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Elihu Estey

Publications and source records attributed to Elihu Estey.

67 records · Page 4Linked to original sources
PubMed2003

Single agent thalidomide in patients with relapsed or refractory acute myeloid leukaemia.

Thalidomide is a putative anti-angiogenesis agent that has significant anti-tumour activity in haematological malignancies with increased bone marrow angiogenesis, including multiple myeloma (MM) and myelodysplastic syndromes (MDS). Increased levels of the mitogen for angiogenesis, vascular endothelial growth factor (VEGF), correlate with worse survival in acute myeloid leukaemia (AML). A phase II trial of thalidomide was conducted in patients with relapsed- or refractory-AML previously treated with cytarabine-containing regimens. A total of 16 patients with refractory- or relapsed-AML were treated with thalidomide 200-800 mg orally daily (median dose 400 mg daily) for a median of 27 d (range, 3-94 d). Overall, one patient (6%) achieved complete remission (CR) lasting for 36 months, and two patients had a transient reduction in marrow blasts from 8% and 7% to less than 5% in both cases. There was no correlation between reduction in levels of angiogenesis markers and response. Toxicities related to thalidomide were significant, and precluded dose escalation beyond 400 mg orally daily in most patients. Although there appears to be some evidence of biological activity, single agent thalidomide is not an optimal choice of therapy for salvaging patients with relapsed- or refractory-AML. Thalidomide analogues with more potent immunomodulatory activities and more favourable toxicity profiles may offer more promise as anti-AML therapy.

Acute Disease↗
PubMed2003

Circulating blasts following chemotherapy in pediatric patients: implications for complete remission definition in acute leukemia.

We assessed the incidence of circulating blasts occurring post-chemotherapy in 1000 consecutive pediatric blood samples. Blasts with myeloid morphology (<1-3%) were present in post-chemotherapy samples in 19 of 294 (6.4%) patients with acute leukemia in remission and in 11 of 361 (3.4%) patients with solid tumors, non-Hodgkin or Hodgkin lymphoma, and were associated with ANC>1.5x10(9)/l in 13 of 30 (43%) samples, and platelets >100x10(9)/l in 25 of 30 (83%) samples. Our findings suggest that the absence of circulating blasts may not be a prerequisite for remission in acute myeloid leukemia (AML).

Acute Disease↗
PubMed2002

Pilot study of Mylotarg, idarubicin and cytarabine combination regimen in patients with primary resistant or relapsed acute myeloid leukemia.

PURPOSE: Mylotarg has moderate activity as a single agent in patients with CD33-positive refractory or relapsed acute myelogenous leukemia (AML). A combination of an anthracycline and cytarabine (ara-C) is the core of most AML induction regimens. We conducted a pilot study of Mylotarg combined with idarubicin and ara-C in patients with refractory or relapsed AML. METHODS: Mylotarg was administered at 6 mg/m(2) intravenously on days 1 and 15, idarubicin 12 mg/m(2) daily on days 2 through 4, and ara-C at 1.5 g/m(2) daily on days 2 through 5 (MIA) RESULTS: Of 14 patients were treated, 4 (29%) had primary resistant AML, and 10 (71%) relapsed AML. The median age of the patients was 61 years (range 34-74 years). MIA induced complete remission (CR) in three patients (21%) and CR with incomplete platelet recovery (CRp) in three patients (21%). The median survival was 8 weeks (range 2-64 weeks), and the median failure-free survival of CR patients was 27 weeks (range 11-64 weeks). All patients developed grade 3/4 myelosuppression - severe sepsis occurred in ten patients (71%). Other grade 3/4 nonhematologic toxicities included hepatic transaminitis, oral mucositis, and diarrhea. Two patients (14%) developed hepatic venoocclusive disease (VOD). CONCLUSIONS: The addition of Mylotarg to idarubicin and ara-C is feasible. MIA has significant activity in patients with refractory AML. Hepatotoxicity and VOD are significant toxicities of Mylotarg-based combinations.

Adult↗
PubMed2002

Mylotarg combined with topotecan and cytarabine in patients with refractory acute myelogenous leukemia.

