Venetoclax abrogates the prognostic impact of splicing factor gene mutations in newly diagnosed acute myeloid leukemia.

Mutations in splicing factor (SF) genes SRSF2, U2AF1, SF3B1, and ZRSR2 are now considered adverse risk in the European LeukemiaNet 2022 acute myeloid leukemia (AML) risk stratification. The prognostic impact of SF mutations in AML has been predominantly derived from younger patients treated with intensive (INT) therapy. We evaluated 994 patients with newly diagnosed AML, including 266 (27%) with a SFmut. Median age was 67 years overall, with patients with SFmut being older at 72 years. SRSF2 (n = 140, 53%) was the most common SFmut. In patients treated with INT, median relapse-free survival (RFS) (9.6 vs 21.4 months, P = .04) and overall survival (OS) (15.9 vs 26.7 months, P = .06) were shorter for patients with SFmut than without SFwt, however this significance abrogated when evaluating patients who received venetoclax with INT therapy (RFS 15.4 vs 20.3 months, P = .36; OS 19.6 vs 30.7 months, P = .98). In patients treated with LI, median RFS (9.3 vs 7.7 months, P = .35) and OS (12.3 vs 8.5 months, P = .14) were similar for patients with and without SFmut , and outcomes improved in all groups with venetoclax. On multivariate analysis, SFmut did not affect hazards of relapse and death for INT arm but reduced both these hazards in LI arm. In a large AML data set with >60% of patients receiving venetoclax with LI/INT therapy, SFmut had no independent negative prognostic impact. Newer prognostic models that consider LI therapy and use of venetoclax among other factors are warranted.

TP53 copy number and protein expression inform mutation status across risk categories in acute myeloid leukemia.

Mutant TP53 is an adverse risk factor in acute myeloid leukemia (AML), but large-scale integrated genomic-proteomic analyses of TP53 alterations in patients with AML remain limited. We analyzed TP53 mutational status, copy number (CN), and protein expression data in AML (N = 528) and provide a compilation of mutation sites and types across disease subgroups among treated and untreated patients. Our analysis shows differential hotspots in subsets of AML and uncovers novel pathogenic variants involving TP53 splice sites. In addition, we identified TP53 CN loss in 70.2% of TP53-mutated AML cases, which have more deleterious TP53 mutations, as well as copy neutral loss of heterozygosity in 5/32 (15.6%) AML patients who had intact TP53 CN. Importantly, we demonstrate that mutant p53 protein expression patterns by immunohistochemistry evaluated using digital image-assisted analysis provide a robust readout that integrates TP53 mutation and allelic states in patients with AML. Expression of p53 by immunohistochemistry informed mutation status irrespective of TP53 CN status. Genomic analysis of comutations in TP53-mutant AML shows a muted landscape encompassing primarily mutations in genes involved in epigenetic regulation (DNMT3A and TET2), RAS/MAPK signaling (NF1, KRAS/NRAS, PTPN11), and RNA splicing (SRSF2). In summary, our data provide a rationale to refine risk stratification of patients with AML on the basis of integrated molecular and protein-level TP53 analyses.

Outcomes and genetic dynamics of acute myeloid leukemia at first relapse.

Patients with relapsed acute myeloid leukemia (rAML) experience dismal outcomes. We performed a comprehensive analysis of patients with rAML to determine the genetic dynamics and survival predictive factors. We analyzed 875 patients with newly diagnosed AML who received intensive treatment (IT) or low-intensity treatment (LIT). Of these patients, 197 experienced subsequent rAML. Data was available for 164 patients, with a median time from CR/CRi to relapse of 6.5 months. Thirty-five of the 164 patients (21%) experienced relapse after allogeneic hematopoietic stem cell transplantation (alloSCT). At relapse mutations in genes involved in pathway signaling tended to disappear, whereas clonal hematopoiesis-related mutations or TP53 tended to persist. Patients with normal karyotypes tended to acquire cytogenetic abnormalities at relapse. Patients treated with IT had a higher emergence rate of TP53 mutations (16%), compared to patients treated with LIT (1%, P = 0.009). The overall response rates were 38% and 35% for patients treated with salvage IT or LIT, respectively. Seventeen patients (10%) underwent alloSCT after salvage therapy. The median overall survival (OS) duration after relapse was 5.3 months, with a 1-year OS rate of 17.6%. Complex karyotype (hazard ratio [HR] = 2.14, P < 0.001), a KMT2A rearrangement (HR = 3.52, P = 0.011), time in remission < 12 months (HR = 1.71, P = 0.011), and an elevated white blood cell count at relapse (HR = 2.38, P = 0.005) were independent risk factors for OS duration. More effective frontline and maintenance therapies are warranted to prevent rAML.

