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Biomedical subjects

Pierre Fenaux

Publications and source records attributed to Pierre Fenaux.

At least 37 records · Page 2Linked to original sources
PubMed2005

Mesenchymal cells generated from patients with myelodysplastic syndromes are devoid of chromosomal clonal markers and support short- and long-term hematopoiesis in vitro.

Myelodysplastic syndromes (MDS) are clonal malignant stem cell disorders characterized by inefficient hematopoiesis. The role of the marrow microenvironment in the pathogenesis of the disease has been controversial and no study has been performed so far to characterize mesenchymal cells (MC) from MDS patients and to analyse their ability to support hematopoiesis. To this end, we have isolated and characterized MC at diagnostic marrow samples (n=12) and have purified their CD34+CD38- and CD34+CD38+ counterparts (n=7) before using MC as a short- and long-term hematopoietic support. We show that MC can be readily isolated from MDS marrow and exhibit a major expansion potential as well as an intact osteoblastic differentiation ability. They do not harbor the abnormal marker identified by FISH in the hematopoietic cells and they stimulate the growth of autologous clonogenic cells. Conversely, highly purified stem cells and their cytokine-expanded progeny harbor the clonal marker with variable frequencies, and both normal and abnormal long-term culture-initiating cell-derived progeny can be effectively supported by autologous MC. Thus, we demonstrate that MDS marrow is an abundant source of MC appearing both cytogenetically and functionally noninvolved by the malignant process and able to support hematopoiesis, suggesting their possible usefulness in future cell therapy approaches.

ADP-ribosyl Cyclase↗
PubMed2005

Role of multiplex FISH in identifying chromosome involvement in myelodysplastic syndromes and acute myeloid leukemias with complex karyotypes: a report on 28 cases.

Chromosomal abnormalities are found by conventional cytogenetic (CC) analysis in about 50% of myelodysplastic syndromes (MDS) and 70% of acute myeloid leukemias (AML). When cytogenetic abnormalities are complex, multiplex fluorescence in situ hybridization (M-FISH) can help clarify complex chromosomal abnormalities and identify rearrangements with prognostic value or cryptic translocations, which could be preliminary steps in identifying new genes. We studied by M-FISH 28 cases of MDS and AML with complex chromosomal abnormalities, 10 of them were therapy-related. M-FISH allowed the characterization of unidentified chromosomal material in 26 cases (93%). One or several unbalanced rearrangements were observed in 27 cases (96%), generally interpreted as deletions or additional material by CC. Among those translocations, 4 involved 3 chromosomes. Eighteen cryptic translocations undetected by CC were found in 13 cases. By FISH analysis using locus specific probes, TP53 deletion, additional copies of MLL, and additional copies or deletions of RUNX1/AML1 were observed in 16, 4, and 3 cases, respectively. Thus, M-FISH is an important tool to characterize complex chromosomal abnormalities which identified unbalanced and cryptic translocations in 96% and 46% of the cases studied, respectively. Complementary FISH helped us identify involvement of TP53, MLL, and RUNX1/AML1 genes in 82% of cases, confirming their probable role in leukemogenesis.

Acute Disease↗
PubMed2005

A new variant t(6;15;17)(q25;q22;q21) in acute promyelocytic leukemia: fluorescence in situ hybridization confirmation.

Acute promyelocytic leukemia (APL) is characterized by the t(15;17)(q22;q21), which results in the fusion of the promyelocytic leukemia (PML) gene at 15q22 with the retinoic acid alpha-receptor (RARalpha) at 17q21. The 2 chimeric genes PML/RARalpha and RARalpha/PML are thought to play a role in leukemogenesis. We report a case of APL in a patient carrying an apparently complex variant translocation identified as t(6;15;17) by R-banding and whole chromosome 15 and 17 painting. However, FISH analysis with a PML/RARalpha dual-color kit showed a more complex translocation, resulting presumably from a two-step rearrangement, with PML-RARalpha fusion gene located as expected on the der(15) but the residual 5'-RARalpha signal located on the der(6). The patient achieved complete remission with all-trans retinoic acid treatment associated with chemotherapy. This case illustrates the usefulness of combined cytogenetics, FISH, and molecular biology to evidence the PML/RARalpha fusion gene in complex cases.

