Tarlock, Katherine

AbstractBackgroundOutcomes for children with relapsed/refractory (R/R) acute myeloid leukemia (AML) and myelodysplastic syndrome (MDS) are poor, and new therapies are needed. Pevonedistat is an inhibitor of the NEDD‐8 activating enzyme, a key regulator of the ubiquitin proteasome system that is responsible for protein turnover, with protein degradation regulating cell growth and survival.ProcedureWe evaluated the feasibility, toxicity, and pharmacokinetics (PK) of pevonedistat (20 mg/m2 days 1, 3, 5) in combination with azacitidine, fludarabine, cytarabine (aza‐FLA) in children with R/R AML and MDS (NCT03813147). Twelve patients were enrolled, median age was 13 years (range 1–21). Median number of prior chemotherapeutic regimens was two (range one to five), and two (25%) patients had prior hematopoietic cell transplantation. Diagnoses were AML NOS (n = 10, 83%), acute monocytic leukemia (n = 1), and therapy‐related AML (n = 1).ResultsOverall, three of 12 (25%) patients experienced DLTs. The day 1 mean ± SD (n = 12) Cmax, VSS, T1/2, and CL were 223 ± 91 ng/mL, 104 ± 53.8 L/m2, 4.3 ± 1.2 hours, and 23.2 ± 6.9 L/h/m2, respectively. T1/2, VSS, and Cmax, but not CL, were significantly different between age groups. The overall response rate was 25%, with n = 3 patients achieving a complete remission with incomplete hematologic recovery (CRi).ConclusionsPevonedistat 20 mg/m2 combined with Aza‐FLA was tolerable in children with R/R AML with similar toxicity profile to other intensive AML regimens. However, within the confines of a phase 1 study, we did not observe that the pevonedistat + Aza‐FLA combination demonstrated significant anti‐leukemic activity.

AbstractSomatic mutations in isocitrate dehydrogenase (IDH) genes occur frequently in adult acute myeloid leukemia (AML) and less commonly in pediatric AML. The objective of this study was to describe the prevalence, mutational profile, and prognostic significance of IDH mutations in AML across age. Our cohort included 3141 patients aged between <1 month and 88 years treated on Children’s Cancer Group/Children’s Oncology Group (n = 1872), Southwest Oncology Group (n = 359), Eastern Cooperative Oncology Group (n = 397) trials, and in Beat AML (n = 333) and The Cancer Genome Atlas (n = 180) genomic characterization cohorts. We retrospectively analyzed patients in 4 age groups (age range, n): pediatric (0-17, 1744), adolescent/young adult (18-39, 444), intermediate-age (40-59, 640), older (≥60, 309). IDH mutations (IDHmut) were identified in 9.2% of the total cohort (n = 288; IDH1 [n = 123, 42.7%]; IDH2 [n = 165, 57.3%]) and were strongly correlated with increased age: 3.4% pediatric vs 21% older, P < .001. Outcomes were similar in IDHmut and IDH-wildtype (IDHWT) AML (event-free survival [EFS]: 35.6% vs 40.0%, P = .368; overall survival [OS]: 50.3% vs 55.4%, P = .196). IDH mutations frequently occurred with NPM1 (47.2%), DNMT3A (29.3%), and FLT3-internal tandem duplication (ITD) (22.4%) mutations. Patients with IDHmut AML with NPM1 mutation (IDHmut/NPM1mut) had significantly improved survival compared with the poor outcomes experienced by patients without (IDHmut/NPM1WT) (EFS: 55.1% vs 17.0%, P < .001; OS: 66.5% vs 35.2%, P < .001). DNTM3A or FLT3-ITD mutations in otherwise favorable IDHmut/NPM1mut AML led to inferior outcomes. Age group analysis demonstrated that IDH mutations did not abrogate the favorable prognostic impact of NPM1mut in patients aged <60 years; older patients had poor outcomes regardless of NPM1 status. These trials were registered at www.clinicaltrials.gov as #NCT00070174, #NCT00372593, #NCT01371981, #NCT00049517, and #NCT00085709.

