Clinical outcomes of hypomethylating agents plus Venetoclax as frontline treatment in patients 75 years and older with acute myeloid leukemia: Real-world data from eight US academic centers.

Venetoclax (VEN) combined with hypomethylating agents (HMAs) is the standard of care for the treatment of patients with newly diagnosed acute myeloid leukemia (AML) unfit for intensive chemotherapy. To date, real-world data published on HMAs plus VEN have been either single-center studies or using community-based electronic databases with limited details on mutational landscape, tolerability, and treatment patterns in elderly patients. Therefore, we conducted a multicenter retrospective study to assess the real-world experience of 204 elderly patients (≥75 years) with newly diagnosed AML treated with HMAs plus VEN from eight academic centers in the United States. Overall, 64 patients achieved complete remission (CR; 38%) and 43 CR with incomplete count recovery (CRi; 26%) for a CR/CRi rate of 64%, with a median duration of response of 14.2 months (95% CI: 9.43, 22.1). Among responders, 63 patients relapsed (59%) with median overall survival (OS) after relapse of 3.4 months (95% CI, 2.4, 6.7). Median OS for the entire population was 9.5 months (95% CI, 7.85-13.5), with OS significantly worse among patients with TP53-mutated AML (2.5 months) and improved in patients harboring NPM1, IDH1, and IDH2 mutations (13.5, 18.3, and 21.1 months, respectively). The 30-day and 60-day mortality rates were 9% and 19%, respectively. In conclusion, HMAs plus VEN yielded high response rates in elderly patients with newly diagnosed AML. The median OS was inferior to that reported in the VIALE-A trial. Outcomes are dismal after failure of HMAs plus VEN, representing an area of urgent unmet clinical need.

Phase 1b trial of tagraxofusp in combination with azacitidine with or without venetoclax in acute myeloid leukemia.

ABSTRACT: CD123, a subunit of the interleukin-3 receptor, is expressed on ∼80% of acute myeloid leukemias (AMLs). Tagraxofusp (TAG), recombinant interleukin-3 fused to a truncated diphtheria toxin payload, is a first-in-class drug targeting CD123 approved for treatment of blastic plasmacytoid dendritic cell neoplasm. We previously found that AMLs with acquired resistance to TAG were re-sensitized by the DNA hypomethylating agent azacitidine (AZA) and that TAG-exposed cells became more dependent on the antiapoptotic molecule BCL-2. Here, we report a phase 1b study in 56 adults with CD123-positive AML or high-risk myelodysplastic syndrome (MDS), first combining TAG with AZA in AML/MDS, and subsequently TAG, AZA, and the BCL-2 inhibitor venetoclax (VEN) in AML. Adverse events with 3-day TAG dosing were as expected, without indication of increased toxicity of TAG or AZA+/-VEN in combination. The recommended phase 2 dose of TAG was 12 µg/kg/day for 3 days, with 7-day AZA +/- 21-day VEN. In an expansion cohort of 26 patients (median age 71) with previously untreated European LeukemiaNet adverse-risk AML (50% TP53 mutated), triplet TAG-AZA-VEN induced response in 69% (n=18/26; 39% complete remission [CR], 19% complete remission with incomplete count recovery [CRi], 12% morphologic leukemia-free state [MLFS]). Among 13 patients with TP53 mutations, 7/13 (54%) achieved CR/CRi/MLFS (CR = 4, CRi = 2, MLFS = 1). Twelve of 17 (71%) tested responders had no flow measurable residual disease. Median overall survival and progression-free survival were 14 months (95% CI, 9.5-NA) and 8.5 months (95% CI, 5.1-NA), respectively. In summary, TAG-AZA-VEN shows encouraging safety and activity in high-risk AML, including TP53-mutated disease, supporting further clinical development of TAG combinations. The study was registered on ClinicalTrials.gov as #NCT03113643.

Cutaneous Manifestations of Myeloid Neoplasms Exhibit Broad and Divergent Morphologic and Immunophenotypic Features but Share Ancestral Clonal Mutations With Bone Marrow.

