Two Cases of Possible Familial Chronic Myeloid Leukemia in a Family with Extensive History of Cancer.

CML is defined by the presence of an oncogenic fusion protein caused by a reciprocal translocation between chromosomes 9q and 22q. While our molecular understanding of CML pathogenesis has revolutionized drug development for this disease, we have yet to identify many predisposing factors for CML. Familial occurrence of CML has been rarely reported. Here, we describe 2 cases of CML in a 24-year-old woman and in her 73-year-old maternal great aunt. We describe genetic variants in these patients and report on their environmental exposures that may have contributed to CML pathogenesis. The possible familial association of these 2 cases of CML warrants further investigation into more definitive etiologies of this disease.

First Report of Sorafenib in Patients With Acute Myeloid Leukemia Harboring Non-Canonical FLT3 Mutations.

The prognostics implications of patients with acute myeloid leukemia harboring non-canonical FLT3 is unknown. The use of tyrosine kinase inhibitors in this patient population has not been previously reported. We report successful targeted therapy against non-ITD, non-D835 driver FLT3 alterations in two patient case studies with acute myeloid leukemia.

Genomic context and TP53 allele frequency define clinical outcomes in TP53-mutated myelodysplastic syndromes.

TP53 mutations are associated with adverse outcomes and shorter response to hypomethylating agents (HMAs) in myelodysplastic syndrome (MDS). Limited data have evaluated the impact of the type, number, and patterns of TP53 mutations in response outcomes and prognosis of MDS. We evaluated the clinicopathologic characteristics, outcomes, and response to therapy of 261 patients with MDS and TP53 mutations. Median age was 68 years (range, 18-80 years). A total of 217 patients (83%) had a complex karyotype. TP53 mutations were detected at a median variant allele frequency (VAF) of 0.39 (range, 0.01-0.94). TP53 deletion was associated with lower overall response rate (ORR) (odds ratio, 0.3; P = .021), and lower TP53 VAF correlated with higher ORR to HMAs. Increase in TP53 VAF at the time of transformation was observed in 13 patients (61%), and previously undetectable mutations were observed in 15 patients (65%). TP53 VAF was associated with worse prognosis (hazard ratio, 1.02 per 1% VAF increase; 95% confidence interval, 1.01-1.03; P < .001). Integration of TP53 VAF and karyotypic complexity identified prognostic subgroups within TP53-mutant MDS. We developed a multivariable model for overall survival that included the revised International Prognostic Scoring System (IPSS-R) categories and TP53 VAF. Total score for each patient was calculated as follows: VAF TP53 + 13 × IPSS-R blast score + 16 × IPSS-R cytogenetic score + 28 × IPSS-R hemoglobin score + 46 × IPSS-R platelet score. Use of this model identified 4 prognostic subgroups with median survival times of not reached, 42.2, 21.9, and 9.2 months. These data suggest that outcomes of patients with TP53-mutated MDS are heterogeneous and that transformation may be driven not only by TP53 but also by other factors.

Idarubicin, cytarabine, and nivolumab in patients with newly diagnosed acute myeloid leukaemia or high-risk myelodysplastic syndrome: a single-arm, phase 2 study.

