References of "BARON, Frédéric"
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See detailTandem high-dose therapy (HDT) for multiple myeloma: recombinant human erythropoietin therapy given between first and second HDT allows second peripheral blood stem cell transplantation without red blood cell transfusion.
Baron, Frédéric ULg; Frere, Pascale ULg; Fillet, Georges ULg et al

in British Journal of Haematology (2003), 123(1), 103-5

We evaluated the ability of recombinant human erythropoietin (rHuEpo) therapy, given before high-dose therapy (HDT), to allow autologous peripheral blood stem cell transplantation (PBSCT) without red ... [more ▼]

We evaluated the ability of recombinant human erythropoietin (rHuEpo) therapy, given before high-dose therapy (HDT), to allow autologous peripheral blood stem cell transplantation (PBSCT) without red blood cell (RBC) transfusions. Eleven multiple myeloma patients underwent tandem HDT and autologous PBSC, receiving 500 U/kg/week rHuEpo from d 30 after initial transplant. Haemoglobin levels were 9.5 +/- 1.1 g/dl and 12.5 +/- 0.9 g/dl at the first and second transplant respectively (P < 0.001). RBC transfusions were required for 10/11 patients for the first transplant versus 1/11 for the second (P < 0.001). To conclude, a short course of rHuEpo therapy before HDT facilitates the performance of an autologous transplant without RBC transfusions. [less ▲]

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See detailRecombinant human erythropoietin therapy is very effective after an autologous peripheral blood stem cell transplant when started soon after engraftment.
Baron, Frédéric ULg; Frere, Pascale ULg; Fillet, Georges ULg et al

in Clinical Cancer Research : An Official Journal of the American Association for Cancer Research (2003), 9(15), 5566-72

PURPOSE: Previous trials of recombinant human erythropoietin (rHuEpo) therapy after autologous hematopoietic stem cell transplantation have administered very high doses of i.v. rHuEpo starting on day 1 ... [more ▼]

PURPOSE: Previous trials of recombinant human erythropoietin (rHuEpo) therapy after autologous hematopoietic stem cell transplantation have administered very high doses of i.v. rHuEpo starting on day 1 and continuing for 1-2 months until erythroid engraftment and have shown no benefit of rHuEpo therapy. We sought to establish a more effective use of rHuEpo in this setting. EXPERIMENTAL DESIGN: In this report, we show in a first cohort of 45 lymphoma or myeloma patients undergoing peripheral blood stem cell transplant (control group) that endogenous erythropoietin levels are high for the degree of anemia during the first 3 weeks after transplant but become adequate or slightly decreased thereafter. We thus enrolled 41 consecutive similar patients in a trial of rHuEpo therapy at a dose of 500 units/kg/week started on day 30 after the transplant. RESULTS: The 12-week probability of achieving hemoglobin (Hb) levels of 13 g/dl was 87% in rHuEpo-treated patients versus 14% in controls (P = 0.0001). Mean Hb levels were significantly higher in the rHuEpo group than in the control group from day 42 through day 150 after transplant (Ps of <0.05 to <0.001). Two of 41 patients in the rHuEpo group versus 12 of 45 patients in the control group had Hb levels of <9 g/dl between day 42 and day 100 after the transplant (P = 0.0078). CONCLUSIONS: Anemia after autologous peripheral blood stem cell transplant is exquisitely sensitive to rHuEpo when therapy is started soon after engraftment. This is the first convincing report showing that rHuEpo is effective in this setting. Our data set the stage for a more rational use of rHuEpo after autologous hematopoietic stem cell transplantation and should renew interest in erythropoietin therapy in this setting. Prospective, randomized trials should investigate the impact of rHuEpo therapy on transfusion requirements and quality of life. [less ▲]

