AKT/FOXO signaling enforces reversible differentiation blockade in myeloid leukemias.

AKT activation is associated with many malignancies, where AKT acts, in part, by inhibiting FOXO tumor suppressors. We show a converse role for AKT/FOXOs in acute myeloid leukemia (AML). Rather than decreased FOXO activity, we observed that FOXOs are active in ∼40% of AML patient samples regardless of genetic subtype. We also observe this activity in human MLL-AF9 leukemia allele-induced AML in mice, where either activation of Akt or compound deletion of FoxO1/3/4 reduced leukemic cell growth, with the latter markedly diminishing leukemia-initiating cell (LIC) function in vivo and improving animal survival. FOXO inhibition resulted in myeloid maturation and subsequent AML cell death. FOXO activation inversely correlated with JNK/c-JUN signaling, and leukemic cells resistant to FOXO inhibition responded to JNK inhibition. These data reveal a molecular role for AKT/FOXO and JNK/c-JUN in maintaining a differentiation blockade that can be targeted to inhibit leukemias with a range of genetic lesions.

Ivosidenib induces deep durable remissions in patients with newly diagnosed IDH1-mutant acute myeloid leukemia.

Ivosidenib (AG-120) is an oral, targeted agent that suppresses production of the oncometabolite 2-hydroxyglutarate via inhibition of the mutant isocitrate dehydrogenase 1 (IDH1; mIDH1) enzyme. From a phase 1 study of 258 patients with IDH1-mutant hematologic malignancies, we report results for 34 patients with newly diagnosed acute myeloid leukemia (AML) ineligible for standard therapy who received 500 mg ivosidenib daily. Median age was 76.5 years, 26 patients (76%) had secondary AML, and 16 (47%) had received ≥1 hypomethylating agent for an antecedent hematologic disorder. The most common all-grade adverse events were diarrhea (n = 18; 53%), fatigue (n = 16; 47%), nausea (n = 13; 38%), and decreased appetite (n = 12; 35%). Differentiation syndrome was reported in 6 patients (18%) (grade ≥3 in 3 [9%]) and did not require treatment discontinuation. Complete remission (CR) plus CR with partial hematologic recovery (CRh) rate was 42.4% (95% confidence interval [CI], 25.5% to 60.8%); CR 30.3% (95% CI, 15.6% to 48.7%). Median durations of CR+CRh and CR were not reached, with 95% CI lower bounds of 4.6 and 4.2 months, respectively; 61.5% and 77.8% of patients remained in remission at 1 year. With median follow-up of 23.5 months (range, 0.6-40.9 months), median overall survival was 12.6 months (95% CI, 4.5-25.7). Of 21 transfusion-dependent patients (63.6%) at baseline, 9 (42.9%) became transfusion independent. IDH1 mutation clearance was seen in 9/14 patients achieving CR+CRh (5/10 CR; 4/4 CRh). Ivosidenib monotherapy was well-tolerated and induced durable remissions and transfusion independence in patients with newly diagnosed AML. This trial was registered at www.clinicaltrials.gov as #NCT02074839.

Durable Remissions with Ivosidenib in IDH1-Mutated Relapsed or Refractory AML.

