Martin S. Tallman

Phase III Trial of Fludarabine Plus Cyclophosphamide Compared With Fludarabine for Patients With Previously Untreated Chronic Lymphocytic Leukemia: US Intergroup Trial E2997

PURPOSEnThe combination of fludarabine and cyclophosphamide is an effective regimen for patients with chronic lymphocytic leukemia (CLL). However, it may be accompanied by increased toxicity compared with fludarabine alone. E2997 is a phase III randomized Intergroup trial comparing fludarabine and cyclophosphamide (FC arm) versus fludarabine (F arm) alone in patients receiving their first chemotherapy regimen for CLL.nnnPATIENTS AND METHODSnSymptomatic, previously untreated patients with CLL were randomly assigned to receive either fludarabine 25 mg/m2 intravenously (IV) days 1 through 5 or cyclophosphamide 600 mg/m2 IV day 1 and fludarabine 20 mg/m2 IV days 1 through 5. These cycles were repeated every 28 days for a maximum of six cycles.nnnRESULTSnA total of 278 patients were randomly assigned in this Intergroup study. Treatment with fludarabine and cyclophosphamide was associated with a significantly higher complete response (CR) rate (23.4% v 4.6%; P < .001) and a higher overall response (OR) rate (74.3% v 59.5%, P = .013) than treatment with fludarabine as a single agent. Progression-free survival (PFS) was also superior in patients treated with fludarabine and cyclophosphamide than those treated with fludarabine (31.6 v 19.2 months, P < .0001). Fludarabine and cyclophosphamide caused additional hematologic toxicity, including more severe thrombocytopenia (P = .046), but it did not increase the number of severe infections (P = .812).nnnCONCLUSIONnFludarabine and cyclophosphamide produced an increase in OR and CR, and it improved PFS in patients with previously untreated CLL compared with fludarabine alone and was not associated with an increase in infectious toxicity.

Mitoxantrone, etoposide, and cytarabine with or without valspodar in patients with relapsed or refractory acute myeloid leukemia and high-risk myelodysplastic syndrome: A phase III trial (E2995)

PURPOSEnTo determine whether adding the multidrug resistance gene-1 (MDR-1) modulator valspodar (PSC 833; Novartis Pharmaceuticals, Hanover, NJ) to chemotherapy provided clinical benefit to patients with poor-risk acute myeloid leukemia (AML) and high-risk myelodysplastic syndrome (MDS).nnnPATIENTS AND METHODSnA phase III randomized study was performed using valspodar plus mitoxantrone, etoposide, and cytarabine (PSC-MEC; n=66) versus MEC (n=63) to treat patients with relapsed or refractory AML and high-risk MDS.nnnRESULTSnFor the PSC-MEC versus MEC arms, complete response (CR) was achieved in 17% versus 25% of patients, respectively (P=not significant). For patients who had not received prior intensive chemotherapy (ie, with secondary AML or high-risk MDS), the CR rate was increased--35% versus 15% for the remaining patients (P=.018); CR rates did not differ between treatment arms. The median disease-free survival in those achieving CR was similar in the two arms (10 versus 9.3 months) as was the patients overall survival (4.6 versus 5.4 months). The CR rates in MDR+ (69% of patients) versus MDR- patients were similar for those receiving either chemotherapy regimen (16% versus 24%). The CR rate for unfavorable cytogenetic patients (45% of patients) was 13% compared to the remainder, 28% (P=.09). Population pharmacokinetic analysis demonstrated that the clearances of mitoxantrone and etoposide were decreased by 59% and 50%, respectively, supporting the empiric dose reductions in the PSC-MEC arm designed in anticipation of drug interactions between valspodar and the chemotherapeutic agents.nnnCONCLUSIONnCR rates and overall survival were not improved by using PSC-MEC compared to MEC chemotherapy alone in patients with poor-risk AML or high-risk MDS.