A retrospective study of cladribine and low-dose cytarabine-based regimens for the treatment of chronic myelomonocytic leukemia and secondary acute myeloid leukemia.

BACKGROUND: Patients with higher risk chronic myelomonocytic leukemia (CMML) have limited therapeutic options beyond hydroxyurea and hypomethylating agents (HMAs). Regimens based on a backbone of cladribine (CLAD), low-dose cytarabine (LDAC), and an HMA are effective low-intensity therapies for acute myeloid leukemia (AML). METHODS: The authors conducted a retrospective chart review to evaluate the efficacy of CLAD/LDAC/HMA in CMML and secondary acute myeloid leukemia (sAML) arising from CMML. Responses were evaluated according to the 2006 International Working Group criteria for CMML and the 2017 European LeukemiaNet criteria for AML. The overall survival (OS), leukemia-free survival (LFS), and duration of response were evaluated with the Kaplan-Meier method. Patients were stratified on the basis of prior HMA exposure. RESULTS: The authors identified 21 patients with CMML (eight with HMA-naive CMML and 13 with HMA-failure CMML) and 33 patients with sAML (11 with HMA-naive sAML and 22 with HMA-failure sAML) treated with CLAD/LDAC/HMA-based regimens. The CMML cohort was enriched for high-risk features (proliferative type, elevated blasts, and RAS/MAPK mutations). The overall response rate was 33% in CMML (50% in HMA-naive CMML and 23% in HMA-failure CMML) and 48% in sAML (82% in HMA-naive sAML and 32% in HMA-failure sAML). The median OS was 14.4, 8.8, 42.9, and 2.9 months for HMA-naive CMML, HMA-failure CMML, HMA-naive sAML, and HMA-failure sAML, respectively. The median LFS was 14.4 and 3.9 months for HMA-naive CMML and HMA-failure CMML, respectively. CONCLUSIONS: CLAD/LDAC/HMA-based regimens are effective in a subset of patients with higher risk CMML and sAML arising from CMML who have not previously experienced HMA failure. These findings must be confirmed in prospective studies.

Phenotypic subtypes of leukaemic transformation in chronic myelomonocytic leukaemia.

Chronic myelomonocytic leukaemia (CMML) is a haematological disorder with high risk of transformation to acute myeloid leukaemia (AML). To characterize the phenotypic and genomic patterns of CMML progression, we evaluated a cohort of 189 patients with AML evolving from CMML. We found that transformation occurs through distinct trajectories characterized by genomic profiles and clonal evolution: monocytic (Mo-AML, 53%), immature myeloid (My-AML, 43%) or erythroid (Ery-AML, 2%). Mo-AML, characterized by expansion of monoblasts and promonocytes (low CD34, CD117 expression; high CD14, CD33, CD56 and CD64 expression), were defined by SRSF2, TET2 and RAS pathway mutation co-dominance and were more likely to evolve from SRSF2-TET2 co-mutant CMML through emergence/expansion of RAS pathway mutant clones. Conversely, My-AML, characterized by expansion of immature myeloid blasts (high frequency of CD34, CD38, CD117; low frequency of CD14, CD64 and CD56 expression) were less likely to exhibit SRSF2-TET2 co-mutations or RAS pathway mutations and had higher frequency of CEBPA mutations. Ery-AML was defined by complex karyotypes and TP53 mutations. A trend towards improved OS and EFS with hypomethylating agent-venetoclax combination was observed in My-AML, but not Mo-AML. These findings define distinct progression of CMML and set the basis for future studies evaluating the role of phenotype-specific therapeutics.

