Biomedical subjects

Camille N Abboud

Publications and source records attributed to Camille N Abboud.

11 recordsLinked to original sources

PubMed2026

Consolidation Therapy Based on Mutation Clearance in Acute Myeloid Leukemia.

BACKGROUND: Optimal consolidation therapy for patients with intermediate-risk acute myeloid leukemia (AML) in first complete remission (CR1) is controversial. Retrospective studies have suggested that the clearance of leukemia-associated mutations (LAMs) in CR1 may predict lower relapse risk and better outcomes with high-dose cytarabine (HiDAC) consolidation. We tested this hypothesis prospectively. METHODS: We performed a phase II, multicenter study of intermediate-risk, transplant-eligible, de novo AML in patients 18-60 years of age who achieved a complete remission (CR) or CR with incomplete count recovery (CRi) after induction therapy. Tumor and normal whole-exome sequencing was performed at presentation to identify somatic LAMs (median ∼30 LAMs/patient). In remission marrow samples, LAM variant allele frequencies (VAFs) were then remeasured using a VAF cutoff of less than 2.5% to define clearance. Patients who met this LAM clearance threshold received HiDAC consolidation, whereas those with persistent LAMs (VAF ≥2.5%) were recommended to undergo allogeneic hematopoietic cell transplantation. The primary endpoint compared relapse-free survival (RFS) of intermediate-risk patients with complete LAM clearance to historical cohorts with intermediate-risk AML who received HiDAC-based regimens in CR1. To account for an unplanned interim assessment, the significance threshold for the primary analysis was 0.01. RESULTS: Among 100 patients who were evaluated, intermediate-risk patients who cleared all LAMs in CR1 (n=33) had a median RFS of 33.1 months (95% confidence interval, 11.7-NA) compared to a median RFS of 11.7 months in the historical cohort (n=239; 95% confidence interval, 9.9-15.6, P=0.015). CONCLUSIONS: Among patients with intermediate-risk AML, clearance of LAMs after induction, followed by HiDAC consolidation in CR1, was associated with longer RFS compared with similarly treated historical controls. Although this result did not meet the prespecified threshold for statistical significance, the reported association sets the stage for a randomized trial to further evaluate this strategy. (ClinicalTrials.gov number, NCT02756962.).

Humans↗

PubMed2026

Magrolimab Plus Azacitidine Versus Placebo Plus Azacitidine in Patients With Untreated Higher-Risk Myelodysplastic Syndromes: The Phase III ENHANCE Study.

PURPOSE: To evaluate the efficacy and safety of the cluster of differentiation 47-targeted antibody magrolimab plus azacitidine (Magro/Aza) versus azacitidine alone in treatment-naïve patients with higher-risk myelodysplastic syndromes (MDS) in the phase III ENHANCE study (ClinicalTrials.gov identifier: NCT04313881). METHODS: Based on the Revised International Prognostic Scoring System, patients with intermediate- to very-high-risk MDS were randomly assigned to receive Magro (1 mg/kg on days [D]1 and 4; 15 mg/kg on D8; 30 mg/kg on D11 and D15, and then once per week for five doses, followed by 30 mg/kg maintenance doses once every 2 weeks)/Aza (75 mg/m2 daily on D1-7 or on D1-5 and 8-9 in 28-day cycles) or matched placebo plus azacitidine (Placebo/Aza). Dual primary end points were complete remission (CR) rate (per 2006 International Working Group criteria) and overall survival (OS). RESULTS: At final analysis, 539 patients were randomly assigned to Magro/Aza (n = 268) or Placebo/Aza (n = 271) arms. Baseline characteristics were generally well balanced between treatment arms. In the Magro/Aza versus Placebo/Aza arms, the CR rate was 21.3% versus 23.6% (odds ratio, 0.876 [95% CI, 0.585 to 1.312]; P = .5218), and median OS was 15.9 versus 18.6 months (hazard ratio, 1.203 [95% CI, 0.947 to 1.528]; P = .1299). Magro/Aza had a higher incidence of grade ≥3 adverse events (AEs; 92.8% v 79.2%), AE-associated study drug discontinuations (24.0% v 12.1%), serious AEs (71.9% v 51.5%), and fatal AEs (15.2% v 9.8%) versus Placebo/Aza. CONCLUSION: ENHANCE did not meet the primary end points of CR rate and OS, and showed more frequent severe AEs in patients treated in the Magro/Aza arm.

Humans↗

PubMed2005

Apoptosis and complement-mediated lysis of myeloma cells by polyclonal rabbit antithymocyte globulin.