Chromosome Banding↗
PubMed2005

Inhibitors of DNA methylation: beyond myelodysplastic syndromes.

DNA methyltransferase (DNMT) inhibitors, azacitidine (Vidaza, Pharmion, Boulder, CO, USA) and decitabine (Dacogen; SuperGen Inc, Dublin, CA, USA, and MGI Pharma Inc, Bloomington, MN, USA), have had a significant impact on the treatment paradigm of myelodysplastic syndromes (MDSs), previously managed mainly by supportive care and hematopoietic-stem-cell transplantation. The positive clinical experience seen in MDS to date coupled with the persistent challenges faced in the treatment of other hematologic malignancies has served as the impetus for further exploration of the therapeutic value of DNMT inhibitors beyond MDS. In that respect, the majority of data for these agents are in the setting of acute myelogenous leukemia (AML). Experience with these agents in patients with refractory anemia with excess blasts in transformation (reclassified by the World Health Organization as AML) was also reported in the clinical trials submitted to the FDA for approval of azacitidine for MDS. Some use has also been described in chronic myelogenous leukemia and acute lymphocytic leukemia. Further studies are needed to clarify the appropriate dose and the number and duration of cycles in the treatment of leukemias, and to identify ideal candidates for therapy, explore the role of DNMT inhibitors in combination with other agents, especially histone deacetylase inhibitors, delineate differences between the commercially available agents, and establish the long-term safety of these agents. To this end, experience with DNMT inhibitors in hematologic malignancies other than MDS is reviewed in an effort to better understand the therapeutic potential of these agents and to define areas of future exploration in these settings.

Antimetabolites, Antineoplastic↗
PubMed2005

Response assessments in low-risk and high-risk myelodysplastic syndromes (MDS).

The myelodysplastic syndromes (MDS) are a heterogeneous group of hematopoietic disorders that differ with regard to etiology, pathologic and clinical features, treatment, and outcomes. MDS are chronic, progressive diseases that may be broadly categorized into early phase ("low-risk") and late-phase ("high-risk") groups based on prognostic criteria and the differential pathologic and cytogenetic features that drive the MDS phenotype in these disease phases. Consequently, the goals for treatment and management options also differ for low-risk MDS compared with high-risk MDS. Alleviation of disease-related complications, including transfusion requirements, and hematologic improvement are key treatment goals in low-risk MDS. In contrast, altering the natural history of disease, including improvements in overall survival and progression-free survival, are the most important treatment goals in high-risk MDS. To address the heterogeneity of MDS in patient populations enrolled in clinical trials and to resolve problems resulting from variability in the quality and quantity of responses to treatment, the International Working Group has developed standardized response criteria for MDS that are relevant for both low-risk and high-risk categories. The application of the standardized International Working Group response criteria in clinical trials is enabling the comparison of results from various clinical trials in MDS. Furthermore, the International Working Group response criteria provide an important framework for clinical development of new treatments options that may be particularly appropriate for specific MDS subsets.

Clinical Trials as Topic↗
PubMed2005

Outcome of patients less than 55 years of age with high-risk acute leukemia who did not have an human leukocyte antigen-identical related donor: a long-term study of 97 consecutive patients.