The outcomes of patients with chronic myeloid leukemia treated with third-line BCR::ABL1 tyrosine kinase inhibitors.

The BCR::ABL1 tyrosine kinase inhibitors (TKIs) have improved the outcomes of patients with chronic myeloid leukemia (CML). After failing second-generation TKI (2G-TKI), the optimal third-line therapy in chronic phase CML (CML-CP) is not well established. We analyzed 354 patients with CML-CP treated with a third-line BCR::ABL1 TKI at our institution, and in the PACE and OPTIC trials, and evaluated the outcome after alternate 2G-TKIs or ponatinib. We performed a propensity score matching analysis to compare outcomes and multivariate analysis to identify variables associated with survival. One hundred seventy-three (49%) patients received 2G-TKIs and 181 (51%) ponatinib. Patients in the ponatinib group had more cardiovascular risk factors (34% versus 19%) and higher disease burden (BCR::ABL1 transcript levels >1%, 165/175 [94%] versus 75/135 [55%]; p < .001) compared with the 2G-TKI group. Among the 173 evaluable patients treated with ponatinib, 89 (52%) achieved 2 + -log reduction of baseline transcripts (20% 2-log reduction and 32% 3 + -log reduction). Among the 128 evaluable patients treated with 2G-TKIs, 44 (34%) achieved 2 + -log reduction of baseline transcripts (13% 2-log reduction and 21% 3 + -log reduction). With a median follow-up of 46 months, the 3-year progression-free survival was 59% (60% before matching) with 2G-TKI and 83% (81% before matching) with ponatinib (p < .001). The 3-year survival was 83% (81% before matching) with 2G-TKI and 87% (89% before matching) with ponatinib (p = .03). By multivariate analysis, third-line therapy with ponatinib was the only independent factor associated with better survival (p = .003). In conclusion, ponatinib is an optimal treatment for patients with CML-CP failing two prior TKIs.

Performance of IPSS-M in patients with myelodysplastic syndrome after hypomethylating agent failure.

Evaluation of IPSS-M and exploratory prognostic model for MDS at the time of HMA failure.

Evolving trends and outcomes in older patients with acute myeloid leukemia including allogeneic stem cell transplantation.

Outcomes in older patients with acute myeloid leukemia (AML) have historically been poor. Given advances in low-intensity therapy (LIT) and stem cell transplantation (SCT), we performed a retrospective single-center study to evaluate the contemporary outcomes of this population. We reviewed all patients ≥60 years with newly diagnosed AML between 2012 and 2021 and analyzed treatment and SCT-related trends and outcomes. We identified 1073 patients with a median age of 71 years. Adverse clinical and cytomolecular findings were frequent within this cohort. In total, 16% of patients were treated with intensive chemotherapy, 51% with LIT alone, and 32% with LIT plus venetoclax. The composite complete remission rate with LIT plus venetoclax was 72%, which was higher than with LIT alone (48%, p < .0001) and comparable to intensive chemotherapy (74%, p = .6). The median overall survival (OS) with intensive chemotherapy, LIT, and LIT plus venetoclax was 20.1, 8.9, and 12.1 months, respectively. 18% of patients received SCT. SCT rates were 37%, 10%, and 22% in patients treated with intensive chemotherapy, LIT, and LIT plus venetoclax, respectively. The 2-year OS, relapse-free survival (RFS), cumulative incidence (CI) of relapse, and CI of treatment-related mortality with frontline SCT (n = 139) were 59%, 52%, 27%, and 22%, respectively. By landmark analysis, patients undergoing frontline SCT had superior OS (median 39.6 vs. 21.4 months, p < .0001) and RFS (30.9 vs. 12.1 months, p < .0001) compared with responding patients who did not. Outcomes in older patients with AML are improving with more effective LIT. Measures should be pursued to increase access to SCT in older patients.

Relevant Clinical Factors in Patients with Myelofibrosis on Ruxolitinib for 5 or More Years.

