Untreated Acute Myeloid Leukemia Research Articles

Phase 1/ 2 Study of Sapacitabine and Decitabine Administered Sequentially in Elderly Patients with Newly Diagnosed AML,

Abstract 3630 Background:Sapacitabine is a novel nucleoside analogue with a unique ability to induce single-strand DNA breaks after incorporation into DNA, leading to production of double strand DNA breaks and/or G2 cell cycle arrest. It is orally administered and has demonstrated promising activity in patients with acute myeloid leukemia (AML). In AML cell lines, the active metabolite of sapacitabine, CNDAC, is synergistic with hypomethylating agents with the synergy being more apparent if cells are treated with hypomethylating agents first. We are conducting a phase 1/ 2 study to evaluate the safety and efficacy of administering sapacitabine in alternating cycles with decitabine in elderly patients with newly diagnosed AML. Methods: Decitabine 20 mg/m2 was administered intravenously daily × 5 days of a 4-week cycle (odd cycles) alternating with sapacitabine 300 mg po b.i.d. × 3 days/week × 2 weeks of a 4-week cycle (even cycles). After these doses were shown to be safe in the phase 1 part, patients were treated in the Phase 2 part to reach a planned sample size of approximately 24 patients. The primary efficacy endpoint is response rate (CR, CRp, PR, or major HI). The regimen will be considered active if response rate is ≥30%. Eligible patients must be ≥70 years with untreated AML unsuitable for or unwilling to receive standard induction chemotherapy; patients who received hypomethylating agents for prior MDS or MPD are excluded. Results: As of August 2011, 25 patients were treated with the above regimen and 23 had ≥ 60 days of follow-up. Median age is 76 years (range, 72–90). No DLTs were observed. Four patients achieved CR, 3 PR and 2 major HIs in platelets. Median time to response is 2 cycles (range 2– 6). Fifteen patients have received ≥4 cycles of treatment. Three patients died within 60-days and the deaths were unrelated to study drugs by investigator assessment. Common adverse events (regardless of causality) included weakness, anorexia, nausea, constipation, diarrhea, dyspnea, edema, pneumonia, febrile neutropenia, neutropenia, thrombocytopenia, anemia, and hypocalcemia, mostly moderate in intensity. Conclusion: The sequential combination of decitabine and sapacitabine is safe and active in elderly AML. Disclosures:Off Label Use: Decitabine for the treatment of elderly AML. Wetzler:Cyclacel Limited: Research Funding. Chiao:Cyclacel Limited: Employment, Equity Ownership.

MUC1 Inhibition Reverses the Poor Immunogenicity of Leukemia Stem Cells Rendering Them Susceptible to Immunotherapy

Abstract 1883 Introduction:Acute myeloid leukemia (AML) arises from a malignant stem cell (LSC) population that is resistant to cytotoxic therapy and represents a reservoir for disease recurrence. A focus of research interest lies in developing cellular immunotherapy for the treatment of AML, in order to immunologically eradicate disease without the toxicity associated with allogeneic transplantation. In this study, we evaluated whether LSCs are effective targets for leukemia specific immunotherapy. To investigate this issue, we have developed a novel class of human T Cell Receptor-Like (TCRL) recombinant antibodies, which target MHC-peptide complexes mimicking their recognition. TCRL can be utilized to quantify the density of antigen presentation by LSCs; however, being able to distinguish LCSs from normal stem cells immunologically has been challenging. The tumor associated complex glycoprotein MUC1 may be used to define such an immature cell population. Methods and Results:We have previously demonstrated that LSCs strongly express the tumor associated antigen, MUC1, in contrast to normal hematopoietic stem cells. TCRL specific for the HLA-A2/MUC1 complex detectable by flow cytometry were constructed in order to quantify MUC1 antigen presentation. CD34+ cells were isolated from HLA-A2.1 AML patients with active disease and were analyzed for expression of MUC1 protein with the DF3 anti-MUC1 antibody and for HLA presentation of MUC1 peptide with the HLA-A2.1/MUC1 TCRL. Remarkably, despite the strong cell surface expression of the MUC1 protein (mean expression 68%, n=8), minimal levels of HLA bound MUC1 peptide was detected (mean expression 7.6%, n=8). CD34+ leukemia cells strongly expressed HLA-A2, indicating that the lack of TCRL recognition of the HLA-MUC1 complex was due to the lack of processing and presentation of the MUC1 peptide. Similarly, we demonstrated that leukemia progenitors minimally express HLA-A2-WT1 peptide complexes (mean expression 5%, n=3). These findings suggest that leukemia progenitors exhibit an immuno-privileged phenotype, potentially shielding them from leukemia specific immunotherapy. We have developed a MUC1 inhibitor peptide, G0-203, that has been shown to induce differentiation and apoptosis of leukemia progenitors. We evaluated whether, in addition to inducing differentiation of leukemia progenitors, exposure to GO-203 would augment antigen presentation. Isolated CD34+ AML cells were treated with 5μM GO-203 for 24 hours. Expression of HLA-A2/MUC1 peptide complexes, as determined by binding of the MUC1 TCRL antibody, was assessed before and after treatment. Exposure to GO-203 markedly upregulated the mean expression of HLA-A2.1/MUC1 peptide complexes by CD34+ leukemia cells (10% to 62%; n=4, p<0.05). Similarly, an upregulation in the mean expression of HLA-A2.1/WT1 peptide complexes was observed on CD34+ progenitors following exposure to GO-203 (mean expression 5% to 44%, n=3, p<0.05). Consistent with these findings, GO-203-treated leukemia progenitors exhibited an increase in potency as antigen presenting cells, as manifested by a 2 fold increase in autologous T cell proliferation in response to stimulation with GO-203 treated compared to untreated progenitors. In addition, an increase in MUC1 pentamer positive T cells was observed following stimulation with GO-203 treated compared to untreated AML progenitors (6.5% versus 3% MUC1 pentamer positive cells respectively, n=2). We subsequently evaluated whether the upregulation of antigen presentation correlated with enhanced targeting by immune effector cells. We have previously demonstrated that DC/AML fusion cells potently stimulate the expansion of leukemia specific T cells. We now show that GO-203 exposure results in an increased susceptibility of leukemia progenitors to targeting by vaccine stimulated T cells, as manifested by a 3-fold increase in cytotoxic T lymphocyte-mediated lysis as measured by Granzyme B activity. Conclusions:The results demonstrate that leukemia progenitors exhibit low levels of HLA presentation of leukemia specific antigens such as MUC1 and WT1, resulting in their poor immunogenicity and potential resistance to tumor specific immunotherapy. Exposure of leukemia progenitors to a MUC1 inhibitor peptide, GO-203, upregulates HLA-based presentation of leukemia associated antigens, rendering these cells more susceptible to immune based targeting. Disclosures:Kufe:genus oncology: Consultancy, Equity Ownership.