Between January 1993 and December 2000, an unrelated donor search (UDS) was initiated for 97 consecutive patients [46 acute lymphoblastic leukemia (ALL) and 51 acute myeloid leukemia (AML)]. Leukemia was considered to be of poor prognosis in cases of refractory disease (n=70), unfavourable karyotype (n=22) or miscellaneous (n=5). All patients had previously received various chemotherapies and 9 had undergone an autologous stem cell transplantation (SCT). The median age at UDS initiation was 25 (range 2.7-55) years. The median time to identify a suitable living donor or cord blood (CB) was 60 days. Eventually, 33 patients received unrelated allo-SCT (including 9 CB), 12 auto-SCT, 39 chemotherapy and 13 palliative treatment. At a median of 54 months, 18 patients were alive, including 15 in remission. The 4-year overall survival rates were 32%, 37%, 15% and 0% for allo-SCT, auto-SCT, chemotherapy or palliative treatment, respectively. Patients who received either allo- or auto-SCT had better survival than those who did not (P<0.0001). For ALL, only allo-SCT significantly improved survival (P<0.007). Finally, patients who received allo-SCT died less often of relapse than patients who did not (P<0.0001). Unrelated allo-SCT gives a substantial long-term survival and cure in patients with high-risk acute leukemia. For patients who achieve remission and for whom UDS fails, auto-SCT may prove to be a good approach. For patients who fail to enter into remission, intensive salvage chemotherapy has a very limited effect.

Adolescent↗
PubMed2005

A non-randomised dose-escalating phase II study of thalidomide for the treatment of patients with low-risk myelodysplastic syndromes: the Thal-SMD-2000 trial of the Groupe Français des Myélodysplasies.

Patients (n=47) with low-risk myelodysplastic syndrome were treated with thalidomide [200 mg/d, increased by 200 mg/d/4 weeks up to week 16]. Responses were evaluated according to the International Working Group criteria at week 16 for 39 patients who received at least 8 weeks of treatment. Twenty-three (59%) patients showed haematological improvement (HI): four major erythroid response (HI-EM), 15 minor erythroid response, six major neutrophil response, two major platelet response. Side effects caused 22/39 to stop thalidomide before week 16. Nine of 23 responders continued thalidomide after week 16 [19% of trial patients] with sustained response in eight of nine. Six reached week 56, including the four HI-EM patients [13% of trial patients]. Nineteen of 36 red blood cell transfusion-dependent patients (53%) showed erythroid response, but only four became transfusion-independent. Among the 23 responders, the median duration of response was 260 d (range 30-650). Responses were sustained in all patients except one, and were observed between week 4 and week 8 in 85% of patients, at doses ranging from 200 to 400 mg. Only two patients responded at 600 mg/d and none at 800 mg/d. No clinical characteristics of responding versus non-responding patients were identified. The erythroid response rate was identical in all cytogenetic subgroups, including 5q31.1 deletions. Pretreatment vascular endothelial growth factor levels were lower in responders compared with non-responders (P=0.004). Microvessel density (MVD) increased and apoptosis decreased in four of six and in all six responders studied respectively whereas MVD and apoptosis were unchanged in three non-responders.

Aged↗
PubMed2005

Mutations of PTPN11 are rare in adult myeloid malignancies.

The PTPN11 gene encodes the phospho-tyrosyine phosphatase protein SHP-2. Constitutional mutations of this gene are involved in Noonan's syndrome, a developmental disorder in which children have a predisposition to develop a myeloid disorder called juvenile myelomonocytic leukemia. Recently, studies have shown that somatic mutations of PTPN11 can be found in children with myeloid malignancies. We evaluated the incidence of acquired mutation of PTPN11 in 76 adults with acute or chronic myeloid malignancies and summarized our results together with others published recently.

Adult↗
PubMed2005

Arsenic trioxide in the treatment of acute promyelocytic leukemia. A review of current evidence.

Recent studies have demonstrated the beneficial effects of arsenic trioxide (ATO) in the treatment of relapsed acute promyelocytic leukemia (APL). The aim of this review is to discuss the role of ATO in the management of APL. Based on the available clinical evidence, a tentative algorithm is proposed for the treatment of patients who relapse after or are refractory to all trans-retinoic acid-based therapy. Other opportunities for the use of ATO in front-line treatment of APL are also discussed, especially its potential use in patients at high risk of relapse and in those with contraindications to chemotherapy or in whom the amount of chemotherapy should be reduced.

Arsenic Trioxide↗
PubMed2004

Supportive care including growth factors in myelodysplastic syndromes.