INTRODUCTION: Median duration of therapy with the first JAK1/2 inhibitor ruxolitinib (RUX) approved for patients with intermediate or high-risk myelofibrosis (MF) is about 3 years. METHODS: In this retrospective study, we aimed to evaluate clinical features, predictive factors, and outcome of patients presenting to our institution who were able to remain on RUX for ≥5 years (RUX ≥5y, n = 73). RESULTS: Comparing baseline demographics of patients who remained on RUX ≥5y (n = 73) with patients who were on RUX for 6 months to 3 years (n = 203), we confirmed that patients on RUX ≥5y lacked advanced clinical features at the start of therapy, such as anemia, neutropenia, thrombocytopenia, higher blasts or monocytes. Predictive independent factors for staying on RUX ≥5y were hemoglobin >10 g/dL, circulating blasts <1%, platelets >150 × 109/L, neutrophils >70%, and having primary MF. Age over 65 years remained significant for outcome in patients on RUX ≥5y. CONCLUSION: In this retrospective study, we report on the relevance of absence of advanced clinical features for long RUX therapy and confirm the role of age on outcome despite therapy.

Pneumonitis after immune checkpoint inhibitor therapies in patients with acute myeloid leukemia: A retrospective cohort study.

BACKGROUND: Immune checkpoint inhibitors (ICI), combined with hypomethylating agents, can be used to treat acute myeloid leukemia (AML), but this strategy results in a high rate of pneumonitis. The authors sought to determine risk factors for pneumonitis development and whether pneumonitis increased mortality. METHODS: The authors conducted a retrospective review of 258 AML patients who received ICI-containing regimens from 2016 to 2018. A multidisciplinary adjudication committee diagnosed pneumonia and pneumonitis by reviewing symptoms, imaging, microbiology, and response to therapies. To measure risk factors for pneumonitis and mortality, multivariate Cox proportional hazards models were constructed. Pneumonia, pneumonitis, and disease progression were modeled as a time-dependent variable and incorporated a standard risk set modifying variables into the models. RESULTS: Thirty patients developed pneumonitis (12%). Of these, 17 had partial or complete resolution, whereas 13 patients died from pneumonitis. Increasing age (hazard ratio [HR], 1.04 per year; 95% confidence interval [CI], 1.00-1.08), and baseline shortness of breath increased pneumonitis risk (HR, 2.51; 95% CI, 1.13-5.55). Female sex (HR, 0.33; 95% CI, 0.15-0.70) and increasing platelet count (HR, 0.52 per log-unit increase; 95% CI, 0.30-0.92) decreased pneumonitis risk. In adjusted models, ICI-related pneumonitis significantly increased mortality (HR, 2.84; 95% CI, 1.84-4.37). CONCLUSIONS: ICI-related pneumonitis occurs at a high rate in AML patients and increases mortality. LAY SUMMARY: Immune checkpoint inhibitors (ICIs) remove inhibitory signals that reduce T-cell function and allow T-cells to better attack cancer cells. In acute myeloid leukemia (AML), the effectiveness of ICIs is limited in part by inflammation of the lung, called pneumonitis. This study reviewed 258 patients with AML who received ICIs and identified 30 patients who developed pneumonitis, nearly half of whom died. Older age and baseline shortness of breath increased pneumonitis risk, whereas female sex and higher baseline platelet counts decreased pneumonitis risk. Pneumonitis increased mortality by nearly 3-fold. This work highlights the significant harm imposed by pneumonitis after ICI therapies.

Urgent cytoreduction for newly diagnosed acute myeloid leukemia patients allows acquisition of pretreatment genomic data and enrollment on investigational clinical trials.

