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Eckburg PB, Clarke D, Long J, Chanda S, Krause KM, Easom E, Talbot G, Rubino CM, Molga A. 1727. Phase 1b Dose-ranging Study Demonstrates Tolerability and Pharmacokinetics (PK) of Oral Epetraborole at the Predicted Therapeutic Dosage for Mycobacterium avium Complex (MAC) Lung Disease. Open Forum Infect Dis 2022; 9:ofac492.1357. [PMCID: PMC9752554 DOI: 10.1093/ofid/ofac492.1357] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Background Epetraborole (EBO) — an orally available bacterial leucyl transfer RNA synthetase inhibitor with potent activity against nontuberculous mycobacteria — is under clinical development for treatment of MAC lung disease. We conducted a Phase 1b dose-ranging study of EBO tablets in healthy adult volunteers, to inform dose selection in the treatment of MAC lung disease. Methods In this double-blind, placebo-controlled trial, EBO or placebo tablets were administered (n=8/cohort, 3:1 randomization) at dosages of 250-1000 mg q24h or 500 mg or 1000 mg q48h for up to 28 days. Standard Ph1 clinical and laboratory evaluations and treatment-emergent adverse events (TEAEs) were assessed. Based on prior human studies using significantly higher EBO daily doses, gastrointestinal (GI) events and anemia were predetermined AEs of special interest (AESIs). Plasma concentrations of EBO were measured by validated LC-MS/MS methods. Plasma PK parameters were determined using non-compartmental methods. Results A total of 43 subjects were enrolled; the 1000 mg q24h cohort was terminated early due to local COVID restrictions. Overall, 80.6% EBO subjects and 83.3% placebo subjects experienced ≥1 TEAE, none of which was serious or severe (Table). Most TEAEs were mild in severity (90%), and the remainder were moderate (10%). No TEAE leading to withdrawal from study was reported. The most frequent types of TEAEs were GI events (48.4% EBO, 41.7% placebo subjects), the most common being mild nausea. Two subjects had premature discontinuation of EBO due to a TEAE (asymptomatic liver enzyme elevations in a 250 mg q24h subject and mild nausea in a 1000 mg q48h subject). One 1000mg q24h subject had a TEAE of anemia. No clinically significant findings or TEAEs were observed for physical examinations, ECGs, or urine laboratory tests. Plasma Cmax and AUC0-∞ of EBO increased in a linear, dose-proportional manner across cohorts. Tmax was observed at ∼1 h post dose; mean t1/2 ranged from 7.63 to 11.1 h.
![]() Conclusion Oral EBO administered for 28-day dosing was generally well tolerated at the predicted therapeutic dose (500mg q24h) Predictable PK characteristics facilitate its use in MAC lung disease Further evaluation in a Phase 2/3 treatment-refractory MAC lung disease study is planned
Disclosures Paul B. Eckburg, MD, Paratek Pharmaceuticals, Inc.: Safety Review Board|Spero Therapeutics, Inc.: Advisor/Consultant Sanjay Chanda, PhD, AN2 Therapeutics: Stocks/Bonds George Talbot, MD, AN2 Therapeutics, Inc.: Advisor/Consultant|AN2 Therapeutics, Inc.: Co-founder Christopher M. Rubino, PharmD, Adagio Therapeutics: Grant/Research Support|Amplyx Pharmaceuticals, Inc: Grant/Research Support|AN2 Therapeutics: Grant/Research Support|Antabio SAS: Grant/Research Support|Arcutis Biotherapeutics, Inc: Grant/Research Support|B. Braun Medical Inc.: Grant/Research Support|Basilea Pharmaceutica: Grant/Research Support|Boston Pharmaceuticals: Grant/Research Support|Bravos Biosciences: Ownership Interest|Celdara Medical LLC: Grant/Research Support|Cidara Therapeutics Inc: Grant/Research Support|Cipla USA: Grant/Research Support|Crestone Inc: Grant/Research Support|CXC: Grant/Research Support|Debiopharm International SA: Grant/Research Support|Entasis Therapeutics: Grant/Research Support|Evopoint Biosciences Co.: Grant/Research Support|Fedora Pharmaceuticals: Grant/Research Support|GlaxoSmithKline: Grant/Research Support|Hoffmann-La Roche: Grant/Research Support|ICPD: Ownership Interest|ICPD Biosciences, LLC.: Ownership Interest|Insmed Inc.: Grant/Research Support|Iterum Therapeutics Limited: Grant/Research Support|Kaizen Bioscience, Co.: Grant/Research Support|KBP Biosciences USA: Grant/Research Support|Lassen Therapeutics: Grant/Research Support|Matinas Biopharma: Grant/Research Support|Meiji Seika Pharma Co., Ltd.: Grant/Research Support|Melinta Therapeutics: Grant/Research Support|Menarini Ricerche S.p.A: Grant/Research Support|Mutabilis: Grant/Research Support|Nabriva Therapeutics AG: Grant/Research Support|Novartis Pharmaceuticals Corp.: Grant/Research Support|Paratek Pharmaceuticals, Inc.: Grant/Research Support|PureTech Health: Grant/Research Support|Sfunga Therapeutics: Grant/Research Support|Spero Therapeutics,: Grant/Research Support|Suzhou Sinovent Pharmaceuticals Co.: Grant/Research Support|TauRx Therapeutics: Grant/Research Support|Tetraphase Pharmaceuticals: Grant/Research Support|tranScrip Partners: Grant/Research Support|Utility Therapeutics: Grant/Research Support|Valanbio Therapeutics, Inc.: Grant/Research Support|VenatoRx: Grant/Research Support|Wockhardt Bio AG: Grant/Research Support.
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Ganesan H, Courtney Safir M, Bhavnani SM, Bhavnani SM, Bhavnani SM, Krause KM, Rubino CM. 593. Population Pharmacokinetic Model Development for Epetraborole and Mycobacterium avium Complex (MAC) Lung Disease Patients Using Data from Phase 1 and 2 Studies. Open Forum Infect Dis 2022. [PMCID: PMC9752197 DOI: 10.1093/ofid/ofac492.645] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Background Epetraborole (EBO), an orally available bacterial leucyl transfer RNA synthetase inhibitor with potent activity against nontuberculous mycobacteria, is under clinical development for treatment of MAC lung disease. A population pharmacokinetic (PK) model describing the disposition of EBO after oral (PO) and intravenous (IV) administration was developed to support EBO PK-PD analyses and dose selection for patients with MAC lung disease. Methods Model development was conducted using NONMEM (v.7.4.3). Models were attempted for oral absorption, systemic compartments, and linear vs. non-linear elimination. Model evaluation involved goodness-of-fit plots and prediction-corrected visual predictive plots, which describe the ability of model-based simulations to capture the observed data. Included were data from 5 Phase 1 (3 IV and 2 PO) and 2 Phase 2 studies (IV only) (Table 1).
![]() Results The pooled dataset included 2637 EBO PK samples from 138 subjects/patients. A robust fit to observed data across studies was obtained using a three-compartment model with linear elimination (Table 2). The impact of body weight on PK was included using an allometric scaling approach to accommodate observed lower body weight in MAC lung disease patients. PO dosing was modeled using an absolute bioavailability term (F) and transit compartments with separate absorption rates for fed and fasted administration. Interindividual variability (IIV) in systemic clearance was low (7.9%), but IIV in F (32.7%) contributed to slightly higher variability in PK for PO vs. IV administration. Moderate shrinkage was observed for the IIV in the model parameters. This was considered acceptable given inclusion of patients with limited PK data in the model and the objective to facilitate simulations designed to inform dose selection. The prediction-corrected visual predictive check plots for the data obtained from a recently completed Phase 1b study evaluating 28-day oral dosing regimens (NCT04892641) are provided in Figure 1.
![]() ![]() Conclusion This model is useful for describing expected PK in MAC lung disease patients and was used to conduct simulations for the advancement of the oral EBO 500 mg q24h dosing regimen into clinical studies in patients with MAC lung disease. Disclosures Harish Ganesan, MS, Adagio Therapeutics, Inc.: Grant/Research Support|Amplyx Pharmaceuticals, Inc.: Grant/Research Support|AN2 Therapeutics: Grant/Research Support|Antabio SAS: Grant/Research Support|Arcutis Biotherapeutics, Inc.: Grant/Research Support|B. Braun Medical Inc.: Grant/Research Support|Basilea Pharmaceutica: Grant/Research Support|Boston Pharmaceuticals: Grant/Research Support|Celdara Medical LLC: Grant/Research Support|Cidara Therapeutics Inc.: Grant/Research Support|Cipla USA: Grant/Research Support|Crestone Inc.: Grant/Research Support|CXC: Grant/Research Support|Debiopharm International SA: Grant/Research Support|Entasis Therapeutics: Grant/Research Support|Evopoint Biosciences Co.: Grant/Research Support|Fedora Pharmaceuticals: Grant/Research Support|GlaxoSmithKline: Grant/Research Support|Hoffmann-La Roche: Grant/Research Support|Insmed Inc.: Grant/Research Support|Iterum Therapeutics Limited: Grant/Research Support|Kaizen Bioscience, Co.: Grant/Research Support|KBP Biosciences USA: Grant/Research Support|Lassen Therapeutics: Grant/Research Support|Matinas Biopharma: Grant/Research Support|Meiji Seika Pharma Co.Meiji Seika Pharma Co., Ltd: Grant/Research Support|Melinta Therapeutics: Grant/Research Support|Menarini Ricerche S.p.A: Grant/Research Support|Mutabilis: Grant/Research Support|Nabriva Therapeutics AG: Grant/Research Support|Novartis Pharmaceuticals Corp.: Grant/Research Support|Paratek Pharmaceuticals, Inc.: Grant/Research Support|PureTech Health: Grant/Research Support|Sfunga Therapeutics: Grant/Research Support|Spero Therapeutics: Grant/Research Support|Suzhou Sinovent Pharmaceuticals Co.: Grant/Research Support|TauRx Therapeutics: Grant/Research Support|Tetraphase Pharmaceuticals: Grant/Research Support|tranScrip Partners: Grant/Research Support|Utility Therapeutics: Grant/Research Support|Valanbio Therapeutics, Inc.: Grant/Research Support|VenatoRx: Grant/Research Support|Wockhardt Bio AG: Grant/Research Support M. Courtney Safir, PharmD, Adagio Therapeutics, Inc: Grant/Research Support|Amplyx Pharmaceuticals, Inc.: Grant/Research Support|AN2 Therapeutics: Grant/Research Support|Antabio SAS: Grant/Research Support|Arcutis Biotherapeutics, Inc.: Grant/Research Support|B. Braun Medical Inc.: Grant/Research Support|Basilea Pharmaceutica: Grant/Research Support|Boston Pharmaceuticals: Grant/Research Support|Celdara Medical LLC: Grant/Research Support|Cidara Therapeutics Inc: Grant/Research Support|Cipla USA: Grant/Research Support|Crestone Inc: Grant/Research Support|CXC: Grant/Research Support|Debiopharm International SA: Grant/Research Support|Entasis Therapeutics: Grant/Research Support|Evopoint Biosciences Co: Grant/Research Support|Fedora Pharmaceuticals: Grant/Research Support|GlaxoSmithKline: Grant/Research Support|Hoffmann-La Roche: Grant/Research Support|Insmed Inc.: Grant/Research Support|Iterum Therapeutics Limited,: Grant/Research Support|Kaizen Bioscience, Co.: Grant/Research Support|KBP Biosciences USA: Grant/Research Support|Lassen Therapeutics: Grant/Research Support|Matinas Biopharma: Grant/Research Support|Meiji Seika Pharma Co., Ltd.: Grant/Research Support|Melinta Therapeutics: Grant/Research