BACKGROUND: Mutations in the gene encoding isocitrate dehydrogenase 1 ( IDH1) occur in 6 to 10% of patients with acute myeloid leukemia (AML). Ivosidenib (AG-120) is an oral, targeted, small-molecule inhibitor of mutant IDH1. METHODS: We conducted a phase 1 dose-escalation and dose-expansion study of ivosidenib monotherapy in IDH1-mutated AML. Safety and efficacy were assessed in all treated patients. The primary efficacy population included patients with relapsed or refractory AML receiving 500 mg of ivosidenib daily with at least 6 months of follow-up. RESULTS: Overall, 258 patients received ivosidenib and had safety outcomes assessed. Among patients with relapsed or refractory AML (179 patients), treatment-related adverse events of grade 3 or higher that occurred in at least 3 patients were prolongation of the QT interval (in 7.8% of the patients), the IDH differentiation syndrome (in 3.9%), anemia (in 2.2%), thrombocytopenia or a decrease in the platelet count (in 3.4%), and leukocytosis (in 1.7%). In the primary efficacy population (125 patients), the rate of complete remission or complete remission with partial hematologic recovery was 30.4% (95% confidence interval [CI], 22.5 to 39.3), the rate of complete remission was 21.6% (95% CI, 14.7 to 29.8), and the overall response rate was 41.6% (95% CI, 32.9 to 50.8). The median durations of these responses were 8.2 months (95% CI, 5.5 to 12.0), 9.3 months (95% CI, 5.6 to 18.3), and 6.5 months (95% CI, 4.6 to 9.3), respectively. Transfusion independence was attained in 29 of 84 patients (35%), and patients who had a response had fewer infections and febrile neutropenia episodes than those who did not have a response. Among 34 patients who had a complete remission or complete remission with partial hematologic recovery, 7 (21%) had no residual detectable IDH1 mutations on digital polymerase-chain-reaction assay. No preexisting co-occurring single gene mutation predicted clinical response or resistance to treatment. CONCLUSIONS: In patients with advanced IDH1-mutated relapsed or refractory AML, ivosidenib at a dose of 500 mg daily was associated with a low frequency of grade 3 or higher treatment-related adverse events and with transfusion independence, durable remissions, and molecular remissions in some patients with complete remission. (Funded by Agios Pharmaceuticals; ClinicalTrials.gov number, NCT02074839 .).

Molecular remission and response patterns in patients with mutant-IDH2 acute myeloid leukemia treated with enasidenib.

Approximately 8% to 19% of patients with acute myeloid leukemia (AML) have isocitrate dehydrogenase-2 (IDH2) mutations, which occur at active site arginine residues R140 and R172. IDH2 mutations produce an oncometabolite, 2-hydroxyglutarate (2-HG), which leads to DNA and histone hypermethylation and impaired hematopoietic differentiation. Enasidenib is an oral inhibitor of mutant-IDH2 proteins. This first-in-human phase 1/2 study evaluated enasidenib doses of 50 to 650 mg/d, administered in continuous 28-day cycles, in patients with mutant-IDH2 hematologic malignancies. Overall, 214 of 345 patients (62%) with relapsed or refractory (R/R) AML received enasidenib, 100 mg/d. Median age was 68 years. Forty-two patients (19.6%) attained complete remission (CR), 19 patients (10.3%) proceeded to an allogeneic bone marrow transplant, and the overall response rate was 38.8% (95% confidence interval [CI], 32.2-45.7). Median overall survival was 8.8 months (95% CI, 7.7-9.6). Response and survival were comparable among patients with IDH2-R140 or IDH2-R172 mutations. Response rates were similar among patients who, at study entry, were in relapse (37.7%) or were refractory to intensive (37.5%) or nonintensive (43.2%) therapies. Sixty-six (43.1%) red blood cell transfusion-dependent and 53 (40.2%) platelet transfusion-dependent patients achieved transfusion independence. The magnitude of 2-HG reduction on study was associated with CR in IDH2-R172 patients. Clearance of mutant-IDH2 clones was also associated with achievement of CR. Among all 345 patients, the most common grade 3 or 4 treatment-related adverse events were hyperbilirubinemia (10%), thrombocytopenia (7%), and IDH differentiation syndrome (6%). Enasidenib was well tolerated and induced molecular remissions and hematologic responses in patients with AML for whom prior treatments had failed. The study is registered at www.clinicaltrials.gov as #NCT01915498.

A phase I study of lenalidomide plus chemotherapy with mitoxantrone, etoposide, and cytarabine for the reinduction of patients with acute myeloid leukemia.