10018 Background: Outcomes for children with relapsed/refractory (R/R) AML and MDS are poor and new therapies are needed. Pevonedistat is an inhibitor of the NEDD-8 activating enzyme, a key regulator of the ubiquitin proteasome system that is responsible for protein turnover, cell growth and survival. In preclinical models, pevonedistat was synergistic with cytarabine (AraC) and azacitidine (aza). The combination of pevonedistat + aza in adults with AML demonstrated improved responses compared to either single agent. We evaluated the feasibility, toxicity and pharmacokinetics (PK) of pevonedistat in combination with aza, fludarabine, AraC (Aza-FLA) in children with R/R AML and MDS. Methods: Pevonedistat 20 mg/m2, IV days 1, 3, 5, the recommended adult dose, was administered in combination with aza (75 mg/m2, days 1-5), fludarabine (30 mg/m2, days 6-10), and AraC (2000 mg/m2, days 6-10). Intrathecal AraC was administered at the start of therapy and additional doses given to patients with CNS leukemia. If < 33% of the initial 6 enrolled patients experienced dose limiting toxicity (DLT) during cycle 1 the regimen would be considered tolerable and 6 additional patients could enroll to further assess tolerability and PK. Pevonedistat PK was determined during cycle 1 following doses 1 and 5. Response was evaluated after cycle 1. Results: A total of 12 patients were enrolled, median age was 13 years (range 1-21). All patients received prior chemotherapy, median number of prior regimens was 2 (range 1-5) and 3 (25%) patients had prior hematopoietic stem cell transplant. Diagnoses were AML NOS (n = 10, 83%), acute monocytic leukemia (n = 1), and therapy related AML (n = 1). One of the initial 6 patients had DLTs (hypertension, GGT elevation, and proteinuria); pevonedistat 20 mg/m2 + Aza-FLA was considered tolerable. Six additional patients were enrolled, two had DLTs (weight loss, hypoxia). Overall, 3/12 (25%) of patients experienced DLTs. As expected, using the intensive Aza-FLA backbone, myelosuppression, electrolyte abnormalities, and hepatic transaminase elevation were common. Day 1 PK parameters (n = 12, mean±SD) were: Cmax= 223±91 ng/mL, AUC0-24h= 892±216 ng/hr/mL, T1/2=4.3±1.2 hours, CL = 23.2±6.9 L/hr/m2. PK parameters were similar following doses 1 and 5, for patients < 12 (n = 6) and ≥ 12 (n = 6) years, and to adult PK profiles. Ten patients were evaluable for response. The overall response rate was 30% (95% CI: 7,75) with 3 patients achieving a CR with incomplete hematologic recovery (CRi). Conclusions: Pevonedistat 20 mg/m2 combinedwith Aza-FLA was tolerable in children with R/R AML. The toxicity of the regimen was similar to other intensive AML regimens. PK parameters were similar among the two age groups and were comparable to adults. Within the confines of a phase I study, there was limited anti-leukemic activity of the combination of pevonedistat +Aza-FLA in R/R AML. Clinical trial information: NCT03813147.

Background: Somatic mutations in the IDH genes are common in acute myeloid leukemia (AML). Mutations occur at active site arginine residues in IDH1 (R132) and IDH2 (R140, R172). IDH inhibitors, ivosidenib (IDH1) and enasidenib (IDH2), have shown improved clinical outcomes in patients with relapsed/refractory IDH-mutant AML and are approved for use in this setting, while investigations in combination with chemotherapy are underway in de novo AML. The prognostic significance of IDH mutations remains controversial. We hypothesize that refining our understanding of IDH-mutated AML will contribute to risk-adapted treatment strategies, including optimal use of IDH-targeted agents. The objective of our study was to identify characteristics that affect outcome in de novo IDH-mutated AML across the age spectrum utilizing a large cohort of patients enrolled on several pediatric and adult trials. Methods: The total cohort (N=3588) included patients age &lt;1 month - 88 years. Pediatric and young adult (YA) patients were treated on recent CCG/COG AML trials (CCG2961, COG 03P1, 0531, 1031, N=2231) and YA/adult patients were treated on SWOG S0106 (N=396), ECOG E1900 AML trials (N=398), Beat AML (N=363), or included in the TCGA biology study (N=200; outcomes not evaluated for this group). Patients were analyzed according to three defined age groups: "younger" 0-29 years of age (N=2401), "intermediate" 30-59 years of age (N=819) and "older" 60 years of age and above (N=319). Data regarding clinical characteristics and treatment outcomes were collected and evaluated according to the standard practices of each cooperative or research groups for the respective studies. Mutational profiling was performed by targeted sequencing for patient samples from COG trials, Beat-AML, ECOG, and SWOG; whole-genome or whole-exome sequencing for the TCGA cohort. Prevalence of IDH mutations, co-occurring mutations, and outcomes (5-year event-free survival [EFS]) were analyzed across the defined age groups. Results: The prevalence of IDH mutations among the entire cohort was 8.6% (N=276). Analysis according to mutation type demonstrated that IDH2 mutations comprised 57% (N=158) and IDH1 mutations 43% (N=118). The