Differences in ex-vivo Chemosensitivity to Anthracyclines in First Line Acute Myeloid Leukemia.

BACKGROUND: Induction schedules in acute myeloid leukemia (AML) are based on combinations of cytarabine and anthracyclines. The choice of the anthracycline employed has been widely studied in multiple clinical trials showing similar complete remission rates. MATERIALS AND METHODS: Using an ex vivo test we have analyzed if a subset of AML patients may respond differently to cytarabine combined with idarubicin, daunorubicin or mitoxantrone. Bone marrow (BM) samples of 198 AML patients were incubated for 48 hours in 96 well plates, each well containing different drugs or drug combinations at different concentrations. Ex vivo drug sensitivity analysis was made using the PharmaFlow platform maintaining the BM microenvironment. Drug response was evaluated as depletion of AML blast cells in each well after incubation. Annexin V-FITC was used to quantify the ability of the drugs to induce apoptosis, and pharmacological responses were calculated using pharmacokinetic population models. RESULTS: Similar dose-respond graphs were generated for the three anthracyclines, with a slight decrease in EC50 with idarubicin (p=1.462E-06), whereas the interpatient variability of either drug was large. To identify those cases of selective sensitivity to anthracyclines, potency was compared, in terms of area under the curve. Differences in anthracycline monotherapy potency greater than 30% from 3 pairwise comparisons were identified in 28.3% of samples. Furthermore, different sensitivity was detected in 8.2% of patients comparing combinations of cytarabine and anthracyclines. DISCUSSION: A third of the patients could benefit from the use of this test in the first line induction therapy selection, although it should be confirmed in a clinical trial specifically designed.

[Spanish consensus statement for diagnosis and treatment of paroxysmal nocturnal haemoglobinuria]. / Consenso español para el diagnóstico y tratamiento de la hemoglobinuria paroxística nocturna.

Paroxysmal nocturnal haemoglobinuria (PNH) is an acquired clonal disorder of the haematopoietic progenitor cells due to a somatic mutation in theX-linked phosphatidylinositol glycan class A gene. The disease is characterized by intravascular haemolytic anaemia, propensity to thromboembolic events and bone marrow failure. Other direct complications of haemolysis include dysphagia, erectile dysfunction, abdominal pain, asthenia and chronic renal failure (65% of patients). The disease appears more often in the third decade of life and there is no sex or age preference. Detection of markers associated with glucosyl phosphatidyl inositol deficit by flow cytometry is currently used in the diagnosis of PNH. For years, transfusions have been the mainstay of therapy for PNH. A breakthrough in treatment has been the approval of the humanized monoclonal antibody eculizumab, which works by blocking the C5 complement protein, preventing its activation and therefore haemolysis. Several studies have confirmed that treatment with eculizumab avoids or decreases the need for transfusions, decreases the probability of thrombosis, improves the associated symptomatology and the quality of life in patients with PNH, showing an increase in survival. Because of rapid advances in the knowledge of the disease and its treatment, it may become necessary to adapt and standardize clinical guidelines for the management of patients with PNH.

Pharmacological profiles of acute myeloid leukemia treatments in patient samples by automated flow cytometry: a bridge to individualized medicine.

BACKGROUND: We have evaluated the ex vivo pharmacology of single drugs and drug combinations in malignant cells of bone marrow samples from 125 patients with acute myeloid leukemia using a novel automated flow cytometry-based platform (ExviTech). We have improved previous ex vivo drug testing with 4 innovations: identifying individual leukemic cells, using intact whole blood during the incubation, using an automated platform that escalates reliably data, and performing analyses pharmacodynamic population models. PATIENTS AND METHODS: Samples were sent from 24 hospitals to a central laboratory and incubated for 48 hours in whole blood, after which drug activity was measured in terms of depletion of leukemic cells. RESULTS: The sensitivity of single drugs is assessed for standard efficacy (EMAX) and potency (EC50) variables, ranked as percentiles within the population. The sensitivity of drug-combination treatments is assessed for the synergism achieved in each patient sample. We found a large variability among patient samples in the dose-response curves to a single drug or combination treatment. CONCLUSION: We hypothesize that the use of the individual patient ex vivo pharmacological profiles may help to guide a personalized treatment selection.