Patients with relapsed AML have a poor prognosis and limited responses to standard chemotherapy. Lenalidomide is an immunomodulatory drug that may modulate anti-tumor immunity. We performed a study to evaluate the safety and tolerability of lenalidomide with mitoxantrone, etoposide and cytarabine (MEC) in relapsed/refractory AML. Adult patients with relapsed/refractory AML were eligible for this phase I dose-escalation study. We enrolled 35 patients using a "3 + 3" design, with a 10 patient expansion cohort at the maximum tolerated dose (MTD). Lenalidomide was initially given days 1-14 and MEC days 4-8; due to delayed count recovery, the protocol was amended to administer lenalidomide days 1-10. The dose of lenalidomide was then escalated starting at 5 mg/d (5-10-25-50). The primary objective was tolerability and MTD determination, with secondary outcomes including overall survival (OS). The MTD of lenalidomide combined with MEC was 50 mg/d days 1-10. Among the 35 enrolled patients, 12 achieved complete remission (CR) (34%, 90%CI 21-50%); 30-day mortality was 6% and 60-day mortality 13%. The median OS for all patients was 11.5 months. Among 17 patients treated at the MTD, 7 attained CR (41%); the median OS was not reached while 12-month OS was 61%. Following therapy with MEC and lenalidomide, patient CD4+ and CD8+ T-cells demonstrated increased inflammatory responses to autologous tumor lysate. The combination of MEC and lenalidomide is tolerable with an RP2D of lenalidomide 50 mg/d days 1-10, yielding encouraging response rates. Further studies are planned to explore the potential immunomodulatory effect of lenalidomide and MEC.

Phase I study of the aurora A kinase inhibitor alisertib with induction chemotherapy in patients with acute myeloid leukemia.

Aberrant expression of aurora kinase A is implicated in the genesis of various neoplasms, including acute myeloid leukemia. Alisertib, an aurora A kinase inhibitor, has demonstrated efficacy as monotherapy in trials of myeloid malignancy, and this efficacy appears enhanced in combination with conventional chemotherapies. In this phase I, dose-escalation study, newly diagnosed patients received conventional induction with cytarabine and idarubicin, after which alisertib was administered for 7 days. Dose escalation occurred via cohorts. Patients could then receive up to four cycles of consolidation, incorporating alisertib, and thereafter alisertib maintenance for up to 12 months. Twenty-two patients were enrolled. One dose limiting toxicity occurred at dose level 2 (prolonged thrombocytopenia), and the recommended phase 2 dose was established at 30mg twice daily. Common therapy-related toxicities included cytopenias and mucositis. Only three (14%) patients had persistent disease at mid-cycle, requiring "5+2" reinduction. The composite remission rate (complete remission and complete remission with incomplete neutrophil recovery) was 86% (nineteen of twenty-two patients; 90% CI 68-96%). Among those over age 65 and those with high-risk disease (secondary acute leukemia or cytogenetically high-risk disease), the composite remission rate was 88% and 100%, respectively. The median follow up was 13.5 months. Of those treated at the recommended phase 2 dose, the 12-month overall survival and progression-free survival were 62% (90% CI 33-81%) and 42% (90% CI 17-65%), respectively. Alisertib is well tolerated when combined with induction chemotherapy in acute myeloid leukemia, with a promising suggestion of efficacy. (clinicaltrials.gov Identifier:01779843).

Phase 2 study of intensified chemotherapy and allogeneic hematopoietic stem cell transplantation for older patients with acute lymphoblastic leukemia.

BACKGROUND: Outcomes among older patients with acute lymphoblastic leukemia remain poor. This study sought to determine the efficacy of an intensified, multi-agent approach derived from a Dana-Farber consortium trial in younger adults for patients older than 50 years (trial identifier NCT00973752). METHODS: The primary endpoint was overall survival (OS) at 1 year. Patients received induction chemotherapy with vincristine, prednisone, doxorubicin, and pegylated asparaginase. Imatinib was incorporated for Philadelphia chromosome-positive disease. After induction, the first consolidation incorporated clofarabine. Patients in remission could proceed to allogeneic hematopoietic cell transplantation (HCT) after induction and consolidation I. Those not receiving HCT went on to receive central nervous system, consolidation II, and continuation phases of treatment. RESULTS: Thirty patients were enrolled: 19 achieved a complete remission (CR) after induction and 1 achieved CR after consolidation I for a CR rate of 67%. Sixteen patients underwent HCT. The proportion surviving at 1 year was 63%, and this met the primary endpoint. The 2-year OS rate was 52% (n = 30), and the 2-year disease-free survival rate was 52% for patients achieving CR (n = 20). There was no survival advantage among those undergoing HCT. Therapy-related hyperbilirubinemia prompted adjustments and limitations to asparaginase dosing. CONCLUSIONS: Intensified chemotherapy can result in improved outcomes in comparison with historical data. Additional studies of similarly intensive regimens are warranted in this population. Cancer 2016;122:2379-2388. © 2016 American Cancer Society.

