potential reasons for observed differences and clinical implications of known pathogenic mutations vs putative VUS. Disclosures Borate: Daiichi Sankyo: Consultancy; AbbVie: Consultancy; Novartis: Consultancy; Takeda: Consultancy; Pfizer: Consultancy. Vergilio:Foundation Medicine: Employment; Roche Holding AG: Equity Ownership. Stein:Novartis: Membership on an entity's Board of Directors or advisory committees; Celgene Corporation: Membership on an entity's Board of Directors or advisory committees; Daiichi Sankyo, Inc.: Membership on an entity's Board of Directors or advisory committees; Agios: Consultancy, Membership on an entity's Board of Directors or advisory committees; Astellas Pharma US, Inc: Membership on an entity's Board of Directors or advisory committees; Bioline: Membership on an entity's Board of Directors or advisory committees; Genentech: Membership on an entity's Board of Directors or advisory committees; PTC Therapeutics: Membership on an entity's Board of Directors or advisory committees; Syros: Membership on an entity's Board of Directors or advisory committees. Patel:France Foundation: Honoraria; Dava Oncology: Honoraria; Celgene: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau. Baer:Astellas: Research Funding; Abbvie: Research Funding; AI Therapeutics: Research Funding; Forma: Research Funding; Incyte: Research Funding; Kite: Research Funding; Takeda: Research Funding. Stock:Daiichi: Membership on an entity's Board of Directors or advisory committees; Astellas: Membership on an entity's Board of Directors or advisory committees; Agios: Membership on an entity's Board of Directors or advisory committees; Research to Practice: Honoraria; UpToDate: Honoraria; Kite, a Gilead Company: Membership on an entity's Board of Directors or advisory committees; Pfizer: Membership on an entity's Board of Directors or advisory committees. Schiller:Amgen: Other, Research Funding; Astellas: Research Funding; Biomed Valley Discoveries: Research Funding; Bristol Myer Squibb: Research Funding; Celgene: Research Funding, Speakers Bureau; Constellation Pharmaceutical: Research Funding; Daiichi Sankyo: Research Funding; Eli Lilly and Company: Research Funding; FujiFilm: Research Funding; Genzyme: Research Funding; Gilead: Research Funding; Incyte: Research Funding; J&J: Research Funding; Jazz Pharmaceuticals: Honoraria, Research Funding; Karyopharm: Research Funding; Novartis: Research Funding; Onconova: Research Funding; Pfizer Pharmaceuticals: Equity Ownership, Research Funding; Sangamo Therapeutics: Research Funding; Agios: Research Funding, Speakers Bureau. Blum:AmerisourceBergen: Consultancy; Boehringer Ingelheim: Research Funding; Celgene: Research Funding; Astellas,: Research Funding; Xencor: Research Funding; Forma: Research Funding. Kovacsovics:Pfizer: Research Funding; Jazz: Consultancy; Novartis: Research Funding; Abbvie: Research Funding; Amgen: Consultancy, Research Funding. Foran:Agios: Honoraria, Research Funding. Druker:Pfizer: Research Funding; OHSU (licensing fees): Patents & Royalties: #2573, Constructs and cell lines harboring various mutations in TNK2 and PTPN11, licensing fees ; Cepheid: Consultancy, Honoraria; Aileron Therapeutics: #2573, Constructs and cell lines harboring various mutations in TNK2 and PTPN11, licensing fees , Membership on an entity's Board of Directors or advisory committees; ALLCRON: Membership on an entity's Board of Directors or advisory committees; Amgen: Equity Ownership, Membership on an entity's Board of Directors or advisory committees; Aptose Biosciences: Consultancy, Equity Ownership, Membership on an entity's Board of Directors or advisory committees; Beta Cat: Membership on an entity's Board of Directors or advisory committees, Other: Stock options; GRAIL: Equity Ownership, Other: former member of Scientific Advisory Board; Patient True Talk: Consultancy; The RUNX1 Research Program: Membership on an entity's Board of Directors or advisory committees; Vivid Biosciences: Membership on an entity's Board of Directors or advisory committees, Other: Stock options; Beat AML LLC: Other: Service on joint steering committee; CureOne: Membership on an entity's Board of Directors or advisory committees; Celgene: Consultancy; Gilead Sciences: Other: former member of Scientific Advisory Board; ICON: Other: Scientific Founder of Molecular MD, which was acquired by ICON in Feb. 2019; Monojul: Other: former consultant; Novartis: Other: PI or co-investigator on clinical trial(s) funded via contract with OHSU., Patents & Royalties: Patent 6958335, Treatment of Gastrointestinal Stromal Tumors, exclusively licensed to Novartis, Research Funding; Bristol-Myers Squibb: Other: PI or co-investigator on clinical trial(s) funded via contract with OHSU., Research Funding; Pfizer: Other: PI or co-investigator on clinical trial(s) funded via contract with OHSU., Research Funding; Merck & Co: Patents & Royalties: Dana-Farber Cancer Institute license #2063, Monoclonal antiphosphotyrosine antibody 4G10, exclusive commercial license to Merck & Co; Dana-Farber Cancer Institute (antibody royalty): Patents & Royalties: #2524, antibody royalty; Burroughs Wellcome Fund: Membership on an entity's Board of Directors or advisory committees; Blueprint Medicines: Consultancy, Equity Ownership, Membership on an entity's Board of Directors or advisory committees; Bristol-Myers Squibb: Patents & Royalties, Research Funding. Byrd:Gilead: Other: Travel Expenses, Research Funding, Speakers Bureau; Genentech: Research Funding; Acerta: Research Funding; TG Therapeutics: Other: Travel Expenses, Research Funding, Speakers Bureau; Novartis: Other: Travel Expenses, Speakers Bureau; Pharmacyclics LLC, an AbbVie Company: Other: Travel Expenses, Research Funding, Speakers Bureau; Janssen: Consultancy, Other: Travel Expenses, Research Funding, Speakers Bureau; BeiGene: Research Funding; Ohio State University: Patents & Royalties: OSU-2S. Levine:C4 Therapeutics: Membership on an entity's Board of Directors or advisory committees; Isoplexis: Membership on an entity's Board of Directors or advisory committees; Celgene: Consultancy, Research Funding; Roche: Consultancy, Research Funding; Loxo: Membership on an entity's Board of Directors or advisory committees; Qiagen: Membership on an entity's Board of Directors or advisory committees; Amgen: Honoraria; Prelude Therapeutics: Research Funding; Novartis: Consultancy; Gilead: Consultancy; Lilly: Honoraria; Imago Biosciences: Membership on an entity's Board of Directors or advisory committees. Mims:Jazz Pharmaceuticals: Membership on an entity's Board of Directors or advisory committees; Astellas Pharmaceuticals: Membership on an entity's Board of Directors or advisory committees; PTC Therapeutics: Membership on an entity's Board of Directors or advisory committees; Agios Pharmaceuticals: Membership on an entity's Board of Directors or advisory committees; Abbvie: Membership on an entity's Board of Directors or advisory committees.