BACKGROUND: Outcomes for younger patients with acute myeloid leukaemia have moderately improved over the past two decades owing to better supportive care and recent introduction of novel targeted agents. Blocking PD-1 and its ligand's pathways enhances antileukaemia responses by enabling T cells in murine models. We aimed to assess the addition of nivolumab to frontline therapy with idarubicin and cytarabine in patients with newly diagnosed acute myeloid leukaemia or high-risk myelodysplastic syndrome. METHODS: This single-arm, phase 2 part of the phase 1-2 study of nivolumab in combination with idarubicin and cytarabine was done at the University of Texas MD Anderson Cancer Center (Houston, TX, USA). Eligible patients were aged 18-60 years (or >60 years if suitable for intensive chemotherapy), and had newly diagnosed acute myeloid leukaemia or high-risk myelodysplastic syndrome, and an Eastern Cooperative Oncology Group performance status of 0-2. Induction included cytarabine 1·5 g/m2 by 24-h continuous infusion daily on days 1-4 (3 days in patients >60 years) and idarubicin 12 mg/m2 daily on days 1-3. Nivolumab 3 mg/kg was started on day 24 (range 22-26) and continued every 2 weeks for up to a year in responders. Responders received either up to five consolidation cycles of attenuated doses of idarubicin and cytarabine, or allogeneic stem cell transplantation if eligible. The primary endpoint was event-free survival. Efficacy and safety analyses were done in all patients who received at least one dose of study treatment. Secondary endpoints were relapse-free survival and overall survival. This ongoing trial is registered with ClinicalTrials.gov, number NCT02464657. FINDINGS: Between Aug 7, 2015, and June 2, 2018, 44 patients were enrolled of whom 22 (50%) had adverse genetic risk by European Leukaemia Network classification. All patients were evaluable for safety and efficacy. At a median follow-up of 17·25 months (IQR 0·50-30·40), median event-free survival was not reached (95% CI 7·93-NR). Median relapse-free survival of responders was 18·54 months (95% CI 8·20-23·22). The median overall survival was 18·54 months (95% CI 10·81-28·81). Six patients had seven grade 3-4 immune-related adverse events with two cases of rash, two of colitis, and one each of transaminitis, pancreatitis, and cholecystitis. 19 (43%) of 44 patients achieved a response and proceeded to allogeneic stem cell transplantation, with grade 3-4 graft-versus-host disease observed in five (26%). No treatment related deaths were attributed to nivolumab. INTERPRETATION: Addition of nivolumab to induction chemotherapy with idarubicin and cytarabine is feasible in patients with newly diagnosed acute myeloid leukaemia or high-risk myelodysplastic syndrome. Post-transplant severe graft-versus-host disease could be improved, and earlier initiation of checkpoint inhibitor therapy is warranted in future studies. FUNDING: The MD Anderson Cancer Center Support Grant CA016672, and the MD Anderson Cancer Center Leukaemia SPORE CA100632 from the National Cancer Institute, Bristol Myers Squibb.

Proteomic Profiling of Signaling Networks Modulated by G-CSF/Plerixafor/Busulfan-Fludarabine Conditioning in Acute Myeloid Leukemia Patients in Remission or with Active Disease prior to Allogeneic Stem Cell Transplantation.

To characterize intracellular signaling in peripheral blood (PB) cells of acute myeloid leukemia (AML) patients undergoing pretransplant conditioning with CXCR4 inhibitor plerixafor, granulocyte colony-stimulating factor (G-CSF), and busulfan plus fludarabine (Bu+Flu) chemotherapy, we profiled 153 proteins in 33 functional groups using reverse phase protein array. CXCR4 inhibition mobilized AML progenitors and clonal AML cells, and this was associated with molecular markers of cell cycle progression. G-CSF/plerixafor and G-CSF/plerixafor/Bu+Flu modulated distinct signaling networks in AML blasts of patients undergoing conditioning with active disease compared to nonleukemic PB cells of patients in remission. We identified AML-specific proteins that remained aberrantly expressed after chemotherapy, representing putative chemoresistance markers in AML.

DDX41 mutations in myeloid neoplasms are associated with male gender, TP53 mutations and high-risk disease.

Myeloid neoplasms with germline DDX41 mutations have been incorporated into the 2017 WHO classification. Limited studies describing the clinicopathologic features and mutation profile are available. We searched for myeloid neoplasms with a DDX41 gene mutation tested by an 81-gene next-generation sequencing panel over a 7-month period. We identified 34 patients with myeloid neoplasms with DDX41 abnormalities; 26 (76%) men and 8 women (24%) [median age, 70 years], 20 acute myeloid leukemia (AML), 10 myelodysplastic syndrome (MDS), 1 chronic myelomonocytic leukemia (CMML) and 3 myeloproliferative neoplasms (MPN). Fifty-nine DDX41 variants were detected: 27 (46%) appeared somatic and 32 (54%) were presumably germline mutations. The majority of presumed germline mutations were upstream of the Helicase 2 domain (93%) and involved loss of the start codon (30%). The majority of somatic mutations were within the Helicase 2 domain (78%), with the missense mutation p.R525H being most common (67%). There was a significant difference in the location of germline or somatic mutations (P < .0001). Concomitant mutations were detected involving 19 genes, but only TP53 (n = 11, 32%), ASXL1 (n = 8, 24%), and JAK2 (n = 4, 12%) were recurrent. Twenty (59%) patients showed diploid cytogenetics. Twenty-three (68%) patients presented with AML or MDS-EB-2, suggesting an association with high-grade myeloid neoplasm. Patients with myeloid neoplasms carrying DDX41 mutations show male predominance (3:1), higher age at presentation, association with TP53 mutations, and association with high-grade myeloid neoplasms in our cohort at a referral cancer center setting. These findings support the recognition of myeloid neoplasms with DDX41 mutation as unique, need for germline confirmation, and further assessment of family members.