Health care utilization and end-of-life care for older patients with acute myeloid leukemia.

BACKGROUND: Health care utilization in older adults (age ≥60 years) with acute myeloid leukemia (AML) has not been well studied. METHODS: We conducted a retrospective analysis of 330 consecutive older patients who were diagnosed with AML between May 1, 2005 and December 23, 2011, at 2 hospitals in Boston to examine their health care utilization and end-of-life care. Using multivariable logistic and linear regression models adjusting for covariates, we also compared health care utilization between patients who received intensive induction chemotherapy (n = 197; cytarabine/ anthracycline combination) versus nonintensive chemotherapy (n = 133; single-agent therapy). RESULTS: The median number of hospitalizations for the entire cohort was 4.2 (range, 1-18 hospitalizations). Patients who died spent a mean of 28.3% of their life after diagnosis in the hospital and 13.8% of their life attending outpatient clinic appointments. Although the majority of patients (87.9%) died during the 2-year follow-up period, a minority received palliative care (16.2%) or hospice (23.1%) services. Within 30 days of death, 84.5% of patients were hospitalized, and 61% died in the hospital. Among the patients who died, those who received intensive induction therapy (vs nonintensive therapy) spent 30% more of their life after diagnosis in the hospital (P < .0001) and were less likely to receive hospice services (odds ratio, 0.45; P = .05). CONCLUSIONS: The current findings highlight the intensity of health care utilization among older patients with AML, regardless of treatment modality. Despite the poor prognosis, palliative care and hospice services are rarely used. Future work should study novel health care delivery models to optimize care throughout the course of illness and at the end of life.

Arsenic trioxide during consolidation for patients with previously untreated low/intermediate risk acute promyelocytic leukaemia may eliminate the need for maintenance therapy.

Aa total of 105 patients (age ≥18 years) with newly diagnosed low or intermediate risk acute promyelocytic leukaemia (APL) were treated with a standard induction and consolidation regimen including arsenic trioxide (ATO). Sixty-eight patients who were polymerase chain reaction (PCR) negative for PML-RARA post-consolidation were randomized to either 1 year of maintenance with tretinoin, mercaptopurine and methotrexate, or observation. Enrollment in this non-inferiority trial was stopped prematurely due to slow accrual. With a median follow up of 36·1 months, the overall survival of the 105 patients was 93%, and there have been no relapses in the patients randomized to maintenance or observation. These results demonstrate that cures can be expected in >90% of patients with low and intermediate risk APL and suggest that maintenance therapy may not be needed if patients are treated with an intensive post-remission regimen including ATO. This trial was registered at clinicaltrials.gov as #NCT00492856.

Get out--and stay out.

Leaving the safety of home exposes our vulnerabilities. In this issue of Blood, Uy and coauthors explore the clinical benefit of interrupting the protective niches in which leukemia cells live in an effort to enhance the benefit of chemotherapy in treating patients with acute myeloid leukemia (AML).

Prospective serial evaluation of 2-hydroxyglutarate, during treatment of newly diagnosed acute myeloid leukemia, to assess disease activity and therapeutic response.

Mutations of genes encoding isocitrate dehydrogenase (IDH1 and IDH2) have been recently described in acute myeloid leukemia (AML). Serum and myeloblast samples from patients with IDH-mutant AML contain high levels of the metabolite 2-hydroxyglutarate (2-HG), a product of the altered IDH protein. In this prospective study, we sought to determine whether 2-HG can potentially serve as a noninvasive biomarker of disease burden through serial measurements in patients receiving conventional therapy for newly diagnosed AML. Our data demonstrate that serum, urine, marrow aspirate, and myeloblast 2-HG levels are significantly higher in IDH-mutant patients, with a correlation between baseline serum and urine 2-HG levels. Serum and urine 2-HG, along with IDH1/2-mutant allele burden in marrow, decreased with response to treatment. 2-HG decrease was more rapid with induction chemotherapy compared with DNA-methyltransferase inhibitor therapy. Our data suggest that serum or urine 2-HG may serve as noninvasive biomarkers of disease activity for IDH-mutant AML.