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See detailTransmission of chronic myeloid leukemia through peripheral-blood stem-cell transplantation.
Baron, Frédéric ULg; Dresse, Marie-Françoise; Beguin, Yves ULg

in New England Journal of Medicine [=NEJM] (2003), 349(9), 913-4

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See detailLow T-cell chimerism is not followed by graft rejection after nonmyeloablative stem cell transplantation (NMSCT) with CD34-selected PBSC.
Baron, Frédéric ULg; Baudoux, Etienne ULg; Frere, Pascale ULg et al

in Bone Marrow Transplantation (2003), 32(8), 829-34

We investigate the feasibility of CD34-selected peripheral blood stem cell (PBSC) transplantation followed by pre-emptive CD8-depleted donor lymphocyte infusions (DLI) after a minimal conditioning regimen ... [more ▼]

We investigate the feasibility of CD34-selected peripheral blood stem cell (PBSC) transplantation followed by pre-emptive CD8-depleted donor lymphocyte infusions (DLI) after a minimal conditioning regimen. Six patients with advanced hematological malignancies ineligible for a conventional myeloablative transplant (n=5) or metastatic renal cell carcinoma (n=1), and with an HLA-identical (n=4) or alternative (n=2) donor were included. The nonmyeloablative conditioning regimen consisted in 2 Gy TBI alone (n=4), 2 Gy TBI and fludarabine (RCC patient, n=1) or cyclophosphamide and fludarabine (patient who had previously received 12 Gy TBI, n=1). Post transplant immunosuppression was carried out with cyclosporin (CyA) and mycophenolate mofetil (MMF). Initial engraftment was achieved in all patients. One out of six patients (17%) experienced grade > or =2 acute GVHD only after abrupt cyclosporin discontinuation and alpha interferon therapy for life-threatening tumor progression. T-cell chimerism was 23% (19-30) on day 28, 32% (10-35) on day 100, 78% (49-95) on day 180 and 99.5% (99-100) on day 365. Three out of four patients who had measurable disease before the transplant experienced a complete response. We conclude that CD34-selected NMSCT followed by CD8-depleted DLI is feasible and preserves engraftment and apparently also the graft-versus-leukemia (GVL) effect. Further studies are needed to confirm this encouraging preliminary report. [less ▲]

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See detailT-cell reconstitution after unmanipulated, CD8-depleted or CD34-selected nonmyeloablative peripheral blood stem-cell transplantation.
Baron, Frédéric ULg; Schaaf-Lafontaine, Nicole ULg; Humblet-Baron, Stéphanie ULg et al

in Transplantation (2003), 76(12), 1705-13

BACKGROUND: We have previously shown that CD8 depletion or CD34 selection of peripheral blood stem cells (PBSC) reduced the incidence of acute graft-versus-host disease (GvHD) after nonmyeloablative stem ... [more ▼]

BACKGROUND: We have previously shown that CD8 depletion or CD34 selection of peripheral blood stem cells (PBSC) reduced the incidence of acute graft-versus-host disease (GvHD) after nonmyeloablative stem-cell transplantation (NMSCT). In this study, we analyze the effect of CD8 depletion or CD34 selection of the graft on early T-cell reconstitution. METHODS: Nonmyeloablative conditioning regimen consisted in 2 Gy total-body irradiation (TBI) alone, 2 Gy TBI and fludarabine, or cyclophosphamide and fludarabine. Patients 1 to 18 received unmanipulated PBSC, patients 19 to 29 CD8-depleted PBSC, and patients 30 to 35 CD34-selected PBSC. RESULTS: T-cell counts, and particularly CD4+ and CD4CD45RA+ counts, remained low the first 6 months after nonmyeloablative stem-cell transplantation (NMSCT) in all patients. CD34 selection (P<0.0001) but not CD8 depletion of PBSC significantly decreased T-cell chimerism. Donor T-cell count was similar in unmanipulated compared with CD8-depleted PBSC recipients but was significantly lower in CD34-selected PBSC recipients (P=0.0012). T cells of recipient origin remained stable over time in unmanipulated and CD8-depleted PBSC patients but expanded in some CD34-selected PBSC recipients between day 28 and 100 after transplant. Moreover, whereas CD8 depletion only decreased CD8+ counts (P<0.047), CD34 selection reduced CD3+(P<0.001), CD8+(P<0.016), CD4+ (P<0.001), and CD4+CD45RA+ (P<0.001) cell counts. T-cell repertoire was restricted in all patients on day 100 after hematopoietic stem-cell transplantation but was even more limited after CD34 selection (P=0.002). CONCLUSIONS: Despite of the persistence of a significant number of T cells of recipient origin, T-cell counts were low the first 6 months after NMSCT. Moreover, contrary with CD8 depletion of the graft that only affects CD8+ lymphocyte counts, CD34 selection dramatically decreased both CD8 and CD4 counts. [less ▲]