Janus kinase 2 variants associated with the transformation of myeloproliferative neoplasms into acute myeloid leukemia.

BACKGROUND: Canonical Janus kinase 2 (JAK2) V617F and exon 12 mutations in myeloid neoplasms are well described. There are limited reports of other JAK2 variants of potential clinical relevance. This study was designed to survey JAK2 variants in patients with myeloproliferative neoplasms (MPNs) and acute myeloid leukemia (AML) and to determine their contributions to disease pathogenesis. METHODS: Next-generation sequencing of the coding region of JAK2 and 27 other genes was performed on bone marrow DNA samples. The study population was classified into 3 cohorts: chronic MPNs only (the MPN cohort); MPNs transformed into AML (the MPN>>AML cohort); and AML only, with MPN>>AML patients excluded (the AML cohort). RESULTS: Testing was performed for 2154 patients, and non-V617F/non-exon 12 JAK2 sequence variants were identified in 114 (5.3%). They included 35 unique JAK2 variants across all functional domains. Sixteen of the 114 JAK2 variants occurred without somatic mutations in the remaining 27 genes. JAK2 variants were detected at a higher frequency in the MPN>>AML cohort (15.3%) in comparison with the MPN (4.6%; P < .001) and AML cohorts (5.2%; P < .001). Detected variants occurred at higher than expected frequencies in patients with MPNs and AML in comparison with the population, and N1108S had a significantly increased prevalence in patients with AML. A JAK2 variant in addition to JAK2 V617F (n = 13) in myelofibrosis was associated with an increased cumulative risk of transformation into AML (P = .003). CONCLUSIONS: Specific JAK2 variants detected in MPNs may be predictors for transformation into AML.

Safety and tolerability of lurbinectedin (PM01183) in patients with acute myeloid leukemia and myelodysplastic syndrome.

Trabectedin is an FDA-approved DNA minor groove binder that has activity against translocation-associated sarcomas. Lurbinectedin is a next-generation minor groove binder with preclinical activity against myeloid leukemia cells. A dose-finding phase 1 clinical trial was performed in patients with acute myeloid leukemia (AML) and myelodysplastic syndrome (MDS) with further assessment of safety and tolerability. Forty-two patients with relapsed/refractory AML/MDS received lurbinectedin administered as a 1-hour intravenous infusion in a 3 + 3 study design. Two dosing schedules were used: 3.5, 5, 7, or 6 mg on days 1 and 8 or 2, 3, 1, or 1.5 mg for 3 consecutive days on days 1 to 3. Three patients experienced dose-limiting toxicities of rhabdomyolysis (grade 4), hyperbilirubinemia (grade 3), and oral herpes (grade 3) with the day 1 and 8 schedule. Otherwise, adverse events mainly consisted of gastrointestinal manifestations (n = 11), febrile neutropenia/infections (n = 4), pulmonary toxicity (n = 2), and renal failure (n = 2). The most common laboratory abnormalities observed were an increase in creatinine (93%) and anemia, neutropenia, and thrombocytopenia (100%). Overall, 33 of 42 patients (79%) had reduction in blasts in peripheral blood or bone marrow. One patient achieved a partial response and 2 patients a morphologic leukemia-free state. Most (n = 30, 71%) were discontinued due to progressive disease. Early deaths occurred from disease-related causes that were not attributable to lurbinectedin. Four patients with a chromosome 11q21-23 abnormality had significantly greater bone marrow blast reduction than those without such abnormality, with decrease of 31 ± 14% (n = 4) vs 8 ± 8% (n = 16), respectively (P = .04). Overall, lurbinectedin was safe and tolerated using the schedules and dose levels tested. While no sustained remissions were observed, single-agent lurbinectedin was transiently leukemia suppressive for some patients.

Treatment with a 5-day versus a 10-day schedule of decitabine in older patients with newly diagnosed acute myeloid leukaemia: a randomised phase 2 trial.