Current monoclonal antibody therapies for multiple myeloma have had limited success, perhaps due to narrow target specificity. We have previously described the ability of polyclonal rabbit antithymocyte globulin (rATG) to induce caspase- and cathepsin-mediated apoptosis in human B and plasma cells. We now extend this observation to myeloma cells. Complement independent cell death was measured after addition of rATG (1-1000 microg/mL) to cultures of myeloma cell lines or primary CD138+ isolates from patient bone marrow aspirates. rATG induced significant levels of apoptosis in myeloma cells as assayed by caspase induction, annexin V binding, subdiploid DNA fragmentation, plasma-membrane permeability, and loss of mitochondrial-membrane potential. Addition of complement greatly augmented myeloma-cell death. Binding of rATG to individual myeloma cell-surface proteins, primarily CD38, CD52, CD126, and CD138, was demonstrated by competitive inhibition experiments with targeted monoclonal antibodies. Three pathways of cell death were identified involving caspase activation, cathepsin D, and the genistein sensitive tyrosine kinase pathway. Fab'2 fragments of rATG had reduced proapoptotic activity, which was restored by coincubation with Fc fragments, and anti-CD32 or anti-CD64 antibodies. We conclude that rATG is an effective agent for in vitro induction of apoptosis in multiple myeloma, and that exploratory clinical trials may be warranted.

Animals↗

PubMed2005

Mini-BEAM and autologous hematopoietic stem-cell transplant for treatment of post-transplant lymphoproliferative disorders.

Post-transplant lymphoproliferative disorder (PTLD) represents a spectrum of lymphoid proliferative diseases seen as result of immunosuppression in recipients of solid organ or hematopoietic stem-cell transplantation. Options of treatment include reduction or discontinuation of immunosuppressive agents, antiviral drugs, rituximab, chemotherapy, and radiation. We report two unique cases of PTLD (CNS and plasmacytoma-like) treated successfully with salvage chemotherapy, mini-BEAM chemotherapy, and autologous stem-cell transplant. In both cases, patients were also treated with sirolimus and prednisone as immunosuppression, and neither patient rejected their solid organ transplants. With over 30 months of follow-up, both patients remain in complete remission with excellent allograft function.

Adult↗

PubMed2005

Acute myelogenous leukemia--microenvironment interactions: role of endothelial cells and proteasome inhibition.

How leukemia progenitors interact with marrow microenvironment components is poorly understood. In this work, the effects of endothelial coculture on acute myelogenous leukemia (AML) blast survival is examined as are the effects of endothelial coculture on the impact of a cytotoxic agent such as cytarabine. Similar to marrow stromal cells, endothelial cells are able to increase survival and proliferation of AML blasts and to partially protect against cytarabine effects. The proteasome inhibitor, bortezomib, has inhibitory effects in multiple myeloma in part through effects on marrow stromal cells. Bortezomib has been found to inhibit AML blast survival. Such inhibition is less, however, in the presence of endothelial monolayers. Furthermore, AML blast transmigration through human umbilical vein endothelial cells is inhibited by bortezomib. These studies demonstrate that AML is subject to influence of endothelial cells and of agents such as bortezomib which have potential impact on AML interaction with the microenvironmental niche.

Apoptosis↗

PubMed2004

Donor cell myelodysplastic syndrome after allogeneic stem cell transplantation responding to donor lymphocyte infusion: case report and literature review.

Allogeneic hematopoietic stem cell transplantation (SCT) is a potentially curative treatment for patients with myelodysplastic syndrome (MDS). Relapses after transplantation however, are not uncommon and are usually due to re-emergence of a recipient derived, neoplastic, stem cell clone. We report a unique case of MDS recurring 5 months after non-myeloablative, sibling, allogeneic SCT. Interestingly, chimerism analysis at relapse showed hematopoiesis to be entirely of donor origin confirming donor cell MDS. Donor lymphocyte infusion (DLI) produced a hematological response lasting several months. Our review of the literature shows donor-derived MDS to be very rare, with only four such cases described previously. In this report, we describe the details of our case and discuss putative mechanisms underlying the genesis of donor cell MDS and the observed response to DLI.

Anemia, Refractory↗

PubMed2003

A phase 3 study of three induction regimens and of priming with GM-CSF in older adults with acute myeloid leukemia: a trial by the Eastern Cooperative Oncology Group.

The optimal induction for older adults with acute myeloid leukemia (AML) is unknown. Several anthracyclines have been proposed, but the data remain equivocal. Additionally, few prospective trials of priming with hematopoietic growth factors to cycle leukemia cells prior to induction chemotherapy have been conducted. Three hundred and sixty-two older adults with previously untreated AML were randomized to either daunorubicin, idarubicin or mitoxantrone with a standard dose of cytarabine as induction therapy. In addition, 245 patients were also randomized to receive granulocyte-macrophage colony-stimulating factor (GM-CSF) or placebo beginning 2 days prior to induction chemotherapy and continuing until marrow aplasia. No difference was observed in the disease-free overall survival or in toxicity among patients receiving any of the 3 induction regimens or among those receiving growth factor or placebo for priming. However, the complete remission rate for the first 113 analyzable patients, who did not participate in the priming study and started induction therapy 3 to 5 days earlier than those who did, was significantly higher (50% versus 38%; P =.03). None of the anthracyclines is associated with improved outcome in older adults. Priming with hematopoietic growth factor did not improve response when compared with placebo. Furthermore, delaying induction therapy in older adults may lead to a lower complete remission rate.