Support|Menarini Ricerche S.p.A.: Grant/Research Support|Mutabilis: Grant/Research Support|Nabriva Therapeutics AG: Grant/Research Support|Novartis Pharmaceuticals Corp.: Grant/Research Support|Paratek Pharmaceuticals, Inc.: Grant/Research Support|PureTech Health: Grant/Research Support|Sfunga Therapeutics: Grant/Research Support|Spero Therapeutics: Grant/Research Support|Suzhou Sinovent Pharmaceuticals Co.: Grant/Research Support|TauRx Therapeutics: Grant/Research Support|Tetraphase Pharmaceuticals: Grant/Research Support|tranScrip Partners: Grant/Research Support|Utility Therapeutics: Grant/Research Support|Valanbio Therapeutics, Inc.: Grant/Research Support|VenatoRx: Grant/Research Support|Wockhardt Bio AG: Grant/Research Support Sujata M. Bhavnani, PharmD; MS; FIDSA, Adagio Therapeutics, Inc: Grant/Research Support|Amplyx Pharmaceuticals, Inc: Grant/Research Support|AN2 Therapeutics: Grant/Research Support|Antabio SAS: Grant/Research Support|Arcutis Biotherapeutics, Inc: Grant/Research Support|B. Braun Medical Inc: Grant/Research Support|Basilea Pharmaceutica: Grant/Research Support|Boston Pharmaceuticals: Grant/Research Support|Bravos Biosciences: Ownership Interest|Celdara Medical LLC: Grant/Research Support|Cidara Therapeutics Inc: Grant/Research Support|Cipla USA: Grant/Research Support|Crestone Inc.: Grant/Research Support|CXC: Grant/Research Support|Debiopharm International SA: Grant/Research Support|Entasis Therapeutics: Grant/Research Support|Evopoint Biosciences Co.: Grant/Research Support|Fedora Pharmaceuticals: Grant/Research Support|GlaxoSmithKline: Grant/Research Support|Hoffmann-La Roche: Grant/Research Support|ICPD: Ownership Interest|ICPD Biosciences, LLC.: Ownership Interest|Insmed Inc: Grant/Research Support|Iterum Therapeutics Limited: Grant/Research Support|Kaizen Bioscience, Co.: Grant/Research Support|KBP Biosciences USA: Grant/Research Support|Lassen Therapeutics: Grant/Research Support|Matinas Biopharma: Grant/Research Support|Meiji Seika Pharma Co., Ltd.: Grant/Research Support|Melinta Therapeutics: Grant/Research Support|Menarini Ricerche S.p.A: Grant/Research Support|Mutabilis: Grant/Research Support|Nabriva Therapeutics AG: Grant/Research Support|Novartis Pharmaceuticals Corp: Grant/Research Support|Paratek Pharmaceuticals, Inc.: Grant/Research Support|PureTech Health: Grant/Research Support|Sfunga Therapeutics: Grant/Research Support|Spero Therapeutics: Grant/Research Support|Suzhou Sinovent Pharmaceuticals Co.: Grant/Research Support|TauRx Therapeutics: Grant/Research Support|Tetraphase Pharmaceuticals: Grant/Research Support|tranScrip Partners: Grant/Research Support|Utility Therapeutics: Grant/Research Support|Valanbio Therapeutics, Inc: Grant/Research Support|VenatoRx: Grant/Research Support|Wockhardt Bio AG: Grant/Research Support Sujata M. Bhavnani, PharmD; MS; FIDSA, Adagio Therapeutics, Inc: Grant/Research Support|Amplyx Pharmaceuticals, Inc: Grant/Research Support|AN2 Therapeutics: Grant/Research Support|Antabio SAS: Grant/Research Support|Arcutis Biotherapeutics, Inc: Grant/Research Support|B. Braun Medical Inc: Grant/Research Support|Basilea Pharmaceutica: Grant/Research Support|Boston Pharmaceuticals: Grant/Research Support|Bravos Biosciences: Ownership Interest|Celdara Medical LLC: Grant/Research Support|Cidara Therapeutics Inc: Grant/Research Support|Cipla USA: Grant/Research Support|Crestone Inc.: Grant/Research Support|CXC: Grant/Research Support|Debiopharm International SA: Grant/Research Support|Entasis Therapeutics: Grant/Research Support|Evopoint Biosciences Co.: Grant/Research Support|Fedora Pharmaceuticals: Grant/Research Support|GlaxoSmithKline: Grant/Research Support|Hoffmann-La Roche: Grant/Research Support|ICPD: Ownership Interest|ICPD Biosciences, LLC.: Ownership Interest|Insmed Inc: Grant/Research Support|Iterum Therapeutics Limited: Grant/Research Support|Kaizen Bioscience, Co.: Grant/Research Support|KBP Biosciences USA: Grant/Research Support|Lassen Therapeutics: Grant/Research Support|Matinas Biopharma: Grant/Research Support|Meiji Seika Pharma Co., Ltd.: Grant/Research Support|Melinta Therapeutics: Grant/Research Support|Menarini Ricerche S.p.A: Grant/Research Support|Mutabilis: Grant/Research Support|Nabriva Therapeutics AG: Grant/Research Support|Novartis Pharmaceuticals Corp: Grant/Research Support|Paratek Pharmaceuticals, Inc.: Grant/Research Support|PureTech Health: Grant/Research Support|Sfunga Therapeutics: Grant/Research Support|Spero Therapeutics: Grant/Research Support|Suzhou Sinovent Pharmaceuticals Co.: Grant/Research Support|TauRx Therapeutics: Grant/Research Support|Tetraphase Pharmaceuticals: Grant/Research Support|tranScrip Partners: Grant/Research Support|Utility Therapeutics: Grant/Research Support|Valanbio Therapeutics, Inc: Grant/Research Support|VenatoRx: Grant/Research Support|Wockhardt Bio AG: Grant/Research Support Sujata M. Bhavnani, PharmD; MS; FIDSA, Adagio Therapeutics, Inc: Grant/Research Support|Amplyx Pharmaceuticals, Inc: Grant/Research Support|AN2 Therapeutics: Grant/Research Support|Antabio SAS: Grant/Research Support|Arcutis Biotherapeutics, Inc: Grant/Research Support|B. Braun Medical Inc: Grant/Research Support|Basilea Pharmaceutica: Grant/Research Support|Boston Pharmaceuticals: Grant/Research Support|Bravos Biosciences: Ownership Interest|Celdara Medical LLC: Grant/Research Support|Cidara Therapeutics Inc: Grant/Research Support|Cipla USA: Grant/Research Support|Crestone Inc.: Grant/Research Support|CXC: Grant/Research Support|Debiopharm International SA: Grant/Research Support|Entasis Therapeutics: Grant/Research Support|Evopoint Biosciences Co.: Grant/Research Support|Fedora Pharmaceuticals: Grant/Research Support|GlaxoSmithKline: Grant/Research Support|Hoffmann-La Roche: Grant/Research Support|ICPD: Ownership Interest|ICPD Biosciences, LLC.: Ownership Interest|Insmed Inc: Grant/Research Support|Iterum Therapeutics Limited: Grant/Research Support|Kaizen Bioscience, Co.: Grant/Research Support|KBP Biosciences USA: Grant/Research Support|Lassen Therapeutics: Grant/Research Support|Matinas Biopharma: Grant/Research Support|Meiji Seika Pharma Co., Ltd.: Grant/Research Support|Melinta Therapeutics: Grant/Research Support|Menarini Ricerche S.p.A: Grant/Research Support|Mutabilis: Grant/Research Support|Nabriva Therapeutics AG: Grant/Research Support|Novartis Pharmaceuticals Corp: Grant/Research Support|Paratek Pharmaceuticals, Inc.: Grant/Research Support|PureTech Health: Grant/Research Support|Sfunga Therapeutics: Grant/Research Support|Spero Therapeutics: Grant/Research Support|Suzhou Sinovent Pharmaceuticals Co.: Grant/Research Support|TauRx Therapeutics: Grant/Research Support|Tetraphase Pharmaceuticals: Grant/Research Support|tranScrip Partners: Grant/Research Support|Utility Therapeutics: Grant/Research Support|Valanbio Therapeutics, Inc: Grant/Research Support|VenatoRx: Grant/Research Support|Wockhardt Bio AG: Grant/Research Support Kevin M. Krause, MBA, AN2 Therapeutics: Employee|AN2 Therapeutics: Stocks/Bonds Christopher M. Rubino, PharmD, Adagio Therapeutics: Grant/Research Support|Amplyx Pharmaceuticals, Inc: Grant/Research Support|AN2 Therapeutics: Grant/Research Support|Antabio SAS: Grant/Research Support|Arcutis Biotherapeutics, Inc: Grant/Research Support|B. Braun Medical Inc.: Grant/Research Support|Basilea Pharmaceutica: Grant/Research Support|Boston Pharmaceuticals: Grant/Research Support|Bravos Biosciences: Ownership Interest|Celdara Medical LLC: Grant/Research Support|Cidara Therapeutics Inc: Grant/Research Support|Cipla USA: Grant/Research Support|Crestone Inc: Grant/Research Support|CXC: Grant/Research Support|Debiopharm International SA: Grant/Research Support|Entasis Therapeutics: Grant/Research Support|Evopoint Biosciences Co.: Grant/Research Support|Fedora Pharmaceuticals: Grant/Research Support|GlaxoSmithKline: Grant/Research Support|Hoffmann-La Roche: Grant/Research Support|ICPD: Ownership Interest|ICPD Biosciences, LLC.: Ownership Interest|Insmed Inc.: Grant/Research Support|Iterum Therapeutics Limited: Grant/Research Support|Kaizen Bioscience, Co.: Grant/Research Support|KBP Biosciences USA: Grant/Research Support|Lassen Therapeutics: Grant/Research Support|Matinas Biopharma: Grant/Research Support|Meiji Seika Pharma Co., Ltd.: Grant/Research Support|Melinta Therapeutics: Grant/Research Support|Menarini Ricerche S.p.A: Grant/Research Support|Mutabilis: Grant/Research Support|Nabriva Therapeutics AG: Grant/Research Support|Novartis Pharmaceuticals Corp.: Grant/Research Support|Paratek Pharmaceuticals, Inc.: Grant/Research Support|PureTech Health: Grant/Research Support|Sfunga Therapeutics: Grant/Research Support|Spero Therapeutics,: Grant/Research Support|Suzhou Sinovent Pharmaceuticals Co.: Grant/Research Support|TauRx Therapeutics: Grant/Research Support|Tetraphase Pharmaceuticals: Grant/Research Support|tranScrip Partners: Grant/Research Support|Utility Therapeutics: Grant/Research Support|Valanbio Therapeutics, Inc.: Grant/Research Support|VenatoRx: Grant/Research Support|Wockhardt Bio AG: Grant/Research Support.
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Bhavnani SM, Bhavnani SM, Bhavnani SM, Hammel JP, Ganesan H, Courtney Safir M, Rubino CM, Ambrose PG, Krause KM. 619. Pharmacokinetic-Pharmacodynamic (PK-PD) Target Attainment Analyses to Support Epetraborole Dose Selection for the Treatment of Patients with Mycobacterium avium Complex (MAC) Lung Disease. Open Forum Infect Dis 2022. [DOI: 10.1093/ofid/ofac492.671] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Abstract
Background
Epetraborole (EBO) is an orally available, bacterial leucyl transfer RNA synthetase inhibitor that concentrates in alveolar macrophages and exhibits potent activity against nontuberculous mycobacteria. PK-PD target attainment (PTA) analyses using plasma exposures were performed to support the selection of an EBO oral (PO) dosing regimen for clinical development in MAC lung disease.
Methods
Hill-type models were used to characterize the PK-PD relationships between EBO free-drug plasma AUC:MIC ratio and change in log10 CFU from baseline for 5 MAC isolates (EBO MIC range 2-8 mg/L) in a murine chronic MAC lung infection model. Change in log10 CFU was calculated by comparing lung CFUs after 56 days of EBO dosing (100 to 300 mg/kg/day) to CFUs of untreated controls prior to dosing. Data from PK studies were used to determine AUC by EBO dose.
EBO PK parameters were calculated for 10,000 simulated MAC lung disease patients using an EBO population PK model with inflated PK variance to generate total-drug plasma concentration-time profiles at steady-state after administration of EBO 250 mg and 500 mg PO q24h for 21 days in a fasted state. Free-drug plasma AUC values were calculated using a human protein binding estimate of 0%. Percent probabilities of PTA were assessed using median, randomly assigned, and the highest of the free-drug plasma AUC:MIC ratio targets from the Hill models developed using the above-described in vivo efficacy study data.