Description: Introduction: In contrast to younger pts with AML, those ages 60 years (y) and above often have multiple, sequentially acquired, somatic mutations that drive leukemogenesis. Long-term 10-y event-free survival (EFS) of non-transplanted older AML pts receiving intensive cytarabine/daunorubicin induction (7 and 3) is 2% and the median overall survival (OS) is less than 1 y (Vasu et al., Blood Adv 2018;2:1645-50). Divergent pathogenesis based upon sequentially acquired mutations with targetable founder alterations and recent introduction of new targeted therapies have prompted interest in precision medicine-based treatment of AML. In order to determine if new therapeutic treatment strategies perform better than current standards of care, it is important to understand the historical outcomes for defined genomic groups in older AML pts. Methods: In anticipation of a precision medicine-based trial initiated by the Leukemia and Lymphoma Society (LLS AML Master Study), we designed a precision medicine-based stratification considering "assignment to curative therapy with 7 and 3" for known responsive groups [i.e., core-binding factor (CBF) AML and NPM1-mutated(+)/FLT3-ITD- pts] followed by pts with defined driving cytogenetic aberrations [11q23/MLL-rearranged and TP53 wild-type/complex karyotype (≥3 chromosome abnormalities)] and pts with mutation clone with VAF ≥0.3 by next generation sequencing. For pts not assigned to any genomic group during the initial stratification, a second run-through of the algorithm was performed assessing for a mutation clone with VAF ≥0.2 (Figure 1). The following priority (in order of highest to lowest) was used: CBF-AML, NPM1+/FLT3-ITD-, 11q23/MLL-rearranged, IDH2+, IDH1+, TP53+, TP53 wild-type/complex karyotype, FLT3-ITD+ (both high and low allelic ratios included) or FLT3-TKD+, WT1+ or TET2+, and marker negative (all other karyotypes and mutations not defined by previous grouping). A well-characterized data set of 589 pts aged ≥60 y (range, 60-92) from the Alliance was analyzed to show outcomes of pts within specific genomic groups (Table 1). Identification of a second multi-institutional pt data set is currently on-going to validate these findings. Results: In the Alliance cohort, 516 of 589 (88%) pts were assigned solely based upon cytogenetic group or dominant mutational clone with VAF ≥0.3 and 11 (1%) patients were assigned based off of VAF ≥0.2, thus providing support for this algorithm. The remaining 62 pts were assigned to the marker-negative group. As this algorithm is designed to assign therapy and assess outcome on an intent-to-treat basis, pts who suffered early death (ED), defined as death within 30 days of starting therapy irrespective of cause, were included. Baseline characteristics among groups were similar with the following exceptions: 1) CBF-AML and NPM1+/FLT3-ITD- pts having equal male and female pts with other groups having male predominance; 2) white blood cell counts being highest in NPM1+/FLT3-ITD-, 11q23/MLL-rearranged and FLT3-ITD+ or TKD+ groups; 3) percent of bone marrow blasts were lowest in the TP53+ group. Outcome endpoints are summarized in Table 1. Early death (ED) occurred in 20% of pts, most commonly in TP53+ (41%), IDH1+ (24%) and FLT3-ITD+ or TKD+ (23%) groups. Considering ED, the complete remission (CR) rates were above 50% in the CBF-AML (72%), and NPM1+/FLT3-ITD- (67%) groups, whereas in other groups they ranged between 30% and 50%, except for TP53+ at 17%. The 3-y disease-free survival (DFS) ranged from 0 to 13% for most groups, whereas only NPM1+/FLT3-ITD- (27%) and CBF-AML (30%) pts appeared to gain long-term benefit from 7 and 3. Three-y OS was 0-16% for most groups, except NPM1+/FLT3-ITD- pts at 27% and CBF-AML pts at 33%. Conclusion: Our analysis of a large older AML pt cohort provides evidence of the feasibility of classifying this disease based upon long-term benefit from 7 and 3. We also use cytogenetic/dominant mutation clone identification for precision medicine-based assignment to novel targeted therapies where 7 and 3 lacks impact on long-term outcome. These data can also serve as a historical control population for pts treated as part of the LLS AML Master Study and for other efforts brought forth to advance novel therapies in select genomic groups of older AML pts. Support: U10CA180821, U10CA180882, U10CA180861, U24CA196171 ClinicalTrials.gov Identifiers: NCT00048958 (8461) and NCT00900224 (20202) Disclosures Mims: Agios Pharmaceuticals: Consultancy, Membership on an entity's Board of Directors or advisory committees; Abbvie Pharmaceuticals: Membership on an entity's Board of Directors or advisory committees; Novartis: Consultancy. Borate:Agios: Consultancy; Novartis: Consultancy. Stein:Celgene: Consultancy; Bayer: Consultancy; Pfizer: Consultancy; Agios: Consultancy; Novartis: Consultancy; Daiichi Sankyo: Consultancy. Kolitz:Magellan Health: Consultancy, Honoraria. Wang:Jazz: Speakers Bureau; Pfizer: Consultancy, Membership on an entity's Board of Directors or advisory committees; Novartis: Speakers Bureau; Novartis: Speakers Bureau; Jazz: Speakers Bureau; Abbvie: Consultancy, Membership on an entity's Board of Directors or advisory committees; Amgen: Consultancy; Pfizer: 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; Amgen: Consultancy. Powell:Rafael Pharmaceuticals: Membership on an entity's Board of Directors or advisory committees. Levine:Epizyme: Patents & Royalties; Qiagen: Equity Ownership, Membership on an entity's Board of Directors or advisory committees; Prelude: Research Funding; Loxo: Consultancy, Equity Ownership; C4 Therapeutics: Equity Ownership; Isoplexis: Equity Ownership; Gilead: Honoraria; Janssen: Consultancy, Honoraria; Roche: Consultancy, Research Funding; Novartis: Consultancy; Celgene: Consultancy, Research Funding; Imago: Equity Ownership. Druker:Celgene: Consultancy; Leukemia & Lymphoma Society: Membership on an entity's Board of Directors or advisory committees, Research Funding; Henry Stewart Talks: Patents & Royalties; Millipore: Patents & Royalties; Cepheid: Consultancy, Membership on an entity's Board of Directors or advisory committees; Novartis Pharmaceuticals: Research Funding; Beta Cat: Membership on an entity's Board of Directors or advisory committees; ARIAD: Research Funding; Blueprint Medicines: Consultancy, Equity Ownership, Membership on an entity's Board of Directors or advisory committees; McGraw Hill: Patents & Royalties; Vivid Biosciences: Membership on an entity's Board of Directors or advisory committees; Aileron Therapeutics: Consultancy; Monojul: Consultancy; Fred Hutchinson Cancer Research Center: Research Funding; Bristol-Meyers Squibb: Research Funding; Gilead Sciences: Consultancy, Membership on an entity's Board of Directors or advisory committees; GRAIL: Consultancy, Membership on an entity's Board of Directors or advisory committees; MolecularMD: Consultancy, Equity Ownership, Membership on an entity's Board of Directors or advisory committees; Amgen: Membership on an entity's Board of Directors or advisory committees; Patient True Talk: Consultancy; Oregon Health & Science University: Patents & Royalties; ALLCRON: Consultancy, Membership on an entity's Board of Directors or advisory committees; Third Coast Therapeutics: Membership on an entity's Board of Directors or advisory committees; Aptose Therapeutics: Consultancy, Equity Ownership, Membership on an entity's Board of Directors or advisory committees.

Description: A multitude of somatic genomic alterations contribute to the pathogenesis of acute myeloid leukemia (AML). Despite these important biologic insights, current therapeutic approaches to AML remain limited, particularly in adults ≥ 60. The Leukemia & Lymphoma Society (LLS)-led Beat AML trial was designed to assess whether a multi-center clinical trial could use genetic profiling to assign patients (pts) to molecularly defined, subtype-specific therapies within 7 days, and to delineate the role of new therapies in the first-line treatment of AML, with the goal of improving outcomes in older pts with AML through the use of mechanism based novel therapies. Pt eligibility included age ≥ 60 years with non-APML AML, no CNS leukemia, no prior hypomethylating agent (HMA) therapy and no clinical need for emergent therapy. Eligible pts were profiled using local cytogenetics and next generation sequencing (NGS) assay (Foundation Medicine, Inc.) with all molecular data required for treatment assignment (TA) obtained ≤ 7 days. TA was made centrally using a prioritization schema incorporating cytogenetics [t(8;21], inv(16), MLL rearrangement, complex karyotype ≥ 3 abn) and somatic mutations present in a dominant AML clone with a variant allele frequency (VAF) 〉0.3. If no cytogenetic abnormality or mutation with VAF ≥ 0.3 was observed, VAF ≥ 0.2 was used for TA. The trial opened with 3 arms but currently has 11 treatment arms with 7 novel agents (NA) shown in Table 1. Treatment among different arms include either NA followed by combination of NA + HMA if no response, upfront combination of NA + HMA, or NA + intensive chemotherapy for select groups. Current treatment prioritization and TA based upon enrollment are shown in Table 2. Enrollment began November 2016 with a data cut off of April 30, 2018. At data cutoff, 268 pts have enrolled with a median age of 72 years (range: 60 to 92) and 38% being ≥ 75 years; 43% were female; median WBC was 4.8 x 109/L (range: 0.5 to 194.1) and WBC 〉 50 x 109/L in 9.3%; median Hgb was 8.4 g/dL (range: 3.9 to 15); median platelet count was 61 x 109/L (range: 7 to 649). Of the 268 patients, 210 had AML with TA. 53 pts were ineligible for enrollment, most commonly due to an alternative diagnosis, and 5 pts have a treatment decision pending. All pts had cytogenetic results available by 7 days. We achieved TA within 7 days in 106 of the 109 (97.2%) pts in the feasibility phase, and 200/210 (95.2%) of the overall cohort, meeting feasibility requirements. Of the 10 pts with delayed treatment assignment, 1 pt had suboptimal specimen quality whereas 9 pts had delayed TA due to technical (7/10) or instrumentation