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See detailComment je traite ... la leucemie myeloide chronique (LMC).
Hafraoui, Kaoutar ULg; Humblet-Baron, Stéphanie ULg; Baron, Frédéric ULg et al

in Revue Médicale de Liège (2003), 58(1), 7-12

This review article describes the identification of the tyrosine kinase BCR/ABL as the hallmark of chronic myeloid leukemias (CML) as well as the development of a specific inhibitor of this tyrosine ... [more ▼]

This review article describes the identification of the tyrosine kinase BCR/ABL as the hallmark of chronic myeloid leukemias (CML) as well as the development of a specific inhibitor of this tyrosine kinase, the STI571 (Glivec, imatinib mesylate). The authors discuss the results of a phase I and three phase II trials reporting the efficacy of STI571 as treatment for CML patients and propose two simplified algorithms that may help to guide decision-making for the individual patient. [less ▲]

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See detailClonal chromosome aberrations in Philadelphia-negative cells from chronic myelocytic leukemia patients treated with imatinib mesylate: report of two cases.
Herens, Christian ULg; Baron, Frédéric ULg; Croisiau, Christiane et al

in Cancer Genetics & Cytogenetics (2003), 147(1), 78-80

Imatinib mesylate (tested as STI571), an abl kinase inhibitor, induces sustained, complete hematologic and cytogenetic responses in chronic myelocytic leukemia (CML) patients; however, emergence of clonal ... [more ▼]

Imatinib mesylate (tested as STI571), an abl kinase inhibitor, induces sustained, complete hematologic and cytogenetic responses in chronic myelocytic leukemia (CML) patients; however, emergence of clonal chromosomal aberrations in Philadelphia-negative (Ph-) cells during treatment has been reported. We describe two CML patients in chronic phase who presented with complete cytogenetic responses during imatinib mesylate therapy but developed new clonal chromosomal rearrangements in Ph- cells. The first patient presented with a duplication of chromosome 1, dup(1)(q21q42), and the second showed two new clonal aberrations consisting of inv(1)(q12q32) and del(7)(q22) in the same clone. [less ▲]

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See detailTraitement moléculaire du cancer: le STI571, un inhibiteur des tyrosines kinases
Humblet-Baron, Stéphanie ULg; Baron, Frédéric ULg; Pirson, Laurence ULg et al

in Revue Médicale Suisse (2002), 60(598), 1504-1508

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See detailLeukemic target susceptibility to natural killer cytotoxicity: relationship with BCR-ABL expression.
Baron, Frédéric ULg; Turhan, Ali G; Giron-Michel, Julien et al

in Blood (2002), 99(6), 2107-13

Chronic myeloid leukemia is a clonal myeloproliferative expansion of transformed primitive hematopoietic progenitor cells characterized by high-level expression of BCR-ABL chimeric gene, which induces ... [more ▼]