Busulfan dose intensity and outcomes in reduced-intensity allogeneic peripheral blood stem cell transplantation for myelodysplastic syndrome or acute myeloid leukemia.

Comparisons of myeloablative conditioning versus reduced-intensity conditioning (RIC) have demonstrated a tradeoff between relapse and toxicity. Dose intensity across RIC regimens vary and may affect treatment outcomes. In this retrospective analysis, we investigated the effect of i.v. busulfan dosing (total dose 3.2 mg/kg versus 6.4 mg/kg) in RIC regimens that combined fludarabine and busulfan on outcomes in patients who were undergoing hematopoietic stem cell transplantation (HSCT) for myelodysplastic syndrome (MDS) or acute myeloid leukemia (AML). A total of 217 consecutive patients with MDS or AML underwent first busulfan and fludarabine RIC peripheral blood stem cell transplantation from well-matched related or unrelated donors at our institutions between 2004 and 2009. Of the 217 patients, 135 patients received Bu1 (3.2 mg/kg of busulfan) and 82 patients received Bu2 (6.4 mg/kg of busulfan), both with daily fludarabine (30 mg/m(2)/day for 4 days). The choice of RIC regimen was based on temporal institutional standard, enrollment on protocols, and physician choice. Patients had similar characteristics with a few notable differences: Patients who received Bu1 were younger (median age 61 versus 64 years, P < . 001), received more single-antigen mismatched unrelated grafts (14.1% versus 1.2%, P < . 001), received more sirolimus-based graft-versus-host disease (GVHD) prophylaxis regimens (63% versus 45%, P < .0001), received less antithymocyte globulin for GVHD prophylaxis (0% versus 22%, P < .001), and had less enrollment on a clinical trial that used prophylactic rituximab for the prevention of chronic GVHD (2.2% versus 11.0%, P = .011). Clinical disease status was similar between the groups. Median follow-up for survivors was 4.4 years for Bu1 and 3.2 years for Bu2. Because of the differences in characteristics, the 2 groups were compared with the adjustment of a propensity score that predicted Bu2 to account for measured differences. The day +200 cumulative incidence rates of grades II to IV acute GVHD (Bu1, 17%, versus Bu2, 8.5%; hazard ratio [HR], .56; 95% confidence interval [CI], .22 to 1.41; P = .22) or grades III to IV acute GVHD (Bu1, 6.7%, versus Bu2, 4.9%) were not different. The 2-year cumulative incidence of chronic GVHD was not significantly different between Bu1 and Bu2 (41.5% versus 28%, respectively; HR, .70; CI, .42 to 1.17; P = .09). Two-year nonrelapse mortality rates were similar for Bu1 and Bu2 (8.9% versus 9.8%, respectively; HR, .80; CI, .29 to 2.21; P = .67). Two-year progression-free survival and overall survival were also similar between Bu1 and Bu2 (progression-free survival: 40.6% versus 39.3%, respectively; HR, .82; CI, .57 to 1.30; P = .33; and overall survival: 47.4% versus 48.8%, respectively; HR, .96; CI, .64 to 1.44; P = .85). Subset analysis defined by clinical disease and cytogenetic risk with the propensity risk score applied suggest that in patients with high clinical disease risk and nonadverse cytogenetics, the higher dose busulfan RIC regimen may be of marginal benefit (2-year progression-free survival: HR, .54; CI, .29 to 1.03; P = .062). For the majority of patients with MDS or AML undergoing busulfan and fludarabine RIC peripheral blood stem cell transplantation, however, the dose of busulfan (3.2 mg/kg versus 6.4 mg/kg) is not associated with significant differences in overall outcomes.

Association between baseline body mass index and overall survival among patients over age 60 with acute myeloid leukemia.