failure (2/10). All pts had cytogenetics available by 7 days. TA is shown in Table 2. These data confirm the feasibility of a precision medicine TA trial in newly diagnosed pts with AML. The Beat AML trial is dynamic by design, with different arms opening over time and all trial arms designed to detect for substantive clinical efficacy. As shown in Figure 1, of the 210 eligible AML pts enrolled, 7 pts (3.3%) died during the first 7 days prior to TA, 12 pts (5.7%) received alternative treatments prior to TA and 81 pts (38.6%) received an alternative treatment after TA. At time of analysis, weekly safety calls assessed that 23 pts went on an alternative clinical trial deemed better for them than Beat AML, and 40 pts received other standard-of-care therapies, 13 pts received palliative care and 5 pts were not specified. Special events of interest (disease worsening or progression) were assessed in 19 (9.0%) of pts. Of those going onto treatment, 110 pts (52.4%) received treatment on one of the Beat AML sub-studies. At time of abstract submission, one sub-study had completed phase 2 enrollment with positive results using monotherapy as measured by CR/CRi attainment (Study S3 with enasidenib +/- HMA: 43% CR/Cri rate) and is currently in expansion to further assess efficacy of this NA in newly diagnosed AML. Three additional studies have completed phase 1b dose escalation for combined NA + HMA therapy. An update including overall (for all enrolled pts) survival, sub-study-specific survival, and survival of patients receiving alternative treatment will be presented. Our data support the feasibility of a rapid precision medicine approach in older pts with previously untreated AML. The Beat AML trial is a model for dynamic, mechanism- based clinical trials in blood cancers where genomic analysis may inform, accelerate, and improve drug development. Disclosures Levine: Roche: Consultancy, Research Funding; Novartis: Consultancy; Isoplexis: Equity Ownership; Janssen: Consultancy, Honoraria; Prelude: Research Funding; Imago: Equity Ownership; Epizyme: Patents & Royalties; Celgene: Consultancy, Research Funding; C4 Therapeutics: Equity Ownership; Qiagen: Equity Ownership, Membership on an entity's Board of Directors or advisory committees; Gilead: Honoraria; Loxo: Consultancy, Equity Ownership. Mims:Agios Pharmaceuticals: Consultancy, Membership on an entity's Board of Directors or advisory committees; Abbvie Pharmaceuticals: Membership on an entity's Board of Directors or advisory committees; Novartis: Consultancy. Borate:Agios: Consultancy; Novartis: Consultancy. Stein:Novartis: Consultancy; Daiichi Sankyo: Consultancy; Pfizer: Consultancy; Celgene: Consultancy; Bayer: Consultancy; Agios: Consultancy. Patel:Celgene: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; France Foundation: Honoraria; Dava Oncology: Honoraria. Stock:Jazz Pharmaceuticals: Consultancy. Deininger:Pfizer: Consultancy, Membership on an entity's Board of Directors or advisory committees; Blueprint: Consultancy. Vergilio:Foundation Medicine Inc: Employment. Brennan:Foundation: Employment, Equity Ownership. Vietz:Foundation Medicine: Employment, Equity Ownership. Druker:ARIAD: Research Funding; Oregon Health & Science University: Patents & Royalties; MolecularMD: Consultancy, Equity Ownership, Membership on an entity's Board of Directors or advisory committees; Aileron Therapeutics: Consultancy; ALLCRON: Consultancy, Membership on an entity's Board of Directors or advisory committees; Millipore: Patents & Royalties; Celgene: Consultancy; Bristol-Meyers Squibb: Research Funding; McGraw Hill: Patents & Royalties; Third Coast Therapeutics: Membership on an entity's Board of Directors or advisory committees; Novartis Pharmaceuticals: Research Funding; Monojul: Consultancy; Blueprint Medicines: Consultancy, Equity Ownership, Membership on an entity's Board of Directors or advisory committees; GRAIL: Consultancy, Membership on an entity's Board of Directors or advisory committees; Beta Cat: Membership on an entity's Board of Directors or advisory committees; Patient True Talk: Consultancy; Henry Stewart Talks: Patents & Royalties; Leukemia & Lymphoma Society: Membership on an entity's Board of Directors or advisory committees, Research Funding; Cepheid: Consultancy, Membership on an entity's Board of Directors or advisory committees; Fred Hutchinson Cancer Research Center: Research Funding; Vivid Biosciences: Membership on an entity's Board of Directors or advisory committees; Gilead Sciences: Consultancy, Membership on an entity's Board of Directors or advisory committees; Aptose Therapeutics: Consultancy, Equity Ownership, Membership on an entity's Board of Directors or advisory committees; Amgen: Membership on an entity's Board of Directors or advisory committees.

Description: Introduction: The BeatAML master trial is evaluating the use of precision medicine via genomically guided therapy in acute myeloid leukemia (AML). A variety of assays are used to test patient samples including cytogenetic karyotyping, fluorescence in situ hybridization (FISH), and next-generation sequencing (NGS)-based approaches to analyze genomic alterations. We developed an algorithm to extract karyotype information from NGS-based genomic sequencing data in the BeatAML cohort. We also utilized this algorithm to retrospectively study 1603 unique AML samples collected during routine clinical care. Methods: Comprehensive genomic profiling (CGP) was performed using a CLIA/CAP/NYS approved DNA and RNA hybrid capture-based next-generation sequencing assay that sequences 426 genes in DNA and 265 genes to capture fusions by RNA. We analyzed aneuploidy by comparing the log ratio of read counts in tumor DNA to a process matched normal control and developed signal to noise metrics to measure chromosome arm copy number. A chromosome arm was considered altered if 〉50% of the arm was altered. Chromosome (chr) 5q was also considered lost if only chr5q31 (containing EGR1) was lost. Based on the noise metrics of each sample, we also calculated a per sample limit of detection, which was defined as the lowest percentage of cells that could have a single copy gain or loss and be detected. We validated chr5q loss, chr7q loss, and chr8 gain using FISH results obtained from available BeatAML samples as the gold standard. To better understand the genomic landscape of AML, we also included 1603 samples run in standard clinical practice. False discovery rate (FDR) was assessed using the Bonferroni method. Results: We developed a method to analyze chr5q loss, chr7q loss and chr8 gain that had 95% concordance across all chromosomes compared to the FISH gold standard. The median limit of detection was 10.1% (percentage of cells required to have a single copy gain/loss to be detected). Overall concordance adjusted for limit of detection was 97% with 92% sensitivity (55/60 chromosomes) and 99% specificity (162/164 chromosomes) with similar performance across chromosomes. For chr7q loss and chr8 gain, over 50% of the chromosomal region was altered. However, the size of the loss on chr5q varied widely from the entire arm to a single gene (EGR1). We next applied the algorithm to 1603 unique patient samples analyzed by CGP during routine clinical care. We detected loss of chr5q in 10.9% (174), loss of chr7q in 10.4% (166), and gain of chr8 in 9.2% (147) of AML samples. Frequently altered genes in this cohort included FLT3 (21%, 337), RUNX1 (20.5%, 328), DNMT3A (17.5% 280), and TP53 (17.5%, 280). To further explore the genomic landscape, we analyzed the cooccurrence of each chromosomal alteration with all genes assayed. All three chromosomal aberrations exhibited significant cooccurrence with each other and TP53 (FDR P 〈 0.05). TP53 was altered in 75% (130/174) of chr5q loss samples 49% (82/166) of chr7q loss samples and 37% (55/147) of chr8 gain samples. Loss of chr5q also exhibited significant mutual exclusivities with FLT3, DNMT3A, NPM1, SRSF2, ASXL1, CEBPA, and WT1 (FDR P 〈 0.05). Loss of chr7q exhibited a slightly different mutual exclusivity profile with FLT3, NPM1, and PTPN11 (FDR P 〈 0.05). The difference in the cooccurrence profile between chr5q and chr7q was not a matter of p-value cutoffs since the magnitude of effect varied widely between groups. Conclusions: We demonstrated an NGS-based algorithm to determine karyotype that has a high concordance with FISH results. Limit of detection was equivalent to karyotyping by metaphase analysis but slightly worse than FISH assays on freshly prepared samples. We identified a previously described genomic stratification of TP53-aneuploidy since chromosomal aberrations and TP53 exhibited significant cooccurrence. However, only 50% of samples with loss of chr5q exhibited loss of chr7q and vice versa. While both were mutually exclusive with FLT3 and NPM1, loss of chr5q was mutually exclusive with several genes of prognostic significance including chromatin factors (DNMT3A) and splice factors (SRSF2). This study shows how NGS-based approaches can capture both chromosome arm level copy number alterations as well as all four categories of genomic alterations, thereby enabling risk stratification and identification of potential treatment options as defined in current NCCN guidelines. Disclosures Pavlick: Foundation Medicine Inc: Employment. Montesion:Foundation Medicine Inc: Employment. Severson:Foundation Medicine Inc: Employment. Brennan:Foundation Medicine Inc: Employment. Frampton:Foundation Medicine Inc: Employment, Other: Employee and stockholder. He:Foundation Medicine Inc: Employment. Levine:Roche: Consultancy, Research Funding; Epizyme: Patents & Royalties; Celgene: Consultancy, Research Funding; Isoplexis: Equity Ownership; Prelude: Research Funding; Qiagen: Equity Ownership, Membership on an entity's Board of Directors or advisory committees; Gilead: Honoraria; Janssen: Consultancy, Honoraria; Novartis: Consultancy; C4 Therapeutics: Equity Ownership; Imago: Equity Ownership; Loxo: Consultancy, Equity Ownership. Vergilio:Foundation Medicine Inc: Employment. Albacker:Foundation Medicine Inc: Employment; Foundation Medicine Inc: Employment.