PURPOSE: Mylotarg, a humanized anti-CD33 antibody linked to an antitumor antibiotic, is approved for the treatment of patients with relapsed acute myeloid leukemia (AML). Topotecan and cytarabine (ara-C) is an effective anti-AML regimen. A pilot study of Mylotarg combined with topotecan and ara-C (MTA) was conducted in patients with refractory AML. METHODS: MTA consisted of Mylotarg 9 mg/m(2) intravenously (i.v.) over 2 h on day 1, ara-C 1 g/m(2) over 2 h i.v. on days 1 through 5, and topotecan 1.25 mg/m(2) by continuous infusion i.v. on days 1 through 5. RESULTS: A group of 17 patients (9 primary resistant, 8 relapsed) with AML or advanced myelodysplastic syndrome (MDS) received 20 courses of MTA. The median age of the patients was 55 years (20-70 years). Two patients (12%) achieved complete remission. The median overall survival was 8.2 weeks. Five patients (29%) developed grade 3/4 hepatic transaminitis, including one patient (6%) who died with hepatic venoocclusive disease. CONCLUSIONS: MTA was moderately effective and associated with significant toxicity in patients with refractory AML.

Acute Disease↗
PubMed2002

Clinical significance of plasma endostatin in acute myeloid leukemia/myelodysplastic syndrome.

BACKGROUND: Endostatin, a C-terminal fragment of collagen XVIII, is an endogenous angiogenesis inhibitor. While endostatin is being investigated for its usefulness in treating solid tumors, its significance in hematologic malignancies is unknown. METHODS: The authors evaluated plasma endostatin (PE) levels using an enzyme linked immunoassay in 71 patients with acute myeloid leukemia (AML) and 43 patients with myelodysplastic syndrome (MDS), and correlated PE with various clinical parameters. RESULTS: There was no significant difference in the median PE level between AML/MDS patients and the normal controls. Nevertheless, patients who achieved complete remission (CR) had a significantly lower median PE level compared to those who did not. In multivariate analysis, PE was found to be a significant (P = 0.03) predictor of overall survival (OS) with adjustment of the other baseline covariates, including patient age, history of antecedent hematologic disorders, and the use of protective environments. The prognostic value of PE was also evaluated by dividing MDS/AML patients into high and low PE groups using the median PE level of normal controls as the cut-off. The authors found that patients in the high PE group survived for a significantly shorter time than those patients in the low PE group. CONCLUSIONS: PE is a useful prognostic predictor of CR and OS for AML/MDS patients. The mechanism underlying the association between high PE and poor clinical outcome is unclear, although it may be related to the possible PE reflection of tumor burden.

Acute Disease↗
PubMed2002

Comparison between pediatric acute myeloid leukemia (AML) and adult AML in VEGF and KDR (VEGF-R2) protein levels.

We reported previously that high levels of vascular endothelial growth factor (VEGF) were associated with shorter survival in adult acute myeloid leukemia (AML) patients. In this study, cellular VEGF and its receptor, VEGF-R2 (kinase domain receptor (KDR)), were analyzed in 45 pediatric AML patients using Western blot and solid-phase radioimmunoassay (RIA). Cellular VEGF levels were significantly lower in pediatric AML compared to adult AML patients. In contrast, there was no significant difference in VEGF-R2 levels between adult and pediatric AML. Higher VEGF and VEGF-R2 levels in pediatric AML patients correlated with higher white blood cell (WBC). Unlike in adults, VEGF and VEGF-R2 levels in pediatric AML patients did not correlate with survival. This data suggest that the role of VEGF and its receptor VEGF-R2 in pediatrics AML may be different from that in adult AML.

Acute Disease↗
PubMed2002

Proliferation and apoptosis in acute and chronic leukemias and myelodysplastic syndrome.

Clonal expansion of leukemic cells is thought to be due to proliferation in excess of apoptosis. To define and compare proliferation and apoptosis between various leukemias and myelodysplastic syndrome (MDS), we measured proliferating cell nuclear antigen (PCNA) and bromodeoxyuridine (BrdU) incorporation as surrogate markers for proliferation and caspase 3 activity and annexin V surface binding as surrogate markers for activation of the apoptotic cascade in patients with MDS, chronic myelomonocytic leukemia (CMML), acute myeloid leukemia (AML), acute lymphoblastic leukemia (ALL), chronic lymphocytic leukemia (CLL), and chronic myeloid leukemia (CML). We found high proliferation in bone marrow cells from MDS and CMML as measured by PCNA and BrdU incorporation. The lowest level of proliferation was found in CLL. Apoptosis was also highest in MDS and CMML as measured by annexin V and caspase 3 activity. Unexpectedly, we found no significant difference in proliferation in bone marrow CD34+ cells from various leukemias or MDS. Apoptosis was significantly higher in bone marrow CD34+ cells from MDS and CML in chronic phase as compared to CD34+ cells from AML patients. Our results illustrate differences in proliferation and apoptosis between acute and chronic leukemias and MDS. These differences may have diagnostic and therapeutic implications.