A multicenter phase II trial of decitabine as first-line treatment for older patients with acute myeloid leukemia judged unfit for induction chemotherapy

The treatment of acute myeloid leukemia of older, medically non-fit patients still poses a highly unmet clinical need, and only few large, prospective studies have been performed in this setting. Given the established activity of hypomethylating agents such as 5-aza-2'-deoxycytidine (decitabine) in myelodysplastic syndromes and acute myeloid leukemia with 20-30% bone marrow blasts, we investigated whether this drug is also active in patients with more than 30% blasts. To evaluate the efficacy and toxicity of decitabine in patients over 60 years old with untreated acute myeloid leukemia ineligible for induction chemotherapy, 227 patients (median age, 72 years), many with comorbidities, adverse cytogenetics and/or preceding myelodysplastic syndrome were treated with this hypomethylating agent. During the initial decitabine treatment (135 mg/m(2) total dose infused intravenously over 72 hours every 6 weeks), a median of two cycles was administered (range, 1-4). All-trans retinoic acid was administered to 100 patients during course 2. Fifty-two patients who completed four cycles of treatment subsequently received a median of five maintenance courses (range, 1-19) with a lower dose of decitabine (20 mg/m(2)) infused over 1 hour on 3 consecutive days every 4-6 weeks. The complete and partial remission rate was 26%, 95% CI (20%, 32%), and an antileukemic effect was noted in 26% of patients. Response rates did not differ between patients with or without adverse cytogenetics; patients with monosomal karyotypes also responded. The median overall survival from the start of decitabine treatment was 5.5 months (range, 0-57.5+) and the 1-year survival rate was 28%, 95%CI (22%,34%). Toxicities were predominantly hematologic. Decitabine is well tolerated by older, medically non-fit patients with acute myeloid leukemia; myelosuppression is the major toxicity. The response rate and overall survival were not adversely influenced by poor-risk cytogenetics or myelodysplastic syndrome. Because of these encouraging results, randomized studies evaluating single-agent decitabine versus conventional treatment are warranted. The study is registered with the German Clinical Trials Registry, number DRKS00000069.

Serum levels of endothelium-derived endocan are increased inpatients with untreated acute myeloid leukemia

Endocan is a soluble proteoglycan expressed only by vascular endotheliumand is also found circulating in the bloodstream. Inflammatory cytokines aswell as proangiogenic growth factors increase its expression, and increasedserum levels are found in immunocompetent patients with sepsis. We investigatedserum endocan levels in patients with untreated acute myeloid leukemia (AML)and AML patients during chemotherapy-induced bone marrow failure. We observedincreased levels in 40 AML patients compared with healthy controls, whichwas also confirmed in a second cohort. The serum levels decreased after intensivechemotherapy and subsequent severe chemotherapy-induced cytopenia, and increasedlevels were thereafter observed during bone marrow regeneration. However,even for these severely immunocompromized patients, serum endocan levels increasedduring complicating bacterial infections before a decrease was seen duringantibiotic therapy. To conclude, serum endocan is a disease marker in AML,but serum levels are also affected by complicating infections and bone marrowregeneration.