In spite of recent advances in the treatment of myelodysplastic syndromes (MDS), supportive care remains a very important part of the therapy. Red blood cells transfusions are the most important component of this supportive care. They transiently relieve anemia symptoms and alleviate their effects on quality of life and daily functioning. Platelet transfusion therapy is less frequently needed, at least in low-risk MDS. Dealing with an increased risk of infections linked to neutropenia, mainly by broad spectrum antibiotics, is also needed, more often in advanced stages of [dict: MDS] or when the MDS evolves to acute myeloid leukemia. Chronic red blood cell transfusions expose patients to various side-effects, including blood components intolerance reactions and alloimmunization risks, but also increased frequency of iron overload, a more significant problem in low-risk heavily transfused MDS patients, who have prolonged life expectancy. The use of growth factors is becoming a more and more important part of current supportive care. High-dose erythropoietin is able to reduce or suppress red blood cell transfusions needs in selected subgroups of MDS. The short-term use of granulocyte colony-stimulating factor is also often proposed in infections, although not formally established by prospective trials. Although trials of growth factors with thrombopoeitic activity have been performed with interleukin 11 and are underway with thrombopoeitin, none of them are available for routine use.

Anemia↗
PubMed2004

Outcome of treatment in adults with acute lymphoblastic leukemia: analysis of the LALA-94 trial.

PURPOSE: We analyzed the benefits of a risk-adapted postremission strategy in adult lymphoblastic leukemia (ALL), and re-evaluated stem-cell transplantation (SCT) for high-risk ALL. PATIENTS AND METHODS: A total of 922 adult patients entered onto the trial according to risk groups: standard-risk ALL (group 1), high-risk ALL (group 2), Philadelphia chromosome-positive ALL (group 3), and CNS-positive ALL (group 4). All received a standard four-drug/4-week induction course. Patients from group 1 who achieved a complete remission (CR) after one course of induction therapy were randomly assigned between intensive and less intensive postremission chemotherapy, whereas those who achieved CR after salvage therapy were then included in group 2. Patients in groups 2, 3, and 4 with an HLA-identical sibling were assigned to allogeneic SCT. In groups 3 and 4, autologous SCT was offered to all other patients, whereas in group 2 they were randomly assigned between chemotherapy and autologous SCT. RESULTS: Overall, 771 patients achieved CR (84%). Median disease-free survival (DFS) was 17.5 months, with 3-year DFS at 37%. In group 1, the 3-year DFS rate was 41%, with no difference between arms of postremission randomization. In groups 2 and 4, the 3-year DFS rates were 38% and 44%, respectively. In group 2, autologous SCT and chemotherapy resulted in comparable median DFS. Patients with an HLA-matched sibling (groups 2 and 4) had improved DFS. Three-year DFS was 24% in group 3. CONCLUSION: Allogeneic SCT improved DFS in high-risk ALL in the first CR. Autologous SCT did not confer a significant benefit over chemotherapy for high-risk ALL.

Adolescent↗
PubMed2004

Randomized comparison of double induction and timed-sequential induction to a "3 + 7" induction in adults with AML: long-term analysis of the Acute Leukemia French Association (ALFA) 9000 study.

Between 1990 and 1996, we conducted a randomized trial in adults with newly diagnosed acute myeloid leukemia (AML) in order to compare relapse-free interval (RFI) after double induction (arm B), timed-sequential induction (arm C), or control "3 + 7" induction (arm A). Patients achieving complete remission (CR) after induction +/- salvage received the same consolidation chemotherapy, which included a dosage stratification according to patient's age (younger or older than 50 years). This long-term analysis was performed in 592 patients (arm A/B/C, 197/198/197 patients). Overall CR rate was 76% without differences between the 3 arms, even if a salvage course was less frequently needed in arm B. Treatment-related mortality, either during the induction or the postremission phase, was not significantly higher in arms B and C than in arm A. Among the 449 CR patients, 250 relapsed (arm A/B/C, 90/87/73 patients) without significant differences in RFI in arms B and C versus arm A (P = .39 and .15, by the Gray test). However, when analyzing the 345 patients younger than 50, RFI was significantly improved in younger patients receiving timed-sequential induction (P = .038 by the Gray test), while not in those receiving double induction. Event-free survival and overall survival were similar in the 3 randomization arms.