Results
Table 1 summarizes the free-drug plasma AUC:MIC ratio targets for each MAC isolate. For EBO 250 mg q24h, percent probabilities of PTA were ≥ 90% for a 1-log10 CFU reduction (Figure 1) at an MIC of 4 mg/L (all PK-PD targets) or 8 mg/L (median target only) and for a 2-log10 CFU reduction (Figure 2) at an MIC of 2 mg/L (all PK-PD targets) or 4 mg/L (median target only). For EBO 500 mg q24h, percent probabilities of PTA were ≥ 90% for a 1-log10 CFU reduction at an MIC of 8 mg/L (all PK-PD targets) or 16 mg/L (median target only) and for a 2-log10 CFU reduction at an MIC of 4 mg/L (median and randomly assigned PK-PD targets) or 8 mg/L (median target only).
Conclusion
The high PTA associated with plasma exposures after oral EBO 500 mg q24h support advancing this dosing regimen into clinical studies in patients with MAC lung disease.
Disclosures
Sujata M. Bhavnani, PharmD; MS; FIDSA, Adagio Therapeutics, Inc: Grant/Research Support|Amplyx Pharmaceuticals, Inc: Grant/Research Support|AN2 Therapeutics: Grant/Research Support|Antabio SAS: Grant/Research Support|Arcutis Biotherapeutics, Inc: Grant/Research Support|B. Braun Medical Inc: Grant/Research Support|Basilea Pharmaceutica: Grant/Research Support|Boston Pharmaceuticals: Grant/Research Support|Bravos Biosciences: Ownership Interest|Celdara Medical LLC: Grant/Research Support|Cidara Therapeutics Inc: Grant/Research Support|Cipla USA: Grant/Research Support|Crestone Inc.: Grant/Research Support|CXC: Grant/Research Support|Debiopharm International SA: Grant/Research Support|Entasis Therapeutics: Grant/Research Support|Evopoint Biosciences Co.: Grant/Research Support|Fedora Pharmaceuticals: Grant/Research Support|GlaxoSmithKline: Grant/Research Support|Hoffmann-La Roche: Grant/Research Support|ICPD: Ownership Interest|ICPD Biosciences, LLC.: Ownership Interest|Insmed Inc: Grant/Research Support|Iterum Therapeutics Limited: Grant/Research Support|Kaizen Bioscience, Co.: Grant/Research Support|KBP Biosciences USA: Grant/Research Support|Lassen Therapeutics: Grant/Research Support|Matinas Biopharma: Grant/Research Support|Meiji Seika Pharma Co., Ltd.: Grant/Research Support|Melinta Therapeutics: Grant/Research Support|Menarini Ricerche S.p.A: Grant/Research Support|Mutabilis: Grant/Research Support|Nabriva Therapeutics AG: Grant/Research Support|Novartis Pharmaceuticals Corp: Grant/Research Support|Paratek Pharmaceuticals, Inc.: Grant/Research Support|PureTech Health: Grant/Research Support|Sfunga Therapeutics: Grant/Research Support|Spero Therapeutics: Grant/Research Support|Suzhou Sinovent Pharmaceuticals Co.: Grant/Research Support|TauRx Therapeutics: Grant/Research Support|Tetraphase Pharmaceuticals: Grant/Research Support|tranScrip Partners: Grant/Research Support|Utility Therapeutics: Grant/Research Support|Valanbio Therapeutics, Inc: Grant/Research Support|VenatoRx: Grant/Research Support|Wockhardt Bio AG: Grant/Research Support Sujata M. Bhavnani, PharmD; MS; FIDSA, Adagio Therapeutics, Inc: Grant/Research Support|Amplyx Pharmaceuticals, Inc: Grant/Research Support|AN2 Therapeutics: Grant/Research Support|Antabio SAS: Grant/Research Support|Arcutis Biotherapeutics, Inc: Grant/Research Support|B. Braun Medical Inc: Grant/Research Support|Basilea Pharmaceutica: Grant/Research Support|Boston Pharmaceuticals: Grant/Research Support|Bravos Biosciences: Ownership Interest|Celdara Medical LLC: Grant/Research Support|Cidara Therapeutics Inc: Grant/Research Support|Cipla USA: Grant/Research Support|Crestone Inc.: Grant/Research Support|CXC: Grant/Research Support|Debiopharm International SA: Grant/Research Support|Entasis Therapeutics: Grant/Research Support|Evopoint Biosciences Co.: Grant/Research Support|Fedora Pharmaceuticals: Grant/Research Support|GlaxoSmithKline: Grant/Research Support|Hoffmann-La Roche: Grant/Research Support|ICPD: Ownership Interest|ICPD Biosciences, LLC.: Ownership Interest|Insmed Inc: Grant/Research Support|Iterum Therapeutics Limited: Grant/Research Support|Kaizen Bioscience, Co.: Grant/Research Support|KBP Biosciences USA: Grant/Research Support|Lassen Therapeutics: Grant/Research Support|Matinas Biopharma: Grant/Research Support|Meiji Seika Pharma Co., Ltd.: Grant/Research Support|Melinta Therapeutics: Grant/Research Support|Menarini Ricerche S.p.A: Grant/Research Support|Mutabilis: Grant/Research Support|Nabriva Therapeutics AG: Grant/Research Support|Novartis Pharmaceuticals Corp: Grant/Research Support|Paratek Pharmaceuticals, Inc.: Grant/Research Support|PureTech Health: Grant/Research Support|Sfunga Therapeutics: Grant/Research Support|Spero Therapeutics: Grant/Research Support|Suzhou Sinovent Pharmaceuticals Co.: Grant/Research Support|TauRx Therapeutics: Grant/Research Support|Tetraphase Pharmaceuticals: Grant/Research Support|tranScrip Partners: Grant/Research Support|Utility Therapeutics: Grant/Research Support|Valanbio Therapeutics, Inc: Grant/Research Support|VenatoRx: Grant/Research Support|Wockhardt Bio AG: Grant/Research Support Sujata M. Bhavnani, PharmD; MS; FIDSA, Adagio Therapeutics, Inc: Grant/Research Support|Amplyx Pharmaceuticals, Inc: Grant/Research Support|AN2 Therapeutics: Grant/Research Support|Antabio SAS: Grant/Research Support|Arcutis Biotherapeutics, Inc: Grant/Research Support|B. Braun Medical Inc: Grant/Research Support|Basilea Pharmaceutica: Grant/Research Support|Boston Pharmaceuticals: Grant/Research Support|Bravos Biosciences: Ownership Interest|Celdara Medical LLC: Grant/Research Support|Cidara Therapeutics Inc: Grant/Research Support|Cipla USA: Grant/Research Support|Crestone Inc.: Grant/Research Support|CXC: Grant/Research Support|Debiopharm International SA: Grant/Research Support|Entasis Therapeutics: Grant/Research Support|Evopoint Biosciences Co.: Grant/Research Support|Fedora Pharmaceuticals: Grant/Research Support|GlaxoSmithKline: Grant/Research Support|Hoffmann-La Roche: Grant/Research Support|ICPD: Ownership Interest|ICPD Biosciences, LLC.: Ownership Interest|Insmed Inc: Grant/Research Support|Iterum Therapeutics Limited: Grant/Research Support|Kaizen Bioscience, Co.: Grant/Research Support|KBP Biosciences USA: Grant/Research Support|Lassen Therapeutics: Grant/Research Support|Matinas Biopharma: Grant/Research Support|Meiji Seika Pharma Co., Ltd.: Grant/Research Support|Melinta Therapeutics: Grant/Research Support|Menarini Ricerche S.p.A: Grant/Research Support|Mutabilis: Grant/Research Support|Nabriva Therapeutics AG: Grant/Research Support|Novartis Pharmaceuticals Corp: Grant/Research Support|Paratek Pharmaceuticals, Inc.: Grant/Research Support|PureTech Health: Grant/Research Support|Sfunga Therapeutics: Grant/Research Support|Spero Therapeutics: Grant/Research Support|Suzhou Sinovent Pharmaceuticals Co.: Grant/Research Support|TauRx Therapeutics: Grant/Research Support|Tetraphase Pharmaceuticals: Grant/Research Support|tranScrip Partners: Grant/Research Support|Utility Therapeutics: Grant/Research Support|Valanbio Therapeutics, Inc: Grant/Research Support|VenatoRx: Grant/Research Support|Wockhardt Bio AG: Grant/Research Support Jeffrey P. Hammel, MS, Adagio Therapeutics, Inc: Grant/Research Support|Amplyx Pharmaceuticals, Inc: Grant/Research Support|AN2 Therapeutics: Grant/Research Support|Antabio SAS: Grant/Research Support|Arcutis Biotherapeutics, Inc.: Grant/Research Support|B. Braun Medical Inc.: Grant/Research Support|Basilea Pharmaceutica: Grant/Research Support|Boston Pharmaceuticals: Grant/Research Support|Celdara Medical LLC: Grant/Research Support|Cidara Therapeutics Inc: Grant/Research Support|Cipla USA: Grant/Research Support|Crestone Inc: Grant/Research Support|CXC: Grant/Research Support|Debiopharm International SA: Grant/Research Support|Entasis Therapeutics: Grant/Research Support|Evopoint Biosciences Co.: Grant/Research Support|Fedora Pharmaceuticals: Grant/Research Support|GlaxoSmithKline: Grant/Research Support|Hoffmann-La Roche: Grant/Research Support|Insmed Inc.: Grant/Research Support|Iterum Therapeutics Limited: Grant/Research Support|Kaizen Bioscience, Co.: Grant/Research Support|KBP Biosciences USA: Grant/Research Support|Lassen Therapeutics: Grant/Research Support|Matinas Biopharma,: Grant/Research Support|Meiji Seika Pharma Co., Ltd.: Grant/Research Support|Melinta Therapeutics: Grant/Research Support|Menarini Ricerche S.p.A,: Grant/Research Support|Mutabilis: Grant/Research Support|Nabriva Therapeutics AG: Grant/Research Support|Novartis Pharmaceuticals Corp.: Grant/Research Support|Paratek Pharmaceuticals, Inc.: Grant/Research Support|PureTech Health: Grant/Research Support|Sfunga Therapeutics: Grant/Research Support|Spero Therapeutics: Grant/Research Support|Suzhou Sinovent Pharmaceuticals Co.: Grant/Research Support|TauRx Therapeutics: Grant/Research Support|Tetraphase Pharmaceuticals: Grant/Research Support|tranScrip Partners: Grant/Research Support|Utility Therapeutics: Grant/Research Support|Valanbio Therapeutics, Inc.: Grant/Research Support|VenatoRx: Grant/Research Support|Wockhardt Bio AG: Grant/Research Support Harish Ganesan, MS, Adagio Therapeutics, Inc.: Grant/Research Support|Amplyx Pharmaceuticals, Inc.: Grant/Research Support|AN2 Therapeutics: Grant/Research Support|Antabio SAS: Grant/Research Support|Arcutis Biotherapeutics, Inc.: Grant/Research Support|B. Braun Medical Inc.: Grant/Research Support|Basilea Pharmaceutica: Grant/Research Support|Boston Pharmaceuticals: Grant/Research Support|Celdara Medical LLC: Grant/Research Support|Cidara Therapeutics Inc.: Grant/Research Support|Cipla USA: Grant/Research Support|Crestone Inc.: Grant/Research Support|CXC: Grant/Research Support|Debiopharm International SA: Grant/Research Support|Entasis Therapeutics: Grant/Research Support|Evopoint Biosciences Co.: Grant/Research Support|Fedora Pharmaceuticals: Grant/Research Support|GlaxoSmithKline: Grant/Research Support|Hoffmann-La Roche: Grant/Research Support|Insmed Inc.: Grant/Research Support|Iterum Therapeutics Limited: Grant/Research Support|Kaizen Bioscience, Co.: Grant/Research Support|KBP Biosciences USA: Grant/Research Support|Lassen Therapeutics: Grant/Research Support|Matinas Biopharma: Grant/Research Support|Meiji Seika Pharma Co.Meiji Seika Pharma Co., Ltd: Grant/Research Support|Melinta Therapeutics: Grant/Research Support|Menarini Ricerche S.p.A: Grant/Research Support|Mutabilis: Grant/Research Support|Nabriva Therapeutics AG: Grant/Research Support|Novartis Pharmaceuticals Corp.: Grant/Research Support|Paratek Pharmaceuticals, Inc.: Grant/Research Support|PureTech Health: Grant/Research Support|Sfunga Therapeutics: Grant/Research Support|Spero Therapeutics: Grant/Research Support|Suzhou Sinovent Pharmaceuticals Co.: Grant/Research Support|TauRx Therapeutics: Grant/Research Support|Tetraphase Pharmaceuticals: Grant/Research Support|tranScrip Partners: Grant/Research Support|Utility Therapeutics: Grant/Research Support|Valanbio Therapeutics, Inc.: Grant/Research Support|VenatoRx: Grant/Research Support|Wockhardt Bio AG: Grant/Research Support M. Courtney Safir, PharmD, Adagio Therapeutics, Inc: Grant/Research Support|Amplyx Pharmaceuticals, Inc.: Grant/Research Support|AN2 Therapeutics: Grant/Research Support|Antabio