In this study, we performed a comprehensive molecular analysis of paired skin and peripheral blood/bone marrow (BM) samples from 17 patients with cutaneous myeloid or cutaneous histiocytic-dendritic neoplasms. The cutaneous manifestations included 10 patients with cutaneous acute myeloid leukemia (c-AML), 2 patients with full or partial Langerhans cell differentiation, 2 patients with blastic plasmacytoid dendritic cell neoplasms (BPDCN), 1 patient with both Langerhans cell differentiation and BPDCN, and 2 patients with full or partial indeterminate dendritic cell differentiation. Seven of the 10 c-AML patients (70%) exhibited concurrent or subsequent marrow involvement by acute myeloid leukemia, with all 7 cases (100%) demonstrating shared clonal mutations in both the skin and BM. However, clonal relatedness was documented in one additional case that never had any BM involvement. Nevertheless, NPM1 mutations were identified in 7 of the 10 (70%) of these c-AML cases while one had KMT2A rearrangement and one showed inv(16). All 3 patients (100%) with Langerhans cell neoplasms, 2 patients with BPDCN (100%), and one of the 2 patients (50%) with other cutaneous dendritic cell neoplasms also demonstrated shared mutations between the skin and concurrent or subsequent myeloid neoplasms. Both BM and c-AML shared identical founding drivers, with a predominance of NPM1, DNMT3A, and translocations associated with monocytic differentiation, with common cutaneous-only mutations involving genes in the signal transduction and epigenetic pathways. Cutaneous histiocytic-dendritic neoplasms shared founding drivers in ASXL1, TET2, and/or SRSF2. However, in the Langerhans cell histiocytosis or histiocytic sarcoma cases, there exist recurrent secondary RAS pathway hits, whereas cutaneous BPDCN cases exhibit copy number or structural variants. These results enrich and broaden our understanding of clonally related cutaneous manifestations of myeloid neoplasms and further illuminate the highly diverse spectrum of morphologic and immunophenotypic features they exhibit.

Optimization of Advanced Molecular Genetic Testing Utilization in Hematopathology: A Goldilocks Approach to Bone Marrow Testing.

PURPOSE: This study investigated the effectiveness of algorithmic testing in hematopathology at the Brigham and Women's Hospital and Dana-Farber Cancer Institute (DFCI). The algorithm was predicated on test selection after an initial pathologic evaluation to maximize cost-effective testing, especially for expensive molecular and cytogenetic assays. MATERIALS AND METHODS: Standard ordering protocols (SOPs) for 17 disease categories were developed and encoded in a decision support application. Six months of retrospective data from application beta testing was obtained and compared with actual testing practices during that timeframe. In addition, 2 years of prospective data were also obtained from patients at one community satellite site. RESULTS: A total of 460 retrospective cases (before introduction of algorithmic testing) and 109 prospective cases (following introduction) were analyzed. In the retrospective data, 61.7% of tests (509 of 825) were concordant with the SOPs while 38.3% (316 of 825) were overordered and 30.8% (227 of 736) of SOP-recommended tests were omitted. In the prospective data, 98.8% of testing was concordant (244 of 247 total tests) with only 1.2% overordered tests (3 of 247) and 7.6% omitted tests (20 of 264 SOP-recommended tests; overall P < .001). The cost of overordered tests before implementing SOP indicates a potential annualized saving of $1,347,520 in US dollars (USD) in overordered testing at Brigham and Women's Hospital/DFCI. Only two of 316 overordered tests (0.6%) returned any additional information, both for extremely rare clinical circumstances. CONCLUSION: Implementation of SOPs dramatically improved test ordering practices, with a just right number of ancillary tests that minimizes cost and has no significant impact on acquiring key informative test results.

Incidence and predictors of anthracycline-related left ventricular dysfunction in acute myeloid leukemia.