Newly diagnosed acute myeloid leukemia is often deemed a medical emergency, requiring urgent treatment. This is in contradiction with the need for accurate cytogenetic and molecular data, which is not immediately available, to select optimal therapy. We hypothesized that cytoreduction with hydroxyurea or cytarabine would enable urgent disease control and provide a bridge to clinical trial enrollment. We analyzed three prospective frontline clinical trials that allowed the use of cytoreduction before treatment initiation. Among 274 patients with a median age of 62 (range, 18-89), there was no significant difference in short- and long-term outcome and safety among patients who did (CytoRed) or did not receive (NoCytoRed) cytoreduction. The overall response rate in CytoRed group was 91%, compared with 86% in NoCytoRed group (p = .264). The 30- and 60-day mortality rates were 2% and 7% in CytoRed group, compared with 2% (p = .978) and 6% (p = .652) in NoCytoRed group, respectively. There was no significant difference in overall survival (OS) between in CytoRed group compared with NoCytoRed group (Hazard ratio 0.97, 95% CI 0.70-1.37, p = .879). Results were unchanged after stratification by age (< or ≥65 years) or after multivariate analyses for OS. Our data suggests that urgent cytoreduction using hydroxyurea or cytarabine is a feasible and safe approach to facilitate acquisition of complete diagnostic information prior to treatment initiation on a clinical trial.

Retrospective comparison of survival and responses to Fludarabine, Cytarabine, GCSF (FLAG) in combination with gemtuzumab ozogamicin (GO) or Idarubicin (IDA) in patients with newly diagnosed core binding factor (CBF) acute myelogenous leukemia: MD Anderson experience in 174 patients.

Fludarabine, cytarabine, GCSF (FLAG)-based induction/consolidation results in high remission rates in core binding factor (CBF) acute myelogenous leukemia. We treated 174 consecutive patients with newly diagnosed CBF-AML in a prospective clinical trial of FLAG-based induction/consolidation in combination with gemtuzumab ozogamicin (FLAG-GO; N = 65) or in combination with idarubicin (FLAG-IDA; N = 109). The 5 year RFS in the FLAG-GO cohort was significantly better than the FLAG-IDA cohort, 78% versus 59%, respectively (p-value = .02). In multivariate analysis for RFS, age (p = .0001), FLAG-GO regimen (p = .04), 4 log reduction in CBF-related fusion transcript by quantitative polymerase chain reaction (qPCR) in bone marrow samples at end of consolidation therapy (p = .03), and additional cytogenetic abnormalities (p = .03) were significant variables. Lower age (p = .0001) and 3 log or more transcript reduction at end of induction (p = .04) were significant variables predicting for better overall survival (OS), while there was strong trend for better OS with FLAG-GO (p = .06) regimen. FLAG-GO regimen was superior in optimal disease specific fusion transcript reduction at end of induction (p = .002), mid-consolidation (p < .01), and end of consolidation (p < .001) therapy. Induction/consolidation with FLAG-GO regimen results in better clinical outcomes in newly diagnosed patients with CBF-AML compared to FLAG-IDA and achieves deeper molecular clearance by qPCR assessment of the fusion transcripts.

Low-dose dasatinib 50 mg/day versus standard-dose dasatinib 100 mg/day as frontline therapy in chronic myeloid leukemia in chronic phase: A propensity score analysis.

Low-dose dasatinib is safe and effective in patients with chronic myeloid leukemia in chronic phase (CML-CP). No randomized trials have compared the outcome with standard-dose dasatinib. This study aims to compare the outcome of patients with CML-CP treated with frontline dasatinib 50 versus 100 mg/day. We analyzed 233 patients with newly diagnosed CML-CP treated with low-dose dasatinib (N = 83) or standard-dose dasatinib (N = 150). Propensity score analysis with 1:1 matching was performed and identified 77 patients in each cohort without significant baseline differences. Response rates were reported as the cumulative incidences of complete cytogenetic response, major molecular response (MMR), molecular response (MR)4, and MR4.5. Failure-free survival (FFS), event-free survival (EFS), transformation-free survival (TFS), and overall survival (OS) were also compared. Patients on low-dose dasatinib with suboptimal response by European LeukemiaNet (ELN) 2013 criteria had the option to increase the dose to 100 mg/day. The overall median follow-up time was 60 months. The 3-year MMR rates were 92% and 84% for low-dose and standard-dose dasatinib, respectively (p = .23). Dasatinib 50 mg/day induced higher cumulative incidence of MR4 (77% vs. 66%; p = .04) and MR4.5 (77% vs. 62%; p = .02) at 3 years. The 4-year FFS, EFS and OS rates were 89% versus 77% (p = .04), 95% versus 92% (p = .06), and 97% versus 96% (p = .78) with low-dose and standard-dose dasatinib, respectively. The rate of any grade pleural effusion was 5% with dasatinib 50 mg/day compared to 21% with 100 mg/day. Dasatinib 50 mg/day is at least as effective as 100 mg/day with a better safety profile and drug exposure.