SAS: Grant/Research Support|Arcutis Biotherapeutics, Inc.: Grant/Research Support|B. Braun Medical Inc.: Grant/Research Support|Basilea Pharmaceutica: Grant/Research Support|Boston Pharmaceuticals: Grant/Research Support|Celdara Medical LLC: Grant/Research Support|Cidara Therapeutics Inc: Grant/Research Support|Cipla USA: Grant/Research Support|Crestone Inc: Grant/Research Support|CXC: Grant/Research Support|Debiopharm International SA: Grant/Research Support|Entasis Therapeutics: Grant/Research Support|Evopoint Biosciences Co: Grant/Research Support|Fedora Pharmaceuticals: Grant/Research Support|GlaxoSmithKline: Grant/Research Support|Hoffmann-La Roche: Grant/Research Support|Insmed Inc.: Grant/Research Support|Iterum Therapeutics Limited,: Grant/Research Support|Kaizen Bioscience, Co.: Grant/Research Support|KBP Biosciences USA: Grant/Research Support|Lassen Therapeutics: Grant/Research Support|Matinas Biopharma: Grant/Research Support|Meiji Seika Pharma Co., Ltd.: Grant/Research Support|Melinta Therapeutics: Grant/Research Support|Menarini Ricerche S.p.A.: Grant/Research Support|Mutabilis: Grant/Research Support|Nabriva Therapeutics AG: Grant/Research Support|Novartis Pharmaceuticals Corp.: Grant/Research Support|Paratek Pharmaceuticals, Inc.: Grant/Research Support|PureTech Health: Grant/Research Support|Sfunga Therapeutics: Grant/Research Support|Spero Therapeutics: Grant/Research Support|Suzhou Sinovent Pharmaceuticals Co.: Grant/Research Support|TauRx Therapeutics: Grant/Research Support|Tetraphase Pharmaceuticals: Grant/Research Support|tranScrip Partners: Grant/Research Support|Utility Therapeutics: Grant/Research Support|Valanbio Therapeutics, Inc.: Grant/Research Support|VenatoRx: Grant/Research Support|Wockhardt Bio AG: Grant/Research Support Christopher M. Rubino, PharmD, Adagio Therapeutics: Grant/Research Support|Amplyx Pharmaceuticals, Inc: Grant/Research Support|AN2 Therapeutics: Grant/Research Support|Antabio SAS: Grant/Research Support|Arcutis Biotherapeutics, Inc: Grant/Research Support|B. Braun Medical Inc.: Grant/Research Support|Basilea Pharmaceutica: Grant/Research Support|Boston Pharmaceuticals: Grant/Research Support|Bravos Biosciences: Ownership Interest|Celdara Medical LLC: Grant/Research Support|Cidara Therapeutics Inc: Grant/Research Support|Cipla USA: Grant/Research Support|Crestone Inc: Grant/Research Support|CXC: Grant/Research Support|Debiopharm International SA: Grant/Research Support|Entasis Therapeutics: Grant/Research Support|Evopoint Biosciences Co.: Grant/Research Support|Fedora Pharmaceuticals: Grant/Research Support|GlaxoSmithKline: Grant/Research Support|Hoffmann-La Roche: Grant/Research Support|ICPD: Ownership Interest|ICPD Biosciences, LLC.: Ownership Interest|Insmed Inc.: Grant/Research Support|Iterum Therapeutics Limited: Grant/Research Support|Kaizen Bioscience, Co.: Grant/Research Support|KBP Biosciences USA: Grant/Research Support|Lassen Therapeutics: Grant/Research Support|Matinas Biopharma: Grant/Research Support|Meiji Seika Pharma Co., Ltd.: Grant/Research Support|Melinta Therapeutics: Grant/Research Support|Menarini Ricerche S.p.A: Grant/Research Support|Mutabilis: Grant/Research Support|Nabriva Therapeutics AG: Grant/Research Support|Novartis Pharmaceuticals Corp.: Grant/Research Support|Paratek Pharmaceuticals, Inc.: Grant/Research Support|PureTech Health: Grant/Research Support|Sfunga Therapeutics: Grant/Research Support|Spero Therapeutics,: Grant/Research Support|Suzhou Sinovent Pharmaceuticals Co.: Grant/Research Support|TauRx Therapeutics: Grant/Research Support|Tetraphase Pharmaceuticals: Grant/Research Support|tranScrip Partners: Grant/Research Support|Utility Therapeutics: Grant/Research Support|Valanbio Therapeutics, Inc.: Grant/Research Support|VenatoRx: Grant/Research Support|Wockhardt Bio AG: Grant/Research Support Paul G. Ambrose, PharmD; MS; FIDSA, Adagio Therapeutics, Inc: Grant/Research Support|Amplyx Pharmaceuticals, Inc.: Grant/Research Support|AN2 Therapeutics: Grant/Research Support|Antabio SAS: Grant/Research Support|Arcutis Biotherapeutics, Inc.: Grant/Research Support|B. Braun Medical Inc.: Grant/Research Support|Basilea Pharmaceutica: Grant/Research Support|Boston Pharmaceuticals: Grant/Research Support|Bravos Biosciences: Ownership Interest|Celdara Medical LLC: Grant/Research Support|Cidara Therapeutics Inc.: Grant/Research Support|Cipla USA: Grant/Research Support|Crestone Inc.: Grant/Research Support|CXC: Grant/Research Support|Debiopharm International SA: Grant/Research Support|Entasis Therapeutics: Grant/Research Support|Evopoint Biosciences Co.: Grant/Research Support|Fedora Pharmaceuticals: Grant/Research Support|GlaxoSmithKline: Grant/Research Support|Hoffmann-La Roche: Grant/Research Support|ICPD: Ownership Interest|ICPD Biosciences, LLC.: Ownership Interest|Insmed Inc.: Grant/Research Support|Iterum Therapeutics Limited: Grant/Research Support|Kaizen Bioscience, Co.: Grant/Research Support|KBP Biosciences USA: Grant/Research Support|Lassen Therapeutics: Grant/Research Support|Matinas Biopharma: Grant/Research Support|Meiji Seika Pharma Co., Ltd.: Grant/Research Support|Melinta Therapeutics: Grant/Research Support|Menarini Ricerche S.p.A: Grant/Research Support|Mutabilis: Grant/Research Support|Nabriva Therapeutics AG: Grant/Research Support|Novartis Pharmaceuticals Corp.: Grant/Research Support|Paratek Pharmaceuticals, Inc.: Grant/Research Support|PureTech Health: Grant/Research Support|Sfunga Therapeutics: Grant/Research Support|Spero Therapeutics: Grant/Research Support|Suzhou Sinovent Pharmaceuticals Co.: Grant/Research Support|TauRx Therapeutics: Grant/Research Support|Tetraphase Pharmaceuticals: Grant/Research Support|tranScrip Partners: Grant/Research Support|Utility Therapeutics: Grant/Research Support|Valanbio Therapeutics, Inc: Grant/Research Support|VenatoRx: Grant/Research Support|Wockhardt Bio AG: Grant/Research Support Kevin M. Krause, MBA, AN2 Therapeutics: Employee|AN2 Therapeutics: Stocks/Bonds.
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Affiliation(s)
| | | | | | | | - Harish Ganesan
- Institute for Clinical Pharmacodynamics , Schenectady, NY
| | | | | | - Paul G Ambrose
- Institute for Clinical Pharmacodynamics , Schenectady, NY
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Bhavnani SM, Krause KM, Ambrose PG. A Broken Antibiotic Market: Review of Strategies to Incentivize Drug Development. Open Forum Infect Dis 2020; 7:ofaa083. [PMID: 32667365 PMCID: PMC7336557 DOI: 10.1093/ofid/ofaa083] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2020] [Accepted: 03/11/2020] [Indexed: 11/12/2022] Open
Abstract
The threat posed by infections arising from antimicrobial-resistant bacteria is a global concern. Despite this trend, the future development of new antimicrobial agents is currently very uncertain. The lack of commercial success for newly launched antimicrobial agents provides little incentive to invest in the development of new agents. To address this crisis, a number of push and pull incentives have been constructed to support antimicrobial drug development. Push incentives, which are designed to lower the cost of developing new antimicrobial agents, include grants, contracts, public-private partnerships, tax credits, and clinical trial networks. Pull incentives, which are designed to facilitate higher financial returns for a newly launched antimicrobial agent, include those that decrease the time for a regulatory review, extend patent exclusivity, or provide premium pricing. Such incentives may also include direct, advanced, or milestone payments or they may be insurance-based whereby healthcare systems pay for the right to access an antimicrobial agent rather than the number of units administered. Another strategy involves the re-evaluation of interpretive criteria for in vitro susceptibility testing (susceptibility breakpoints) of old antimicrobial agents using the same standards applied to that of new agents, which will allow for an accurate determination of antimicrobial resistance. Although each of the above-described strategies will be important to ensure that antimicrobial agents are developed in the decades to come, the update of susceptibility breakpoints for old agents is a strategy that could be implemented quickly and one that could be the most effective for incentivizing drug developers and financiers to reconsider the development of antimicrobial agents.
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Affiliation(s)
| | | | - Paul G Ambrose
- Institute for Clinical Pharmacodynamics, Schenectady, New York, USA
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Castanheira M, Deshpande LM, Woosley LN, Serio AW, Krause KM, Flamm RK. Activity of plazomicin compared with other aminoglycosides against isolates from European and adjacent countries, including Enterobacteriaceae molecularly characterized for aminoglycoside-modifying enzymes and other resistance mechanisms. J Antimicrob Chemother 2019; 73:3346-3354. [PMID: 30219857 DOI: 10.1093/jac/dky344] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2018] [Accepted: 08/01/2018] [Indexed: 11/13/2022] Open
Abstract
Background Plazomicin is a next-generation aminoglycoside that was developed to overcome common aminoglycoside-resistance mechanisms. Objectives We evaluated the activity of plazomicin and comparators against clinical isolates collected from 26 European and adjacent countries during 2014 and 2015 as part of the Antimicrobial Longitudinal Evaluation and Resistance Trends (ALERT) global surveillance programme. Methods All 4680 isolates collected from 45 hospitals were tested for susceptibility to antimicrobials using the reference broth microdilution method. Selected isolates were screened for genes encoding carbapenemases, aminoglycoside-modifying enzymes (AMEs) and 16S rRNA methyltransferases. Results Plazomicin (MIC50/90 0.5/2 mg/L) inhibited 95.8% of Enterobacteriaceae at ≤2 mg/L, including carbapenem-resistant Enterobacteriaceae (MIC50/90 0.25/128 mg/L). Plazomicin was more active compared with other aminoglycosides against isolates carrying blaKPC (MIC50/90 0.25/2 mg/L), isolates carrying blaOXA-48-like (MIC50/90 0.25/16 mg/L) and carbapenemase-negative isolates (MIC50/90 0.25/1 mg/L). Approximately 60% of the isolates harbouring blaVIM and blaNDM-1 carried 16S rRNA methyltransferases (mainly rmtB and armA). AME genes were detected among 728 isolates and 99.0% of these were inhibited by plazomicin at ≤2 mg/L. Plazomicin activity against Pseudomonas aeruginosa (MIC50/90 4/8 mg/L) was similar to amikacin activity (MIC50/90 2/16 mg/L). Plazomicin demonstrated activity against CoNS (MIC50/90 0.12/0.25 mg/L) and Staphylococcus aureus (MIC50/90 0.5/1 mg/L). Plazomicin activity was limited against Acinetobacter spp. (MIC50/90 8/>128 mg/L), Enterococcus spp. (MIC50/90 32/128 mg/L) and Streptococcus pneumoniae (MIC50/90 32/64 mg/L). Conclusions Plazomicin demonstrated activity against Enterobacteriaceae isolates tested in this study, including isolates carrying AMEs and a high percentage of the carbapenem-non-susceptible isolates. Plazomicin displayed activity against staphylococci.