Description: Introduction: Inherited predisposition to myeloid malignancies in adults may be more common than previously suggested with recent studies suggesting a prevalence of candidate predisposition alleles in 15-20% of patients. An inherited predisposition may not be considered in older AML patients despite significant clinical implications for family members as potential stem cell transplant donors. To better define the role of inherited genetic alterations in older AML patients , we analyzed a unique cohort of newly diagnosed older (〉60 years) patients enrolled in) Beat AML® Master Trial(BAMT) for candidate genes associated with a known or putative inherited cancer predisposition. Methods: We analyzed extracted DNA from skin and/or saliva samples compared to paired leukemia samples of 176 AML patients enrolled in the BAMT. All samples underwent genomic profiling using a modified FoundationOne®Heme platform (capture-based) and/or the Oregon Health Sciences University panel (amplicon-based), evaluating 477 and 220 genes respectively, with a known role in hematologic malignancies. Germline(GL) variants were identified by the haplotype-based Bayesian genetic variant detector FreeBayes and using variant allele frequency(VAF) values. The pathogenicity and clinical significance of the variants was interpreted according to the 2015 ACMG/AMP guidelines while the AMP/CAP/ASCO guidelines and various disease databases were used in the somatic variant calls. Results: -The mutational landscape of the 176 newly diagnosed older AML patients is detailed in Table 1. Our cohort has a higher proportion of adverse risk patients, consistent with an older AML patient population. 27 pathogenic or likely pathogenic GL variants were detected in 24 AML patients, with a germline mutation prevalence of 14% in this cohort. Deleterious GL mutations were found in the gene DDX41 (5), followed by SBDS (4), CHEK2 (4), MPL (3), BRCA2 (2), HAX1 (2), DNAH9 (2), FANCA (1), FANCL (1), SAMD9 (1), BLM (1), and ATM (1) (Table 2). The types of mutations included missense mutations (9), nonsense mutations (8), frameshift mutations (7), splice site mutations (2), and an exonic deletion (1). Family history of leukemia was available on 129 patients from this cohort. 12 patients have at least one family member with AML. Of these 12 patients, 2 had a deleterious GL alteration identified. Along with the 14% prevalence of pathogenic/likely pathogenic GL mutations , there were an additional 181 GL variants of unknown significance (VUS) in 102 patients, seen in genes implicated in inherited predisposition to hematologic malignancies, most commonly variants in DOCK8 and CREBBP(〉5% VUS) with both genes being implicated in leukemogenesis . As skin and/or saliva samples were collected at the time of AML diagnosis, tumor-in-normal presence was expectedly observed. The median VAF for somatic mutations was significantly lower (p 〈 0.0001) in skin (median 6%; mean 9%; standard deviation (SD) 10%; N=562 variants) than in saliva (median 17%; mean 21%; SD 16%; N=368 variants). In 37 patients who had both saliva and skin tissue concomitantly ,skin had a significantly lower tumor-in-normal presence (median VAF 5%, mean 8%, SD 8%;) than saliva (median 15%, mean 20%, SD 16%)(p 〈 0.0001). Conclusions: We found a prevalence of 14% pathogenic/ likely pathogenic GL mutations in cancer predisposition genes in this unique cohort of newly diagnosed older AML patients. This finding has potential clinical implications for patients and family members. We also found a large number of VUS in genes implicated in hematological malignancies. Additional studies linking candidate VUS' to familial predisposition to understand contribution to AML predisposition are needed. We are in the process of comparing the manual curation of ACMG classification of pathogenicity with a computational curation algorithm to assess the potential for automated classification of GL variants. Our study suggests the choice of source for germline DNA in patients with AML is variably impacted by leukemic contamination. Cultured skin fibroblasts are the current standard for tumor-normal paired genotyping, with the caveat of being labor intensive and not routinely performed in clinical diagnostic laboratories. This is a critical consideration for rapid GL screening of patients and family members with hematologic malignancies and suspected cancer predisposition. Disclosures Borate: Novartis: Consultancy; Takeda: Consultancy; Pfizer: Consultancy; Daiichi Sankyo: Consultancy; AbbVie: Consultancy. Mims:Abbvie: Membership on an entity's Board of Directors or advisory committees; Agios Pharmaceuticals: Membership on an entity's Board of Directors or advisory committees; PTC Therapeutics: Membership on an entity's Board of Directors or advisory committees; Astellas Pharmaceuticals: Membership on an entity's Board of Directors or advisory committees; Jazz Pharmaceuticals: Membership on an entity's Board of Directors or advisory committees. Stein:Agios: Consultancy, Membership on an entity's Board of Directors or advisory committees; Astellas Pharma US, Inc: Membership on an entity's Board of Directors or advisory committees; Celgene Corporation: Membership on an entity's Board of Directors or advisory committees; Daiichi Sankyo, Inc.: Membership on an entity's Board of Directors or advisory committees; Bioline: Membership on an entity's Board of Directors or advisory committees; Genentech: Membership on an entity's Board of Directors or advisory committees; Novartis: Membership on an entity's Board of Directors or advisory committees; PTC Therapeutics: Membership on an entity's Board of Directors or advisory committees; Syros: Membership on an entity's Board of Directors or advisory committees. Patel:Celgene: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Dava Oncology: Honoraria; France Foundation: Honoraria. Baer:Astellas: Research Funding; Abbvie: Research Funding; AI Therapeutics: Research Funding; Forma: Research Funding; Incyte: Research Funding; Kite: Research Funding; Takeda: Research Funding. Stock:Agios: Membership on an entity's Board of Directors or advisory committees; Astellas: Membership on an entity's Board of Directors or advisory committees; UpToDate: Honoraria; Daiichi: Membership on an entity's Board of Directors or advisory committees; Pfizer: Membership on an entity's Board of Directors or advisory committees; Kite, a Gilead Company: Membership on an entity's Board of Directors or advisory committees; Research to Practice: Honoraria. Schiller:Bristol Myer Squibb: Research Funding; Celgene: Research Funding, Speakers Bureau; Constellation Pharmaceutical: Research Funding; Daiichi Sankyo: Research Funding; Agios: Research Funding, Speakers Bureau; Amgen: Other, Research Funding; Astellas: Research Funding; Biomed Valley Discoveries: Research Funding; Eli Lilly and Company: Research Funding; FujiFilm: Research Funding; Genzyme: Research Funding; Gilead: Research Funding; Incyte: Research Funding; J&J: Research Funding; Jazz Pharmaceuticals: Honoraria, Research Funding; Karyopharm: Research Funding; Novartis: Research Funding; Onconova: Research Funding; Pfizer Pharmaceuticals: Equity Ownership, Research Funding; Sangamo Therapeutics: Research Funding. Blum:AmerisourceBergen: Consultancy; Forma: Research Funding; Xencor: Research Funding; Boehringer Ingelheim: Research Funding; Celgene: Research Funding; Astellas,: Research Funding. Shami:JSK Therapeutics: Employment, Equity Ownership; Amgen: Research Funding; Pfizer: Research Funding; Cantex: Research Funding; Aptevo: Research Funding; Jazz: Consultancy, Honoraria; Abbvie: Consultancy, Honoraria; Agios: Consultancy, Honoraria; Lone Star Thiotherapies: Equity Ownership. Foran:Agios: Honoraria, Research Funding. Byrd:Acerta: Research Funding; Gilead: Other: Travel Expenses, Research Funding, Speakers Bureau; Genentech: Research Funding; Novartis: Other: Travel Expenses, Speakers Bureau; Pharmacyclics LLC, an AbbVie Company: Other: Travel Expenses, Research Funding, Speakers Bureau; TG Therapeutics: Other: Travel Expenses, Research Funding, Speakers Bureau; Ohio State University: Patents & Royalties: OSU-2S; BeiGene: Research Funding; Janssen: Consultancy, Other: Travel Expenses, Research Funding, Speakers Bureau. Druker:OHSU (licensing fees): Patents & Royalties: #2573, Constructs and cell lines harboring various mutations in TNK2 and PTPN11, licensing fees ; Bristol-Myers Squibb: Other: PI or co-investigator on clinical trial(s) funded via contract with OHSU., Research Funding; Novartis: Other: PI or co-investigator on clinical trial(s) funded via contract with OHSU., Patents & Royalties: Patent 6958335, Treatment of Gastrointestinal Stromal Tumors, exclusively licensed to Novartis, Research Funding; Monojul: Other: former consultant; Vivid Biosciences: Membership on an entity's Board of Directors or advisory committees, Other: Stock options; Beat AML LLC: Other: Service on joint steering committee; Merck & Co: Patents & Royalties: Dana-Farber Cancer Institute license #2063, Monoclonal antiphosphotyrosine antibody 4G10, exclusive commercial license to Merck & Co; Dana-Farber Cancer Institute (antibody royalty): Patents & Royalties: #2524, antibody royalty; Aileron Therapeutics: #2573, Constructs and cell lines harboring various mutations in TNK2 and PTPN11, licensing fees , Membership on an entity's Board of Directors or advisory committees; Bristol-Myers Squibb: Patents & Royalties, Research Funding; Pfizer: Research Funding; ALLCRON: Membership on an entity's Board of Directors or advisory committees; Amgen: Equity Ownership, Membership on an entity's Board of Directors or advisory committees; Aptose Biosciences: Consultancy, Equity Ownership, Membership on an entity's Board of Directors or advisory committees; Beta Cat: Membership on an entity's Board of Directors or advisory committees, Other: Stock options; The RUNX1 Research Program: Membership on an entity's Board of Directors or advisory committees; Patient True Talk: Consultancy; GRAIL: Equity Ownership, Other: former member of Scientific Advisory Board; Cepheid: Consultancy, Honoraria; Blueprint Medicines: Consultancy, Equity Ownership, Membership on an entity's Board of Directors or advisory committees; Burroughs Wellcome Fund: Membership on an entity's Board of Directors or advisory committees; Celgene: Consultancy; Pfizer: Other: PI or co-investigator on clinical trial(s) funded via contract with OHSU., Research Funding; ICON: Other: Scientific Founder of Molecular MD, which was acquired by ICON in Feb. 2019; CureOne: Membership on an entity's Board of Directors or advisory committees; Gilead Sciences: Other: former member of Scientific Advisory Board. Vergilio:Foundation Medicine, Inc.: Employment; F. Hoffman La Roche, Ltd.: Equity Ownership. Levine:Imago Biosciences: Membership on an entity's Board of Directors or advisory committees; Prelude Therapeutics: Research Funding; C4 Therapeutics: Membership on an entity's Board of Directors or advisory committees; Roche: Consultancy, Research Funding; Celgene: Consultancy, Research Funding; Amgen: Honoraria; Gilead: Consultancy; Lilly: Honoraria; Qiagen: Membership on an entity's Board of Directors or advisory committees; Isoplexis: Membership on an entity's Board of Directors or advisory committees; Loxo: Membership on an entity's Board of Directors or advisory committees; Novartis: Consultancy.

Description: The majority of patients with acute myeloid leukemia (AML), including nearly all patients older than age 60, present with multiple, sequentially acquired, somatic mutations. The 5-year overall survival (OS) for AML patients ≥ 60 with the current standard-of-care is less than 10 percent and the median OS in most genetically defined subtypes is 〈 1 year. The Leukemia & Lymphoma Society (LLS) Beat AML Master Trial is a precision medicine trial for previously untreated AML pts age ≥ 60. Eligible patients are assigned to an interventional sub-study based upon an algorithm incorporating cytogenetic and mutational analysis, all within 7 days of enrollment. The primary objective of this phase 1B/II sub-study is to assess the efficacy of the oral IDH2 inhibitor enasidenib, as measured by overall response rate, in newly diagnosed AML patients, ≥ 60, with IDH2 mutant AML. Pt eligibility included ECOG performance status of 0-2, AST/ALT 〈 5 x the upper limit of normal (ULN), bilirubin ≤ 2.0 x ULN, creatinine ≤ 1.5 x ULN, cardiac ejection fraction of 40%, and no prior chemotherapy for AML or MDS. Exclusion criteria included symptomatic disseminated intravascular coagulation, leukostasis requiring urgent therapy, active hepatitis, or active second malignancy. Patients were treated with enasidenib 100 mg/day in continuous 28-day cycles. Azacitidine (75 mg/m2 days 1-7) was added to enasidenib for patients not achieving a complete remission or complete remission with incomplete hematologic recovery (CR/CRi) by cycle 5, or those with earlier progression as part of a delayed phase 1b study using a standard 3 + 3 design. At data cut off (April 30, 2018), 24 patients were consented to the trial and 23 received therapy. Of these, 18 (78%) had an IDH2 R140 and 5 (22%) had an IDH2 R172 mutation. The median age was 76 (range 62 -84) and 57% were female. Median WBC was 6.0 x 109/L (range .69-30.1), hemoglobin 8.2 g/dl (range 6.8-12.8) and platelets of 66 x 1012/L (range 6-517). 44% of patients had abnormal cytogenetics, including 17 % which were high risk according to CALGB criteria. Of the 23 patients enrolled, there were no deaths within the first 28 days of treatment. A total of 13 pts experienced one or more serious adverse events on enasidenib monotherapy, the most common being differentiation syndrome (n=4), sepsis (n=4), bleeding (n=3, 1 grade 5), elevated liver tests (n=3), and respiratory failure (n=2). Other common adverse events grade ≥3 occurring in 20% or more patients included fatigue, fever, edema, anorexia, low albumin, low electrolytes, nausea, diarrhea, constipation, insomnia and depression. For the 23 patients receiving enasidenib monotherapy, the median time on any treatment (including combination) is 138 days (min=43, max=312), and the median time on enasidenib monotherapy is 110 days (min=43, max=312). CR/CRi was achieved in 43% (7 CR/2CRi) of patients. Of the 6 pts with RAS or PTPN11 mutations, 1 responded. Reasons for discontinuing monotherapy include proceeding to allogeneic stem cell transplant after attaining CR (2), failure to respond to monotherapy (9), CR or CRi with discontinuation (2) or progression after CR/CRi (1). At the time of data cutoff, five pts have died. Five pts with inadequate response to monotherapy proceeded to the phase 1b portion of the study with enasidenib in combination with azacitidine. The combination was generally well tolerated with one DLT (nausea) and no other safety concerns. One patient attained a CRi and four pts have discontinued combined therapy without response. This trial demonstrates the significant clinical activity of enasidenib in previously untreated IDH2 mutated AML patients who do not choose to receive intensive chemotherapy. Enasidenib in this trial was associated with a low early death rate and an acceptable toxicity profile. These results justify further exploration of single agent enasidenib in newly diagnosed AML and of novel combination strategies building upon the efficacy of enasidenib in newly diagnosed AML patients ≥ 60. Disclosures Stein: Daiichi Sankyo: Consultancy; Pfizer: Consultancy; Agios: Consultancy; Novartis: Consultancy; Bayer: Consultancy; Celgene: Consultancy. Borate:Novartis: Consultancy; Agios: Consultancy. Stock:Jazz Pharmaceuticals: Consultancy. Patel:France Foundation: Honoraria; Celgene: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Dava Oncology: Honoraria. Kovacsovics:Abbvie: Research Funding; Amgen: Honoraria, Research Funding. Blum:Pfizer: Consultancy; Boehringer Ingelheim: Research Funding; Forma: Research Funding; Tolero: Research Funding; Astellas: Consultancy; Xencor: Research Funding. Vergilio:Foundation Medicine Inc: Employment. Druker:Blueprint Medicines: Consultancy, Equity Ownership, Membership on an entity's Board of Directors or advisory committees; ARIAD: Research Funding; McGraw Hill: Patents & Royalties; Aileron Therapeutics: Consultancy; Novartis Pharmaceuticals: Research Funding; Fred Hutchinson Cancer Research Center: Research Funding; Cepheid: Consultancy, Membership on an entity's Board of Directors or advisory committees; Henry Stewart Talks: Patents & Royalties; Gilead Sciences: Consultancy, Membership on an entity's Board of Directors or advisory committees; ALLCRON: Consultancy, Membership on an entity's Board of Directors or advisory committees; Monojul: Consultancy; Aptose Therapeutics: Consultancy, Equity Ownership, Membership on an entity's Board of Directors or advisory committees; Patient True Talk: Consultancy; Amgen: Membership on an entity's Board of Directors or advisory committees; Vivid Biosciences: Membership on an entity's Board of Directors or advisory committees; Bristol-Meyers Squibb: Research Funding; Oregon Health & Science University: Patents & Royalties; Leukemia & Lymphoma Society: Membership on an entity's Board of Directors or advisory committees, Research Funding; Beta Cat: Membership on an entity's Board of Directors or advisory committees; MolecularMD: Consultancy, Equity Ownership, Membership on an entity's Board of Directors or advisory committees; Third Coast Therapeutics: Membership on an entity's Board of Directors or advisory committees; GRAIL: Consultancy, Membership on an entity's Board of Directors or advisory committees; Millipore: Patents & Royalties; Celgene: Consultancy. Levine:Celgene: Consultancy, Research Funding; C4 Therapeutics: Equity Ownership; Isoplexis: Equity Ownership; Epizyme: Patents & Royalties; Gilead: Honoraria; Roche: Consultancy, Research Funding; Loxo: Consultancy, Equity Ownership; Imago: Equity Ownership; Qiagen: Equity Ownership, Membership on an entity's Board of Directors or advisory committees; Prelude: Research Funding; Novartis: Consultancy; Janssen: Consultancy, Honoraria. Mims:Novartis: Consultancy; Abbvie Pharmaceuticals: Membership on an entity's Board of Directors or advisory committees; Agios Pharmaceuticals: Consultancy, Membership on an entity's Board of Directors or advisory committees.