Safety, efficacy and biological predictors of response to sequential azacitidine and lenalidomide for elderly patients with acute myeloid leukemia

Acute myeloid leukemia (AML) is a disease of the elderly. Poor outcomes with standard therapies necessitate novel approaches. Outpatient regimens sufficiently potent and well tolerated to induce remissions and enable continuation therapy may be beneficial. In this phase-1 study, we determined the maximum tolerated dose (MTD) and the efficacy for sequential azacitidine and lenalidomide as remission induction and continuation therapy in elderly, previously untreated patients. We investigated the impact on global DNA methylation and bone marrow cytokines, and sought biological predictors of response. Eighteen patients were enrolled. The MTD was not reached. Median follow-up was 8.2 months (10.3 months for survivors). Common adverse events included fatigue, injection site reactions, constipation, nausea, pruritus and febrile neutropenia. Ten patients responded (56%), and the rate of complete remissions (CRs) or CRs with incomplete recovery of blood counts for evaluable patients was 44% (7/16). The median response duration was 6.2 months. DNA demethylation and changes in bone marrow cytokines were observed; responders had a unique cytokine profile and a trend towards lower methylation levels. Sequential azacitidine and lenalidomide was well tolerated with encouraging clinical and biological activity in previously untreated elderly AML patients. This trial is registered at ClinicalTrials.gov (NCT00890929).

A phase 2 study of lenalidomide monotherapy in patients with deletion 5q acute myeloid leukemia: Southwest Oncology Group Study S0605

AbstractOlder acute myeloid leukemia (AML) patients with a chromosome 5q deletion have poor outcomes with conventional chemotherapy. This phase 2 study explored the safety and efficacy of single-agent lenalidomide in previously untreated older AML patients with del(5q) who declined standard chemotherapy. Patients were treated with lenalidomide 50 mg daily for 28 days as induction therapy and 10 mg daily for 21 days of a 28-day cycle as maintenance until disease progression or unacceptable toxicity. Among 37 evaluable patients, the median age was 74 years (range, 60-94), 21 (57%) were female, 19 (51%) had prior myelodysplastic syndrome, and 30 (81%) had pretreatment cytogenetic studies evaluated centrally. Six had isolated del(5q), 1 had del(5q) and +8, 23 had complex cytogenetics, and 7 others had del(5q) identified locally. Fourteen patients (38%) completed induction therapy: 7 patients died during induction therapy, 8 had disease progression, 7 had nonfatal adverse events, and 1 entered hospice. Eight patients started maintenance therapy. Five patients (14%) achieved a partial or complete response, 2 with isolated del(5q) and 3 with complex cytogenetics. Relapse-free survival was 5 months (range, 0-19). Median overall survival was 2 months for the entire population. In conclusion, lenalidomide as a single agent has modest activity in older del(5q) AML patients. Southwest Oncology Group Study S0605 is registered at www.clinicaltrials.gov as NCT00352365.

AAML03P1, a pilot study of the safety of gemtuzumab ozogamicin in combination with chemotherapy for newly diagnosed childhood acute myeloid leukemia

The development of antigen-targeted therapies may provide additional options to improve outcomes in children with acute myeloid leukemia (AML). The Children's Oncology Group AAML03P1 trial sought to determine the safety of adding 2 doses of gemtuzumab ozogamicin, a humanized anti-CD33 antibody-targeted agent, to intensive chemotherapy during remission induction and postremission intensification for children with de novo AML. AAML03P1 enrolled 350 children with previously untreated AML. Patients with a matched family donor received 3 courses of chemotherapy followed by hematopoietic stem cell transplantation; those without a matched family donor received 5 courses of chemotherapy. Gemtuzumab ozogamicin 3 mg/m(2)/dose was administered on Day 6 of Course 1 and Day 7 of Course 4. Toxicities observed in all courses of therapy were typical of AML chemotherapy regimens, with infection being most common. Patients achieved a complete remission rate of 83% after 1 course and 87% after 2 courses. The mortality rate was 1.5% after the first gemtuzumab ozogamicin-containing induction course and 2.6% after 2 induction courses. The 3-year event-free survival and overall survival rates were 53 ± 6% and 66 ± 5%, respectively. This trial determined that it is safe and feasible to include gemtuzumab ozogamicin in combination with intensive chemotherapy. The survival rates compare favorably with the recently published results of clinical trials worldwide.

