Publications by authors named "Marta Hamilton"

Introduction: Patients undergoing on-pump cardiac surgery are at an increased risk of acute kidney injury. QPI-1002, a small interfering ribonucleic acid, is under clinical development for the prevention of acute kidney injury. The safety, tolerability, and pharmacokinetics of QPI-1002 was evaluated in this first-in-man, Phase 1 study of a small, interfering ribonucleic acid in patients at risk of acute kidney injury after on-pump cardiac surgery.

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The aim of this study was to evaluate the effect of coadministration of acid-reducing agents on the pharmacokinetic exposure of orally administered epidermal growth factor receptor inhibitor erlotinib, a drug that displays pH-dependent solubility. Two studies were conducted, the first with the proton pump inhibitor omeprazole and the second with the H2-receptor antagonist ranitidine. Twenty-four healthy male and female volunteers were enrolled in each study.

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In vitro, erlotinib (0-30 µmol/l) and C-labelled midazolam (MDZ) (5 µmol/l) were incubated with human liver microsomes; separately, microsomes were preincubated with erlotinib (10 µmol/l) before the addition of MDZ. Results showed a time-dependent inhibition of MDZ metabolism by erlotinib, with a Ki of 7.5 µmol/l and an inactivation rate constant of 0.

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Purpose: Erlotinib, N-(3-ethynylphenyl)-6,7-bis(2-methoxyethoxy) quinazolin-4-amine is approved for the treatment for non-small cell lung cancer and pancreatic cancer. Because erlotinib is metabolized predominately by CYP3A4, co-administration of compounds that increase CYP3A4 activity may alter the efficacy and safety of erlotinib therapy. Two phase I studies were conducted in healthy male subjects to evaluate the effect of pre- or co-administered rifampicin, a CYP3A4 inducer, on the pharmacokinetics of erlotinib.

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Vascular endothelial growth factor (VEGF) and epidermal growth factor receptor (EGFR) signaling are established contributors to malignant glioma (MG) biology. We, therefore, evaluated bevacizumab, a humanized anti-VEGF monoclonal antibody, in combination with the EGFR tyrosine kinase inhibitor erlotinib, in this phase 2 study for recurrent MG patients (www.ClinicalTrials.

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Purpose: We conducted a phase I and pharmacokinetic study of the epidermal growth factor receptor (EGFR) inhibitor erlotinib as a single agent and in combination with temozolomide in children with refractory solid tumors.

Patients And Methods: Erlotinib was administered orally once daily to cohorts of three to six children for a single 28-day course. Patients then received the combination of daily erlotinib and temozolomide daily for 5 days for all subsequent 28-day courses.

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Background: Erlotinib is an orally active antitumor agent. Analyses in vitro using human liver microsomes and recombinant enzymes showed that erlotinib was metabolized primarily by CYP3A4, with a secondary contribution from CYP1A2.

Methods: A computer-based simulation model, SimCYP, predicted that CYP3A4 contributed to approximately 70% of the metabolic elimination of erlotinib, with CYP1A2 being responsible for the other approximately 30%.

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Purpose: To assess the feasibility of administering erlotinib, an inhibitor of epidermal growth factor receptor (EGFR) tyrosine kinase, in combination with paclitaxel and carboplatin, and to identify pharmacokinetic interactions, evaluate downstream effects of EGFR inhibition on surrogate tissues, and seek preliminary evidence for clinical activity.

Experimental Design: Patients with advanced solid malignancies were treated continuously with erlotinib at doses of 100, 125, and 150 mg/d orally along with fixed i.v.

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Purpose: The purpose of this phase IB trial was to evaluate the tolerability, pharmacokinetics and preliminary evidence of antitumor activity of erlotinib plus gemcitabine in patients with pancreatic cancer and other solid tumors.

Patients And Methods: Patients included those with advanced pancreatic adenocarcinoma or other malignancies potentially responsive to gemcitabine. In the escalating phase of the trial, patients were enrolled in sequential cohorts using 100 or 150 mg oral daily dosing of erlotinib.

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Objective: Our objective was to assess the pharmacokinetics of erlotinib in a large patient population with solid tumors, identify covariates, and explore relationships between exposure and safety outcomes (rash and diarrhea) in patients with non-small cell lung cancer receiving single-agent erlotinib.

Methods: The population pharmacokinetic analysis was performed by use of NONMEM based on 4068 concentration samples from 1047 patients receiving erlotinib as a single agent or in combination with chemotherapy. By use of a 1-compartment model with first-order absorption, the influence of demographic and clinical characteristics on clearance and volume was examined.