Acute Disease↗
PubMed2002

Clinical relevance of vascular endothelial growth factor receptors 1 and 2 in acute myeloid leukaemia and myelodysplastic syndrome.

We have previously reported that high levels of cellular vascular endothelial growth factor (VEGF) protein correlated with short survival of patients with acute myeloid leukaemia (AML). As VEGF exerts its effects via two receptors, VEGF receptor 1 (VEGFR-1) and VEGFR-2, we evaluated the significance of VEGFR-1 and VEGFR-2 protein levels in AML and myelodysplastic syndrome (MDS), and their relationship to VEGF protein levels. Western blot analysis and radioimmunoassay confirmed and quantified specific protein levels in bone marrow samples from 41 MDS and 66 AML previously untreated patients. VEGFR-1 levels were significantly higher in AML than in MDS (P = 0.0004), but no significant difference was found in the VEGFR-2 levels (P = 0.5). No significant correlation between VEGFRs levels and duration of survival was found. VEGF protein levels were significantly higher in MDS than in AML (P < 0.0001). A Cox proportional-hazard regression model showed increasing VEGF levels to significantly correlate with shorter survival of patients with MDS (P = 0.008), a finding similar to our previous report of the inverse relationship between VEGF levels and survival of AML patients. We found a significant correlation between VEGF and VEGFR-2 levels in both AML and MDS (P < 0.0000001 andP < 0.0002 respectively) but not between VEGF and VEGFR-1 levels. These data suggest that VEGF expression, rather than the expression of its receptors, is the determining factor in the biological behaviour of AML and MDS, and that VEGFRs are differentially expressed in AML and MDS.

Acute Disease↗
PubMed2002

The anti-apoptotic genes Bcl-X(L) and Bcl-2 are over-expressed and contribute to chemoresistance of non-proliferating leukaemic CD34+ cells.

In acute myeloid leukaemia (AML), cell kinetic quiescence has been postulated to contribute to drug resistance. As the anti-apoptotic genes Bcl-2 and Bcl-X(L) have been implicated in cell cycle regulation, we investigated the expression of these genes in non-proliferating (Q) and proliferating (P) AML and normal CD34+ progenitor cells. Using reverse transcription polymerase chain reaction, Bcl-X(L) and Bcl-2 were overexpressed in Q versus P AML cells, whereas no difference in Bcl-XS and Bax expression was found. Furthermore, the Bcl-X(L)/X(S) but not the Bcl-2/Bax ratio was higher in Q AML compared with normal CD34+ Q cells (P = 0.001). An inverse correlation between Bcl-2 expression of leukaemic Q cells and their ability to enter the cell cycle was found. Treatment with all-trans retinoic acid (ATRA) reduced Bcl-2 and Bcl-X(L) expression in the leukaemic Q cells, and enhanced their chemosensitivity to cytosine arabinoside (ara-C). These findings demonstrate overexpression of the anti-apoptotic proteins Bcl-X(L) and Bcl-2 in quiescent CD34+ AML cells and suggest their involvement in the chemoresistance. The observed inverse correlation between Bcl-2 and proliferation suggests a role for Bcl-2 in the cell cycle regulation of AML. These findings could be used in the development of therapies that selectively induce apoptosis in quiescent leukaemic progenitor cells.

Acute Disease↗
PubMed2002

Differences in CD33 intensity between various myeloid neoplasms.