BACKGROUND: Hypomethylating agents, such as decitabine, are the standard of care for older patients with newly diagnosed acute myeloid leukaemia. Single-arm studies have suggested that a 10-day schedule of decitabine cycles leads to better outcomes than the usual 5-day schedule. We compared the efficacy and safety of these two schedules. METHODS: Eligible patients were aged 60 years or older with acute myeloid leukaemia but unsuitable for intensive chemotherapy (or <60 years if unsuitable for intensive chemotherapy with an anthracycline plus cytarabine). The first 40 patients were allocated equally to the two treatment groups by computer-generated block randomisation (block size 40), after which a response-adaptive randomisation algorithm used all previous patients' treatment and response data to decide the allocation of each following patient favouring the group with superior response. Patients were assigned to receive 20 mg/m2 decitabine intravenously for 5 or 10 consecutive days as induction therapy, every 4-8 weeks for up to three cycles. Responding patients received decitabine as consolidation therapy on a 5-day schedule for up to 24 cycles. We assessed a composite primary endpoint of complete remission, complete remission with incomplete platelet recovery (CRp), and complete remission with incomplete haematological recovery (CRi) achieved at any time and assessed by intention to treat. This trial is registered with ClinicalTrials.gov, number NCT01786343. FINDINGS: Between Feb 28, 2013, and April 12, 2018, 71 patients were enrolled. 28 received decitabine for 5 days and 43 for 10 days, and all were assessable for efficacy and safety. The primary endpoint was achieved in similar proportions of patients in the two treatment groups (12 [43%] of 28 in the 5-day schedule group, 95% credible interval 26-60, and 17 [40%] of 43 in the 10-day schedule group, 26-54, p=0·78; difference 3%, -21 to 27). Total follow-up was 38·2 months, during which the median duration of overall survival was 5·5 months (IQR 2·1-11·7) in the 5-day group and 6·0 months (1·9-11·7) in the 10-day group. 1-year overall survival was 25% in both groups. Complete remission, CRp, CRi, and overall survival did not differ between groups when stratified by cytogenetics, de-novo versus secondary or therapy-related acute myeloid leukaemia, or TP53mut status. The most common grade 3-4 adverse events were neutropenic fever (seven patients [25%] in the 5-day group and 14 [33%] in the 10-day group) and infection (five [18%] and 16 [37%], respectively). One patient (4%) died from sepsis in the context of neutropenic fever, infection, and haemorrhage in the 5-day group, and in the 10-day group six patients (14%) died from infection. Early mortality was similar in the two groups. INTERPRETATION: In older patients with newly diagnosed acute myeloid leukaemia, efficacy and safety did not differ by the 5-day or the 10-day decitabine schedule. FUNDING: University of Texas MD Anderson Cancer Center and National Cancer Institute Specialized Programs of Research Excellence.

Early detection of transformation to BPDCN in a patient with MDS.

BACKGROUND: Blastic plasmacytoid dendritic cell neoplasm (BPDCN) is a rare and aggressive hematologic malignancy characterized by neoplastic cells that are positive for CD123, CD4, BDCA2, and TCL1 and aberrant expression of CD56. Historically, patients with BPDCN have an unfavorable prognosis and the optimal treatment is not established due to lack of prospective data. CASE REPORT: In this report we describe a patient with Felty's syndrome and myelodysplastic syndrome (MDS) in whom a population of aberrant plasmacytoid dendritic cells emerged while on treatment with decitabine. Approximately 4 months later he transformed to leukemic BPDCN with skin and eye manifestations. Cytogenetic analysis showed diploid karyotype and molecular analysis showed mutations in KRAS, NOTCH1, and RUNX1 genes. He was treated with CD123-targeted therapy and had significant response in his marrow, skin, eyes, and functional status after one cycle. CONCLUSION: The case demonstrates that minimal transformative disease of BPDCN may be detectable in patients with MDS well before fulminant progression. Early detection of emerging leukemic clones may allow for alternative monitoring and treatment considerations.

Cladribine and low-dose cytarabine alternating with decitabine as front-line therapy for elderly patients with acute myeloid leukaemia: a phase 2 single-arm trial.