Chronic myeloid leukemia is a clonal myeloproliferative expansion of transformed primitive hematopoietic progenitor cells characterized by high-level expression of BCR-ABL chimeric gene, which induces growth factor independence. However, the influence of BCR-ABL expression on cell-mediated cytotoxicity is poorly understood. In the present study, we asked whether BCR-ABL expression interferes with leukemic target sensitivity to natural killer (NK) cell cytolysis. Our approach was based on the use of 2 BCR-ABL transfectants of the pluripotent hematopoietic cell line UT-7 expressing low (UT-7/E8, UT-7/G6) and high (UT-7/9) levels of BCR-ABL. As effector cells, we used CD56(bright), CD16-, CD2- NK cells differentiated in vitro from CD34 cord blood progenitors. We demonstrated that BCR-ABL transfectants UT-7/9 were lysed by NK cells with a higher efficiency than parental and low UT-7/E8.1 and UT-7/G6 transfectants. This enhanced susceptibility to lysis correlated with an increase in expression of intercellular adhesion molecule 1 (ICAM-1) by target cells. Treatment of UT-7/9 cells by STI571 (a specific inhibitor of the abl kinase) resulted in a decrease in NK susceptibility to lysis and ICAM-1 down-regulation in target cells. Furthermore, the constitutive activation of nuclear factor-kappaB (NF-kappaB) detected in BCR-ABL transfectant UT-7/9, was significantly attenuated when cells were treated by STI571. Interestingly, inhibition of NF-kappaB activation by BAY11-67082 (a specific NF-kappaB inhibitor) resulted in down-regulation of ICAM-1 expression and a subsequent decrease in NK-induced killing of UT-7/9 transfectants. Our results show that oncogenic transformation by BCR-ABL may increase susceptibility of leukemic progenitors to NK cell cytotoxicity by a mechanism involving overexpression of ICAM-1 as a consequence of NF-kappaB activation. [less ▲]

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See detailPre-emptive immunotherapy with CD8-depleted donor lymphocytes after CD34-selected allogeneic peripheral blood stem cell transplantation.
Baron, Frédéric ULg; Siquet, Jean; Schaaf-Lafontaine, Nicole ULg et al

in Haematologica (2002), 87(1), 78-88

BACKGROUND AND OBJECTIVES: To maximize graft-versus-leukemia (GVL) effects while minimizing the risk of graft-versus-host disease (GVHD), we undertook a study of allogeneic CD34-selected peripheral blood ... [more ▼]

BACKGROUND AND OBJECTIVES: To maximize graft-versus-leukemia (GVL) effects while minimizing the risk of graft-versus-host disease (GVHD), we undertook a study of allogeneic CD34-selected peripheral blood stem cell (PBSC) transplantation followed by CD8-depleted donor lymphocyte infusion (DLI). DESIGN AND METHODS: Twenty-four patients with advanced hematologic malignancies were included. PBSC were collected in matched (N=16) or one-mismatch (N=8) related donors and CD34-selected. On day 60, donors donated lymphocytes that were CD8-depleted and separated into 3 aliquots containing 2 x 10(6), 1 x 10(7) and 5 x 10(7) CD3+ cells/kg (patients 1-13) or into 2 aliquots containing 1 x 10(7) and 5 x 10(7) CD3+ cells/kg (patients 14-24). The 1st aliquot was infused on day 60 and the other 1 (2) cryopreserved and infused on days 100 (and 140). RESULTS: An average of 100%, 100% and 84% of the scheduled dose could be administered in DLI 1, 2 and 3, respectively. Although the study group was at very high risk of GVHD, the actuarial incidence of grade II-IV acute GVHD was 28% (13% for HLA-identical siblings) with only 1 patient developing grade III-IV GVHD (after DLI). The actuarial 2-year probability of extensive chronic GVHD was similarly low (13% for all patients and 0% for HLA-identical siblings). Individual cases as well as a 30% relapse rate (0% for standard-risk patients versus 55% for high-risk patients) indicated preservation of the GVL effect. INTERPRETATION AND CONCLUSIONS: We conclude that allogeneic transplantation of CD34-selected PBSC followed by pre-emptive CD8-depleted DLI is feasible with rapid engraftment and minimizes the risk of severe GVHD. Large prospective trials are required to prove that it preserves the GVL effect fully. [less ▲]