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Cohen F, Aggen JB, Andrews LD, Assar Z, Boggs J, Choi T, Dozzo P, Easterday AN, Haglund CM, Hildebrandt DJ, Holt MC, Joly K, Jubb A, Kamal Z, Kane TR, Konradi AW, Krause KM, Linsell MS, Machajewski TD, Miroshnikova O, Moser HE, Nieto V, Phan T, Plato C, Serio AW, Seroogy J, Shakhmin A, Stein AJ, Sun AD, Sviridov S, Wang Z, Wlasichuk K, Yang W, Zhou X, Zhu H, Cirz RT. Optimization of LpxC Inhibitors for Antibacterial Activity and Cardiovascular Safety. ChemMedChem 2019; 14:1560-1572. [DOI: 10.1002/cmdc.201900287] [Citation(s) in RCA: 40] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2019] [Revised: 07/03/2019] [Indexed: 11/10/2022]
Affiliation(s)
- Frederick Cohen
- Achaogen Inc. 1 Tower Place, Suite 400 South San Francisco CA 94080 USA
| | - James B. Aggen
- Achaogen Inc. 1 Tower Place, Suite 400 South San Francisco CA 94080 USA
| | - Logan D. Andrews
- Achaogen Inc. 1 Tower Place, Suite 400 South San Francisco CA 94080 USA
| | - Zahra Assar
- Cayman Chemical Co. 1180 East Ellsworth Ann Arbor MI 48108 USA
| | - Jen Boggs
- Achaogen Inc. 1 Tower Place, Suite 400 South San Francisco CA 94080 USA
| | - Taylor Choi
- Achaogen Inc. 1 Tower Place, Suite 400 South San Francisco CA 94080 USA
| | - Paola Dozzo
- Achaogen Inc. 1 Tower Place, Suite 400 South San Francisco CA 94080 USA
| | | | - Cat M. Haglund
- Achaogen Inc. 1 Tower Place, Suite 400 South San Francisco CA 94080 USA
| | | | - Melissa C. Holt
- Cayman Chemical Co. 1180 East Ellsworth Ann Arbor MI 48108 USA
| | - Kristin Joly
- Plato BioPharma Inc. 7581 West 103rd Avenue, Unit 300 Westminster CO 80021 USA
| | - Adrian Jubb
- Achaogen Inc. 1 Tower Place, Suite 400 South San Francisco CA 94080 USA
| | - Zeeshan Kamal
- Nanosyn Inc. 3100 Central Expressway Santa Clara CA 95051 USA
| | - Timothy R. Kane
- Achaogen Inc. 1 Tower Place, Suite 400 South San Francisco CA 94080 USA
| | | | - Kevin M. Krause
- Achaogen Inc. 1 Tower Place, Suite 400 South San Francisco CA 94080 USA
| | - Martin S. Linsell
- Achaogen Inc. 1 Tower Place, Suite 400 South San Francisco CA 94080 USA
| | | | | | - Heinz E. Moser
- Achaogen Inc. 1 Tower Place, Suite 400 South San Francisco CA 94080 USA
| | - Vincent Nieto
- Achaogen Inc. 1 Tower Place, Suite 400 South San Francisco CA 94080 USA
| | - Thu Phan
- Nanosyn Inc. 3100 Central Expressway Santa Clara CA 95051 USA
| | - Craig Plato
- Plato BioPharma Inc. 7581 West 103rd Avenue, Unit 300 Westminster CO 80021 USA
| | - Alisa W. Serio
- Achaogen Inc. 1 Tower Place, Suite 400 South San Francisco CA 94080 USA
| | - Julie Seroogy
- Achaogen Inc. 1 Tower Place, Suite 400 South San Francisco CA 94080 USA
| | - Anton Shakhmin
- Nanosyn Inc. 3100 Central Expressway Santa Clara CA 95051 USA
| | - Adam J. Stein
- Cayman Chemical Co. 1180 East Ellsworth Ann Arbor MI 48108 USA
| | - Alex D. Sun
- Nanosyn Inc. 3100 Central Expressway Santa Clara CA 95051 USA
| | | | - Zhan Wang
- Nanosyn Inc. 3100 Central Expressway Santa Clara CA 95051 USA
| | - Kenneth Wlasichuk
- Achaogen Inc. 1 Tower Place, Suite 400 South San Francisco CA 94080 USA
| | - Wen Yang
- Nanosyn Inc. 3100 Central Expressway Santa Clara CA 95051 USA
| | - Xiaoming Zhou
- Pharmaron Inc. 6 Tai-He Road, BDA Beijing 100176 China
| | - Hai Zhu
- Nanosyn Inc. 3100 Central Expressway Santa Clara CA 95051 USA
| | - Ryan T. Cirz
- Achaogen Inc. 1 Tower Place, Suite 400 South San Francisco CA 94080 USA
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Serio AW, Keepers T, Krause KM. Plazomicin Is Active Against Metallo-β-Lactamase-Producing Enterobacteriaceae. Open Forum Infect Dis 2019; 6:ofz123. [PMID: 30968059 PMCID: PMC6446133 DOI: 10.1093/ofid/ofz123] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2018] [Accepted: 03/08/2019] [Indexed: 01/05/2023] Open
Abstract
Plazomicin is an aminoglycoside that was approved in June 2018 by the US Food and Drug Administration for the treatment of complicated urinary tract infections, including pyelonephritis, due to Escherichia coli, Klebsiella pneumoniae, Enterobacter cloacae, and Proteus mirabilis. Plazomicin was engineered to overcome the most common aminoglycoside resistance mechanism, inactivation by aminoglycoside-modifying enzymes, but is not active against the less common 16S ribosomal RNA methyltransferases (16S-RMTase), which confer target site modification. As an aminoglycoside, plazomicin maintains activity against Enterobacteriaceae that express resistance mechanisms to other antibiotic classes, including metallo-β-lactamases. Therefore, in the absence of a 16S-RMTase, plazomicin is active against metallo-β-lactamase-producing Enterobacteriaceae.
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Affiliation(s)
- Alisa W Serio
- Department of Clinical Microbiology, Achaogen, Inc., South San Francisco, California
| | - Tiffany Keepers
- Department of Clinical Microbiology, Achaogen, Inc., South San Francisco, California
| | - Kevin M Krause
- Department of Clinical Microbiology, Achaogen, Inc., South San Francisco, California
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Wagenlehner FME, Cloutier DJ, Komirenko AS, Cebrik DS, Krause KM, Keepers TR, Connolly LE, Miller LG, Friedland I, Dwyer JP. Once-Daily Plazomicin for Complicated Urinary Tract Infections. N Engl J Med 2019; 380:729-740. [PMID: 30786187 DOI: 10.1056/nejmoa1801467] [Citation(s) in RCA: 127] [Impact Index Per Article: 25.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
BACKGROUND The increasing multidrug resistance among gram-negative uropathogens necessitates new treatments for serious infections. Plazomicin is an aminoglycoside with bactericidal activity against multidrug-resistant (including carbapenem-resistant) Enterobacteriaceae. METHODS We randomly assigned 609 patients with complicated urinary tract infections (UTIs), including acute pyelonephritis, in a 1:1 ratio to receive intravenous plazomicin (15 mg per kilogram of body weight once daily) or meropenem (1 g every 8 hours), with optional oral step-down therapy after at least 4 days of intravenous therapy, for a total of 7 to 10 days of therapy. The primary objective was to show the noninferiority of plazomicin to meropenem in the treatment of complicated UTIs, including acute pyelonephritis, with a noninferiority margin of 15 percentage points. The primary end points were composite cure (clinical cure and microbiologic eradication) at day 5 and at the test-of-cure visit (15 to 19 days after initiation of therapy) in the microbiologic modified intention-to-treat population. RESULTS Plazomicin was noninferior to meropenem with respect to the primary efficacy end points. At day 5, composite cure was observed in 88.0% of the patients (168 of 191 patients) in the plazomicin group and in 91.4% (180 of 197 patients) in the meropenem group (difference, -3.4 percentage points; 95% confidence interval [CI], -10.0 to 3.1). At the test-of-cure visit, composite cure was observed in 81.7% (156 of 191 patients) and 70.1% (138 of 197 patients), respectively (difference, 11.6 percentage points; 95% CI, 2.7 to 20.3). At the test-of-cure visit, a higher percentage of patients in the plazomicin group than in the meropenem group were found to have microbiologic eradication, including eradication of Enterobacteriaceae that were not susceptible to aminoglycosides (78.8% vs. 68.6%) and Enterobacteriaceae that produce extended-spectrum β-lactamases (82.4% vs. 75.0%). At late follow-up (24 to 32 days after initiation of therapy), fewer patients in the plazomicin group than in the meropenem group had microbiologic recurrence (3.7% vs. 8.1%) or clinical relapse (1.6% vs. 7.1%). Increases in serum creatinine levels of 0.5 mg or more per deciliter (≥40 μmol per liter) above baseline occurred in 7.0% of patients in the plazomicin group and in 4.0% in the meropenem group. CONCLUSIONS Once-daily plazomicin was noninferior to meropenem for the treatment of complicated UTIs and acute pyelonephritis caused by Enterobacteriaceae, including multidrug-resistant strains. (Funded by Achaogen and the Biomedical Advanced Research and Development Authority; EPIC ClinicalTrials.gov number, NCT02486627.).
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Affiliation(s)
- Florian M E Wagenlehner
- From the Justus Liebig University, Giessen, Germany (F.M.E.W.); Achaogen, South San Francisco (D.J.C., A.S.K., D.S.C., K.M.K., T.R.K., L.E.C., I.F.), the David Geffen School of Medicine, University of California Los Angeles (UCLA), Los Angeles (L.G.M.), and Los Angeles Biomedical Research Institute at Harbor-UCLA Medical Center, Torrance (L.G.M.) - all in California; and Vanderbilt University Medical Center, Nashville (J.P.D.)
| | - Daniel J Cloutier
- From the Justus Liebig University, Giessen, Germany (F.M.E.W.); Achaogen, South San Francisco (D.J.C., A.S.K., D.S.C., K.M.K., T.R.K., L.E.C., I.F.), the David Geffen School of Medicine, University of California Los Angeles (UCLA), Los Angeles (L.G.M.), and Los Angeles Biomedical Research Institute at Harbor-UCLA Medical Center, Torrance (L.G.M.) - all in California; and Vanderbilt University Medical Center, Nashville (J.P.D.)
| | - Allison S Komirenko
- From the Justus Liebig University, Giessen, Germany (F.M.E.W.); Achaogen, South San Francisco (D.J.C., A.S.K., D.S.C., K.M.K., T.R.K., L.E.C., I.F.), the David Geffen School of Medicine, University of California Los Angeles (UCLA), Los Angeles (L.G.M.), and Los Angeles Biomedical Research Institute at Harbor-UCLA Medical Center, Torrance (L.G.M.) - all in California; and Vanderbilt University Medical Center, Nashville (J.P.D.)
| | - Deborah S Cebrik
- From the Justus Liebig University, Giessen, Germany (F.M.E.W.); Achaogen, South San Francisco (D.J.C., A.S.K., D.S.C., K.M.K., T.R.K., L.E.C., I.F.), the David Geffen School of Medicine, University of California Los Angeles (UCLA), Los Angeles (L.G.M.), and Los Angeles Biomedical Research Institute at Harbor-UCLA Medical Center, Torrance (L.G.M.) - all in California; and Vanderbilt University Medical Center, Nashville (J.P.D.)