Clinical outcomes and impact of therapeutic intervention in patients with acute myeloid leukemia who experience measurable residual disease (MRD) recurrence following MRD-negative remission.

Recurrence of MRD in AML is associated with imminent relapse unless intervened upon. Change in chemotherapy regimen and/or immediate transplant improve outcomes.

Implications of RAS mutational status in subsets of patients with newly diagnosed acute myeloid leukemia across therapy subtypes.

Activating mutations in RAS have been reported in about 10-15% of patients with AML; previous studies have not identified a prognostic significance. However, RAS mutations have emerged as a potential resistance mechanism to treatment with inhibitors of FLT3, IDH, and BCL2. We aimed to determine the characteristics and outcomes of patients with RAS-mutated (RAS-mut) AML across therapy subsets of 1410 patients newly diagnosed (ND AML). RAS-mut was observed in 273 (20%) patients. Overall, patients with RAS-mut AML had an estimated 3-year survival rate of 38% vs. 28% in those with RAS wild type (RAS-wt), p = .01. Among patients with RAS-mut, favorable karyotype and concomitant NPM1 mutations were associated with a higher CR/CRi rate, OR 23.2 (95% CI: 2.7-192.7; p < .001) and OR 2.8 (95% CI: 1.1-6.9; p = .02), respectively, while secondary and treated secondary (ts)-AML were associated with low response rates, OR 0.34 (95% CI: 0.1-0.9; p = .04) and OR 0.22 (95% CI: 0.09-0.5; p = .001), respectively. Intensive chemotherapy was associated with high response rates OR 5.9 (95% CI: 2.9-12.2; p < .001). Better median OS was observed among those with favorable karyotype, HR 0.28 (95% CI: 0.1-0.6; p = .002), and those treated with intensive chemotherapy, HR 0.42 (95% CI: 0.2-0.6 p < .001). Conversely, ts- AML and co-occurrence of mutations in TP53 were associated with poor median OS; HR 2.3 (95% CI: 1.4-3.9; p = .001) and HR 1.7 (95% CI: 0.9-3.1; p = .06), respectively. The addition of venetoclax was associated with a non-significant improvement in CR/CRi and OS.

Prediction of early (4-week) mortality in acute myeloid leukemia with intensive chemotherapy.

The progress with intensive chemotherapy and supportive care measures has improved survival in patients with newly diagnosed acute myeloid leukemia (AML). Given the recent development of effective low intensity therapies, an optimal decision on the therapy intensity may improve survival through the avoidance of early mortality. We reviewed the outcome of 3728 patients with newly diagnosed AML who received intensive chemotherapy between August 1980 and May 2020. Intensive chemotherapy was defined as a cumulative cytarabine dose ≥ 700 mg/m2 during induction therapy. We divided the whole cohort into a training and validation group at a 3:1 ratio. The population was divided into a training (2790 patients) and a validation cohort (938 patients). The median age was 55 years (range, 15-99). Among them, 442 patients (12%) had core-binding factor AML. Binary logistic regression identified older age, worse performance status, hyperbilirubinemia, elevated creatinine, hyperuricemia, cytogenetic abnormalities other than CBF and -Y, and pneumonia as adverse prognostic factors for an early 4-week mortality. This risk classification for early mortality was verified in the validation cohort of patients. In the validation cohort of more recently treated patients from 2000 to 2017, the 4-week mortality rates with intensive chemotherapy were 2%, 14%, and 50% in the low-, high-, and very high-risk group, respectively. The mortality rates with low intensity therapies were 3%, 9%, and 20%, respectively. The risk classification guides treatment intensity by the assessment of age, frailty, organ dysfunction, cytogenetic abnormality, and infection to avoid early mortality.