Description: *equal contribution of AB, RLL, BD and JCB Background: Acute myeloid leukemia (AML) is common with increasing age, and older adults with AML rarely achieve long-term remission with chemotherapy. Gene discovery studies in older adults with AML have shown that this malignancy is characterized by a multitude of somatic genomic alterations beginning with initiating somatic events followed by acquisition of collaborative transforming mutations. Despite these important biologic insights, current therapeutic approaches to AML remain limited, particularly in adults ≥ 60 years of age. The Beat AML trial was designed to assess the feasibility of using genetic profiling to assign patients (pts) to molecularly defined, subtype-specific therapies within 7 days of the initial diagnosis in a multi-center clinical trial setting, and to delineate the role of molecularly informed first-line treatment of AML with mechanism based novel therapies. Methods: Treatment-naïve patients with AML were enrolled in this prospective trial which offered accelerated cytogenetic and comprehensive mutational testing within 7 days followed by treatment assignment using these molecular data. Pt eligibility included age ≥ 60 years with non-APML AML, no known CNS leukemia, no prior hypomethylating agent (HMA) therapy and no clinical need for emergent therapy. Eligible pts were profiled by local cytogenetics analysis and using a central next generation sequencing (NGS) assay (Foundation Medicine, Inc.) with all molecular data required for treatment assignment (TA) obtained 〈 7 days. TA was made centrally using a pre-determined algorithm considering somatic cytogenetic and molecular alterations in the dominant clone, available targeted therapeutics for specific AML subsets, and the likelihood of cure with intensive chemotherapy. Results: From November 2016 to January 2019, 487 pts with a suspected diagnosis of AML had enrolled at 14 clinical sites; 395 were eligible for the study (77% of the patients not eligible for the study had an alternative diagnosis). The median age of eligible patients was 72 years (range: 60 to 92) with 38% being≥ 75 years and 16% with treatment-related AML. From the 395 eligible patients, 374 (94.7%) were centrally assigned to the different cytogenetic/genomic groups within 7 days. The most common groups were TP53 mutated (19%) and marker negative (18%) molecular groups. The Beat AML trial is dynamic by design, thereby allowing different arms to open over time; all trial arms are designed to evaluate for substantial clinical efficacy in small, molecularly defined patient subsets. As shown in Figure 1, 224 patients (57%) had a TA and consented to a BEAT AML sub-study. Of the remaining 171 patients, 103 received standard therapy defined as induction therapy (7+3) or hypomethylation agent (25 before TA and 78 after TA), 28 received an alternative investigational agent (5 before TA and 23 after TA), 38 received palliative care, and 2 had an unknown treatment status and are grouped with the palliative care patients in subsequent analyses; 9 patients died before TA (2 who received standard therapy and 7 in the palliative care group). Demographic, clinical, performance and molecular characteristics were not largely different between pts who elected targeted therapy as part of the BEAT AML trial versus those who elected standard therapy. As shown in Figure 2, the overall survival was significantly longer for patients enrolled in a targeted therapy arm as part of the BEAT AML trial compared to those who elected standard therapy. (p

Description: Background: The prognosis for acute myeloid leukemia (AML) patients age 〉60 years is poor. Rapid pre-treatment identification of molecular disease subsets may allow specific targeting with novel agents, presenting an opportunity to improve outcomes. The Leukemia and Lymphoma Society (LLS)-sponsored Beat AML master trial was initiated for previously untreated AML patients ≥60 years, with treatment assignment to a sub-study (S1, S2, etc.) based upon cytogenetics and dominant clone by next generation sequencing; patients with multiple mutations are assigned a sub-study according to variant allele frequency and a predetermined prioritization schema. Methods: Patients within two molecular subsets were selected for a phase 1b/2 dose escalation study (S2) of the Fc engineered (for increased binding to FcyRIIIa) CD33 antibody BI 836858 plus azacitidine (AZA). Group A was comprised of patients with mutations that drive hypermethylation, with potential for enhanced sensitivity to AZA: TET2/WT1 or IDH1/2 (for IDH1/2, if no specific targeting agent available). Group B was comprised of "marker-negative" AML (those not eligible for any available targeted sub-study). Both groups were pooled in the phase 1b portion reported herein. Patient eligibility included ECOG performance status 〈 3, no prior chemotherapy for AML or myelodysplastic syndrome, and preserved organ function. Patients received AZA (75 mg/m2) IV or SQ days 1-7 of 28 day cycles. BI 836858 was given weekly beginning day 9 (provided WBC 〈 10 x 109/L) and monthly once complete remission with or without sufficient blood count recovery (CR/CRi) was obtained. A standard 3 + 3 design for toxicity was used to guide dosing decisions, with consideration of dose level expansion based on toxicity and CD33 saturation. Dose-limiting toxicity (DLT) was defined by select grade 3/4 toxicities during cycle 1, or failure to recover counts by day 56 in the setting of no residual AML. Results: At data cut off (April 30, 2018) 39 patients were enrolled; 31 were treated with the combination. Eight were not treated with BI 836858 due to failure to start any therapy (3), withdrawal (1), high white blood cell (WBC) count (2), adverse event (1), and early death (1). Median age of the 31 patients was 71 years (range 62-85); median WBC at study enrollment was 5.3 x 109/L (range 0.5-46.7) and platelets 52 x 109/L (range 10-681). Seventeen (55%) were in Group A (9 TET2, 1 with both TET2 and WT1, 3 IDH1, 4 IDH2). Among 27 with known cytogenetics, 16 (59%) were abnormal including 5 (19%) with complex karyotype. Of 31 patients, 8 were treated at 20 mg, 11 at 40 mg, 9 at 80 mg, and 3 at 160 mg. Six patients (3 at 80 mg and 3 at 160 mg) are currently in cycle 1 and have not fully been assessed for DLT or response. One patient had grade 4 decreased neutrophils in the absence of detectable AML at 20 mg and one had grade 3 portal hypertension at 40 mg, which were considered DLTs. Infusion reactions occurred in 5 BI 836858-treated patients, including 3 grade 3/4. Common grade 3/4 toxicities observed included: anemia (45%), febrile neutropenia (36%), hypophosphatemia (32%), hyponatremia (26%), and decreased platelet (42%), neutrophil (39%), and WBC count (36%). Pharmacokinetics of BI 836858 at dose levels 1-3 (20-80 mg) showed proportional increases by dose without trough accumulation at 4 weeks. Blast CD33 saturation by BI 836858 in the blood and bone marrow was not observed at dose levels 1-3. Pharmacodynamic studies of NK cells pre/post dose of BI 836858 demonstrated evidence of activation in a subset of patients. Among 28 eligible patients who received at least one dose of AZA, had adequate follow-up, and did not withdraw consent prior to response evaluation, there have been 5 CR/CRi (18%) and 4 morphologic leukemia free state (14%) responses, to date. Fifteen patients remain on treatment at data cut off. Reasons for discontinuing combination therapy include proceeding to allogeneic stem cell transplant (1), failure to respond (5), progression after response (4), adverse events (5), and patient withdrawal (1). Conclusions: This phase 1b sub-study of Beat AML demonstrates acceptable tolerability and activity of the combination of AZA with a novel CD33 glycoengineered antibody. Dose escalation as part of this sub-study continues, which will allow further assessment of efficacy and toxicity of this regimen in molecularly defined AML subsets. Disclosures Blum: Forma: Research Funding; Tolero: Research Funding; Astellas: Consultancy; Boehringer Ingelheim: Research Funding; Pfizer: Consultancy; Xencor: Research Funding. Mims:Novartis: Consultancy; Abbvie Pharmaceuticals: Membership on an entity's Board of Directors or advisory committees; Agios Pharmaceuticals: Consultancy, Membership on an entity's Board of Directors or advisory