Azacitidine for the treatment of patients with acute myeloid leukemia

The efficacy of azacitidine for the treatment of high-risk myelodysplastic syndromes has prompted the issue of its potential role even in the treatment of acute myeloid leukemia (AML). The authors analyzed 82 patients with AML who were diagnosed according to World Health Organization criteria. The median patient age was 72 years (range, 29-87 years), and 27 patients (33%) had secondary AML. Of 62 patients with evaluable cytogenetics, 18 patients (29%) had a poor-risk karyotype, and 44 patients (71%) had an intermediate karyotype. Thirty-five patients (43%) received azacitidine as front-line treatment, and 47 patients (57%) had previously received 1 or more line of chemotherapy. The overall response rate was 32% (26 of 82 patients) and included 12 (15%) complete remissions (CRs), 4 (5%) CRs with incomplete blood count recovery (CRi), and 10 (12%) partial responses (PRs). Responses were observed more frequently among untreated patients compared with pretreated patients; in fact, 17 of 35 untreated patients (48%) responded, including 11 responses (31%) classified as CR/CRi. Conversely, only 9 of 47 pretreated patients (19%) responded, including 5 responses (11%) that were classified as CR/Cri. The response rate was significantly higher for untreated patients (P = .006) and those who had white blood cell counts <10 × 10(9) /L (P = .006). For untreated patients who achieved a response, the median overall response duration was 13 months, and the 1-year and 2-years overall survival rates were 58% and 24%, respectively. The current results indicated that azacitidine promises to be an effective therapy for elderly patients with untreated AML and with white blood cell counts <10 × 10(9) /L.

Clinical scale expansion of cytokine-induced killer cells is feasible from healthy donors and patients with acute and chronic myeloid leukemia at various stages of therapy

In our clinical studies involving cytokine-induced killer (CIK) cells for patients with hematological malignancies, starting cells came from a heterogeneous group of patients and donors. Here we study the feasibility of expansion and analyzed the characteristics of the end product from starting cells derived from different sources and at different disease states. Seventy-five clinical scale cultures were grown from 28 patients and 20 donors in Good Manufacturing Practices facilities under CIK condition. CIK cells could be successfully expanded from healthy donors, patients with acute myeloid leukemia recovering from chemotherapy, untreated patients with acute myeloid leukemia or myelodysplastic syndrome with circulating leukemic blasts, and patients with chronic myeloid leukemia on imatinib. Furthermore, CIK cells of donor origin could be expanded from leukapheresis product collected from patients who relapsed post-allogeneic transplantation, thereby offering a useful method of obtaining activated donor cells in patients for whom further donor cells were unavailable. Interestingly, CIK cells cultured from patients with untreated acute myeloid leukemia and myelodysplastic syndrome had a significantly higher proportion of CD3(+)CD56(+) subset and higher fold expansion of CD3(+) cells as compared to other groups of patients or healthy donors. Multivariate analysis showed that fresh starting cells expanded better than frozen-thawed cells, while prior exposure to granulocyte colony-stimulating factor or imatinib before harvesting did not adversely affect CIK cell expansion. Clinical scale expansion of CIK cells is feasible from both healthy donors and leukemia patients at various stages of treatment. This robust system allows clinical translation using CIK cells as immunotherapy in various clinical settings.

Cytarabine Dose of 36 g/m2 Compared With 12 g/m2 Within First Consolidation in Acute Myeloid Leukemia: Results of Patients Enrolled Onto the Prospective Randomized AML96 Study

To assess the optimal cumulative dose of cytarabine for treatment of young adults with acute myeloid leukemia (AML) within a prospective multicenter treatment trial. Between 1996 and 2003, 933 patients (median age, 47 years; range 15 to 60 years) with untreated AML were randomly assigned at diagnosis to receive cytarabine within the first consolidation therapy at either a intermediate-dose of 12 g/m² (I-MAC) or a high-dose of 36 g/m² (H-MAC) combined with mitoxantrone. Autologous hematopoietic stem-cell transplantation or intermediate-dose cytarabine (10 g/m²) were offered as second consolidation. Patients with a matched donor could receive an allogeneic transplantation in a risk-adapted manner. After double induction therapy including intermediate-dose cytarabine (10 g/m²), mitoxantrone, etoposide, and amsacrine, complete remission was achieved in 66% of patients. In the primary efficacy analysis population, a consolidation with either I-MAC or H-MAC did not result in significant differences in the 5-year overall (30% v 33%; P = .77) or disease-free survival (37% v 38%; P = .86) according to the intention-to-treat analysis. Besides a prolongation of neutropenia and higher transfusion demands in the H-MAC arm, rates of serious adverse events were comparable in the two groups. In young adults with AML receiving intermediate-dose cytarabine induction, intensification of the cytarabine dose beyond 12 g/m² within first consolidation did not improve treatment outcome.

Phase I/II study of sapacitabine and decitabine administered sequentially in elderly patients with newly diagnosed acute myeloid leukemia.

