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Etienne Dumont

Bio: Etienne Dumont is an academic researcher from Hoffmann-La Roche. The author has contributed to research in topics: Pharmacokinetics & Medicine. The author has an hindex of 2, co-authored 2 publications receiving 647 citations.

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Journal ArticleDOI
TL;DR: Capecitabine is a novel fluoropyrimidine carbamate rationally designed to generate 5-fluorouracil preferentially in tumors, which is explained to a great extent by the activity of TP in colorectal tumor tissue, (the enzyme responsible for the conversion of 5′-DFUR to 5-FU), which is approximately four times that in adjacent healthy tissue.
Abstract: Purpose: Capecitabine (Xeloda) is a novel fluoropyrimidine carbamate rationally designed to generate 5-fluorouracil (5-FU) preferentially in tumors. The purpose of this study was to demonstrate the preferential activation of capecitabine, after oral administration, in tumor in colorectal cancer patients, by the comparison of 5-FU concentrations in tumor tissues, healthy tissues and plasma. Methods: Nineteen patients requiring surgical resection of primary tumor and/or liver metastases received 1,255 mg/m2 of capecitabine twice daily p.o. for 5–7 days prior to surgery. On the day of surgery, samples of tumor tissue, adjacent healthy tissue and blood samples were collected simultaneously from each patient, 2 to 12 h after the last dose of capecitabine had been administered. Concentrations of 5-FU in various tissues and plasma were determined by HPLC. The activities of the enzymes (CD, TP and DPD) involved in the formation and catabolism of 5-FU were measured in tissue homogenates, by catabolic assays. Results: The ratio of 5-FU concentrations in tumor to adjacent healthy tissue (T/H) was used as the primary marker for the preferential activation of capecitabine in tumor. In primary colorectal tumors, the concentration of 5-FU was on average 3.2 times higher than in adjacent healthy tissue (P=0.002). The mean liver metastasis/healthy tissue 5-FU concentration ratio was 1.4 (P=0.49, not statistically different). The mean tissue/plasma 5-FU concentration ratios exceeded 20 for colorectal tumor and ranged from 8 to 10 for other tissues. Conclusions: The results demonstrated the preferential activation of capecitabine to 5-FU in colorectal tumor, after oral administration to patients. This is explained to a great extent by the activity of TP in colorectal tumor tissue, (the enzyme responsible for the conversion of 5′-DFUR to 5-FU), which is approximately four times that in adjacent healthy tissue. In the liver, TP activity is approximately equal in metastatic and healthy tissue, which explains the lack of preferential activation of capecitabine in these tissues.

647 citations

Journal ArticleDOI
TL;DR: Data for gepotidacin from nonclinical studies, including in vitro activity, in vivo animal efficacy, and pharmacokinetic (PK) and Pharmacokinetic/pharmacodynamic (PK/PD) models that informed dose selection for phase III clinical evaluation are reviewed.
Abstract: Antibiotics are the current standard-of-care treatment for uncomplicated urinary tract infections (uUTIs). However, increasing rates of bacterial antibiotic resistance necessitate novel therapeutic options. ABSTRACT Antibiotics are the current standard-of-care treatment for uncomplicated urinary tract infections (uUTIs). However, increasing rates of bacterial antibiotic resistance necessitate novel therapeutic options. Gepotidacin is a first-in-class triazaacenaphthylene antibiotic that selectively inhibits bacterial DNA replication by interaction with the bacterial subunits of DNA gyrase (GyrA) and topoisomerase IV (ParC). Gepotidacin is currently in clinical development for the treatment of uUTIs and other infections. In this article, we review data for gepotidacin from nonclinical studies, including in vitro activity, in vivo animal efficacy, and pharmacokinetic (PK) and pharmacokinetic/pharmacodynamic (PK/PD) models that informed dose selection for phase III clinical evaluation of gepotidacin. Based on this translational package of data, a gepotidacin 1,500-mg oral dose twice daily for 5 days was selected for two ongoing, randomized, multicenter, parallel-group, double-blind, double-dummy, active-comparator phase III clinical studies evaluating the safety and efficacy of gepotidacin in adolescent and adult female participants with uUTIs (ClinicalTrials.gov identifiers NCT04020341 and NCT04187144).