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Purpose: To compare the pharmacokinetic variables of erlotinib in current smokers with nonsmokers after receiving a single oral 150 or 300 mg dose of erlotinib.

Experimental Design: This was a single-center, open-label pharmacokinetic study in healthy male subjects. Subjects were enrolled into two treatment cohorts based on smoking status (current smokers and nonsmokers).

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A randomized, open-label, 2-period crossover study was conducted to evaluate the bioequivalence of 6 tablets of erlotinib 25 mg and 1 tablet of erlotinib 150 mg (arm A, n = 42) and the oral bioavailability of the 150-mg tablet versus a 25-mg intravenous infusion (arm B, n = 20) in healthy subjects. The washout period was 2 weeks between treatments. Plasma concentrations of erlotinib and its active metabolite, OSI-420, were measured after each dose.

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Metabolism and excretion of erlotinib, an orally active inhibitor of epidermal growth factor receptor tyrosine kinase, were studied in healthy male volunteers after a single oral dose of [14C]erlotinib hydrochloride (100-mg free base equivalent, approximately 91 microCi/subject). The mass balance was achieved with approximately 91% of the administered dose recovered in urine and feces. The majority of the total administered radioactivity was excreted in feces (83+/-6.

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To study tenofovir transfer into milk, two lactating macaques were given a subcutaneous dose of tenofovir (30 mg/kg of body weight). Peak concentrations and area under the curve values of tenofovir in milk were approximately 3 and approximately 20% of those detected in serum, respectively.

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Purpose: Liposomal lurtotecan (OSI-211) is a liposomal formulation of the water-soluble topoisomerase I inhibitor lurtotecan (GI147211), which demonstrated superior levels of activity compared with topotecan in preclinical models. We studied two schedules of OSI-211 in a randomized design in relapsed ovarian cancer to identify the more promising of the two schedules for further study.

Patients And Methods: Eligible patients had measurable epithelial ovarian, fallopian, or primary peritoneal cancer that was recurrent after one or two prior regimens of chemotherapy.

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Purpose: Epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) are active in cancer therapy. Mechanisms engaged during these clinical responses need to be determined. We reported previously that epidermal growth factor stimulation markedly increased cyclin D1 protein expression in human bronchial epithelial (HBE) cells, and this was opposed by chemoprevention with all-trans-retinoic acid.

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The purpose of the use of analytical instruments is to generate reliable data. Instrument qualification helps fulfill this purpose. No authoritative guide exists that considers the risk of instrument failure and combines that risk with users' scientific knowledge and ability to use the instrument to deliver reliable and consistent data.

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The reverse transcriptase inhibitor 9-[2-(phosphonomethoxy)propyl]adenine (PMPA; tenofovir) was previously found to offer strong prophylactic and therapeutic benefits in an infant macaque model of pediatric human immunodeficiency virus (HIV) infection. We now summarize the toxicity and safety of PMPA in these studies. When a range of PMPA doses (4 to 30 mg/kg of body weight administered subcutaneously once daily) was administered to 39 infant macaques for a short period of time (range, 1 day to 12 weeks), no adverse effects on their health or growth were observed; this included a subset of 12 animals which were monitored for more than 2 years.

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Background: OSI-211 is a low-clearance, unilamellar liposomal formulation of a water-soluble camptothecin analogue, lurtotecan. OSI-211 has significant activity in severe combined immunodeficient mouse models of human leukemia.

Methods: This study was conducted to define the dose-limiting toxicities (DLT) and pharmacokinetics of OSI-211 in patients with refractory myeloid leukemias.

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An additional chromatographic peak was observed in plasma samples of patients receiving NX 211, a liposomal formulation of the topoisomerase I inhibitor lurtotecan. We have isolated and purified this product by sequential solid-phase extractions, and we report its structure and cytotoxicity relative to lurtotecan and related agents. Nuclear magnetic resonance data indicate that cleavage of the piperazino moiety occurred at the N-C bond of the B-ring, yielding 7-methyl-10,11-ethylenedioxy-20(S)-camptothecin (MEC).

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Purpose: To determine the maximum-tolerated and recommended dose, toxicity profile, and pharmacokinetics of the liposomal topoisomerase I inhibitor lurtotecan (NX 211) administered as a 30-minute intravenous infusion once every 3 weeks in cancer patients.

Patients And Methods: NX 211 was administered by peripheral infusion. Dose escalation decisions were based on all toxicities during the first cycle as well as pharmacokinetic parameters.

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