6587 Background: Sapacitabine is a novel nucleoside analogue with a unique ability to cause irreparable single-strand DNA breaks and induce G2 cell cycle arrest. It is orally administered and has demonstrated promising activity in patients with acute myeloid leukemia (AML). In AML cell lines, the active metabolite of sapacitabine, CNDAC, is synergistic with hypomethylating agents with the synergy being more apparent if cells are treated with hypomethylating agents first. We are conducting a phase 1/ 2 study to evaluate the safety and efficacy of administering sapacitabine in alternating cycles with decitabine in elderly patients with newly diagnosed AML. Methods: Decitabine 20 mg/m2 is infused intravenously daily x 5 days of a 4-weeks cycle (odd cycles) alternating with sapacitabine 300 mg po b.i.d. x 3 days/week x 2 weeks of a 4-weeks cycle (even cycles). These doses are considered tolerable if dose limiting toxicity (DLT) occurs in ≤ 2 of 6 patients in the phase 1. The planned sample size for phase 2 is 24 patients including those who receiving the same doses of both drugs in the phase 1. The primary efficacy endpoint is response rate (CR, CRp, PR, or major HI). The regimen will be considered active if response rate is ≥ 30%. Eligible patients must be ≥70 years with untreated AML, unsuitable for or unwilling to receive standard induction chemotherapy; patients who received hypomethylating agents for prior MDS or MPD are excluded. Results: As of January 2011, 21 patients were treated with the above regimen and 16 had ≥ 60 days of follow-up. Median age is 76 years (range, 72-88). No DLT were observed. Three patients achieved CR, 2 PR and 1 major HI in platelets. Time to response is 2-4 cycles. Eight patients have received ≥ 4 cycles of treatment. Two patients died within 60-days and the deaths were unrelated to study drugs by investigator assessment. Common adverse events (regardless of causality) included weakness, anorexia, nausea, diarrhea, dehydration, dyspnea, edema, pneumonia, febrile neutropenia, neutropenia, thrombocytopenia, anemia, and hypocalcemia, mostly moderate in intensity. Conclusions: The sequential combination of decitabine and sapacitabine is safe and active in elderly AML.

Randomized study of induction therapy comparing standard-dose idarubicin with high-dose daunorubicin in adult patients with previously untreated acute myeloid leukemia: the JALSG AML201 Study

AbstractWe conducted a multi-institutional randomized study to determine whether high-dose daunorubicin would be as effective as standard-dose idarubicin in remission-induction therapy for newly diagnosed adult patients younger than 65 years of age with acute myeloid leukemia. Of 1064 patients registered, 1057 were evaluable. They were randomly assigned to receive either daunorubicin (50 mg/m2 daily for 5 days) or idarubicin (12 mg/m2 daily for 3 days) in combination with 100 mg/m2 of cytarabine by continuous infusion daily for 7 days as induction therapy. Complete remission was achieved in 407 (77.5%) of 525 patients in the daunorubicin group and 416 (78.2%) of 532 in the idarubicin group (P = .79). Patients achieving complete remission received intensive postremission therapy that consisted of either 3 courses of high-dose cytarabine or 4 courses of standard-dose therapy. Overall survival rates at 5 years were 48% for the daunorubicin group and 48% for the idarubicin group (P = .54), and relapse-free survival rates at 5 years were 41% and 41% (P = .97), respectively. Thus, high-dose daunorubicin and standard-dose idarubicin were equally effective for the treatment of adult acute myeloid leukemia, achieving a high rate of complete remission and good long-term efficacy. This study is registered at http://www.umin.ac.jp/ctrj/ as C000000157.

Influence of residual normal metaphases in acute myeloid leukemia patients with monosomal karyotype

Influence of residual normal metaphases in acute myeloid leukemia patients with monosomal karyotype

A phase 2 study of high-dose lenalidomide as initial therapy for older patients with acute myeloid leukemia

AbstractOlder patients with acute myeloid leukemia (AML) have limited treatment options and a poor prognosis, thereby warranting novel therapeutic strategies. We evaluated the efficacy of lenalidomide as front-line therapy for older AML patients. In this phase 2 study, patients 60 years of age or older with untreated AML received high-dose (HD) lenalidomide at 50 mg daily for up to 2 28-day cycles. If patients achieved a complete remission (CR)/CR with incomplete blood count recovery (CRi) or did not progress after 2 cycles of HD lenalidomide, they received low-dose lenalidomide (10 mg daily) until disease progression, an unacceptable adverse event, or completion of 12 cycles. Thirty-three AML patients (median age, 71 years) were enrolled with intermediate (55%), unfavorable (39%), or unknown (6%) cytogenetic risk. Overall CR/CRi rate was 30%, and 53% in patients completing HD lenalidomide. The CR/CRi rate was significantly higher in patients presenting with a low (< 1000/μL) circulating blast count (50%, P = .01). The median time to CR/CRi was 30 days, and duration of CR/CRi was 10 months (range, 1- ≥ 17 months). The most common grades ≥ 3 toxicities were thrombocytopenia, anemia, infection, and neutropenia. HD lenalidomide has evidence of clinical activity as initial therapy for older AML patients, and further study of lenalidomide in AML and MDS is warranted. This study is registered at www.clinicaltrials.gov as #NCT00546897.