Enasidenib in mutant IDH2 relapsed or refractory acute myeloid leukemia

Recurrent mutations in isocitrate dehydrogenase 2 (IDH2) occur in ∼12% of patients with acute myeloid leukemia (AML). Mutated IDH2 proteins neomorphically synthesize 2-hydroxyglutarate resulting in DNA and histone hypermethylation, which leads to blocked cellular differentiation. Enasidenib (AG-221/CC-90007) is a first-in-class, oral, selective inhibitor of mutant-IDH2 enzymes. This first-in-human phase 1/2 study assessed the maximum tolerated dose (MTD), pharmacokinetic and pharmacodynamic profiles, safety, and clinical activity of enasidenib in patients with mutant-IDH2 advanced myeloid malignancies. We assessed safety outcomes for all patients and clinical efficacy in the largest patient subgroup, those with relapsed or refractory AML, from the phase 1 dose-escalation and expansion phases of the study. In the dose-escalation phase, an MTD was not reached at doses ranging from 50 to 650 mg per day. Enasidenib 100 mg once daily was selected for the expansion phase on the basis of pharmacokinetic and pharmacodynamic profiles and demonstrated efficacy. Grade 3 to 4 enasidenib-related adverse events included indirect hyperbilirubinemia (12%) and IDH-inhibitor-associated differentiation syndrome (7%). Among patients with relapsed or refractory AML, overall response rate was 40.3%, with a median response duration of 5.8 months. Responses were associated with cellular differentiation and maturation, typically without evidence of aplasia. Median overall survival among relapsed/refractory patients was 9.3 months, and for the 34 patients (19.3%) who attained complete remission, overall survival was 19.7 months. Continuous daily enasidenib treatment was generally well tolerated and induced hematologic responses in patients for whom prior AML therapy had failed. Inducing differentiation of myeloblasts, not cytotoxicity, seems to drive the clinical efficacy of enasidenib. This trial was registered at www.clinicaltrials.gov as #NCT01915498.

Role of Reduced-Intensity Conditioning Allogeneic Hematopoietic Stem-Cell Transplantation in Older Patients With De Novo Myelodysplastic Syndromes: An International Collaborative Decision Analysis

PURPOSEnMyelodysplastic syndromes (MDS) are clonal hematopoietic disorders that are more common in patients aged ≥ 60 years and are incurable with conventional therapies. Reduced-intensity conditioning (RIC) allogeneic hematopoietic stem-cell transplantation is potentially curative but has additional mortality risk. We evaluated RIC transplantation versus nontransplantation therapies in older patients with MDS stratified by International Prognostic Scoring System (IPSS) risk.nnnPATIENTS AND METHODSnA Markov decision model with quality-of-life utility estimates for different MDS and transplantation states was assessed. Outcomes were life expectancy (LE) and quality-adjusted life expectancy (QALE). A total of 514 patients with de novo MDS aged 60 to 70 years were evaluated. Chronic myelomonocytic leukemia, isolated 5q- syndrome, unclassifiable, and therapy-related MDS were excluded. Transplantation using T-cell depletion or HLA-mismatched or umbilical cord donors was also excluded. RIC transplantation (n = 132) stratified by IPSS risk was compared with best supportive care for patients with nonanemic low/intermediate-1 IPSS (n = 123), hematopoietic growth factors for patients with anemic low/intermediate-1 IPSS (n = 94), and hypomethylating agents for patients with intermediate-2/high IPSS (n = 165).nnnRESULTSnFor patients with low/intermediate-1 IPSS MDS, RIC transplantation LE was 38 months versus 77 months with nontransplantation approaches. QALE and sensitivity analysis did not favor RIC transplantation across plausible utility estimates. For intermediate-2/high IPSS MDS, RIC transplantation LE was 36 months versus 28 months for nontransplantation therapies. QALE and sensitivity analysis favored RIC transplantation across plausible utility estimates.nnnCONCLUSIONnFor patients with de novo MDS aged 60 to 70 years, favored treatments vary with IPSS risk. For low/intermediate-1 IPSS, nontransplantation approaches are preferred. For intermediate-2/high IPSS, RIC transplantation offers overall and quality-adjusted survival benefit.