INTRODUCTION: Anthracycline-related left ventricular dysfunction (ARLVD) is a concern in patients with acute myeloid leukemia (AML) undergoing anthracyclinecontaining induction chemotherapy. However, the incidence of ARLVD in the modern era of routine pretreatment left ventricular ejection fraction (LVEF) echocardiographic assessment, as well as the clinical and genetic predictors of ARLVD are not well understood. METHODS: Consecutive adult patients with AML receiving anthracycline-containing induction chemotherapy at the Dana-Farber Cancer Institute from 2014 to 2022 were studied. Inclusion criteria included availability of a pre and post chemotherapy echocardiogram to assess the LVEF, pre-treatment LVEF > 50 %, as well as comprehensive diagnostic next generation sequencing assessing for the presence of myeloid mutations. The primary endpoint was the incidence of ARLVD defined as LVEF < 50 % post-induction. RESULTS: Out of 419 patients meeting inclusion criteria, 34 (8%) patients developed ARLVD. Among the 122/419 patients who did not undergo planned allogeneic stem cell transplantation (allo-SCT), ARLVD was the deciding factor for ineligibility in 4 patients (1%). Baseline cardiovascular comorbidities (hypertension, diabetes mellitus, hyperlipidemia, smoking and coronary artery disease) and cumulative anthracycline dose were not predictive of post-induction ARLVD. However, the presence of a JAK2 mutation (but not other myeloid mutations) was associated with an increased risk of ARLVD in multivariable analysis (OR 8.34, 95 % CI 1.55-39.3, p = 0.007). DISCUSSION: In a group of AML patients with normal LVEF prior to anthracycline-containing induction chemotherapy, ARLVD was infrequent and did not commonly preclude post-remission allo-SCT consolidation. Genetic predictors of ARLVD require further investigation in a larger patient cohort.

Eprenetapopt combined with venetoclax and azacitidine in TP53-mutated acute myeloid leukaemia: a phase 1, dose-finding and expansion study.

BACKGROUND: TP53-mutated acute myeloid leukaemia is associated with poor outcomes. Eprenetapopt (APR-246) is a first-in-class, small-molecule p53 reactivator. We aimed to evaluate the combination of eprenetapopt and venetoclax with or without azacitidine in patients with TP53-mutated acute myeloid leukaemia. METHODS: This phase 1, multicentre, open-label, dose-finding and cohort expansion study was done at eight academic research hospitals in the USA. Inclusion criteria were age of at least 18 years; at least one pathogenic TP53 mutation; treatment-naive acute myeloid leukaemia according to the 2016 WHO classification; an ECOG performance status of 0-2; and a life expectancy of at least 12 weeks. In dose-finding cohort 1 patients received previous therapy with hypomethylating agents for myelodysplastic syndromes. In dose-finding cohort 2, previous use of hypomethylating agents was not permitted. Treatment cycles were 28 days. Patients in cohort 1 received intravenous eprenetapopt 4·5 g/day on days 1-4 and oral venetoclax 400 mg/day on days 1-28; those in cohort 2 also received subcutaneous or intravenous azacitidine 75 mg/m2 on days 1-7. The expansion part of the study proceeded with patients enrolled as in cohort 2. Primary endpoints were safety in all cohorts (assessed in patients receiving at least one dose of assigned treatment) and complete response in the expansion cohort (assessed in patients who completed at least one treatment cycle and had at least one post-treatment clinical response assessment). The trial is registered with ClinicalTrials.gov, NCT04214860, and is complete. FINDINGS: Between Jan 3, 2020, and July 22, 2021, 49 patients were enrolled across all cohorts. Six patients were initially enrolled into each of dose-finding cohorts 1 and 2; after no dose-limiting toxicities were observed, cohort 2 was expanded to enrol an additional 37 patients. The median age was 67 years (IQR 59-73). 24 (49%) of 49 patients were female and 25 (51%) male, and 40 (82%) were White. At data cutoff (Oct 1, 2021), the median length of follow-up was 9·5 months (IQR 6·1-11·5). No dose-limiting toxicities were recorded and the recommended phase 2 dose for eprenetapopt combinations was 4·5 g/day on days 1-4. Across all patients, adverse events of grade 3 or worse occurring in at least 20% of patients were febrile neutropenia (23 [47%] of 49 patients), thrombocytopenia (18 [37%] patients), leukopenia (12 [25%] patients), and anaemia (11 [22%] patients). Treatment-related serious adverse events occurred in 13 (27%) of 49 patients and there was one (2%) treatment-related death (sepsis). 25 (64%, 95% CI 47-79) of 39 patients had an overall response with eprenetapopt and venetoclax with azacytidine; 15 (38%, 23-55) had a complete response. INTERPRETATION: Eprenetapopt and venetoclax with azacitidine had an acceptable safety profile and encouraging activity, supporting further frontline evaluation of this combination in the treatment of TP53-mutated acute myeloid leukaemia. FUNDING: Aprea Therapeutics.