BACKGROUND: Front-line therapy for elderly or unfit patients with acute myeloid leukaemia (AML) remains unsatisfactory with poor outcomes and excessive toxicity. We studied a new low-intensity regimen of cladribine combined with low-dose cytarabine alternating with decitabine, aimed at improving outcomes in this population. Based on our previous experience, we hypothesised that this combination would be safe and more effective than current approaches with hypomethylating agents. METHODS: In this single-arm, open-label, single-centre phase 2 study, we enrolled patients aged 60 years or older with previously untreated AML or high-risk myelodysplastic syndrome who had adequate organ function and an Eastern Cooperative Oncology Group performance status of 2 or less. Patients were treated with cladribine plus low-dose cytarabine for two 28-day cycles alternating with decitabine for two 28-day cycles, for up to 18 cycles. Induction therapy (cycle 1) consisted of cladribine 5 mg/m2 intravenously over 1-2 h on days 1-5 and cytarabine 20 mg subcutaneously twice daily on days 1-10. Patients who had remission during this induction regimen moved on to consolidation therapy (cladribine 5 mg/m2 intravenously over 1-2 h on days 1-3 and cytarabine 20 mg twice daily on days 1-10, alternating with decitabine 20 mg/m2 intravenously on days 1-5). The primary outcome measure was disease-free survival. Secondary outcomes were overall survival, proportion of patients achieving complete response, proportion of patients achieving response, toxicity, and induction mortality. All treated patients were included in the analyses. This trial is ongoing and is registered with ClinicalTrials.gov, number NCT01515527. FINDINGS: Between Feb 17, 2012, and July 6, 2017, 118 patients were enrolled and treated, among whom 48 (41%) had an adverse karyotype, 20 (17%) had therapy-related AML, 18 (15%) had treated secondary AML, and 20 (17%) had TP53 mutations. Median disease-free survival was 10·8 months (IQR 5·4-25·9). 80 (68%) patients achieved objective response: 69 (58%) achieved a complete response and 11 (9%) patients had complete response with incomplete count recovery. The median overall survival was 13·8 months (6·9-28·6). The regimen was well tolerated, with one (1%) death within the first 4 weeks and eight (7%) deaths within the first 8 weeks. The most common non-haematological adverse events of grade 3 or worse were infection (88 [75%] patients), elevated total bilirubin (26 [22%] patients), rash (13 [11%] patients), and nausea (13 [11%] patients). INTERPRETATION: The combination of cladribine and low-dose cytarabine alternating with decitabine appears to be a safe and highly effective regimen for the treatment of elderly or unfit patients with newly diagnosed AML. Further testing of this regimen is warranted, and could help to provide a new, effective option for reduced-intensity therapy in this population. FUNDING: Part supported by the National Institutes of Health.

Prognosis of patients with intermediate risk IPSS-R myelodysplastic syndrome indicates variable outcomes and need for models beyond IPSS-R.

The International Prognostic Scoring System-Revised (IPSS-R) is one standard for myelodysplastic syndrome (MDS) risk stratification. It divides patients into five categories including an intermediate subset (IPSS-R int-risk). Outcomes and clinical interventions for patients with IPSS-R int-risk are not well defined. We performed an analysis of outcomes of this group of patients. Out of 3167 patients, a total of 298 were identified with IPSS-R int-risk MDS and retrospectively analyzed to assess characteristics affecting outcomes. Cox proportional hazard models for overall survival (OS) were performed to identify statistically significant clinical factors that influence survival. Age of 66 years or greater, peripheral blood blasts of 2% or more, and history of red blood cell (RBC) transfusion were significantly associated with inferior survival. Based on these features, MDS patients with IPSS-R int-risk were classified into two prognostic risk groups for analysis, an int-favorable group and an int-adverse group, and had significantly divergent outcomes. Sequential prognostication was validated using two independent datasets comprising over 700 IPSS-R int-risk patients. The difference in median survival between int-favorable and int-adverse patients was 3.7 years in the test cohort, and 1.8 and 2.0 years in the two validation cohorts. These results confirm significantly variable outcomes of patients with IPSS-R int-risk and need for different prognostic systems.

Improving the detection of patients with inherited predispositions to hematologic malignancies using next-generation sequencing-based leukemia prognostication panels.

Recognizing and referring patients with possible inherited cancer predisposition syndromes for appropriate genetic evaluation and testing provides insights into optimal patient treatment approaches and also can provide education and testing opportunities for family members. Next-generation sequencing (NGS)-based, targeted genotyping for somatic mutations is increasingly used in the diagnosis, prognostication, and treatment selection for patients with hematologic malignancies. However, certain mutations that may be somatically acquired can also be present as germline mutations in some individuals and families. Whether the results of NGS-based leukemia panels can be used to inform decisions and subsequent evaluation of patients with possible inherited cancer predispositions has not been described previously. Because a normal control often is not available when using NGS panels in patients with hematologic malignancies, NGS panel results offer both an opportunity and a challenge to determine the origin and pathogenicity of identified mutations. In the absence of a matched germline control, variant allele frequency (VAF) estimation and data from publically available data sets provide important clues to the possible germline origin of a variant. Careful annotation and review of NGS panels in patients with hematologic malignancies can provide a useful screening tool to systematically improve upon the detection of potentially pathogenic germline variants. Cancer 2018;124:2704-2713. © 2018 American Cancer Society.