Aged↗

PubMed2003

Flavonoid effects on normal and leukemic cells.

Quercetin and flavopiridol, both flavonoids which influence oxidative milieu, proliferation, and apoptosis of various cell types, were examined for their effects on acute myelogenous leukemic cells and normal progenitors. Both quercetin and flavopiridol inhibited the growth and viability of various acute myelogenous leukemia (AML) cell lines and AML blasts isolated afresh from patients with AML of various subtypes. The effects on inhibition of proliferation and decreased viability were also significant in normal CD34+ cells isolated from normal marrow donors. In certain AML cases, the effects of flavopiridol appeared to be mediated through activation of caspase 3, offering one possible mechanism for the apoptosis evident after exposure to flavopiridol as measured by annexin V expression. These flavonoid compounds might find use in various therapeutic settings in AML.

Adult↗

PubMed2002

Optimal cytokine stimulation for the enhanced generation of leukemic dendritic cells in short-term culture.

Dendritic cells (DCs) are professional antigen presenting cells derived from myeloid or lymphoid precursors. Functional DCs have been generated from the malignant counterpart of these precursor cells. Herein, we describe the generation of DCs from different leukemias and determine the optimal culture conditions with minimal manipulation. Primary leukemic cells were cultured for 1, 3, and 5 days in 11 different cytokine combinations and analyzed for the expression of a mature DC phenotype. Optimal growth and DC characteristics were obtained with GM-CSF, FL, and SCF in 3-5 day cultures, suggesting a practical strategy for the immunotherapy of leukemia.

Acute Disease↗

PubMed2002

The effects of pegylated recombinant human megakaryocyte growth and development factor (PEG-rHuMGDF) on platelet recovery in breast cancer patients undergoing autologous bone marrow transplantation.

OBJECTIVE: To assess the safety and efficacy of pegylated recombinant human megakaryocyte growth and development factor (PEG-rHuMGDF) administered after autologous bone marrow transplantation (ABMT). PATIENTS AND METHODS: Two randomized, double-blind, placebo-controlled studies were done. In the phase 1/2 study, 75 breast cancer patients underwent a bone marrow harvest and myeloablative STAMP V chemotherapy and were randomized to receive placebo or one of three doses of PEG-rHuMGDF. In the phase 3 study, 64 patients were randomized to receive placebo or the minimally effective dose of PEG-rHuMGDF. The study drug was administered daily starting on the day of bone marrow infusion until the platelet count was greater than or equal to 50 x 10(9)/L (without transfusion) or for a maximum of 28 days. All patients received 10 microg/kg/day filgrastim starting on day 2 until neutrophil count recovery. RESULTS: PEG-rHuMGDF appeared to be safe and well tolerated. No significant differences were noted in mortality or disease progression rates. Antibodies to MGDF were not observed. In the phase 1/2 study, the time to platelet recovery to greater than or equal to 20 x 10(9)/L and platelet transfusion requirements were significantly reduced for patients treated with PEG-rHuMGDF compared with placebo (p < 0.05). In the phase 3 study, no significant differences in the kinetics of early thrombopoiesis or platelet transfusions after ABMT were observed. CONCLUSIONS: PEG-rHuMGDF was not consistently efficacious in reducing the duration of severe thrombocytopenia. The maximum platelet counts for PEG-rHuMGDF-treated patients occurred a median of 2 weeks after the last dose of drug, suggesting that the biologic effects of this hematopoietic cytokine are delayed compared with other hematopoietic cytokines.

Adult↗

PubMed2002

Oral valacyclovir versus intravenous acyclovir in preventing herpes simplex virus infections in autologous stem cell transplant recipients.

Patients who are seropositive for herpes simplex virus (HSV) and are undergoing autologous marrow or peripheral blood stem cell transplantation require prophylaxis for HSV infection. Most prophylaxis regimens have used intravenous acyclovir (ACY). Oral valacyclovir (VAL), the L-valyl ester of ACY, can be used to achieve plasma concentrations equivalent to levels achieved with intravenous ACY. In this study, adults undergoing autologous stem cell transplantation were randomized to receive ACY, 250 mg/m2 intravenously (IV) every 12 hours from day 0 to engraftment, or VAL, 1 g orally every 12 hours from day 0 to engraftment. The primary study objective was to compare cost of HSV prophylaxis between study groups. Thirty patients were randomized to receive either oral VAL (n = 14) or IV ACY (n = 16) prophylaxis. Mean pharmacy cost of HSV prophylaxis in the patient group randomized to IV ACY was $1080 versus $320 for the group randomized initially to VAL. This study demonstrates the feasibility and significant cost savings of using oral VAL for HSV prophylaxis.

Acyclovir↗