| | - Kevin M Krause
- From the Justus Liebig University, Giessen, Germany (F.M.E.W.); Achaogen, South San Francisco (D.J.C., A.S.K., D.S.C., K.M.K., T.R.K., L.E.C., I.F.), the David Geffen School of Medicine, University of California Los Angeles (UCLA), Los Angeles (L.G.M.), and Los Angeles Biomedical Research Institute at Harbor-UCLA Medical Center, Torrance (L.G.M.) - all in California; and Vanderbilt University Medical Center, Nashville (J.P.D.)
| | - Tiffany R Keepers
- From the Justus Liebig University, Giessen, Germany (F.M.E.W.); Achaogen, South San Francisco (D.J.C., A.S.K., D.S.C., K.M.K., T.R.K., L.E.C., I.F.), the David Geffen School of Medicine, University of California Los Angeles (UCLA), Los Angeles (L.G.M.), and Los Angeles Biomedical Research Institute at Harbor-UCLA Medical Center, Torrance (L.G.M.) - all in California; and Vanderbilt University Medical Center, Nashville (J.P.D.)
| | - Lynn E Connolly
- From the Justus Liebig University, Giessen, Germany (F.M.E.W.); Achaogen, South San Francisco (D.J.C., A.S.K., D.S.C., K.M.K., T.R.K., L.E.C., I.F.), the David Geffen School of Medicine, University of California Los Angeles (UCLA), Los Angeles (L.G.M.), and Los Angeles Biomedical Research Institute at Harbor-UCLA Medical Center, Torrance (L.G.M.) - all in California; and Vanderbilt University Medical Center, Nashville (J.P.D.)
| | - Loren G Miller
- From the Justus Liebig University, Giessen, Germany (F.M.E.W.); Achaogen, South San Francisco (D.J.C., A.S.K., D.S.C., K.M.K., T.R.K., L.E.C., I.F.), the David Geffen School of Medicine, University of California Los Angeles (UCLA), Los Angeles (L.G.M.), and Los Angeles Biomedical Research Institute at Harbor-UCLA Medical Center, Torrance (L.G.M.) - all in California; and Vanderbilt University Medical Center, Nashville (J.P.D.)
| | - Ian Friedland
- From the Justus Liebig University, Giessen, Germany (F.M.E.W.); Achaogen, South San Francisco (D.J.C., A.S.K., D.S.C., K.M.K., T.R.K., L.E.C., I.F.), the David Geffen School of Medicine, University of California Los Angeles (UCLA), Los Angeles (L.G.M.), and Los Angeles Biomedical Research Institute at Harbor-UCLA Medical Center, Torrance (L.G.M.) - all in California; and Vanderbilt University Medical Center, Nashville (J.P.D.)
| | - Jamie P Dwyer
- From the Justus Liebig University, Giessen, Germany (F.M.E.W.); Achaogen, South San Francisco (D.J.C., A.S.K., D.S.C., K.M.K., T.R.K., L.E.C., I.F.), the David Geffen School of Medicine, University of California Los Angeles (UCLA), Los Angeles (L.G.M.), and Los Angeles Biomedical Research Institute at Harbor-UCLA Medical Center, Torrance (L.G.M.) - all in California; and Vanderbilt University Medical Center, Nashville (J.P.D.)
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McKinnell JA, Dwyer JP, Talbot GH, Connolly LE, Friedland I, Smith A, Jubb AM, Serio AW, Krause KM, Daikos GL. Plazomicin for Infections Caused by Carbapenem-Resistant Enterobacteriaceae. N Engl J Med 2019; 380:791-793. [PMID: 30786196 DOI: 10.1056/nejmc1807634] [Citation(s) in RCA: 124] [Impact Index Per Article: 24.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Affiliation(s)
| | | | | | | | | | | | | | | | | | - George L Daikos
- National and Kapodistrian University of Athens, Athens, Greece
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10
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Castanheira M, Davis AP, Serio AW, Krause KM, Mendes RE. In vitro activity of Plazomicin against Enterobacteriaceae isolates carrying genes encoding aminoglycoside-modifying enzymes most common in US Census divisions. Diagn Microbiol Infect Dis 2018; 94:73-77. [PMID: 30661726 DOI: 10.1016/j.diagmicrobio.2018.10.023] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2018] [Revised: 09/28/2018] [Accepted: 10/04/2018] [Indexed: 10/27/2022]
Abstract
Aminoglycoside-nonsusceptible isolates of Escherichia coli, Klebsiella, Proteus, and Enterobacter species (480/3675) from US hospitals collected during 2014-2015 were screened for 16S rRNA methyltransferase and aminoglycoside-modifying enzyme (AME) genes. Only 5 isolates had high aminoglycoside MICs and carried 16S rRNA methyltransferases. AME genes were observed among 89.7% (426/475) of isolates and the most common genes were aac(3)-IIa (n = 270) and aac(6')-Ib (n = 269). Among other genes, ant(2″)-Ia, aac(3)-Iva, and aph(3')-VIa were observed among 36, 23, and 3 isolates, respectively. Forty-nine (10.3%) isolates yielded negative results for the investigated AME genes. Plazomicin (MIC50/90, 0.5/1 μg/ml) inhibited 99.3% of the AME-carrying isolates at its susceptible breakpoint while amikacin, gentamicin, and tobramycin inhibited 90.1%, 20.9%, and 18.3%, respectively. Plazomicin was approved by the US Food and Drug Administration in June 2018 for the treatment of complicated urinary tract infections when limited treatment options are available. This agent displayed activity against isolates carrying AMEs that were resistance to other aminoglycosides and comparator agents.
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11
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Serio AW, Smith A, Krause KM, Galani I, Gales AC, Jubb A, Connolly LE. 1964. Microbiological Outcomes With Plazomicin (PLZ) vs. Colistin (CST) in Patients With Bloodstream Infections (BSI) Caused by Carbapenem-Resistant Enterobacteriaceae (CRE) in the CARE Study. Open Forum Infect Dis 2018. [PMCID: PMC6253793 DOI: 10.1093/ofid/ofy210.1620] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Background PLZ is a next-generation aminoglycoside with structural modifications that protect it from aminoglycoside-modifying enzymes (AMEs) and in vitro activity against multidrug-resistant (MDR) Enterobacteriaceae, including aminoglycoside- and carbapenem-resistant strains. In the CARE study, PLZ was associated with improvement in 28-day all-cause mortality vs. CST in patients with CRE BSI. We report the microbiological outcomes in the CARE study by pathogen and key resistance mechanism. Methods CARE was a multinational, open-label trial that enrolled BSI patients with documented or presumed CRE into two cohorts. Patients in the randomized cohort received PLZ (15 mg/kg q24h IV) or CST (300-mg load [CST base activity] then 5 mg/kg/day IV) plus adjunctive tigecycline or meropenem. Patients in the observational cohort received PLZ plus investigator’s choice of adjunctive agent. Treatment duration was 7–14 days. Isolate identification and susceptibility testing were conducted by a central laboratory. Whole-genome sequencing was used to identify AME and carbapenemase genes. Microbiological outcomes were assessed in patients with confirmed CRE who received ≥1 dose of study drug (mMITT population). Results Of 45 BSI patients enrolled, 43 had confirmed CRE (mMITT), including Klebsiella pneumoniae (n = 42) and Enterobacter aerogenes (n = 1). Against CRE, PLZ MICs ranged from 0.12 to >128 µg/mL; 25/28 (89.3%) isolates from PLZ-treated patients had a PLZ MIC ≤4 µg/mL, while 3 had a PLZ MIC ≥128 µg/mL and a confirmed 16S ribosomal methyltransferase gene. CST MICs ranged from 0.25 to >128 µg/mL; 6/16 (37.5%) isolates from CST-treated patients had an MIC >2 µg/mL. There were 47 distinct Enterobacteriaceae pathogens isolated from 43 patients, and of these, AME genes were detected in 43/47 (91.5%), most commonly aac(6’)-Ib (n = 29). Carbapenemase genes were detected in 45/47 (95.7%) isolates, most commonly blaKPC (n = 33). PLZ demonstrated higher microbiological eradication rates than CST against CRE, including AME- and carbapenemase-producing isolates (table). Conclusion The results provide evidence of the efficacy of PLZ-based therapy for patients with BSI due to MDR Enterobacteriaceae, including AME- and carbapenemase-producing organisms. ![]()
Disclosures A. W. Serio, Achaogen, Inc.: Employee and Shareholder, Salary. A. Smith, Achaogen, Inc.: Employee and Shareholder, Salary. K. M. Krause, Achaogen, Inc.: Employee, Salary. I. Galani, Achaogen, Inc.: Scientific Advisor, Research funding and honoraria. MSD: Scientific Advisor, Honoraria. A. C. Gales, MSD: Consultant and Speaker, Consulting fee. Pfizer: Consultant and Speaker, Consulting fee. BD: Consultant, Consulting fee. Bayer: Consultant, Consulting fee. A. Jubb, Achaogen, Inc.: Employee and Shareholder, Salary. L. E. Connolly, Achaogen, Inc.: Consultant, Consulting fee.
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Affiliation(s)
| | - Alex Smith
- Achaogen, Inc., South San Francisco, California
| | | | - Irene Galani
- Infectious Diseases Research Laboratory, 4th Department of Internal Medicine, University General Hospital Attikon, National and Kapodistrian University of Athens, Athens, Greece
| | - Ana Cristina Gales
- Division of Infectious Diseases, Department of Internal Medicine, Escola Paulista de Medicina/Universidade Federal de São Paulo (EPM/UNIFESP), São Paulo, Brazil
| | - Adrian Jubb
- Achaogen, Inc., South San Francisco, California
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12
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Jacobs MR, Good CE, Abdelhamed AM, Rhoads DD, Hujer KM, Hujer AM, Rudin SD, Domitrovic TN, Connolly L, Krause KM, Richter SS, Van Duin D, Kreiswirth BN, Bonomo RA. 1348. In vitro Activity of Plazomicin, a Next-Generation Aminoglycoside, Against Carbapenemase-Producing Klebsiella pneumoniae. Open Forum Infect Dis 2018. [PMCID: PMC6254231 DOI: 10.1093/ofid/ofy210.1179] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Background Methods Results Conclusion Disclosures
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Affiliation(s)
- Michael R Jacobs
- Case Western Reserve University and University Hospitals Cleveland Medical Center, Cleveland, Ohio
| | - Caryn E Good
- Pathology, Case Western Reserve University and University Hospitals Cleveland Medical Center, Cleveland, Ohio
| | - Ayman M Abdelhamed
- Case Western Reserve University and University Hospitals Cleveland Medical Center, Cleveland, Ohio
| | - Daniel D Rhoads
- Case Western Reserve University and University Hospitals Cleveland Medical Center, Cleveland, Ohio
| | - Kristine M Hujer
- Louis Stokes Cleveland Veterans Affairs Medical Center, Cleveland, Ohio,Case Western Reserve University, Cleveland, Ohio
| | - Andrea M Hujer
- Louis Stokes Cleveland Veterans Affairs Medical Center, Cleveland, Ohio,Case Western Reserve University, Cleveland, Ohio
| | - Susan D Rudin
- Louis Stokes Cleveland Veterans Affairs Medical Center, Cleveland, Ohio,Case Western Reserve University, Cleveland, Ohio
| | - T Nicholas Domitrovic
- Louis Stokes Cleveland Veterans Affairs Medical Center, Cleveland, Ohio,Case Western Reserve University, Cleveland, Ohio
| | | | | | - Sandra S Richter
- Department of Laboratory Medicine, Cleveland Clinic, Cleveland, Ohio
| | - David Van Duin
- Medicine, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
| | - Barry N Kreiswirth
- Public Health Research Institute, Rutgers New Jersey Medical School, Newark, New Jersey
| | - Robert A Bonomo
- Louis Stokes Cleveland Veterans Affairs Medical Center, Cleveland, Ohio,Case Western Reserve University, Cleveland, Ohio
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13
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Castanheira M, Streit JM, Serio AW, Krause KM, Flamm RK. 1345. Comparative Activity of Plazomicin and Other Aminoglycosides Against Enterobacteriaceae Isolates From Various Infection Sources From Hospitalized Patients in the United States. Open Forum Infect Dis 2018. [PMCID: PMC6253586 DOI: 10.1093/ofid/ofy210.1176] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Abstract
Background
Plazomicin is a next-generation aminoglycoside that is currently under review at the United States Food and Drug Administration for complicated urinary tract infections (cUTIs), including acute pyelonephritis, and bloodstream infections (BSIs) due to certain Enterobacteriaceae (ENT) in patients who have limited or no alternative treatment options. We evaluated the activity of plazomicin and aminoglycosides against ENT isolates collected in US hospitals during 2014 to 2017 by site of infection.