23 citations

Journal ArticleDOI
TL;DR: The pharmacokinetics of 9‐cis‐retinoic acid were linear over the dose range studied and adverse events observed were consistent with findings of other retinoids and included headache and xeroderma at high dose levels.
Abstract: A double-blind, placebo-controlled, randomized study using single ascending oral doses of 5 mg, 15 mg, 40 mg, 80 mg, and 150 mg of 9-cis-retinoic acid was performed to assess the single-dose pharmacokinetics, tolerability, and pharmacodynamic effects of 9-cis-retinoic acid in healthy men. Forty participants received treatment (six taking the active treatment and two taking placebo for each dose level). The pharmacokinetics of 9-cis-retinoic acid were linear over the dose range studied. Peak plasma concentrations were achieved within 3 to 4 hours on average. The half-life was in the range of 1.3 to 2.4 hours. Metabolism was the major pathway of elimination. 4-Oxo-9-cis-retinoic acid, one of four metabolites measured, which included all-trans-retinoic acid and 13-cis-retinoic acid, was the main metabolite in plasma, achieving peak plasma levels of 41% to 83% of those of 9-cis-retinoic acid. Dose-/concentration-dependent reductions of retinol in plasma, with a maximum of 30% from baseline, were observed 24 hours after administration. Baseline levels were recovered after 5 days. Concentrations of retinol binding protein remained unchanged. Overall, the drug was well tolerated at all dose levels. Adverse events observed were consistent with findings of other retinoids (all-trans-retinoic acid and 13-cis-retinoic acid) and included headache and xeroderma at high dose levels.

19 citations

Journal ArticleDOI
TL;DR: Gepotidacin was generally well‐tolerated, with no drug‐related serious adverse events reported, and these PK and safety data across a wide range of doses in healthy participants aged greater than or equal to 18 years support the development of gepotIDacin in further clinical studies.
Abstract: Gepotidacin, a novel, first‐in‐class triazaacenaphthylene antibiotic, inhibits bacterial DNA replication by a distinct mechanism of action. We report the pharmacokinetics (PKs), safety, and tolerability of gepotidacin following single or multiple ascending doses. Studies 1 and 2 were randomized, single‐blind, placebo‐controlled trials in healthy adults aged 18–60 years, who received single (study 1 [NCT02202187]; 100–3000 mg) or repeat (study 2 [NCT01706315]; 400 mg twice daily to 2000 mg thrice daily) ascending doses of gepotidacin. Study 3 (NCT02045849) was an open‐label, three‐part, study in healthy adults; here, we report on part 3, a two‐period, repeat‐dose, crossover study. Healthy elderly participants received repeat 1500 mg gepotidacin twice daily with or without a moderate‐fat meal. Primary end points were PKs (studies 1 and 2) and safety (studies 1 and 3 part 3). Gepotidacin PK parameters were comparable across all ages and were dose proportional. In all studies, gepotidacin was readily absorbed with median time to maximum concentration observed ranging from 1.0 to 4.0 h across all doses. Median apparent terminal phase half‐life was consistent across studies and doses (range: 5.97–19.2 h). Steady‐state was achieved following repeated dosing for 3–5 days; gepotidacin PK parameters were time invariant after repeated oral dosing. A moderate‐fat meal did not affect gepotidacin PK parameters. Gepotidacin was generally well‐tolerated, with no drug‐related serious adverse events reported. Collectively, these PK and safety data across a wide range of doses in healthy participants aged greater than or equal to 18 years support the development of gepotidacin in further clinical studies.