prevalence of IDH mutations was strongly correlated with increased age (Fig 1A); according to the age-defined cohorts was 4.0% (N=82) in younger, 15.2% (N=126) in intermediate, and 20.3% (N=65) in older patients (p&lt;0.001). The co-occurring mutational profile demonstrated that IDH mutations commonly co-occurred with NPM1,DNMT3A, and FLT3-ITD mutations (Fig 1B). Among IDH-mutant patients, 48% (N=132) harbored dual mutations (IDHmut/NPM1mut); 11.6% (N=32) triple mutations (IDHmut/NPM1mut/DNMT3Amut), the latter particularly prevalent in intermediate-aged adults (N=27/32, 85%). Analysis of the cohort with outcome data (N=2824) demonstrated that IDHmut and IDH-WT patients experienced similar EFS of 39% vs. 40%, respectively (p=0.723). Given the favorable prognostic significance of NPM1, we subsequently analyzed outcomes of this dual mutant group and found that NPM1 mutations retained favorable prognostic impact in the context of IDH mutant patients (Fig 2A). Notably, this effect was age-dependent, as those with IDHmut/NPM1mut had a favorable EFS compared to IDHmut/NPM1-WT for younger (76% vs. 24%, p&lt;0.001) and intermediate patients (43% vs. 15%, p=0.001, Fig 2B) but this favorable effect was lost in older patients (29% vs. 34%, p=0.456, Fig 2C). Among intermediate age patients, outcome was further stratified by DNMT3A status, and IDHmut/NPM1mut/DNMT3Amut patients experienced an inferior EFS of 25% vs. 57% in IDHmut/NPMmut (p=0.003, Fig 2D). Conclusion: Analysis of this large patient cohort provides the most comprehensive description of IDH mutations in AML across the age spectrum. We confirm age-associated prevalence of IDH mutations and frequent co-occurrence with NPM1 mutation in all ages and in further combination with DNMT3A mutation in intermediate-aged adults. We definitively demonstrate that IDH mutation status is not an independent prognostic determinant of outcome in any age group. Co-occurrence of NPM1 and IDH mutations favorably impacts outcome in patients &lt; 60 years of age with AML, particularly in the absence of DNMT3A mutation. Our data support that IDH inhibitors may be of particular interest in older adults and in patients &lt;60 according to co-occurring NPM1 and DNMT3A mutations. Disclosures Othus: Marck: Consultancy; Daiichi Sankyo: Consultancy; Celgene: Membership on an entity's Board of Directors or advisory committees; Glycomimetics: Membership on an entity's Board of Directors or advisory committees. Radich:Jazz: Consultancy; Novartis Pharmaceuticals Corporation: Consultancy, Research Funding; Amgen: Consultancy; Bristol-Myers Squibb: Consultancy. Abdel-Wahab:Merck: Consultancy; Janssen: Consultancy; Envisagenics Inc.: Current equity holder in private company; H3 Biomedicine Inc.: Consultancy, Research Funding. Tallman:UpToDate: Patents & Royalties; ADC Therapeutics: Research Funding; BioSight: Membership on an entity's Board of Directors or advisory committees, Research Funding; Glycomimetics: Research Funding; Rafael: Research Funding; Amgen: Research Funding; Bioline rx: Membership on an entity's Board of Directors or advisory committees; Daiichi-Sankyo: Membership on an entity's Board of Directors or advisory committees; KAHR: Membership on an entity's Board of Directors or advisory committees; Rigel: Membership on an entity's Board of Directors or advisory committees; Delta Fly Pharma: Membership on an entity's Board of Directors or advisory committees; Oncolyze: Membership on an entity's Board of Directors or advisory committees; Jazz Pharma: Membership on an entity's Board of Directors or advisory committees; Roche: Membership on an entity's Board of Directors or advisory committees; Novartis: Membership on an entity's Board of Directors or advisory committees; Abbvie: Research Funding; Cellerant: Research Funding; Orsenix: Research Funding. Atallah:Jazz: Consultancy; Genentech: Consultancy; Abbvie: Consultancy; Takeda: Consultancy, Research Funding; Pfizer: Consultancy; Novartis Pharmaceutical Corporation: Consultancy. Luger:Daiichi-Sankyo: Honoraria; Pfizer: Honoraria; Bristol-Myers Squibb: Honoraria; Acceleron: Honoraria; Agios: Honoraria; Loxo Oncology: Honoraria; Onconova: Research Funding; Kura: Research Funding; Biosight: Research Funding; Ariad: Research Funding; Hoffman La Roche: Research Funding. Levine:Novartis: Consultancy; Loxo: Current equity holder in private company, Membership on an entity's Board of Directors or advisory committees; Morphosys: Consultancy; Astellas: Consultancy; Janssen: Consultancy; Prelude Therapeutics: Research Funding; Amgen: Honoraria; Gilead: Honoraria; Lilly: Consultancy, Honoraria; Qiagen: Current equity holder in publicly-traded 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; C4 Therapeutics: Current equity holder in private company, Membership on an entity's Board of Directors or advisory committees; Isoplexis: Current equity holder in private company, Membership on an entity's Board of Directors or advisory committees; Celgene: Consultancy, Honoraria, Research Funding; Roche: Consultancy, Honoraria, Research Funding. Cooper:Celgene: Other: Spouse was an employee of Celgene (through August 2019).