Methods
A total of 8,510 ENT isolates were collected from BSIs (2,133), pneumonia in hospitalized patients (PIHP; 1,826), skin and skin structure infections (SSSIs; 1,155), intra-abdominal infections (IAIs; 731), UTIs (2,508), and other or unknown infection sites (others; 157) in 71 US hospitals during 2014 to 2017. Isolates were susceptibility (S) tested by reference broth microdilution methods and results were interpreted using CLSI breakpoints.
Results
Plazomicin (MIC50/90 ranges, 0.25–0.5/1–2 µg/mL) inhibited 98.8–99.9% of the ENT isolates at ≤4 µg/mL across all infection types (figure). At ≤4 µg/mL, plazomicin inhibited 93.8–100% of the carbapenem-resistant ENT (CRE) isolates stratified by infection type. The S rates for amikacin ranged from 98.7% to 99.7% against ENT isolates overall. However, amikacin S rates for CRE ranged from 53.1% for UTI to 100% for IAI isolates. Gentamicin (89.2–93.6%S) and tobramycin (88.8–94.3%S) were slightly less active than plazomicin and amikacin against the ENT isolates stratified by infection source. Gentamicin S rates against CRE isolates ranged from 43.8% to 66.7% while tobramycin inhibited <45% of the CRE isolates from the different infection sources.
Conclusion
The activity of plazomicin and amikacin was similar against ENT isolates from US hospitals and did not vary by infection type; however, amikacin activity against CRE isolates varied by infection source while plazomicin remained active against CRE isolates regardless of infection source. These results highlight the potential role of plazomicin for treating serious infections caused by CRE. This project was partially funded under BARDA Contract No. HHSO100201000046C.
Disclosures
M. Castanheira, Achaogen: Research Contractor, Research support. J. M. Streit, Achaogen: Research Contractor, Research support. A. W. Serio, Achaogen: Employee, Salary. K. M. Krause, Achaogen: Employee, Salary. R. K. Flamm, Achaogen: Research Contractor, Research support.
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Affiliation(s)
| | | | | | | | - Robert K Flamm
- United States Committee on Antimicrobial Susceptibility Testing, Silverton, Oregon
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Cox G, Ejim L, Stogios PJ, Koteva K, Bordeleau E, Evdokimova E, Sieron AO, Savchenko A, Serio AW, Krause KM, Wright GD. Plazomicin Retains Antibiotic Activity against Most Aminoglycoside Modifying Enzymes. ACS Infect Dis 2018; 4:980-987. [PMID: 29634241 DOI: 10.1021/acsinfecdis.8b00001] [Citation(s) in RCA: 75] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Plazomicin is a next-generation, semisynthetic aminoglycoside antibiotic currently under development for the treatment of infections due to multidrug-resistant Enterobacteriaceae. The compound was designed by chemical modification of the natural product sisomicin to provide protection from common aminoglycoside modifying enzymes that chemically alter these drugs via N-acetylation, O-adenylylation, or O-phosphorylation. In this study, plazomicin was profiled against a panel of isogenic strains of Escherichia coli individually expressing twenty-one aminoglycoside resistance enzymes. Plazomicin retained antibacterial activity against 15 of the 17 modifying enzyme-expressing strains tested. Expression of only two of the modifying enzymes, aac(2')-Ia and aph(2″)-IVa, decreased plazomicin potency. On the other hand, expression of 16S rRNA ribosomal methyltransferases results in a complete lack of plazomicin potency. In vitro enzymatic assessment confirmed that AAC(2')-Ia and APH(2'')-IVa (aminoglycoside acetyltransferase, AAC; aminoglycoside phosphotransferase, APH) were able to utilize plazomicin as a substrate. AAC(2')-Ia and APH(2'')-IVa are limited in their distribution to Providencia stuartii and Enterococci, respectively. These data demonstrate that plazomicin is not modified by a broad spectrum of common aminoglycoside modifying enzymes including those commonly found in Enterobacteriaceae. However, plazomicin is inactive in the presence of 16S rRNA ribosomal methyltransferases, which should be monitored in future surveillance programs.
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Affiliation(s)
- Georgina Cox
- M.G. DeGroote Institute for Infectious Disease Research, Department of Biochemistry and Biomedical Sciences, DeGroote School of Medicine, McMaster University, 1280 Main Street West, Hamilton, Ontario L8N 4K1, Canada
| | - Linda Ejim
- M.G. DeGroote Institute for Infectious Disease Research, Department of Biochemistry and Biomedical Sciences, DeGroote School of Medicine, McMaster University, 1280 Main Street West, Hamilton, Ontario L8N 4K1, Canada
| | - Peter J. Stogios
- Center for Structural Genomics of Infectious Diseases (CSGID) and Department of Chemical Engineering and Applied Chemistry, University of Toronto, Toronto, Ontario M5G 1L6, Canada
| | - Kalinka Koteva
- M.G. DeGroote Institute for Infectious Disease Research, Department of Biochemistry and Biomedical Sciences, DeGroote School of Medicine, McMaster University, 1280 Main Street West, Hamilton, Ontario L8N 4K1, Canada
| | - Emily Bordeleau
- M.G. DeGroote Institute for Infectious Disease Research, Department of Biochemistry and Biomedical Sciences, DeGroote School of Medicine, McMaster University, 1280 Main Street West, Hamilton, Ontario L8N 4K1, Canada
| | - Elena Evdokimova
- Center for Structural Genomics of Infectious Diseases (CSGID) and Department of Chemical Engineering and Applied Chemistry, University of Toronto, Toronto, Ontario M5G 1L6, Canada
| | - Arthur O. Sieron
- M.G. DeGroote Institute for Infectious Disease Research, Department of Biochemistry and Biomedical Sciences, DeGroote School of Medicine, McMaster University, 1280 Main Street West, Hamilton, Ontario L8N 4K1, Canada
| | - Alexei Savchenko
- Center for Structural Genomics of Infectious Diseases (CSGID) and Department of Chemical Engineering and Applied Chemistry, University of Toronto, Toronto, Ontario M5G 1L6, Canada
- Department of Microbiology, Immunology and Infectious Diseases, Health Research Innovation Centre, University of Calgary, 3330 Hospital Drive NW, HRIC-2C66, Calgary, Alberta T2N 4N1, Canada
| | - Alisa W. Serio
- Achaogen, One Tower Place, Suite 300, South San Francisco, California 94080, United States
| | - Kevin M. Krause
- Achaogen, One Tower Place, Suite 300, South San Francisco, California 94080, United States
| | - Gerard D. Wright
- M.G. DeGroote Institute for Infectious Disease Research, Department of Biochemistry and Biomedical Sciences, DeGroote School of Medicine, McMaster University, 1280 Main Street West, Hamilton, Ontario L8N 4K1, Canada
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15
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Buyck JM, Luyckx C, Muccioli GG, Krause KM, Nichols WW, Tulkens PM, Van Bambeke F. Pharmacodynamics of ceftazidime/avibactam against extracellular and intracellular forms of Pseudomonas aeruginosa. J Antimicrob Chemother 2018; 72:1400-1409. [PMID: 28137941 DOI: 10.1093/jac/dkw587] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2016] [Accepted: 12/20/2016] [Indexed: 02/05/2023] Open
Abstract
Objectives When tested in broth, avibactam reverses ceftazidime resistance in many Pseudomonas aeruginosa that express ESBLs. We examined whether similar reversal is observed against intracellular forms of P. aeruginosa . Methods Strains: reference strains; two engineered strains with basal non-inducible expression of AmpC and their isogenic mutants with stably derepressed AmpC; and clinical isolates with complete, partial or no resistance to reversion with avibactam. Pharmacodynamic model: 24 h concentration-response to ceftazidime [0.01-200 mg/L alone or with avibactam (4 mg/L)] of bacteria in broth or bacteria phagocytosed by THP-1 monocytes, with calculation of ceftazidime relative potency ( C s : concentration yielding a static effect) and maximal relative effect [ E max : cfu decrease at infinitely large antibiotic concentrations (efficacy in the model)] using the Hill equation. Cellular content of avibactam: quantification by LC-MS/MS. Results For both extracellular and intracellular bacteria, ceftazidime C s was always close to its MIC. For ceftazidime-resistant strains, avibactam addition shifted ceftazidime C s to values close to the MIC of the combination in broth. E max was systematically below the detection limit (-5 log 10 ) for extracellular bacteria, but limited to -1.3 log 10 for intracellular bacteria (except for two isolates) with no effect of avibactam. The cellular concentration of avibactam reflected extracellular concentration and was not influenced by ceftazidime (0-160 mg/L). Conclusions The potential for avibactam to inhibit β-lactamases does not differ for extracellular and intracellular forms of P. aeruginosa , denoting an unhindered access to its target in both situations. The loss of maximal relative efficacy of ceftazidime against intracellular P. aeruginosa was unrelated to resistance via avibactam-inhibitable β-lactamases.
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Affiliation(s)
- J M Buyck
- Pharmacologie cellulaire et moléculaire, Louvain Drug Research Institute, Université catholique de Louvain, Brussels, Belgium
| | - C Luyckx
- Pharmacologie cellulaire et moléculaire, Louvain Drug Research Institute, Université catholique de Louvain, Brussels, Belgium
| | - G G Muccioli
- MASSMET Platform, Louvain Drug Research Institute, Université catholique de Louvain, Brussels, Belgium.,Bioanalysis and Pharmacology of Bioactive Lipids Research Group, Louvain Drug Research Institute, Université catholique de Louvain, Brussels, Belgium
| | | | - W W Nichols
- AstraZeneca Pharmaceuticals, Waltham, MA, USA
| | - P M Tulkens
- Pharmacologie cellulaire et moléculaire, Louvain Drug Research Institute, Université catholique de Louvain, Brussels, Belgium
| | - F Van Bambeke
- Pharmacologie cellulaire et moléculaire, Louvain Drug Research Institute, Université catholique de Louvain, Brussels, Belgium
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16
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Sleger T, Gangl E, Pop-Damkov P, Krause KM, Laud PJ, Slee AM, Nichols WW. Efficacy of ceftazidime-avibactam in a rat intra-abdominal abscess model against a ceftazidime- and meropenem-resistant isolate of Klebsiella pneumoniae carrying bla KPC-2. J Chemother 2017; 30:95-100. [PMID: 29191131 DOI: 10.1080/1120009x.2017.1405609] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Efficacies of ceftazidime-avibactam (4:1 w/w) and ceftazidime were tested against ceftazidime-susceptible (blaKPC-2-negative), and meropenem- and ceftazidime-resistant (blaKPC-2-positive), Klebsiella pneumoniae in a 52-h, multiple dose, abdominal abscess model in the rat. Efficacies corresponded to minimum inhibitory concentrations (MICs) measured in vitro and were consistent with drug exposures modelled from pharmacokinetics in infected animals. The ceftazidime, ceftazidime-avibactam and meropenem control treatments were effective in the rat abscess model against the susceptible strain, whereas only ceftazidime-avibactam was effective against K. pneumoniae harbouring blaKPC-2.