Erythroleukemia-historical perspectives and recent advances in diagnosis and management.

Acute erythroleukemia is a rare form of acute myeloid leukemia recognized by its distinct phenotypic attribute of erythroblastic proliferation. After a century of its descriptive history, many diagnostic, prognostic, and therapeutic implications relating to this unique leukemia subset remain uncertain. The rarity of the disease and the simultaneous involvement of its associated myeloid compartment have complicated in vitro studies of human erythroleukemia cell lines. Although murine and cell line erythroleukemia models have provided valuable insights into pathophysiology, translation of these concepts into treatment are not forthcoming. Integration of knowledge gained through a careful study of these models with more recent data emerging from molecular characterization will help elucidate key mechanistic pathways and provide a much needed framework that accounts for erythroid lineage-specific attributes. In this article, we discuss the evolving diagnostic concept of erythroleukemia, translational aspects of its pathophysiology, and promising therapeutic targets through an appraisal of the current literature.

A mind map for managing minimal residual disease in acute myeloid leukemia.

Advances in detecting traces of leukemia that were previously unidentifiable have increasingly led to the incorporation of information about residual disease into clinical decision making for patients with leukemia in both the postinduction and consolidation settings. This review discusses current concepts related to minimal residual disease (MRD), which is defined as submicroscopic disease detected during morphologic complete remission. The focus is on acute myeloid leukemia (AML). Basic methods for detecting MRD include flow cytometry, reverse transcription-polymerase chain reaction, and mutation analysis. Several studies using these assays have demonstrated prognostic implications based on MRD-positive vs MRD-negative status. As our understanding of the biological factors responsible for MRD in AML evolves, residual disease should be evaluated in the context of other prognostic markers. Current therapeutic options for managing MRD in AML are limited, and the clinical implications of a positive MRD test result can be significant. Regarding individual patients, an evidence-based approach must be applied while the institution- and assay-specific differences that currently exist are considered. Challenges associated with MRD assessment, such as the limited standardization of available assays and the paucity of effective agents to eradicate MRD, will need to be overcome before physicians who treat leukemia can use MRD as a tool for clinical management.

JAK2V617F detection and allele burden measurement in saliva vs. peripheral blood in patients with myelofibrosis.

We previously demonstrated that peripheral blood (PB) is a reliable source for testing JAK2V617F mutation in patients with myelofibrosis (MF); saliva has also been tested to detect such mutation, however its diagnostic accuracy as compared to PB has not been validated. In this study, we prospectively tested 167 patients with MF for JAK2V617F mutation, using both saliva and PB collected at the same time from each patient. The concordance between the 2 sources was 96%, with a sensitivity of 100% and a specificity of 90%. The only factor associated with false positivity on saliva was ongoing transfusion dependency. JAK2V617F testing using saliva is a simple, non-invasive, and potentially a more reliable method than PB for measuring JAK2 status and assessing V617F allelic burden in patients with transfusion dependency.

Targeting Histone Acetylation: Readers and Writers in Leukemia and Cancer.

Chromatin packaging of DNA provides a framework for transcriptional regulation. Modifications to DNA and histone proteins in nucleosomes lead to conformational changes, alterations in the recruitment of transcriptional complexes, and ultimately modulation of gene expression. We provide a focused review of control mechanisms that help modulate the activation and deactivation of gene transcription specifically through histone acetylation writers and readers in cancer. The chemistry of these modifications is subject to clinically actionable targeting, including state-of-the-art strategies to inhibit basic oncogenic mechanisms related to histone acetylation. Although discussed in the context of acute leukemia, the concepts of acetylation writers and readers are not cell-type-specific and are generalizable to other cancers. We review the challenges and resistance mechanisms encountered to date in the development of such therapeutics and postulate how such challenges may be overcome. Because these fundamental cellular mechanisms are dysregulated in cancer biology, continued research and in-depth understanding of histone acetylation reading and writing are desired to further define optimal therapeutic strategies to affect gene activity to target cancer effectively.