Clinical results and issues of acute myeloid leukemia in elderly patients aged 75 years and older

Clinical outcomes of acute myeloid leukemia (AML) in elderly patients still remain unsatisfactory and the optimal treatment has yet to be clearly established. This report describes the results of a retrospective study of clinical outcomes and prognostic factors of AML in patients aged 75 years and older. In addition, we aimed to elucidate the situation of patients with AML accompanied by dementia, which has been largely ignored in previous studies. The subjects consisted of 31 patients with untreated AML (including previous myelodysplastic syndrome: AML/MDS). All patients underwent chemotherapy, with 25 undergoing conventional therapy and six undergoing low-intensity therapy. Complete remission was obtained in 16 of the 31 cases (51.6%), with a 3-year survival rate of 11.5%. However, in seven cases, Alzheimer's disease (AD) was observed. Although we were able to perform induction therapy in each of these cases, consolidation therapy was difficult in cases of moderate AD. The results of this study suggest that even very elderly patients can benefit from chemotherapy. However, it is thought that the treatment selection for cases which are complicated by moderate to severe dementia should be determined carefully while considering the patient's quality of life.

Report of a Phase II Study of Clofarabine and Cytarabine in De Novo and Relapsed and Refractory AML Patients and in Selected Elderly Patients at High Risk for Anthracycline Toxicity

To determine the efficacy and safety of clofarabine and cytarabine (Ara-C) in adult patients with relapsed or refractory acute myeloid leukemia (AML) and in elderly patients with untreated AML and heart disease. Patients with relapsed/refractory AML and older patients for whom there was a concern over toxicity from additional anthracyclines received 5 days of clofarabine, 40 mg/m(2) per day i.v. over 1 hour, followed 4 hours later by Ara-C, 1,000 mg/m(2) per day i.v. over 2 hours. Thirty patients were enrolled. The median age was 67 years (range, 38-82 years) and 18 (60%) had received at least one prior therapy. Eleven (37%) patients had a history of cardiovascular disease and were considered to be at high risk for anthracycline toxicity. High-risk cytogenetic abnormalities were present in 14 (47%) patients. The overall response rate (complete remission [CR] plus partial remission) was 53%, including a CR in 14 patients (47%). Responses were observed in all cytogenetic risk groups and in patients who had received up to five prior therapies. The median disease-free survival interval was 9.5 months. The 30-day mortality rate was 20% (de novo AML, 8%; relapsed/refractory AML, 28%). Of the 14 patients achieving a CR, half were able to proceed to curative hematopoietic stem cell transplantation. Clofarabine in combination with Ara-C is effective in both untreated and previously treated patients with AML. In addition, it represents a useful remission induction strategy to serve as a bridge to transplantation in older patients with AML.

Conditioning regimen using busulfan plus melphalan in hematopoietic stem cell transplantation

Conditioning regimen using busulfan plus melphalan in hematopoietic stem cell transplantation

A Phase I Study of Sequential Azacitidine and Lenalidomide for Elderly Patients with Acute Myeloid Leukemia (AML)