We measured the concentration of CD33 antigen on the surface of cells in 315 bone marrow (BM) samples and 114 corresponding peripheral blood (PB) samples from patients with various leukemias (acute myeloid leukemia [AML], chronic myelogenous leukemia [CML], myeloproliferative disorder [MPD] other than CML, myelodysplastic syndrome [MDS]) and from control subjects. Overall CD33 intensity in total CD33+ cells was significantly higher in BM than in PB. CD33 intensity in total BM CD33+ cells differed significantly with the type of disease. The median number of CD33 molecules per cell was highest in AML, followed by MDS, CML, and control subjects and lowest in MPD. When only CD34+/CD33+ cells were examined, CD33 molecules per cell were highest in CD34+ cells in AML and lowest in MPD (P = .027). Patients with AML or MDS younger than 60 years had significantly higher intensity of CD33 expression on CD34+ cells than patients 60 years or older. Levels of CD33 intensity did not correlate with cytogenetics in patients with AML or MDS. There was no correlation between CD33 intensity and response to therapy or overall survival in 35 patients treated with protocols including Mylotarg. These data demonstrate variation in CD33 intensity between various leukemias.

Aminoglycosides↗
PubMed2002

A phase I study of idarubicin dose escalation with amisfostine and high-dose cytarabine in patients with relapsed acute myelogenous leukemia and myelodysplastic syndromes.

BACKGROUND AND OBJECTIVES: Early studies have suggested that increasing doses of anthracycline improve outcome in younger patients with acute myelogenous leukemia (AML), but dose escalation has been precluded by the acute and chronic toxicities of these agents. Amifostine is a cytoprotective compound that has been shown to protect against the acute cytotoxicities of anthracyclines in animal models. We report the results of a phase I study of dose escalation of idarubicin with amifostine and high-dose ara-C in patients with relapsed or refractory AML or myelodysplastic syndrome (MDS). DESIGN AND METHODS: The continuous reassessment method was used to predict the probability of toxicity. RESULTS: Five patients were treated at an idarubicin dose of 18 mg/m2/day x 3, three of whom developed grade 3 diarrhea or mucositis. Subsequently, three additional patients were treated at a dose of 15 mg/m2 x 3 days, all of whom experienced grade 3 diarrhea or mucositis. One patient achieved complete remission (CR rate 12.5%, 95% CI 0-0.52%). INTERPRETATION AND CONCLUSIONS: The addition of amifostine does not allow dose escalation of idarubicin when combined with high-dose ara-C.

Adult↗
PubMed2000

New Developments in the Therapy of Acute Myelocytic Leukemia.

Current conventional treatment for patients with acute myelogenous leukemia results in a high percentage of clinical responses in most patients. However, a high percentage of patients still remain refractory to primary therapy or relapse later. This review examines the search for new agents and new modes of therapy. In Section I, Dr. Estey discusses new agents directed at various targets, such as CD33, angiogenesis, inappropriately methylated (suppressor) genes, cell cycle checkpoints, proteosomes, multidrug resistance (MDR) gene, mitochondrial apoptotic pathway. He also reviews preliminary results of phase I trials with the nucleoside analog troxacitabine and liposomal anthracyclin and suggests new strategies for trials of new agents. In Section II, Dr. Jones revisits differentiation therapy and presents results of preclinical and clinical studies that demonstrate that a variety of clinically applicable cell cycle inhibitors (interferon, phenylbutyrate, vitamin D, retinoids, bryostatin-1) preferentially augments growth factor-mediated induction of myeloid leukemia terminal differentiation, as well as blocks growth factors' effects on leukemia proliferation. The combination of cell cycle inhibition plus myeloid growth factors may offer a potential treatment for resistant myeloid leukemias. In Section III, Drs. Levitsky and Borrello address the question of tumor vaccination in AML and shows that, although tumor rejection antigens in AML have not been formally identified to date, a growing number of attractive candidates are ripe for testing with defined antigen-specific vaccine strategies. Interestingly, the ability to drive leukemic blasts to differentiate into competent antigen presenting cells such as dendritic cells may be exploited in the creation of cellular vaccines. Ultimately, the successful development of active immunotherapy for AML will require integration with dose-intensive chemotherapy, necessitating a more complete understanding of host immune reconstitution. In Section IV, Dr. Slavin reviews the concept of delivering non-myeloablative stem cell transplantation (NST) and delayed lymphocyte infusion (DLI) to increase tolerance in particular in high risk and older patients, and take advantage of the graft-versus-leukemia (GVL) effect. All these approaches hold promise in reducing morbidity and mortality and differ from the older concepts aiming at delivering the highest possible doses of chemotherapy and/or total body irradiation to reach maximum leukemia cell kill, whatever the toxicity to the patient.

Journal Article↗