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See detailOptimization of recombinant human erythropoietin therapy after allogeneic hematopoietic stem cell transplantation.
Baron, Frédéric ULg; Sautois, Brieuc ULg; Baudoux, Etienne ULg et al

in Experimental hematology (2002), 30(6), 546-54

OBJECTIVE: Allogeneic hematopoietic stem cell transplantation (HSCT) is associated with prolonged anemia caused by defective erythropoietin (Epo) production. We enrolled 34 recipients of an allogeneic ... [more ▼]

OBJECTIVE: Allogeneic hematopoietic stem cell transplantation (HSCT) is associated with prolonged anemia caused by defective erythropoietin (Epo) production. We enrolled 34 recipients of an allogeneic HSCT in three consecutive trials to determine the optimal utilization of recombinant human erythropoietin (rhEpo) therapy in this setting. MATERIALS AND METHODS: In the first trial (n = 7), rhEpo 1400 U/kg/week was given from day 1 until a hemoglobin (Hb) level of 10 g/dL was achieved, for a maximum of 60 days. In the second trial, rhEpo 500 U/kg/week was given to achieve Hb levels of 13 to 14 g/dL in 13 anemic patients with fatigue 56 to 1440 days after transplant. In the third trial, rhEpo was scheduled to start on day 35 in 14 patients at a dose of 500 U/kg/week with the aim of achieving Hb levels of 13 to 14 g/dL. RESULTS: In trial 1, erythroid recovery to 1% reticulocytes and red blood cell transfusion independence were faster, but the number of transfusions was not reduced compared to 10 controls. Responses were brisk in trial 2, with transfusion independence achieved after a median of 1 week in 12 of 13 patients, and 2-g Hb increments or Hb values of 11, 12, and 13 g/dL after 6, 7, 10, and 10 weeks, respectively. Transfusions were significantly reduced in the first month of rhEpo therapy. In trial 3, transfusion independence was obtained after a median of 1 week in 13 of 14 patients, and 2-g Hb increments or Hb values of 11, 12, and 13 g/dL after 3, 4, 6, and 8 weeks, respectively. Transfusions rates were considerably reduced compared to the previous month in the same patients or compared to controls undergoing peripheral blood or marrow transplant without rhEpo. CONCLUSIONS: Anemia after allogeneic HSCT is exquisitely sensitive to rhEpo. The benefit is minimal when it is given early post-transplant, as used in all trials to date. However, the rate of major response is greater than 90% when rhEpo is started after day 35. These data provide the basis on which to conduct a prospective, randomized, placebo-controlled trial of rhEpo therapy after allogeneic HSCT. [less ▲]

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See detailErythropoiesis after nonmyeloablative stem-cell transplantation is not impaired by inadequate erythropoietin production as observed after conventional allogeneic transplantation.
Baron, Frédéric ULg; Fillet, Georges ULg; Beguin, Yves ULg

in Transplantation (2002), 74(12), 1692-6

BACKGROUND: It is now well established that after conventional allogeneic hematopoietic stem-cell transplantation (HSCT), erythropoietic recovery is impaired because erythropoietin (Epo) production ... [more ▼]

BACKGROUND: It is now well established that after conventional allogeneic hematopoietic stem-cell transplantation (HSCT), erythropoietic recovery is impaired because erythropoietin (Epo) production remains inadequate for prolonged periods of time. However, erythropoietic reconstitution after nonmyeloablative SCT (NMSCT) has never been characterized. METHODS: Twelve patients received a nonmyeloablative conditioning regimen consisting of 2 Gy total body irradiation (TBI) alone (n=6), 2 Gy TBI and fludarabine (n=3), or cyclophosphamide and fludarabine (n=3), followed by transplantation of allogeneic peripheral blood stem cells. Graft-versus-host-disease (GvHD) prophylaxis was carried out with mycophenolate mofetil (from day -1 to day 28) plus cyclosporine (from day -1 to day 120 or longer in case of chronic GvHD). Erythropoiesis was quantitated by soluble transferrin receptor (sTfR) levels, and the adequacy of Epo production was evaluated by the observed-to-predicted Epo ratio (O/P Epo). RESULTS: Mean sTfR levels decreased following the conditioning regimen but remained well within the normal range throughout the posttransplant period. The O/P Epo ratio presented an initial surge quite similar to that observed after conventional conditioning. Thereafter, the O/P Epo ratio normalized rapidly, and Epo levels remained adequate during the whole observation period. CONCLUSION: Contrarily to what is observed after myeloablative transplant, Epo levels remained adequate after NMSCT, resulting in normal erythropoiesis. These results suggest that the administration of erythropoietin therapy (rHuEpo) could be less effective after NMSCT than after conventional allogeneic transplant. [less ▲]