AbstractAbstract 3288 Introduction:The elderly constitute the majority of patients (pts) with AML. Effective and tolerable therapeutic alternatives are necessary for these pts, in whom outcomes with standard induction therapy are poor. Azacitidine (AZA), a DNA methyltransferase inhibitor, decreases methylation of tumor suppressor gene (TSG) promoters, which correlates with clinical responses. Lenalidomide (LEN), an immunomodulatory and anti-angiogenic agent, has anti-leukemic activity when used as a single agent. We hypothesized that combining these two agents would decrease promoter methylation and upregulate TSG expression. We present the Phase I results of a Phase I/II clinical trial that sequentially combines AZA with LEN in elderly, previously untreated AML pts. Methods:Eligible pts were ≥ 60 years, had a World Health Organization-confirmed diagnosis of non-M3 AML, a performance status (PS) ≤ 2, adequate organ function, no prior leukemia therapy and were not candidates for standard induction. All pts had a white blood cell count ≤ 10,000/mm3 at the time of study entry; the use of hydroxyurea to attain this was permitted. Pts were enrolled into 4 cohorts using a 3+3 dose escalation design. In cohort 1, pts received 75 mg/m2 AZA SC/IV on d 1–7, followed by 21 days of observation for a 28-day cycle. At the completion of this “cycle 0,” pts were escalated to cycle 1, in which they received the same dose and schedule of AZA followed by LEN 5 mg PO daily on d 8–28, and then observation on d 29–42. Cohorts 2, 3 and 4 received the same dose and schedule of AZA with LEN doses of 10, 25 and 50 mg respectively, at the same schedule described for cycle 1. Intra-cohort dose escalation after cycle 0 was not permitted. Baseline bone marrow biopsies were compared to biopsies obtained after cycles 0, 1, 3, 6 and 12, and response assessments were based on International Working Group criteria. Adverse events (AEs) were graded according to the NCI CTCAE v 3.0. Pts were eligible for a maximum of 12 cycles, provided they tolerated therapy and achieved a response (defined as a complete response [CR], a CR with incomplete recovery of blood counts [CRi] or a partial response [PR]). Result:Eighteen pts were enrolled between April 2009 and July 2010. The median age was 72 years (64-86), 67% were male and 94% were Caucasian. The median PS was 1 (0-2) and the median hematopoietic cell transplant comorbidity index score was 0.5 (0-4). Six of 18 (33%) required hydroxyurea prior to enrollment. Seven of 18 (39%) had de novo AML and 11/18 (61%) had secondary AML (1 therapy-related, 1 evolved from primary myelofibrosis and 9 with myelodysplasia-related changes). The median bone marrow blast percentage was 63.5% (21-91%). Three of 18 (17%) pts had adverse cytogenetics, while 15/18 (83%) pts exhibited intermediate grade cytogenetics (11/15 with normal karyotype). Grade 3 serious AEs with a suspected relationship to treatment included neutropenic fever (NF) (n=5), fatigue (n=3), renal insufficiency (n=2), hyponatremia (n=1) and bleeding (n=1). In Cohort 4, 1/6 pts experienced grade 4 NF; however, 5/6 did not experience DLT, and therefore, the MTD was not reached. Pts have completed a median of 2 treatment cycles (0-6), with a median follow up of 94 days (21-275). Presently, of the 17 evaluable pts, 9/17 (53%) are alive. The overall response rate (ORR; defined as CR+CRi+PR) is 8/17 (47%) and the CR+CRi rate is 4/17 (24%). Thirty-day mortality was 12% (2/17); both deaths occurred in the first cohort in pts who had not received the drug combination, and were related to disease progression. Of the 5 pts enrolled in cohort 1, none responded, and all ultimately died of disease progression. However, among those in cohorts 2–4, 9 of 12 (75%) evaluable pts are alive with an ORR of 67% (CR+CRi= 4/12 [33%]), a median of 104 days after initiation of treatment (42-275). No responder has relapsed to date. Of the 3 post-cohort 1 deaths, 1 was from disease progression and 2 were from infectious complications. Conclusion:The sequential combination of AZA and LEN was well tolerated in elderly, untreated AML pts. The MTD was not reached at the highest dosing cohort, and the Phase II dose and schedule is AZA 75 mg/m2 d 1–7 and LEN 50 mg d 8–28, on a 6-week cycle schedule. The preliminary ORR of 47% is encouraging, as is the 67% ORR in pts who received ≥10 mg of LEN. Six month follow up will be presented. This trial was registered at ClinicalTrials.gov as NCT00890929. Disclosures:Off Label Use: Azacitidine and lenalidomide for AML. Liedtke:Celgene: Lecture Fee, Research Funding.

The Impact of FLT3-ITD Mutation on the Expression of Multidrug Resistance Genes MDR-1, MRP-1, BCRP and LRP In Adult Acute Myeloid Leukemia