Acute myeloid leukemia (AML) is more common and more lethal among patients over the age of 60. Increased body mass index (BMI) has been associated with a higher incidence of various malignancies, including AML. We sought to determine whether patient BMI at the time of AML diagnosis is related to overall survival (OS) among elderly patients. We identified 97 patients with AML diagnosed after the age of 60 and treated with cytarabine-based induction chemotherapy. The median age was 68 years (range 60-87); 52% of patients were male, and our study population was predominantly white (89% of patients). The median OS for all patients was 316 days (95% CI 246-459). The hazard ratio for mortality was increased among patients with a BMI < 25 compared to BMI ≥ 30 (HR 2.14, P = 0.009, 95% CI 1.21-3.77), as well as with older age (HR 1.76, P = 0.015, 95% CI 1.12-2.79) and with secondary versus de novo disease (HR 1.95, P = 0.006, 95% CI 1.21-3.14). After multivariable analysis, we did not find a significant association between OS and other potential confounders such as coronary artery disease or diabetes among these patients. We conclude that increased BMI was independently associated with improved OS among older AML patients at our institution.

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.

Eprenetapopt Plus Azacitidine After Allogeneic Hematopoietic Stem-Cell Transplantation for TP53-Mutant Acute Myeloid Leukemia and Myelodysplastic Syndromes.

PURPOSE: Outcomes are poor in TP53-mutant (mTP53) acute myeloid leukemia (AML) and myelodysplastic syndromes (MDS), even after allogeneic hematopoietic stem-cell transplant (HCT). Eprenetapopt (APR-246) is a first-in-class, small-molecule p53 reactivator. PATIENTS AND METHODS: We conducted a phase II, multicenter, open-label trial to assess efficacy and safety of eprenetapopt combined with azacitidine as maintenance therapy after HCT (ClinicalTrials.gov identifier: NCT03931291). Patients with mTP53 MDS or AML received up to 12 cycles of eprenetapopt 3.7 g once daily intravenously on days 1-4 and azacitidine 36 mg/m2 once daily intravenously/subcutaneously on days 1-5 in 28-day cycles. The primary outcomes were relapse-free survival (RFS) and safety. RESULTS: Of the 84 patients screened for eligibility before HCT, 55 received a transplant. Thirty-three patients ultimately received maintenance treatment (14 AML and 19 MDS); the median age was 65 (range, 40-74) years. The median number of eprenetapopt cycles was 7 (range, 1-12). With a median follow-up of 14.5 months, the median RFS was 12.5 months (95% CI, 9.6 to not estimable) and the 1-year RFS probability was 59.9% (95% CI, 41 to 74). With a median follow-up of 17.0 months, the median overall survival (OS) was 20.6 months (95% CI, 14.2 to not estimable) and the 1-year OS probability was 78.8% (95% CI, 60.6 to 89.3). Thirty-day and 60-day mortalities from the first dose were 0% and 6% (n = 2), respectively. Acute and chronic (all grade) graft-versus-host disease adverse events were reported in 12% (n = 4) and 33% (n = 11) of patients, respectively. CONCLUSION: In patients with mTP53 AML and MDS, post-HCT maintenance therapy with eprenetapopt combined with azacitidine was well tolerated. RFS and OS outcomes were encouraging in this high-risk population.

Eprenetapopt (APR-246) and Azacitidine in TP53-Mutant Myelodysplastic Syndromes.

PURPOSE: Approximately 20% of patients with TP53-mutant myelodysplastic syndromes (MDS) achieve complete remission (CR) with hypomethylating agents. Eprenetapopt (APR-246) is a novel, first-in-class, small molecule that restores wild-type p53 functions in TP53-mutant cells. METHODS: This was a phase Ib/II study to determine the safety, recommended phase II dose, and efficacy of eprenetapopt administered in combination with azacitidine in patients with TP53-mutant MDS or acute myeloid leukemia (AML) with 20%-30% marrow blasts (ClinicalTrials.gov identifier: NCT03072043). RESULTS: Fifty-five patients (40 MDS, 11 AML, and four MDS/myeloproliferative neoplasms) with at least one TP53 mutation were treated. The overall response rate was 71% with 44% achieving CR. Of patients with MDS, 73% (n = 29) responded with 50% (n = 20) achieving CR and 58% (23/40) a cytogenetic response. The overall response rate and CR rate for patients with AML was 64% (n = 7) and 36% (n = 4), respectively. Patients with only TP53 mutations by next-generation sequencing had higher rates of CR (69% v 25%; P = .006). Responding patients had significant reductions in TP53 variant allele frequency and p53 expression by immunohistochemistry, with 21 (38%) achieving complete molecular remission (variant allele frequency < 5%). Median overall survival was 10.8 months with significant improvement in responding versus nonresponding patients by landmark analysis (14.6 v 7.5 months; P = .0005). Overall, 19/55 (35%) patients underwent allogeneic hematopoietic stem-cell transplant, with a median overall survival of 14.7 months. Adverse events were similar to those reported for azacitidine or eprenetapopt monotherapy, with the most common grade ≥ 3 adverse events being febrile neutropenia (33%), leukopenia (29%), and neutropenia (29%). CONCLUSION: Combination treatment with eprenetapopt and azacitidine is well-tolerated yielding high rates of clinical response and molecular remissions in patients with TP53-mutant MDS and oligoblastic AML.