Improved outcomes among newly diagnosed patients with FMS-like tyrosine kinase 3 internal tandem duplication mutated acute myeloid leukemia treated with contemporary therapy: Revisiting the European LeukemiaNet adverse risk classification.

Mutations in fms-like tyrosine kinase 3 (FLT3) gene are common genomic alterations in acute myeloid leukemia (AML). FLT3 internal tandem duplication mutations (FLT3-ITD) have consistently been shown to be adversely prognostic, particularly those with high allelic ratio (AR). Current AML treatment strategies, including high dose cytarabine, purine analogs, FLT3 inhibitors (FLT3i), and with or without allogeneic stem cell transplant (SCT) have been shown to improve the outcomes in patients with FLT3 mutations. We analyzed a consecutive cohort of newly diagnosed patients with AML treated at a large academic medical center from January 2012 to January 2020. A total of 1576 patients with a new diagnosis of AML were reviewed. Among these, 1438 (91%) had molecular testing for FLT3 mutations and 21% (304/1438) had an FLT3 mutation, including 17% with an FLT3-ITD mutation. We show that FLT3-ITD high AR with NPM1 wild-type have significantly improved survival compared with other European LeukemiaNet (ELN) adverse risk disease. In multivariable cox proportional hazards model of patients receiving intensive or low-intensity induction regimens, FLT3 mutations did not have prognostic significance. The use of allogeneic SCT in CR1 for patients with FLT3 mutations appears to improve survival, particularly in those with ELN adverse risk disease. Overall, this data highlights the changing prognostic impact of FLT3 mutations in a contemporary era with appropriate use of induction therapy combined with targeted agents and allogenic SCT.

Contemporary outcomes in IDH-mutated acute myeloid leukemia: The impact of co-occurring NPM1 mutations and venetoclax-based treatment.

Isocitrate dehydrogenase 1 or 2 (IDH1 or IDH2) mutations occur frequently in newly diagnosed (ND) acute myeloid leukemia (AML) often with co-occurring NPM1 mutations, which may influence treatment outcomes. Detailed analysis of IDH-mutated AML treated with venetoclax and influence of co-occurring NPM1 mutations remains unclear. This retrospective single-center cohort study evaluated clinical and molecular demographics,response and survival, and impact of co-occurring NPM1 mutations in patients with IDH1 or IDH2-mutated AML. 556 patients with IDH1, IDH2, and/or NPM1 mutated AML were included. Patients with IDH1mut AML (N = 119) were more likely to have older age, sAML, ELN-adverse risk disease, and adverse-risk cytogenetics compared to those with IDH2mut (N = 229) or IDHwt /NPM1mut AML (N = 208). In multivariate analysis, patients with IDH2mut (HR 0.61 [95%CI: 0.43-0.88], p value: .007) or IDHwt /NPM1mut (HR 0.65 [95% CI: 0.45-0.94], p value: .024) AML had a decreased risk of death versus IDH1mut AML. Venetoclax-based lower-intensity regimens partially abrogated the detrimental effect of IDH1mut with similar OS observed between IDH1mut /NPM1wt , IDH2mut /NPM1wt , and IDHwt /NPM1mut AML. With regards to the influence of IDHmut /NPM1mut cases, IC improved survival in IDH2mut /NPM1mut versus IDH2mut /NPM1wt AML (HR: 0.54 [95% CI: 0.2644-1.082], p value: .077), while venetoclax-based therapy improved survival in IDH1mut /NPM1mut versus IDH1mut /NPM1wt AML (HR: 0.094 [95% CI: 0.01-0.74], p value: .0056). Differing outcomes were observed in IDH1mut versus IDH2mut or NPM1mut AML which were influenced by co-occurring NPM1 mutations and partially abrogated with venetoclax-based therapy. Given the differing biology and survival in IDH1mut AML, investigations incorporating molecularly targeted therapies such as IDH inhibitors remain warranted in this subgroup.

Isavuconazole as Primary Antifungal Prophylaxis in Patients With Acute Myeloid Leukemia or Myelodysplastic Syndrome: An Open-label, Prospective, Phase 2 Study.