Ixazomib, Oral Metronomic Cyclophosphamide, and Dexamethasone for First-Line Treatment of Multiple Myeloma: A Phase II Brown University Oncology Group Study.

BACKGROUND: Newly diagnosed multiple myeloma patients have many available treatment options. While lenalidomide, bortezomib, and dexamethasone (RVD) is the preferred initial treatment for many patients, several other agents may provide similar efficacy with less toxicity and improved ease of administration. METHODS: We evaluated the safety and efficacy of the all-oral regimen of ixazomib, cyclophosphamide, and dexamethasone with the use of metronomic cyclophosphamide dosing in the treatment of patients with newly diagnosed multiple myeloma. RESULTS: The study was stopped prior to planned enrollment due to slow recruitment, with 12 patients available for final analysis. The overall response rate was 58.3% with 2 patients achieving a very good partial response (16.7%) and 5 patients achieving a partial response (41.7%). Median progression-free survival was 16 months, and median overall survival was 43 months. There were no episodes of grade 3 or greater peripheral neuropathy. Grade 3 or greater dermatologic toxicity was experienced in 50% of patients. CONCLUSION: Although limited enrollment prevented full efficacy evaluation, our data do not support further study of metronomic cyclophosphamide in combination with ixazomib and dexamethasone in the treatment of newly diagnosed multiple myeloma. The activity of this regimen in the relapsed/refractory setting requires further study (ClinicalTrials.gov Identifier: NCT02412228).

Targeting MET and FGFR in Relapsed or Refractory Acute Myeloid Leukemia: Preclinical and Clinical Findings, and Signal Transduction Correlates.

PURPOSE: Patients with relapsed/refractory (R/R) acute myeloid leukemia (AML) have poor outcomes and require new therapies. In AML, autocrine production of hepatocyte growth factor (HGF) drives MET signaling that promotes myeloblast growth and survival, making MET an attractive therapeutic target. MET inhibition exhibits activity in AML preclinical studies, but HGF upregulation by the FGFR pathway is a common mechanism of resistance. PATIENTS AND METHODS: We performed preclinical studies followed by a Phase I trial to investigate the safety and biological activity of the MET inhibitor merestinib in combination with the FGFR inhibitor LY2874455 for patients with R/R AML. Study Cohort 1 underwent a safety lead-in to determine a tolerable dose of single-agent merestinib. In Cohort 2, dose-escalation of merestinib and LY2874455 was performed following a 3+3 design. Correlative studies were conducted. RESULTS: The primary dose-limiting toxicity (DLT) observed for merestinib alone or with LY2874455 was reversible grade 3 transaminase elevation, occurring in 2 of 16 patients. Eight patients had stable disease and one achieved complete remission (CR) without measurable residual disease. Although the MTD of combination therapy could not be determined due to drug supply discontinuation, single-agent merestinib administered at 80 mg daily was safe and biologically active. Correlative studies showed therapeutic plasma levels of merestinib, on-target attenuation of MET signaling in leukemic blood, and increased HGF expression in bone marrow aspirate samples of refractory disease. CONCLUSIONS: We provide prospective, preliminary evidence that MET and FGFR are biologically active and safely targetable pathways in AML.