Donor-derived second hematologic malignancies after cord blood transplantation.

Double umbilical cord blood transplantation (UCBT) with a reduced-intensity conditioning regimen is an effective strategy for adult patients without a matched donor. The risk of second malignancies in these patients has not yet been established, however. In the present study, 98 adults with a hematologic malignancy underwent double UCBT. Seventy patients received a reduced-intensity conditioning regimen of fludarabine 30 mg/m(2)/day for 6 days, melphalan 100 mg/m(2)/day for 1 day, and rabbit antithymocyte globulin 1.5 mg/kg/day for 4 days, and 28 patients received a myeloablative total body radiation-containing conditioning regimen. Sixty-three patients received sirolimus-based graft-versus-host disease (GVHD) prophylaxis, and 35 patients received non-sirolimus-based GVHD prophylaxis. The median patient age was 48 years (range, 19-67 years). Eighteen patients developed a second malignancy at a median of 134 days after transplantation. Sixteen patients had lymphoma, and 2 patients had myelodysplasic syndrome/myeloproliferative disorder (MDS/MPD). Sixteen of these second malignancies (both cases of MDS/MPD and 14 of the lymphomas) were donor-derived; the origins of the others were not determined. GVHD prophylaxis, HLA matching, primary disease, age, total nucleated cell dose, and CD34(+) cell dose were not associated with a higher rate of second malignancy. Second myelogenous malignancies of donor origin occur after double UCBT, suggesting that a search for donor origin should be performed in all patients with suspected relapse.

Clinical pharmacokinetics and pharmacodynamics of ivosidenib in patients with advanced hematologic malignancies with an IDH1 mutation.

PURPOSE: Isocitrate dehydrogenase (IDH) mutations lead to formation of the oncometabolite 2-hydroxyglutarate (2-HG), which is elevated in several solid and liquid tumors. Ivosidenib (AG-120) is a targeted, potent, oral inhibitor of the mutant IDH1 protein. We describe detailed pharmacokinetics and pharmacodynamics of ivosidenib in patients with advanced hematologic malignancies with an IDH1 mutation treated in a phase I study (ClinicalTrials.gov NCT02074839). METHODS: Patients received single and multiple oral doses of ivosidenib from 100 mg twice daily to 1200 mg once daily (QD) in 28-day continuous cycles. Concentrations of ivosidenib and 2-HG in plasma, and 2-HG in bone marrow, were assessed at routine intervals. Plasma 4ß-hydroxycholesterol/cholesterol ratios were assessed as a marker of CYP3A activity. RESULTS: Ivosidenib was rapidly absorbed and slowly eliminated (half-life 72-138 h) after single and multiple dosing. Ivosidenib exhibited dose- and time-dependent pharmacokinetics, with exposure increasing sub-proportionally to dose, and clearance increasing with increasing dose. Plasma 2-HG concentrations were maximally and persistently inhibited in the majority of patients receiving 500-mg QD ivosidenib, to concentrations close to those observed in healthy subjects. Ivosidenib pharmacokinetics were not affected by mild or moderate renal impairment, mild hepatic impairment, age, weight, sex, race, or co-administration of weak CYP3A4 inhibitors or inducers. Moderate-to-strong CYP3A4 inhibitors decreased ivosidenib clearance. Ivosidenib also induced CYP3A enzyme activity, with increases in 4ß-hydroxycholesterol/cholesterol ratios of 119-168% at 500-mg QD ivosidenib. CONCLUSIONS: Ivosidenib 500-mg QD has favorable pharmacokinetic and pharmacodynamic profiles in patients with advanced hematologic malignancies with an IDH1 mutation. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov NCT02074839.