Acute Monocytic Leukemia (French-American-British classification M5) Does Not Have a Worse Prognosis Than Other Subtypes of Acute Myeloid Leukemia: A Report From the Eastern Cooperative Oncology Group

PURPOSEnAcute monocytic leukemia is a distinct subtype of acute myeloid leukemia (AML) with characteristic biologic and clinical features. This study was designed to compare the outcome of patients with M5 to that of other subtypes of AML, and to identify differences in M5a and M5b.nnnPATIENTS AND METHODSnWe reviewed all patients with AML M5 entered in three clinical trials for newly diagnosed AML conducted by the Eastern Cooperative Oncology Group between 1989 and 1998. Eighty-one patients, 21 with M5a and 60 with M5b, were identified.nnnRESULTSnThe complete remission rate was 62% for all patients with M5; 52% for patients with M5a and 65% for patients with M5b (P =.3), and 60% for the 1122 patients with non-M5 AML entered on the same clinical trials (P =.8 for M5 v non-M5). The 3-year disease-free survival was 26% for all M5 patients; 18% for M5a and 28% for M5b (P =.31), and 33% for non-M5 patients (P =.13 for M5 v non-M5). The 3-year overall survival was 31% for all M5 patients; 33% for M5a and 30% for M5b (P =.65), and 30% for non-M5 (P =.74 for M5 v non-M5). The karyotypes of patients with AML M5 were heterogeneous. CD11b was the only leukemic cell antigen expressed differently in M5a (53%) compared to M5b (77%) to a significant degree (P =.02).nnnCONCLUSIONnAML M5 represents an immunologically heterogeneous population similar to non-M5 AML with a prognosis that is not dependent on morphology. The disease-free survival and overall survival of patients with M5a, M5b, and non-M5 appear not to differ with currently available therapy.

Therapy-Related Clonal Hematopoiesis in Patients with Non-hematologic Cancers Is Common and Associated with Adverse Clinical Outcomes

Clonal hematopoiesis (CH), as evidenced by recurrent somatic mutations in leukemia-associated genes, commonly occurs among aging human hematopoietic stem cells. We analyzed deep-coverage, targeted, next-generation sequencing (NGS) data of paired tumor and blood samples from 8,810 individuals to assess the frequency and clinical relevance of CH in patients with non-hematologic malignancies. We identified CH in 25% of cancer patients, with 4.5% harboring presumptive leukemia driver mutations (CH-PD). CH was associated with increased age, prior radiation therapy, and tobacco use. PPM1D and TP53 mutations were associated with prior exposure to chemotherapy. CH and CH-PD led to an increased incidence of subsequent hematologic cancers, and CH-PD was associated with shorter patient survival. These data suggest that CH occurs in an age-dependent manner and that specific perturbations can enhance fitness of clonal hematopoietic stem cells, which can impact outcome through progression to hematologic malignancies and through cell-non-autonomous effects on solid tumor biology.

Phase III Open-Label Randomized Study of Cytarabine in Combination With Amonafide L-Malate or Daunorubicin As Induction Therapy for Patients With Secondary Acute Myeloid Leukemia