committees. Stein:Daiichi Sankyo: Consultancy; Celgene: Consultancy; Bayer: Consultancy; Agios: Consultancy; Novartis: Consultancy; Pfizer: Consultancy. Odenike:Celgene: Consultancy, Membership on an entity's Board of Directors or advisory committees; Janssen: Research Funding; Gilead Sciences: Research Funding; Celgene: Research Funding; Agios: Research Funding; Oncotherapy Science: Research Funding; Jazz Pharmaceuticals: Consultancy, Membership on an entity's Board of Directors or advisory committees; Incyte: Consultancy, Membership on an entity's Board of Directors or advisory committees; Dava Oncology: Consultancy, Membership on an entity's Board of Directors or advisory committees; CTI/Baxalta: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Pfizer: Consultancy, Membership on an entity's Board of Directors or advisory committees; ABBVIE: Honoraria, Research Funding; NS Pharma: Research Funding; Astex: Research Funding. Patel:France Foundation: Honoraria; Celgene: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Dava Oncology: Honoraria. Kovacsovics:Amgen: Honoraria, Research Funding; Abbvie: Research Funding. Druker:Vivid Biosciences: Membership on an entity's Board of Directors or advisory committees; Oregon Health & Science University: Patents & Royalties; Bristol-Meyers Squibb: Research Funding; Millipore: Patents & Royalties; Aptose Therapeutics: Consultancy, Equity Ownership, Membership on an entity's Board of Directors or advisory committees; Celgene: Consultancy; Fred Hutchinson Cancer Research Center: Research Funding; Monojul: Consultancy; Third Coast Therapeutics: Membership on an entity's Board of Directors or advisory committees; Aileron Therapeutics: Consultancy; Blueprint Medicines: Consultancy, Equity Ownership, Membership on an entity's Board of Directors or advisory committees; Cepheid: Consultancy, Membership on an entity's Board of Directors or advisory committees; Henry Stewart Talks: Patents & Royalties; Novartis Pharmaceuticals: Research Funding; ALLCRON: Consultancy, Membership on an entity's Board of Directors or advisory committees; Amgen: Membership on an entity's Board of Directors or advisory committees; Patient True Talk: Consultancy; Beta Cat: Membership on an entity's Board of Directors or advisory committees; ARIAD: Research Funding; MolecularMD: Consultancy, Equity Ownership, Membership on an entity's Board of Directors or advisory committees; Leukemia & Lymphoma Society: Membership on an entity's Board of Directors or advisory committees, Research Funding; McGraw Hill: Patents & Royalties; GRAIL: Consultancy, Membership on an entity's Board of Directors or advisory committees; Gilead Sciences: Consultancy, Membership on an entity's Board of Directors or advisory committees. Levine:Roche: Consultancy, Research Funding; Epizyme: Patents & Royalties; Celgene: Consultancy, Research Funding; Isoplexis: Equity Ownership; Imago: Equity Ownership; Novartis: Consultancy; Janssen: Consultancy, Honoraria; C4 Therapeutics: Equity Ownership; Loxo: Consultancy, Equity Ownership; Gilead: Honoraria; Prelude: Research Funding; Qiagen: Equity Ownership, Membership on an entity's Board of Directors or advisory committees. Borate:Agios: Consultancy; Novartis: Consultancy.

Description: Background: ENA is an oral, selective inhibitor of IDH2 approved for the treatment (Tx) of patients (pts) with relapsed/refractory IDH2 mutated (IDH2m) AML. Here we report the results of a Phase 2 expansion and Phase 1b of the Beat AML Master Trial Phase 2/1b sub-study to assess the efficacy of Tx of newly diagnosed (ND) IDH2m AML pts ≥ 60 years of age with ENA monotherapy (ENAm) and subsequent response-driven addition of AZA Tx. (ClinicalTrials.gov NCT03013998). Methods: The study initiated with a 3-outcome, 2-stage Phase 2 design, which enrolled patients on ENAm for up to 5 cycles. Pts without CR/CRi after 5 cycles of ENAm, or progression/intolerance prior to this time, were transferred to Phase 1b to receive ENA + AZA (Figure 1). Key eligibility included ND IDH2m AML pts with age ≥ 60 years and ECOG performance status 0-2. Pts received ENAm 100 mg/day in continuous 28-day cycles and ENA + AZA (75 mg/m2 days 1-7 every 28 days) for Phase 1b. Response was assessed using 2017 ELN AML criteria. The primary endpoint was CR/CRi rate. The 2-stage design required 24 pts and tested the null hypothesis (H0) that CR/CRi rate equaled 20% vs 50% and then expanded to test a revised H0 of 30% vs 50% in 60 pts (conditional alpha=0.025, power=77%). Expansion also allowed further assessment of safety of this treatment regimen. Results: At data cut off (06/18/2020), 60 pts enrolled, received ENAm, and were evaluable for the primary endpoint. Median age was 75 years and 52% were female (Table 1). Median time on ENAm was 4.7 months (mos). At data cut off, 12 pts were still on ENAm Tx. Most common reasons for discontinuing ENAm were Tx failure (defined as no response to treatment) (23 or 38%), disease progression (loss of response to treatment) (7 or 12%) and adverse events (AEs; 6 or 10%). Five pts (8%) went to transplant. CR/CRi was achieved in 28 pts (47%; adjusted 95% CI 28-59, unadjusted exact 95% CI 34-60) (Table 2). Responses were higher (p=0.04) among the 44 pts with IDH2 R140 (55%) as compared to the 16 with IDH2 R172 mutation (25%) further supporting distinct biology between these subsets. After a median follow up of 14.6 mos, the median overall survival (mOS) was 24.4 mos (95% CI 10.6-not reached). The median duration of response was not reached with 12 mos estimation of 57% (95% CI 34-75). Overall, 20 ENA-related serious adverse events (SAEs) occurred in 15 pts, the most common was differentiation syndrome (12 or 20%) and 1 had ENA-related SAE of tumor lysis syndrome (1.7%). One pt had ENA-related Grade 5 AE (renal failure/death). Most common AEs of any grade (in ≥20%) were nausea, anemia, and low potassium (Table 3). The 7-day/30-day/60-day deaths observed with ENAm were 2%/5%/11%, respectively. Phase 1b: Seventeen pts had inadequate response to ENAm and transferred to Phase 1b to receive ENA + AZA. Median time on Tx (including ENAm) was 6.2 mos and median time on Tx after pts started ENA + AZA was 2.1 mos (Table 2). Most common reasons for discontinuing ENA + AZA included Tx failure (5 or 29%), disease progression (2 or 12%), transplant, death and AEs (each 2 or 12%). CR/CRi was 41% (exact 95% CI 18-67). After a median follow up of 12.7 mos, the mOS from start of ENA + AZA combination Tx was 8.9 mos. Four ENA-related SAEs occurred in 3 pts on ENA + AZA Tx and the most common was differentiation syndrome (2 or 12.5%). One dose-limiting toxicity (Grade 3 nausea) related to both Txs was observed. Most common AEs (≥20%) of any grade were anemia, low albumin and vomiting (Table 3). One death occurred at day 13 of ENA + AZA. Conclusions: In newly diagnosed pts ≥60 years old with IDH2m AML, ENA had a low early death rate, high CR/CRi rate (47%, adjusted 95% CI 28-59), and yielded durable remissions. The most common unique toxicity with ENA was differentiation syndrome that occurred in 20% of patients. In pts who did not achieve CR/CRi with ENAm, a subset of patients achieved CR/CRi with addition of AZA. This combined approach of serial therapy with ENA monotherapy followed by AZA addition in pts with sub-optimal response resulted in a mOS exceeding 2 years for pts enrolled on study. Further focus on improving response among patients with IDH2 R172 mutations, identifying subsets of pts not responding to ENA monotherapy, and integrating new targeted agents into this treatment regimen are warranted. Figure 1 Disclosures Stein: Syndax: Consultancy, Research Funding; Celgene Pharmaceuticals: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Daiichi-Sankyo: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Astellas Pharmaceuticals: Consultancy, Membership on an entity's Board of Directors or advisory committees; Seattle Genetics: Consultancy; Agios Pharmaceuticals: Consultancy, Membership on an entity's Board of Directors or advisory committees; Bayer: Research Funding; Genentech: Consultancy, Membership on an entity's Board of Directors or advisory committees; Amgen: Consultancy; Biotheryx: Consultancy; Novartis: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; PTC Therapeutics: Membership on an entity's Board of Directors or advisory committees; Syros: Membership on an entity's