Adolescent↗
PubMed2004

Health, economic, and quality-of-life effects of erythropoietin and granulocyte colony-stimulating factor for the treatment of myelodysplastic syndromes: a randomized, controlled trial.

In myelodysplastic syndromes (MDS), anemia responds to recombinant human erythropoietin (rHuEPO) alone and in combination with recombinant human granulocyte-colony-stimulating factor (rHuGCSF) in 10% to 20% and in 35% to 40% of patients, respectively. We randomly divided 60 patients with low-grade anemic MDS and serum EPO levels lower than 500 IU/L (500 mU/mL) into 2 groups: rHuEPO + rHuG-CSF (arm A) and supportive care (arm B). After 12 weeks, those who had erythroid responses were given rHuEPO alone for 40 additional weeks. They were also given rHuG-CSF if they had relapses. A response was considered major if the hemoglobin (Hb) level was 115 g/L (11.5 g/dL) or higher and minor Hb increase was 15 g/L (1.5 g/dL) or more or if it remained stable without transfusion. Ten of 24 patients responded in arm A, and 0 of 26 responded in arm B (P =.01). Eight patients in arm A continued rHuEPO therapy alone, and 6 had relapses. Responses were always restored when rHuG-CSF was reintroduced. Mean direct costs per patient were 26,723 euros (arm A) and 8,746 euros (arm B). Quality of life was assessed with a Functional Assessment of Cancer Therapy-Anemia (FACT-An) scale. Similar percentages of patients from both arms showed significant clinical improvement. rHuEPO plus rHuG-CSF led to responses in 41.7% of MDS patients. This treatment was expensive. No effect on quality of life was demonstrated.

Adult↗
PubMed2004

A phase II study of intensive chemotherapy with fludarabine, cytarabine, and mitoxantrone in P glycoprotein-negative high-risk myelodysplastic syndromes.

Since leukemic cells primed by exposure to fludarabine exhibit enhanced accumulation of cytarabine triphosphate (the cytotoxic nucleotide of cytarabine), especially with continuous cytarabine (AraC) infusion, a phase II trial was designed to explore the feasibility and efficacy of a combination chemotherapy associating fludarabine, mitoxantrone (MXN), and high-dose cytarabine (continuous infusion) for high-risk P glycoprotein (PGP)-negative myelodysplastic syndromes (MDS) (FAM protocol). The outcomes of FAM-treated patients were compared with those of 32 PGP-negative MDS patients fulfilling identical inclusion and response criteria treated with MXN+AraC (1 g/m(2)/12 h d(1-5), MA protocol). A total of 29 patients (median age 55 years) were included in the FAM group. Six (21%) died from the procedure, and 16 (55%) achieved complete remission (CR). Of these, nine received consolidation chemotherapy, five were autografted and two were allografted in first CR. Abnormal karyotype was the only factor associated with poor survival. The overall median follow-up was 10.9 months. There was no significant difference between FAM and MA protocols with respect to CR rate, treatment-related mortality, duration of leukopenia, neutropenia, autologous stem cell transplantation feasibility, relapse-free survival, or overall survival. The duration of thrombocytopenia was significantly longer in the FAM protocol. In conclusion, the present results suggest that the combination therapy of fludarabine, MXN, and high-dose AraC does not improve CR rate, survival, or disease-free survival in high-risk MDS.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed2004

Myelodysplastic syndromes: From pathogenesis and prognosis to treatment.