Intensity of induction regimen and outcomes among adults with Ph+ALL undergoing allogeneic hematopoietic stem cell transplantation.

Tyrosine kinase inhibitors (TKIs) are essential for the treatment of Philadelphia chromosome-positive acute lymphoblastic leukemia (Ph+ ALL) and have allowed for effective, low intensity induction regimens including no or minimal chemotherapy. Whether the use of low intensity induction regimens impacts outcomes after allogeneic hematopoietic stem cell transplant (alloHCT) is less understood. We identified consecutive adult patients with Ph+ ALL undergoing alloHCT in first complete remission (CR1) at our center from 2010 to 2021 and examined the impact of pre-transplant induction intensity on outcomes. Among the 87 identified patients, 44 (51%) received low intensity induction and 43 (49%) received induction with high intensity chemotherapy. Patients receiving low intensity induction were older (median age 60 vs. 47 years, p < 0.01). Following induction, measurable residual disease (MRD) negativity by BCR::ABL1 RT-PCR was similar in the low and high intensity induction cohorts (54% and 52% respectively). Receipt of reduced intensity transplant conditioning was not associated with intensity of induction regimen (39% vs. 19% in low vs. high, respectively, p = 0.06). At a median follow-up of 21 months from transplant, there was no difference between low and high intensity induction with respect to 2-year disease-free survival (58% vs. 56%), 2-year overall survival (62% vs. 63%), 2-year cumulative incidence of relapse (9% vs. 17%), and 2-year non-relapse mortality (33% vs. 29%). We also found no difference in outcomes when patients were segmented by both induction and conditioning regimen intensities. Our retrospective analysis suggests that induction intensity does not impact post-transplant outcomes among patients with Ph+ ALL transplanted in CR1.

Vemurafenib and Obinutuzumab as Frontline Therapy for Hairy Cell Leukemia.

Vemurafenib and Obinutuzumab for Hairy Cell LeukemiaIn this study of vemurafenib plus obinutuzumab of patients with previously untreated hairy cell leukemia, treatment was administered for four cycles, and the primary end point was complete remission rate. Twenty-seven of 30 patients completed all four cycles of treatment and achieved complete remission. No dose-limiting toxicity was observed.

Outcomes of antifungal prophylaxis for newly diagnosed AML patients treated with a hypomethylating agent and venetoclax.

Antifungal prophylaxis (AFP) is recommended for acute myeloid leukemia (AML) patients receiving the combination of venetoclax (VEN) and a hypomethylating agent (HMA), but the benefit of this practice is unclear. We identified 131 patients with newly diagnosed AML who received frontline VEN/HMA and evaluated the use of AFP and its association with invasive fungal infections (IFIs) and AML outcomes. Seventeen percent of our patients received AFP at any time. Overall incidence of any IFI ('possible,' 'probable,' or 'proven' infection, as defined by the European Mycoses Study Group) was 13%, and the incidence did not differ based on AFP use (p=.74). Median overall survival did not differ based on AFP use or lack thereof (8.1 vs. 12.5 months, respectively; p=.14). Our findings suggest that, at an institution where the incidence of fungal infections is low, there does not appear to be a role for AFP in newly diagnosed AML patients receiving VEN/HMA.

BCOR and BCORL1 Mutations Drive Epigenetic Reprogramming and Oncogenic Signaling by Unlinking PRC1.1 from Target Genes.