PURPOSEnSecondary acute myeloid leukemia (sAML), defined as AML arising after a prior myelodysplastic syndrome or after antineoplastic therapy, responds poorly to current therapies. It is often associated with adverse karyotypic abnormalities and overexpression of proteins that mediate drug resistance. We performed a phase III trial to determine whether induction therapy with cytarabine and amonafide L-malate, a DNA intercalator and non-ATP-dependent topoisomerase II inhibitor that evades drug resistance mechanisms, yielded a superior complete remission rate than standard therapy with cytarabine and daunorubicin in sAML.nnnPATIENTS AND METHODSnPatients with previously untreated sAML were randomly assigned at a one-to-one ratio to cytarabine 200 mg/m(2) continuous intravenous (IV) infusion once per day on days 1 to 7 plus either amonafide 600 mg/m(2) IV over 4 hours on days 1 to 5 (A + C arm) or daunorubicin 45 mg/m(2) IV over 30 minutes once per day on days 1 to 3 (D + C arm).nnnRESULTSnThe complete remission (CR) rate was 46% (99 of 216 patients) in A + C arm and 45% (97 of 217 patients) in D + C arm (P = .81). The 30- and 60-day mortality rates were 19% and 28% in A + C arm and 13% and 21% in D + C arm, respectively.nnnCONCLUSIONnInduction treatment with A + C did not improve the CR rate compared with D + C in patients with sAML.

Maintenance therapy in acute myeloid leukemia: an evidence-based review of randomized trials

### Case 1nnAfter induction using 7+3 cytarabine-idarubicin, a 64-year-old man with cytogenetically normal acute myeloid leukemia (AML) without FLT3 -ITD, NPM1 , and CEBPA mutations achieved a morphologic complete remission (CR). The patient was not interested in allogeneic hematopoietic cell

Phase II trial of 2-chlorodeoxyadenosine in patients with relapsed/refractory acute myeloid leukemia: A study of the Eastern Cooperative Oncology Group (ECOG), E5995

2-Chlorodeoxyadenosine (2-CdA) is a purine analog which has anti-leukemic activity in phase II trials in pediatric acute myeloid leukemia (AML) patients. An adult phase I trial suggested possible similar activity although neurotoxicity at higher doses was seen. We conducted a phase II trial of 2-CdA in patients with relapsed or refractory AML. 2-CdA was administered by continuous intravenous infusion at a dose of 17 mg/m(2) per day x5 days. Patients not achieving aplasia by day 21 were eligible for a second course of therapy. Fifteen patients (nine relapsed and six refractory AML) were enrolled including seven men and eight women with a median age of 60 years and median ECOG PS of 1. There were five deaths on study due to infections (two), AML (two), or hepatic failure (one). The 2-CdA was well tolerated without severe nausea, vomiting or stomatitis (all <grade 2). No severe neurologic complications related to 2-CdA were seen. Grade 4 myelosuppression occurred in nearly all patients with prolonged periods of pancytopenia and BM hypoplasia seen in most. There were no complete responses, though bone marrow aplasia was achieved in eight patients. 2-CdA as a single agent, in the doses used in this study, is ineffective therapy for relapsed or refractory AML.

Incidence of sinusoidal obstruction syndrome following Mylotarg (gemtuzumab ozogamicin): a prospective observational study of 482 patients in routine clinical practice

The purpose of this prospective observational study was to determine the incidence of hepatic sinusoidal obstruction syndrome (SOS), following gemtuzumab ozogamicin (GO) therapy in routine clinical practice. Patients receiving GO for acute myeloid leukemia (AML) were eligible. Assessments were requested to be performed weekly for 6xa0weeks after the start of GO therapy or 4xa0weeks after the last dose (whichever was later), and after 6xa0months. The primary outcome variable was the incidence of SOS as judged by a panel of independent experts. A total of 512 patients were enrolled at 54 US centers and 482 were evaluable. The incidence of SOS in this study population was 9.1xa0% (44/482; 95xa0% confidence interval 6.9–12.0xa0%). Of the 44 patients classified as having SOS, 8 were mild, 17 moderate, and 19 severe; 33 died within 6xa0months (20 of disease progression and 13 of SOS and multiorgan failure). Most (68xa0%) patients in the study died within 6xa0months; most of these deaths (73xa0%) were due to progression of AML. Serious adverse events occurred in 85xa0% of patients, most (81xa0%) due to AML, febrile neutropenia, pyrexia, and sepsis. GO administered in routine clinical practice carries an overall 9.1xa0% risk of SOS and a 2.7xa0% risk of death from SOS and multiorgan failure. No risk factors were identified for the development of SOS.