Enasidenib in patients with mutant IDH2 myelodysplastic syndromes: a phase 1 subgroup analysis of the multicentre, AG221-C-001 trial.

BACKGROUND: Mutations in isocitrate dehydrogenase-2 (IDH2) occur in around 5% of patients with myelodysplastic syndromes. Neomorphic activity of mutant IDH2 proteins results in hypermethylation of DNA and histones, leading to blocked haemopoietic differentiation. Enasidenib, an inhibitor of mutated IDH2 proteins, induces responses in patients with IDH2-mutated, relapsed or refractory acute myeloid leukaemia. We aimed to establish the clinical outcomes of enasidenib monotherapy in a subgroup of patients with myelodysplastic syndromes harbouring mutations in IDH2 from the AG221-C-001 trial. METHODS: The multicentre, open-label, phase 1-2 AG221-C-001 trial enrolled patients with advanced haematological malignancies (2008 WHO criteria) harbouring an IDH2 mutation. The present study is a subgroup analysis of patients with IDH2-mutated myelodysplastic syndromes in the phase 1 dose-escalation and expansion portions of the trial. Patients with myelodysplastic syndromes were aged 18 years or older with an ECOG performance status score of 2 or lower, and were relapsed or refractory to, or ineligible for, standard treatments. Patients received oral doses of enasidenib at 60-300 mg per day in repeated 28-day treatment cycles. In this subgroup analysis, we focused on the safety and activity of enasidenib as main outcomes. Overall response rate, duration of response, and overall and event-free survival analyses were by intention-to-treat. Safety was assessed in all participants who received at least one dose of study drug in terms of treatment-emergent adverse events. The AG221-C-001 trial is registered on ClinicalTrials.gov, NCT01915498, status ongoing but closed to recruitment. FINDINGS: 17 patients with myelodysplastic syndromes harbouring an IDH2 mutation (median age, 67·0 years [IQR 60·5-73·0]) were enrolled between Feb 18, 2014, and Sept 1, 2015. At data cutoff (Oct 1, 2018), after a median follow-up of 11·0 months (IQR 6·8-23·0), all patients had discontinued enasidenib, with a median of 3 treatment cycles (2-15) for all patients (five [29%] received ≥12 cycles). At entry, three (18%) patients had relapsed after allogeneic stem-cell transplants, 13 (76%) had previously received therapy with hypomethylating agents, and ten (59%) had received at least two previous therapies. No dose-limiting toxicities were reported. The most common treatment-emergent adverse events were diarrhoea and nausea (in nine [53%] patients each). Most common grade 3-4 treatment-emergent adverse events were indirect hyperbilirubinaemia (in six [35%] patients), pneumonia (in five [29%] patients), and thrombocytopaenia (in four [24%] patients). Serious treatment-emergent adverse events in more than one patient were pneumonia (in five [29% patients); tumor lysis syndrome (in three [18%] patients); and sepsis, atrial flutter, indirect hyperbilirubinaemia, cerebral hemorrhage, and mental status change (in two [12%] patients each). No treatment-related deaths occurred. An overall response was achieved in 9 patients (53% [95% CI 28-77]), with a median duration of response of 9·2 months (95% CI 1·0-not reached). Six (46%) of 13 patients previously treated with hypomethylating agents responded. Median overall survival was 16·9 months (95% CI 1·5-32·3), and median event-free survival was 11·0 months (1·5-16·7). INTERPRETATION: Enasidenib is generally well tolerated and can induce responses in patients with mutant IDH2 myelodysplastic syndromes, including in those who have had previous therapy with hypomethylating agents. Testing for IDH2 mutations in myelodysplastic syndromes is essential for identifying patients who might benefit from enasidenib therapy, including those patients in whom conventional treatments have been unsuccessful. FUNDING: Celgene and Agios Pharmaceuticals.