Polycomb repressive epigenetic complexes are recurrently dysregulated in cancer. Unlike polycomb repressive complex 2 (PRC2), the role of PRC1 in oncogenesis and therapy resistance is not well-defined. Here, we demonstrate that highly recurrent mutations of the PRC1 subunits BCOR and BCORL1 in leukemia disrupt assembly of a noncanonical PRC1.1 complex, thereby selectively unlinking the RING-PCGF enzymatic core from the chromatin-targeting auxiliary subcomplex. As a result, BCOR-mutated PRC1.1 is localized to chromatin but lacks repressive activity, leading to epigenetic reprogramming and transcriptional activation at target loci. We define a set of functional targets that drive aberrant oncogenic signaling programs in PRC1.1-mutated cells and primary patient samples. Activation of these PRC1.1 targets in BCOR-mutated cells confers acquired resistance to treatment while sensitizing to targeted kinase inhibition. Our study thus reveals a novel epigenetic mechanism that explains PRC1.1 tumor-suppressive activity and identifies a therapeutic strategy in PRC1.1-mutated cancer. SIGNIFICANCE: We demonstrate that BCOR and BCORL1 mutations in leukemia unlink PRC1.1 repressive function from target genes, resulting in epigenetic reprogramming and activation of aberrant cell signaling programs that mediate treatment resistance. Our study provides mechanistic insights into the pathogenesis of PRC1.1-mutated leukemia that inform novel therapeutic approaches. This article is highlighted in the In This Issue feature, p. 85.

Transcriptional differences between JAK2-V617F and wild-type bone marrow cells in patients with myeloproliferative neoplasms.

The JAK2-V617F mutation is the most common cause of myeloproliferative neoplasms. Although experiments have revealed that this gain-of-function mutation is associated with myeloid blood cell expansion and increased production of white cells, red cells, and platelets, the transcriptional consequences of the JAK2-V617F mutation in different cellular compartments of the bone marrow have not yet been fully elucidated. To study the direct effects of JAK2-V617F on bone marrow cells in patients with myeloproliferative neoplasms, we performed joint single-cell RNA sequencing and JAK2 genotyping on CD34+-enriched cells from eight patients with newly diagnosed essential thrombocythemia or polycythemia vera. We found that the JAK2-V617F mutation increases the expression of interferon-response genes (e.g., HLAs) and the leptin receptor in hematopoietic progenitor cells. Furthermore, we sequenced a population of CD34- bone marrow monocytes and found that the JAK2 mutation increased expression of intermediate monocyte genes and the fibrocyte-associated surface protein SLAMF7 in these cells.

Peri-transfusion quality-of-life assessment for patients with myelodysplastic syndromes.

BACKGROUND: Many patients with myelodysplastic syndromes (MDS) receive red cell transfusions to relieve symptoms associated with anemia, with transfusions triggered by hemoglobin level. It is not known if patients' quality of life (QOL) improves after transfusion, nor if peri-transfusion QOL assessment (PTQA) can guide future transfusion decisions. STUDY DESIGN AND METHODS: We conducted a prospective pilot study of adults with MDS at three centers. Participants, who had to have hemoglobin ≥7.5, completed an MDS-specific measure of QOL (the Quality of Life in Myelodysplasia Scale, [QUALMS]) 1 day before and 7 days after red cell transfusion. A report was sent to each patient and provider before the next transfusion opportunity, indicating whether there were clinically significant changes in QOL. We assessed the proportion of patients experiencing changes in QOL, and with a follow-up questionnaire, whether they perceived their PTQA data were used for future transfusion decisions. RESULTS: From 2018 to 2020, 62 patients enrolled (mean age 73 years) and 37 completed both pre- and post-transfusion QOL assessments. Of these, 35% experienced a clinically significant increase in QUALMS score 7 days after transfusion; 46% no change; and 19% a decrease. Among those completing the follow-up questionnaire, 23% reported that PTQA results were discussed by their provider when considering repeat transfusion. CONCLUSIONS: These data suggest PTQA is feasible for patients with MDS. Moreover, while helpful for some, for many others, red cell transfusion may not achieve its intended goal of improving QOL. PTQA offers a strategy to inform shared decision-making regarding red cell transfusion.

Reconstructing the Lineage Histories and Differentiation Trajectories of Individual Cancer Cells in Myeloproliferative Neoplasms.