AbstractAbstract 1808 BackgroundMultidrug resistance (MDR) is a clinically relevant problem in the treatment of acute myeloid leukaemia (AML). From 20–50% of patients with AML are primarily resistant to induction chemotherapy and in the great majority of those who respond well to initial therapy the disease relapses. While some mechanisms of MDR have been well characterized, this phenomenon still remains incompletely understood. Three ATP-dependent drug transporting proteins: p-glycoprotein (Pgp; MDR-1), multidrug resistant protein-1 (MRP-1), breast cancer resistance protein (BCRP) and one major vault protein-lung resistance-related protein (LRP) and the internal tandem duplication (ITD) in the receptor tyrosine kinase FLT3 have been found to have a strong correlation with MDR and poor outcome in AML. About 30% of AML cases harbor FLT3-ITD mutation. Mainly MDR-1 protein and FLT3-ITD mutation are targets for inhibition by numerous agents in clinical practice. ObjectivesIn this retrospective study we estimated expression of MDR genes encoding MDR-1, MRP-1, BCRP, LRP proteins and detected FLT3-ITD mutation in patients with AML. We divided all patients into two groups according to FLT3-ITD mutation and we compared expression of MDR genes and other prognostic factors in AML: age (<60 vs ≥60 years), cytogenetic/molecular aberrations (good, intermediate, poor), de novo/secondary AML, white blood cell count (WBC), extramedullary involvement, type of AML according to the FAB classification, CD34 expression on blast cells and myeloperoxidase activity (<50% of blast cells, ≥50%) between groups Moreover the rate of complete remissions (CR) and relapses and disease free survival (DFS) and overall survival (OS) in both groups were estimated. Materials and MethodsA total of 126 adult patients at median age of 53 years (range 21–87) with newly diagnosed between June 2005 and March 2010, previously untreated AML and 40 healthy donors were included in this study. Diagnosis of AML was based on standard morphological and immunophenotypical criteria according to the WHO classification. Most of the patients were treated with anthracycline and cytarabine during the induction regime. There were 39 FLT3-ITD positive (30,4%) and 87 FLT3-ITD negative (69,6%) patients. DNA was extracted from bone marrow (90 patients) or peripheral blood (36 patients) samples and used to detect FLT3-ITD with PCR method. RNA was extracted from the same samples and following reverse transcription RQ-PCR method was performed for assessment of expression of MDR-1, MRP-1, BCRP and LRP genes. Parameters of RQ-PCR reaction were established based on the Europe Against Cancer protocol. Every tested sample was amplified simultaneously for the presence of control ABL gene for standardization of mRNA level for tested genes. Results of the expression of tested genes were presented as coefficients calculated with an intermediate method according to Pfaffl's rule. ResultsTo our surprise, significant higher expression of MDR-1 gene was found either in bone marrow or peripheral blood samples of the patients who do not harbor FLT3-ITD in contrast to the patients harboring this mutation (median 0,3025 vs 0,0756, p=0,003 total; median 0,2690 vs 0,0583, p= 0,002 bone marrow samples; median 0,5775 vs 0,0920, p=0,001 peripheral blood samples). For MRP-1, BCRP and LRP genes we did not find significant differences in their expression between two groups. When adjusted for other prognostic factors, only WBC was significantly higher in FLT3-ITD positive group of patients: 1–294×109/l, median 74 vs 0–286×109/l, median 6,5 in FLT3-ITD negative group of patients (p=0,0001). We did not observe significant differences in CR and relapses rates, DFS and OS between groups. ConclusionsIt seems that FLT3-ITD mutation may in some mechanisms influence MDR-1 gene expression We observed significant inhibition of MDR-1 expression in FLT3-ITD positive patients. Because risk factors for AML and outcome of AML therapy did not differ between groups it seems that FLT3-ITD mutation and high expression of MDR-1 gene are independent high risk factors which negatively influence results of AML therapy. These results might provide a powerful risk classification and useful information for treatment strategies including inhibitors of tyrosine kinase or MDR-1 protein.This project was supported by grant of The Ministry of Science (N N402 208935). Disclosures:No relevant conflicts of interest to declare.

Phase II Study of the Combination of Clofarabine Plus Idarubicin and Cytarabine (CIA) In Patients with Relapsed/Refractory Acute Myeloid Leukemia (AML).

AbstractAbstract 1061Clofarabine is a second generation nucleoside analog with activity in patients with acute leukemias. Previous studies with the combination of clofarabine plus cytarabine have reported a complete remission rate (CR) of 24% in relapsed AML and 52% in previously untreated AML patients. To explore further combinations with drugs active in AML, we conducted a phase II study of CIA in patients with relapsed and primary refractory AML. Patients were treated at the maximum tolerated dose (MTD) determined from a preceding phase I study: clofarabine 22.5mg/m2 IV daily × 5, idarubicin 6 mg/m2 IV daily × 3, and cytarabine 0.75 g/m2 IV daily × 5 days. A total of 63 patients were enrolled. Patients with prior exposure to clofarabine were not eligible. The median age was 51years (18 - 80years). Twenty-four patients were primary refractory and 39 had relapsed disease. All the patients received CIA in 1st salvage. For patients with relapsed AML, the median duration of the first CR was 36 weeks (3 – 215 weeks). Three patients underwent stem cell transplant (SCT) prior to treatment with CIA and 28 patients had received at least intermediate doses of cytarabine prior to relapse. Fifteen patients had secondary AML following a preceding phase of MDS. Twenty-five percent of patients had -5/-7 and 6% had trisomy 8. Thirteen patients (21%) achieved CR, 7 (11%) CRp (complete remission without platelet recovery), and 4 (6%) a partial remission (PR) for an overall response rate of 38%. The response rate in patients with primary refractory disease was 33% while the response rate in patients with relapsed disease was 41%. Five patients (8%) died during induction (</= 28 days); 4 from septic shock and 1 from diffuse alveolar hemorrhage. Median duration of follow-up was 65 weeks (range 6–161). Median overall survival was 34 weeks (range 1–161). Disease free survival for those patients who achieved CR/CRp was 66 weeks (range 4–156). A total of 24 (38%) patients underwent SCT following CIA. The most common toxicity was nausea/vomiting in 49 (78%) patients followed by hepatic dysfunction in 43 (68%) patients and diarrhea in 42 (67%) patients. In summary, the CIA combination has activity in patients with relapsed/refractory AML. Further evaluation in better prognosis patients is ongoing. Disclosures:Ravandi:Genzyme: Honoraria, Membership on an entity's Board of Directors or advisory committees. Kantarjian:Genzyme: Research Funding. Faderl:Genzyme: Research Funding.