4 citations

Journal ArticleDOI
TL;DR: A translational approach using in vitro pharmacokinetic/pharmacodynamic (PK/PD) and clinical data was used to select a gepotidacin dose for a phase III study.
Abstract: Background Gepotidacin is a novel, first-in-class triazaacenaphthylene antibiotic that inhibits bacterial DNA replication by a distinct mechanism of action and is active against most strains of Neisseria gonorrhoeae (N. gonorrhoeae). Phase II data suggested higher exposures were needed for efficacy and to suppress resistance development. A translational approach using in vitro pharmacokinetic/pharmacodynamic (PK/PD) and clinical data was used to select a gepotidacin dose for a phase III study. In this narrative review of previously shown data, we summarise how a translational approach based on in vitro PK/PD and population PK modelling and simulation data was undertaken to select a dosing regimen for the ongoing phase III gepotidacin study in participants with uncomplicated urogenital gonorrhoea. Methods For dose selection, prior in vitro minimum inhibitory concentrations (MICs) and PK/PD data were available. PK modelling was conducted to determine a dose that would limit plasma concentrations to less than 14 µg/mL (as concentrations above this are associated with QT prolongation and effects associated with acetylcholinesterase inhibition) while maintaining ≥90% probability of target attainment (PTA) for efficacy and resistance suppression against N. gonorrhoeae isolates with gepotidacin MICs ≤1 µg/mL. Results Two 3000 mg gepotidacin doses, administered 10–12 hours apart, resulted in PTA of ≥97.5% and ≥91.7% for gepotidacin MICs ≤1 µg/mL for the ratio of the area under the free drug plasma concentration–time curve over 24 hours to the MIC (fAUC0–24/MIC) efficacy, and resistance suppression targets of 40 and 46, respectively, but limited the occurrence of maximum plasma concentrations ≥14 µg/mL. Conclusions Two gepotidacin 3000 mg oral doses 10–12 hours apart provide ~2-fold higher systemic exposures, increase efficacy for higher gepotidacin MIC N. gonorrhoeae isolates, reduce resistance potential and limit plasma concentrations of potential safety concern, compared with higher doses.

4 citations


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Journal ArticleDOI
TL;DR: This work has shown that novel genes identified in DNA microarray profiling have the potential to identify novel genes that are involved in mediating resistance to 5-FU, and these genes might prove to be therapeutically valuable as new targets for chemotherapy, or as predictive biomarkers of response to5-FU-based chemotherapy.
Abstract: 5-fluorouracil (5-FU) is widely used in the treatment of cancer. Over the past 20 years, increased understanding of the mechanism of action of 5-FU has led to the development of strategies that increase its anticancer activity. Despite these advances, drug resistance remains a significant limitation to the clinical use of 5-FU. Emerging technologies, such as DNA microarray profiling, have the potential to identify novel genes that are involved in mediating resistance to 5-FU. Such target genes might prove to be therapeutically valuable as new targets for chemotherapy, or as predictive biomarkers of response to 5-FU-based chemotherapy.

4,177 citations

Journal ArticleDOI
TL;DR: Oral capecitabine is an effective alternative to intravenous fluorouracil plus leucovorin in the adjuvant treatment of colon cancer.
Abstract: BACKGROUND Intravenous bolus fluorouracil plus leucovorin is the standard adjuvant treatment for colon cancer. The oral fluoropyrimidine capecitabine is an established alternative to bolus fluorouracil plus leucovorin as first-line treatment for metastatic colorectal cancer. We evaluated capecitabine in the adjuvant setting. METHODS We randomly assigned a total of 1987 patients with resected stage III colon cancer to receive either oral capecitabine (1004 patients) or bolus fluorouracil plus leucovorin (Mayo Clinic regimen; 983 patients) over a period of 24 weeks. The primary efficacy end point was at least equivalence in disease-free survival; the primary safety end point was the incidence of grade 3 or 4 toxic effects due to fluoropyrimidines. RESULTS Disease-free survival in the capecitabine group was at least equivalent to that in the fluorouracil-plus-leucovorin group (in the intention-to-treat analysis, P<0.001 for the comparison of the upper limit of the hazard ratio with the noninferiority margin of 1.20). Capecitabine improved relapse-free survival (hazard ratio, 0.86; 95 percent confidence interval, 0.74 to 0.99; P=0.04) and was associated with significantly fewer adverse events than fluorouracil plus leucovorin (P<0.001). CONCLUSIONS Oral capecitabine is an effective alternative to intravenous fluorouracil plus leucovorin in the adjuvant treatment of colon cancer.