Some cancers originate from a single mutation event in a single cell. Blood cancers known as myeloproliferative neoplasms (MPNs) are thought to originate when a driver mutation is acquired by a hematopoietic stem cell (HSC). However, when the mutation first occurs in individuals and how it affects the behavior of HSCs in their native context is not known. Here we quantified the effect of the JAK2-V617F mutation on the self-renewal and differentiation dynamics of HSCs in treatment-naive individuals with MPNs and reconstructed lineage histories of individual HSCs using somatic mutation patterns. We found that JAK2-V617F mutations occurred in a single HSC several decades before MPN diagnosis-at age 9 ± 2 years in a 34-year-old individual and at age 19 ± 3 years in a 63-year-old individual-and found that mutant HSCs have a selective advantage in both individuals. These results highlight the potential of harnessing somatic mutations to reconstruct cancer lineages.

A dose escalation study of RO6870810/TEN-10 in patients with acute myeloid leukemia and myelodysplastic syndrome.

Bromodomain and extra-terminal (BET) proteins can drive carcinogenesis and therapy resistance. RO6870810 (RO) is a novel, small-molecule BET inhibitor. We conducted a study in 32 patients with relapsed/refractory acute myeloid leukemia and hypomethylating agent-refractory myelodysplastic syndrome (NCT02308761). Pharmacodynamic assessments showed decreases in CD11b in peripheral blood mononuclear cells at RO concentrations above 120 ng/mL. Treatment emergent adverse events were generally mild and the most frequent were fatigue, injection site reactions, diarrhea, decreased appetite and nausea. There were no treatment-related deaths. Potential drug-related dose limiting toxicities included decreased appetite, congestive cardiac failure, hypertension, fatigue, increased conjugated bilirubin and increased gamma glutamyltransferase. One AML patient achieved complete remission after withdrawal from study. Eleven AML patients experienced SD. For AML, the median OS was 72.0 days. For MDS, two patients experienced SD. Further development of RO as monotherapy was discontinued due to lack of efficacy, but combinations with other agents are under consideration.

Ivosidenib or enasidenib combined with intensive chemotherapy in patients with newly diagnosed AML: a phase 1 study.

Ivosidenib (AG-120) and enasidenib (AG-221) are targeted oral inhibitors of the mutant isocitrate dehydrogenase (mIDH) 1 and 2 enzymes, respectively. Given their effectiveness as single agents in mIDH1/2 relapsed or refractory acute myeloid leukemia (AML), this phase 1 study evaluated the safety and efficacy of ivosidenib or enasidenib combined with intensive chemotherapy in patients with newly diagnosed mIDH1/2 AML. Ivosidenib 500 mg once daily and enasidenib 100 mg once daily were well tolerated in this setting, with safety profiles generally consistent with those of induction and consolidation chemotherapy alone. The frequency of IDH differentiation syndrome was low, as expected given the concurrent administration of cytotoxic chemotherapy. In patients receiving ivosidenib, the frequency and grades of QT interval prolongation were similar to those observed with ivosidenib monotherapy. Increases in total bilirubin were more frequently observed in patients treated with enasidenib, consistent with this inhibitor's known potential to inhibit UGT1A1, but did not appear to have significant clinical consequences. In patients receiving ivosidenib (n = 60) or enasidenib (n = 91), end-of-induction complete remission (CR) rates were 55% and 47%, respectively, and CR/CR with incomplete neutrophil or platelet recovery (CR/CRi/CRp) rates were 72% and 63%, respectively. In patients with a best overall response of CR/CRi/CRp, 16/41 (39%) receiving ivosidenib had IDH1 mutation clearance and 15/64 (23%) receiving enasidenib had IDH2 mutation clearance by digital polymerase chain reaction; furthermore, 16/20 (80%) and 10/16 (63%), respectively, became negative for measurable residual disease by multiparameter flow cytometry. This trial was registered at www.clinicaltrials.gov as #NCT02632708.