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See detailPreemptive cellular immunotherapy after T-cell-depleted allogeneic hematopoietic stem cell transplantation.
Baron, Frédéric ULg; Beguin, Yves ULg

in Biology of Blood & Marrow Transplantation (2002), 8(7), 351-9

GVHD is a life-threatening complication of allogeneic hematopoietic stem cell transplantation (HSCT). GVHD is due to donor lymphocytes that are cotransplanted with donor stem cells. These donor ... [more ▼]

GVHD is a life-threatening complication of allogeneic hematopoietic stem cell transplantation (HSCT). GVHD is due to donor lymphocytes that are cotransplanted with donor stem cells. These donor lymphocytes are primed by histocompatibility differences between donors and recipients and activated by a cytokine storm caused by the conditioning regimen. The most efficient method for prevention of GVHD consists of T-cell depletion (TCD) of the graft. However, TCD usually leads to an increased risk of leukemia relapse because of the loss of the graft-versus-leukemia (GVL) effect. Several groups have studied the feasibility of preemptive donor lymphocyte infusion (DLI) to lessen the impact of TCD on leukemia relapse. Preemptive DLI is given several weeks to months after the transplantation, ie, after the cytokine storm and after the patient has recovered from conditioning-regimen-related toxicities. After briefly discussing various techniques of TCD of the graft and the efficacy of DLI, this article reviews the first clinical studies evaluating a strategy of TCD of the graft followed by preemptive DLI. [less ▲]

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See detailNonmyeloablative allogeneic hematopoietic stem cell transplantation.
Baron, Frédéric ULg; Beguin, Yves ULg

in Journal of Hematotherapy & Stem Cell Research (2002), 11(2), 243-63

Allogeneic hematopoietic stem cell transplantation (HSCT) is the most effective treatment for selected hematological malignancies. Its curative potential is largely mediated by an immune-mediated ... [more ▼]

Allogeneic hematopoietic stem cell transplantation (HSCT) is the most effective treatment for selected hematological malignancies. Its curative potential is largely mediated by an immune-mediated destruction of malignant cells by donor lymphocytes termed graft-versus-leukemia (GVL) effect. However, because of its toxicity, conventional allogeneic HSCT is restricted to younger and fitter patients. These observations led several groups to set up new (less toxic) transplant protocols (nonmyeloablative stem cell transplantation or NMSCT) based on a two-step approach: first, the use of immunosuppressive (but nonmyeloablative) preparative regimens providing sufficient immunosuppression to achieve engraftment of allogeneic hematopoietic stem cells and, in a second step, destruction of malignant cells by the GVL effect. Preliminary results showed that NMSCT were feasible with a relatively low transplant-related mortality (TRM), even in patients older than 65 years. In addition, strong antitumor responses were observed in several hematological malignancies as well as in some patients with renal cell carcinoma. After discussing the mechanisms and efficacy of the GVL effect as well as the rationale for NMSCT strategies, this article reviews the first results of ongoing clinical trials. Innovative modalities that may permit amplification of the GVL effect while minimizing the risk of GVHD are discussed. Because the benefits of NMSCT over alternative forms of treatment remain to be demonstrated, this strategy should be restricted to patients included in clinical trials. [less ▲]

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