1,117 citations

Journal ArticleDOI
TL;DR: Oral capecitabine was more active than 5-FU/LV in the induction of objective tumor responses and demonstrated clinically meaningful benefits over bolus 5-fu/ LV in terms of tolerability.
Abstract: PURPOSE: To compare the response rate, efficacy parameters, and toxicity profile of oral capecitabine with bolus intravenous (IV) fluorouracil plus leucovorin (5-FU/LV) as first-line treatment in patients with metastatic colorectal cancer. PATIENTS AND METHODS: We prospectively randomized 605 patients to treatment with oral capecitabine for 14 days every 3 weeks or 5-FU/LV by rapid IV injection daily for 5 days in 4-week cycles. RESULTS: The overall objective tumor response rate among all randomized patients was significantly higher in the capecitabine group (24.8%) than in the 5-FU/LV group (15.5%; P = .005). In the capecitabine and 5-FU/LV groups, median times to disease progression were 4.3 and 4.7 months (log-rank P = .72), median times to treatment failure were 4.1 and 3.1 months (P = .19), and median overall survival times were 12.5 and 13.3 months (P = .974), respectively. Capecitabine, compared with bolus 5-FU/LV treatment, produced a significantly lower incidence (P < .0002) of diarrhea, stomatit...

1,108 citations

Journal ArticleDOI
TL;DR: The significantly superior TTP and survival achieved with the addition of capecitabine to docetaxel 75 mg/m(2), with the manageable toxicity profile, indicate that this combination provides clear benefits over single-agent docetAXel 100 mg/ m(2).
Abstract: PURPOSE: Docetaxel and capecitabine, a tumor-activated oral fluoropyrimidine, show high single-agent efficacy in metastatic breast cancer (MBC) and synergy in preclinical studies. This international phase III trial compared efficacy and tolerability of capecitabine/docetaxel therapy with single-agent docetaxel in anthracycline-pretreated patients with MBC. PATIENTS AND METHODS: Patients were randomized to 21-day cycles of oral capecitabine 1,250 mg/m2 twice daily on days 1 to 14 plus docetaxel 75 mg/m2 on day 1 (n = 255) or to docetaxel 100 mg/m2 on day 1 (n = 256). RESULTS: Capecitabine/docetaxel resulted in significantly superior efficacy in time to disease progression (TTP) (hazard ratio, 0.652; 95% confidence interval [CI], 0.545 to 0.780; P = .0001; median, 6.1 v 4.2 months), overall survival (hazard ratio, 0.775; 95% CI, 0.634 to 0.947; P = .0126; median, 14.5 v 11.5 months), and objective tumor response rate (42% v 30%, P = .006) compared with docetaxel. Gastrointestinal side effects and hand-foot ...

1,092 citations

Journal ArticleDOI
TL;DR: Oral capecitabine achieved an at least equivalent efficacy compared with IV 5-FU/LV as first-line treatment for metastatic colorectal cancer and demonstrated clinically meaningful safety advantages and the convenience of an oral agent.
Abstract: Purpose To compare the efficacy and safety of orally administered capecitabine (Xeloda; Roche Laboratories, Inc, Nutley, NJ), a novel fluoropyrimidine carbamate designed to mimic continuous fluorouracil (5-FU) infusion but with preferential activation at the tumor site, with that of intravenous (IV) 5-FU plus leucovorin (5-FU/LV) as first-line treatment for metastatic colorectal cancer. Patients and methods We prospectively randomized 602 patients to treatment with capecitabine 1,250 mg/m(2) administered twice daily days 1 to 14 every 3 weeks, or to the 4-weekly Mayo Clinic regimen (5-FU/LV) until disease progression or unacceptable toxicity. Results The primary objective, to demonstrate at least equivalent response rates in the two treatment groups, was met. The overall response rate was 18.9% for capecitabine and 15.0% for 5-FU/LV. In the capecitabine and 5-FU/LV groups, respectively, median time to disease progression was 5.2 and 4.7 months (log-rank P =.65); median time to treatment failure was 4.2 and 4.0 months (log-rank P =.89); and median overall survival was 13.2 and 12.1 months (log-rank P =.33). The toxicity profiles of both treatments were typical of fluoropyrimidines. However, capecitabine led to significantly lower incidences (P Conclusion Oral capecitabine achieved an at least equivalent efficacy compared with IV 5-FU/LV. Capecitabine demonstrated clinically meaningful safety advantages and the convenience of an oral agent.

1,009 citations