Myelodysplastic syndromes (MDS) are clonal hematologic disorders characterized by ineffective hematopoiesis resulting in peripheral cytopenia and by increased progression to acute myelocytic leukemia (AML). With the exception of allogeneic stem cell transplantation, there is generally no curative treatment for these disorders. As the contribution of diverse pathologic processes to ineffective hematopoiesis in MDS continues to be clarified, promising new avenues for treatment are being identified. Agents that interact with newly defined biologic targets and that are under investigation include arsenic trioxide, DNA methylation inhibitors, farnesyl transferase inhibitors, thalidomide, immunomodulating agents, and histone deacetylase inhibitors.

Antineoplastic Agents↗
PubMed2004

Hydroxyurea-induced apoptosis in an EBV-immortalized lymphoblastoid cell line.

Hydroxyurea (HU) is an inhibitor of nucleotide synthesis extensively used to control the chronic phase of myeloid leukemia. This antimetabolite has been employed in the clinic for several decades but in recent years the leukemogenic potential of HU has been suspected. In the present study, a B-lymphoblastoid cell line transformed by the Epstein-Barr virus was used to investigate the apoptotic effects of HU and delineate some of the molecular pathways implicated in the cytotoxic action. The cell line, characterized by immunophenotyping, cytogenetic and fluorescence in situ hybridization (FISH) studies, showed no chromosomal abnormalities, even after a prolonged exposure to HU. Different flow cytometry assays were used to measure HU-induced impairment of the cell cycle, inhibition of DNA synthesis, and the occurrence of apoptosis. The treatment with HU leads to the appearance of a hypo-diploid DNA content peak (sub-G1) characteristic of the apoptotic cell population. The drug also induces a cell block in S phase as measured by 5-bromo-2'-deoxyuridine (BrdU) incorporation. Inhibition of DNA synthesis precedes induction of apoptosis by HU. A drug-induced loss of plasma membrane asymmetry was characterized by flow cytometry using annexin V-FITC to stain phosphatidylserine residues. The implication of the antiapoptotic protein Bcl-2 and the tumor suppressor p53 in the development of HU-mediated apoptosis was also evidenced. The drug appears to promote cell death by regulating the expression levels of these two proteins. Different criteria define the apoptotic response of the lymphoblastoid cells to the treatment with HU. However, the extent of drug-induced cell death is limited, and no DNA fragmentation and no activation of the caspase cascade was observed in this model. Beyond the specific interest in HU-induced apoptosis, the work reported here illustrates the utility of the EBV immortalization process to investigate the pharmacological activity of specific drugs from clinical samples.

Apoptosis↗
PubMed2003

Prognosis of inv(16)/t(16;16) acute myeloid leukemia (AML): a survey of 110 cases from the French AML Intergroup.

Acute myeloid leukemias (AMLs) carrying inv(16)/t(16;16) chromosomal abnormalities are associated with a good prognosis. However, studies of this AML subtype have been hampered by the few number of patients reported, frequently collectively considered with those with AML carrying the t(8;21) translocation. We performed a retrospective study in 110 patients with inv(16)/t(16;16) AML (median age, 34 years) prospectively enrolled in 6 trials conducted in France between 1987 and 1998, with the aim to investigate prognostic factors for complete remission (CR) achievement and outcome of CR patients in this AML subtype. CR rate was 93%. Bad-prognosis factors for CR achievement were higher white blood cell count (WBC) and lower platelet count (optimal cutpoints at 120 and 30 x 109/L, respectively). At 3 years, estimated overall survival, disease-free survival (DFS), and cumulative incidence of relapse were 58%, 48%, and 42%, respectively. In multivariate analysis, (1) advanced age (optimal cutpoint, 35 years) was the only factor for shorter DFS and (2) advanced age and low platelet count were the 2 factors for shorter survival of CR patients. Outcome of CR patients (1) was not influenced by WBC and cytogenetic findings and (2) was similar among patients allocated to receive allogeneic transplantation, high-dose, or intermediate-dose cytarabine. Interestingly, advanced age was associated with a trend for more frequent additional chromosome abnormalities and predictive of higher cumulative incidence of relapse rather than death in first CR. These results markedly contrast with those reported in patients with t(8;21) AML in whom WBC, and not age, was the main high-risk factor for relapse, DFS, and survival.

Adolescent↗