BACKGROUND: Mold-active primary antifungal prophylaxis (PAP) is routinely recommended in neutropenic patients with newly diagnosed acute myeloid leukemia (AML) or high-risk myelodysplastic syndrome (MDS) undergoing remission-induction chemotherapy (RIC). Isavuconazole (ISAV) is an extended spectrum mold-active triazole and has superior tolerability and fewer significant drug-drug interactions compared with other triazoles. METHODS: In our investigator-initiated, phase 2 trial, treatment-naive adult patients with AML or MDS starting RIC received ISAV per the dosing recommendations in the US label until neutrophil recovery (absolute neutrophil count [ANC] ≥ 0.5 × 109/L) and attainment of complete remission, occurrence of invasive fungal infection (IFI), or for a maximum of 12 weeks. The primary endpoint was the incidence of proven/probable IFI during ISAV PAP and up to 30 days after the last dose. RESULTS: Sixty-five of 75 enrolled patients received ISAV PAP (median age, 67 years, median ANC at enrollment, 0.72 × 109/L). Thirty-two patients (49%) received oral targeted leukemia treatments (venetoclax, FTL3 inhibitors). Including the 30-day follow-up period, probable/proven and possible IFIs were encountered in 4 (6%) and 8 patients (12%), respectively. ISAV trough serum concentrations were consistently > 1 µg/mL, showed low intraindividual variation, and were not significantly influenced by chemotherapy regimen. Tolerability of ISAV was excellent, with only 3 cases (5%) of mild to moderate elevations of liver function tests and no QTc prolongations. CONCLUSIONS: ISAV is a safe and effective alternative for PAP in patients with newly diagnosed AML/MDS undergoing RIC in the era of recently approved or emerging small-molecule antileukemia therapies. CLINICAL TRIALS REGISTRATION: NCT03019939.

A phase 1b/2 study of azacitidine with PD-L1 antibody avelumab in relapsed/refractory acute myeloid leukemia.

BACKGROUND: Patients with relapsed/refractory (R/R) acute myeloid leukemia (AML) have limited treatment options. In preclinical models of AML, inhibition of the PD-1/PD-L1 axis demonstrated antileukemic activity. Avelumab is an anti-PD-L1 immune checkpoint inhibitor (ICI) approved in multiple solid tumors. The authors conducted a phase 1b/2 clinical trial to assess the safety and efficacy of azacitidine with avelumab in patients with R/R AML. METHODS: Patients aged ≥18 years who had R/R AML received azacitidine 75 mg/m2 on days 1 through 7 and avelumab on days 1 and 14 of 28-day cycles. RESULTS: Nineteen patients were treated. The median age was 66 years (range, 22-83 years), 100% had European LeukemiaNet 2017 adverse-risk disease, and 63% had prior exposure to a hypomethylating agent. Avelumab was dosed at 3 mg/kg for the first 7 patients and at 10 mg/kg for the subsequent 12 patients. The most common grade ≥3 treatment-related adverse events were neutropenia and anemia in 2 patients each. Two patients experienced immune-related adverse events of grade 2 and grade 3 pneumonitis, respectively. The overall complete remission rate was 10.5%, and both were complete remission with residual thrombocytopenia. The median overall survival was 4.8 months. Bone marrow blasts were analyzed for immune-related markers by mass cytometry and demonstrated significantly higher expression of PD-L2 compared with PD-L1 both pretherapy and at all time points during therapy, with increasing PD-L2 expression on therapy. CONCLUSIONS: Although the combination of azacitidine and avelumab was well tolerated, clinical activity was limited. High expression of PD-L2 on bone marrow blasts may be an important mechanism of resistance to anti-PD-L1 therapy in AML. LAY SUMMARY: This report describes the results of a phase 1b/2 study of azacitidine with the anti-PD-L1 immune checkpoint inhibitor avelumab for patients with relapsed/refractory acute myeloid leukemia (AML). The clinical activity of the combination therapy was modest, with an overall response rate of 10.5%. However, mass cytometry analysis revealed significantly higher expression of PD-L2 compared with PD-L1 on AML blasts from all patients who were analyzed at all time points. These data suggest a novel potential role for PD-L2 as a means of AML immune escape.