Board of Directors or advisory committees; Abbvie: Consultancy. Borate:Genentech: Membership on an entity's Board of Directors or advisory committees; Daiichi Sankyo: Membership on an entity's Board of Directors or advisory committees; Takeda: Membership on an entity's Board of Directors or advisory committees, Research Funding; Novartis: Membership on an entity's Board of Directors or advisory committees, Research Funding; Jazz Pharmaceuticals: Research Funding; AbbVie: Other: Investigator in AbbVie-funded clinical trials; Pfizer: Membership on an entity's Board of Directors or advisory committees, Research Funding. Baer:Takeda: Other: Institutional research funding; AbbVie: Other: Institutional research funding; Astellas: Other: Institutional research funding; Forma: Other: Institutional research funding; Kite: Other: Institutional research funding; Oscotec: Other: Institutional research funding; Incyte: Other: Institutional research funding. Kovacsovics:Agios: Honoraria; Astella: Honoraria; Pfizer: Research Funding; Novartis: Research Funding; AbbVie: Research Funding; Jazz: Honoraria. Schiller:Astellas Pharma: Honoraria, Research Funding; Celator: Research Funding; Constellation: Research Funding; Abbvie: Research Funding; Actinium: Research Funding; Ariad: Research Funding; Stemline: Speakers Bureau; Cyclacel: Research Funding; Daiichi Sankyo: Research Funding; Deciphera: Research Funding; DeltaFly: Research Funding; Bristol-Myers Squibb: Current equity holder in publicly-traded company, Research Funding; Forma: Research Funding; FujiFilm: Research Funding; Gamida: Research Funding; Genentech-Roche: Research Funding; Geron: Research Funding; Jazz Pharmaceuticals: Research Funding; Karyopharm: Research Funding; Kite Pharma: Research Funding; Mateon: Research Funding; MedImmune: Research Funding; Onconova: Research Funding; Pfizer: Current equity holder in publicly-traded company, Research Funding; Regimmune: Research Funding; Samus: Research Funding; Sangamo: Research Funding; Tolero: Research Funding; Trovagene: Research Funding; Kaiser Permanente: Consultancy; Johnson & Johnson: Current equity holder in publicly-traded company; Agios: Consultancy, Research Funding, Speakers Bureau; Amgen: Consultancy, Current equity holder in publicly-traded company, Research Funding, Speakers Bureau; AstraZeneca: Consultancy; Incyte: Consultancy, Research Funding, Speakers Bureau; Novartis: Consultancy, Research Funding; Ono Pharma: Consultancy; Celgene: Research Funding, Speakers Bureau; Sanofi: Speakers Bureau; Gilead: Speakers Bureau. Olin:Astellas: Other: Site PI; Genentech: Other: Site PI; Pfizer: Other: Site PI; Daiichi Sankyo: Other: Site PI; Genentech: Consultancy; Amgen: Consultancy. Foran:Trillium: Research Funding; Xencor: Research Funding; H3Biosciences: Research Funding; Agios: Honoraria, Research Funding; Pfizer: Membership on an entity's Board of Directors or advisory committees; BMS: Membership on an entity's Board of Directors or advisory committees; Abbvie: Research Funding; Boehringer Ingelheim: Research Funding; Actinium: Research Funding; Aprea: Research Funding; Aptose: Research Funding; Kura Oncology: Research Funding; Takeda: Research Funding; Revolution Medicine: Consultancy; Novartis: Membership on an entity's Board of Directors or advisory committees; Servier: Membership on an entity's Board of Directors or advisory committees. Lin:Trovagene: Research Funding; Tolero Pharmaceuticals: Research Funding; Seattle Genetics: Research Funding; Prescient Therapeutics: Research Funding; Abbvie: Research Funding; Bio-Path Holdings: Research Funding; Astellas Pharma: Research Funding; Aptevo: Research Funding; Incyte: Research Funding; Pfizer: Research Funding; Mateon Therapeutics: Research Funding; Ono Pharmaceutical: Research Funding; Jazz: Research Funding; Gilead Sciences: Research Funding; Genetech-Roche: Research Funding; Celyad: Research Funding; Celgene: Research Funding. Patel:DAVA Pharmaceuticals: Honoraria; Celgene: Consultancy, Speakers Bureau; Agios: Consultancy; France Foundation: Honoraria. Foster:Daiichi Sankyo: Consultancy; Bellicum Pharmaceuticals: Research Funding; Macrogenics: Consultancy, Research Funding. Druker:Leukemia & Lymphoma Society: Research Funding; Henry Stewart Talks: Patents & Royalties; Iterion Therapeutics (formerly Beta Cat Pharmaceuticals): Membership on an entity's Board of Directors or advisory committees; Vivid Biosciences: Membership on an entity's Board of Directors or advisory committees; GRAIL: Consultancy, Current equity holder in private company, Membership on an entity's Board of Directors or advisory committees; Patient True Talks: Consultancy; The RUNX1 Research Program: Membership on an entity's Board of Directors or advisory committees; Third Coast Therapeutics: Membership on an entity's Board of Directors or advisory committees; VB Therapeutics: Membership on an entity's Board of Directors or advisory committees; Gilead Sciences: Consultancy, Membership on an entity's Board of Directors or advisory committees; Millipore (formerly Upstate Biotechnology): Patents & Royalties; MolecularMD (acquired by ICON): Consultancy, Current equity holder in publicly-traded company, Membership on an entity's Board of Directors or advisory committees; Novartis Pharmaceuticals: Membership on an entity's Board of Directors or advisory committees, Patents & Royalties, Research Funding; McGraw Hill: Patents & Royalties; Merck & Co: Patents & Royalties; Cepheid: Consultancy, Membership on an entity's Board of Directors or advisory committees; Dana-Farber Cancer Institute: Patents & Royalties; EnLiven: Consultancy, Research Funding; Aptose Therapeutics Inc. (formerly Lorus): Consultancy, Current equity holder in publicly-traded company, Membership on an entity's Board of Directors or advisory committees; ARIAD: Research Funding; Blueprint Medicines: Consultancy, Current equity holder in private company, Membership on an entity's Board of Directors or advisory committees; ALLCRON: Consultancy, Membership on an entity's Board of Directors or advisory committees; Amgen: Current equity holder in publicly-traded company, Membership on an entity's Board of Directors or advisory committees; Bristol-Myers Squibb: Research Funding; Aileron Therapeutics: Membership on an entity's Board of Directors or advisory committees; Pfizer: Research Funding; Oregon Health & Science University: Patents & Royalties. Byrd:Acerta Pharma: Research Funding; Syndax: Research Funding; Vincera: Research Funding; Pharmacyclics LLC, an AbbVie Company, Janssen, Novartis, Gilead, TG Therapeutics: Other; Pharmacyclics LLC, an AbbVie Company, Gilead, TG Therapeutics, Novartis, Janssen: Speakers Bureau; Novartis: Research Funding; Kartos Therapeutics: Research Funding; Trillium: Research Funding; Leukemia and Lymphoma Society: Other; Janssen: Consultancy; Pharmacyclics LLC, an AbbVie Company, Gilead, TG Therapeutics, BeiGene: Research Funding. Levine:Loxo: Current equity holder in private company, Membership on an entity's Board of Directors or advisory committees; C4 Therapeutics: Current equity holder in private company, Membership on an entity's Board of Directors or advisory committees; Imago: Current equity holder in private company, Membership on an entity's Board of Directors or advisory committees; Celgene: Consultancy, Honoraria, Research Funding; Qiagen: Current equity holder in publicly-traded company, Membership on an entity's Board of Directors or advisory committees; Prelude Therapeutics: Research Funding; Amgen: Honoraria; Astellas: Consultancy; Morphosys: Consultancy; Novartis: Consultancy; Isoplexis: Current equity holder in private company, Membership on an entity's Board of Directors or advisory committees; Janssen: Consultancy; Lilly: Consultancy, Honoraria; Roche: Consultancy, Honoraria, Research Funding; Gilead: Honoraria. Mims:Abbvie: Membership on an entity's Board of Directors or advisory committees; Kura Oncology: Membership on an entity's Board of Directors or advisory committees; Leukemia and Lymphoma Society: Other: Senior Medical Director for Beat AML Study; Jazz Pharmaceuticals: Other: Data Safety Monitoring Board; Syndax Pharmaceuticals: Membership on an entity's Board of Directors or advisory committees; Agios: Consultancy; Novartis: Speakers Bureau. OffLabel Disclosure: Enasidenib is not approved for the treatment of newly diagnosed AML.