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Affiliation(s)
- Taryn Sleger
- a Avastus Preclinical Services , Cambridge , MA , USA
| | - Eric Gangl
- b AstraZeneca Pharmaceuticals , Waltham , MA , USA
| | | | | | - Peter J Laud
- d Statistical Services Unit , University of Sheffield , Sheffield , UK
| | - Andrew M Slee
- a Avastus Preclinical Services , Cambridge , MA , USA
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17
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Castanheira M, Deshpande LM, Hubler CM, Mendes RE, Serio AW, Krause KM, Flamm RK. Activity of Plazomicin against Enterobacteriaceae Isolates Collected in the United States Including Isolates Carrying Aminoglycoside-Modifying Enzymes Detected by Whole Genome Sequencing. Open Forum Infect Dis 2017. [PMCID: PMC5630809 DOI: 10.1093/ofid/ofx163.931] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
Background Plazomicin (PLZ) is a next-generation aminoglycoside (AMG) stable against aminoglycoside-modifying enzymes (AME) that completed Phase 3 studies for complicated urinary tract infections and serious infections due to carbapenem-resistant Enterobacteriaceae (ENT). We evaluated the activity of PLZ and AMGs against ENT collected in US hospitals during 2016. Methods A total of 2,097 ENT were susceptibility (S) tested by CLSI reference broth microdilution methods. E. coli, Klebsiella spp. Enterobacter spp., and P. mirabilis isolates displaying non-S MICs (CLSI criteria) for gentamicin (GEN), amikacin (AMK), and/or tobramycin (TOB) were submitted to WGS, de novo assembly and screening for AME genes. Results Against ENT, PLZ was more active than all 3 clinically available AMGs (Table). PLZ and AMK activities were stable regardless of the infection type; however, differences were observed for GEN and TOB. Bloodstream isolates displayed higher GEN MICs when compared with the other infection sites. TOB activity varied 4-fold, being higher for bloodstream and pneumonia infections and lower for skin/soft tissue and other/unknown specimens. Against 198 isolates carrying 1 or more AME-encoding genes detected among 208 AMG-non-S isolates, the activity of PLZ was 8- to 16-fold greater when compared with the activity of AMK and at least 16-fold higher than the activity of GEN or TOB. Conclusion PLZ was active against ENT isolates from US hospitals regardless of infection type. PLZ displayed activity against isolates carrying AME genes that represent 12.0% of selected species. AME-carrying isolates were considerably more resistant to AMK, GEN, and TOB, highlighting the potential value of PLZ to treat infections caused by these organisms. This project has been funded under BARDA Contract No. HHSO100201000046C. Disclosures M. Castanheira, Achaogen: Research Contractor, Research grant; L. M. Deshpande, Achaogen: Research Contractor, Research grant; C. M. Hubler, Achaogen: Research Contractor, Research grant; R. E. Mendes, Achaogen: Research Contractor, Research grant; A. W. Serio, Achaogen: Employee, Salary; K. M. Krause, Achaogen: Employee, Salary; R. K. Flamm, Achaogen: Research Contractor, Research grant
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18
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Cloutier DJ, Komirenko AS, Cebrik DS, Keepers TR, Krause KM, Connolly LE, Wagenlehner FM. Plazomicin Vs. Meropenem for Complicated Urinary Tract Infection (cUTI) and Acute Pyelonephritis (AP): Diagnosis-specific Results From the Phase 3 EPIC Study. Open Forum Infect Dis 2017. [DOI: 10.1093/ofid/ofx163.1385] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
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19
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Denervaud-Tendon V, Poirel L, Connolly LE, Krause KM, Nordmann P. Plazomicin activity against polymyxin-resistant Enterobacteriaceae, including MCR-1-producing isolates. J Antimicrob Chemother 2017; 72:2787-2791. [DOI: 10.1093/jac/dkx239] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2017] [Accepted: 06/15/2017] [Indexed: 11/13/2022] Open
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20
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Keepers TR, Gomez M, Celeri C, Krause KM, Biek D, Critchley I. Fosfomycin and Comparator Activity Against Select Enterobacteriaceae, Pseudomonas, and Enterococcus Urinary Tract Infection Isolates from the United States in 2012. Infect Dis Ther 2017; 6:233-243. [PMID: 28285420 PMCID: PMC5446363 DOI: 10.1007/s40121-017-0150-5] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2017] [Indexed: 11/30/2022] Open
Abstract
INTRODUCTION Fosfomycin is a broad-spectrum cell wall active agent that inhibits the MurA enzyme involved in peptidoglycan synthesis and is FDA-approved for treatment of uncomplicated urinary tract infections (UTIs) caused by Escherichia coli and Enterococcus faecalis in women. Data regarding the susceptibility of recent UTI isolates to fosfomycin are limited. METHODS This study compared the fosfomycin susceptibility of 658 US UTI isolates with susceptibility to ciprofloxacin, levofloxacin, nitrofurantoin, and trimethoprim/sulfamethoxazole (SXT). Isolates included E. coli (n = 257), Klebsiella spp. (n = 156), Enterobacter spp. (n = 79), Pseudomonas aeruginosa (n = 60), E. faecalis (n = 54), and Proteus spp. (n = 52). Extended-spectrum β-lactamase (ESBL)-producing E. coli, Klebsiella spp., and Proteus mirabilis, ceftazidime-nonsusceptible P. aeruginosa and Enterobacter spp., and vancomycin-nonsusceptible E. faecalis were included. RESULTS Overall, the minimum concentration inhibiting 50% of isolates (MIC50) and 90% of isolates (MIC90) for fosfomycin were 4 and 64 µg/mL, respectively. Of the 257 E. coli isolates, 99.6% were susceptible to fosfomycin. Ciprofloxacin, levofloxacin, SXT, and nitrofurantoin susceptibility rates were 65.4%, 65.8%, 59.9%, and 90.3%, respectively. The fosfomycin-susceptibility rate for E. faecalis (94.4%) was comparable with the nitrofurantoin-susceptibility rate (98.1%). Among the 144 ESBL-producing isolates, the fosfomycin MIC50 and MIC90 values were 2 and 32 µg/mL, respectively. Fosfomycin MIC50 and MIC90 values were 16 and 128 µg/mL for the 38 ceftazidime-nonsusceptible Enterobacter isolates and 64 and 128 µg/mL for the 15 ceftazidime-nonsusceptible P. aeruginosa isolates, respectively. CONCLUSION These results demonstrate that fosfomycin has in vitro activity against many US UTI isolates, including drug-resistant isolates, and may provide another therapeutic option for treatment of UTIs caused by antibiotic-resistant pathogens.
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Affiliation(s)
| | - Marcela Gomez
- Cerexa, Inc., 2100 Franklin Street #900, Oakland, CA, 94612, USA
| | - Chris Celeri
- Cerexa, Inc., 2100 Franklin Street #900, Oakland, CA, 94612, USA
| | - Kevin M Krause
- Cerexa, Inc., 2100 Franklin Street #900, Oakland, CA, 94612, USA
| | - Donald Biek
- Cerexa, Inc., 2100 Franklin Street #900, Oakland, CA, 94612, USA
| | - Ian Critchley
- Cerexa, Inc., 2100 Franklin Street #900, Oakland, CA, 94612, USA. .,Allergan Plc, 2525 Dupont Drive, Irvine, CA, 92612, USA.
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Golan Y, Cloutier DJ, Komirenko AS, Cebrik DS, Keepers TR, Krause KM, Connolly LE, Wagenlehner FM. Improved Outcomes at Late Follow-up (LFU) with Plazomicin Compared with Meropenem in Patients with Complicated Urinary Tract Infection (cUTI) or Acute Pyelonephritis (AP) in the EPIC Study. Open Forum Infect Dis 2017. [DOI: 10.1093/ofid/ofx163.1389] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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Ambler JE, Krause KM, Steenbergen JN, Scangarella-Oman NE, Miller LA, Bhagwat SS, Serio AW, Chesnel L, Mahoney NM, Motyl MR, Critchley IA, Iaconis JP, Stone GG, Alder J, Xerri L, McCurdy SP, van Veenhuyzen DF, Grossman T, Echols RM, Williams G, Bradford PA. New Antimicrobial Agents … but No Susceptibility Tests! Clin Infect Dis 2016; 63:1530-1531. [PMID: 27581762 DOI: 10.1093/cid/ciw603] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Affiliation(s)
- Jane E Ambler
- Wockhardt/Morton Grove Pharmaceuticals, Inc, Morton Grove, Illinois
| | | | | | | | | | - Sachin S Bhagwat
- Discovery Research, Wockhardt Research Centre, Aurangabad, India
| | | | | | | | - Mary R Motyl
- Merck Sharp & Dohme Corp, Kenilworth, New Jersey
| | | | - Joseph P Iaconis
- Antibiotics Business Unit, AstraZeneca Pharmaceuticals, Waltham, Massachusetts
| | - Gregory G Stone
- Antibiotics Business Unit, AstraZeneca Pharmaceuticals, Waltham, Massachusetts
| | - Jeff Alder
- Global Clinical Development, General Medicine Bayer HealthCare, Parsippany, New Jersey
| | - Luigi Xerri
- VenatoRx Pharmaceuticals, Inc, Malvern, Pennsylvania
| | | | | | - Trudy Grossman
- Tetraphase Pharmaceuticals, Inc, Watertown, Massachusetts
| | - Roger M Echols
- Infectious Disease Drug Development Consulting, LLC, Easton, Connecticut
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Pillar CM, Stoneburner A, Shinabarger DL, Krause KM, Nichols WW. The postantibiotic effect and post-β-lactamase-inhibitor effect of ceftazidime, ceftaroline and aztreonam in combination with avibactam against target Gram-negative bacteria. Lett Appl Microbiol 2016; 63:96-102. [PMID: 27221329 DOI: 10.1111/lam.12592] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2016] [Revised: 05/19/2016] [Accepted: 05/20/2016] [Indexed: 11/26/2022]
Abstract
UNLABELLED The magnitudes of the postantibiotic effect (PAE) and post-β-lactamase-inhibitory effect (PLIE) of ceftazidime-avibactam, ceftaroline-avibactam, and aztreonam-avibactam were determined against isolates of Enterobacteriaceae and Pseudomonas aeruginosa that either harboured genes encoding serine and/or metallo-β-lactamases, or did not harbour bla genes. The bla genes included ones that encoded extended spectrum β-lactamases, AmpC and KPC β-lactamases, and one metallo-β-lactamase, NDM-1. No substantial PAE was observed for any combination against any isolate. One substantial PLIE was found: a value of 1·9 h for ceftazidime-avibactam against Klebsiella pneumoniae (blaKPC-2 ). From comparison with results in the literature, we propose that the existence of a substantial PLIE depends on the bacterial isolate and on the specific β-lactamase inhibitor and β-lactam combination. SIGNIFICANCE AND IMPACT OF THE STUDY A wave of new β-lactamase inhibitors is entering either therapeutic use or clinical trials. The present work characterizes the postantibiotic effect (PAE) and post-β-lactamase-inhibitory effect (PLIE) of the clinically most advanced of these compounds, avibactam. We show that the existence of a measurable PLIE is strain- (and possibly compound-) dependent, and cannot be relied upon as a standard component of the primary pharmacology of a new β-lactamase inhibitor. This variability was not reported in earlier studies of clavulanic acid or sulbactam.
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Abstract
Aminoglycosides are natural or semisynthetic antibiotics derived from actinomycetes. They were among the first antibiotics to be introduced for routine clinical use and several examples have been approved for use in humans. They found widespread use as first-line agents in the early days of antimicrobial chemotherapy, but were eventually replaced in the 1980s with cephalosporins, carbapenems, and fluoroquinolones. Aminoglycosides synergize with a variety of other antibacterial classes, which, in combination with the continued increase in the rise of multidrug-resistant bacteria and the potential to improve the safety and efficacy of the class through optimized dosing regimens, has led to a renewed interest in these broad-spectrum and rapidly bactericidal antibacterials.
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Affiliation(s)
| | | | | | - Lynn E Connolly
- Achaogen, South San Francisco, California 94080 Department of Medicine, Division of Infectious Diseases, University of California, San Francisco, San Francisco, California 94143
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Dallow J, Otterson LG, Huband MD, Krause KM, Nichols WW. Microbiological interaction studies between ceftazidime-avibactam and pulmonary surfactant and between ceftazidime-avibactam and antibacterial agents of other classes. Int J Antimicrob Agents 2014; 44:552-6. [DOI: 10.1016/j.ijantimicag.2014.07.023] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2014] [Accepted: 07/23/2014] [Indexed: 10/24/2022]
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Keepers TR, Gomez M, Celeri C, Nichols WW, Krause KM. Bactericidal activity, absence of serum effect, and time-kill kinetics of ceftazidime-avibactam against β-lactamase-producing Enterobacteriaceae and Pseudomonas aeruginosa. Antimicrob Agents Chemother 2014; 58:5297-305. [PMID: 24957838 PMCID: PMC4135815 DOI: 10.1128/aac.02894-14] [Citation(s) in RCA: 84] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2014] [Accepted: 06/17/2014] [Indexed: 01/31/2023] Open
Abstract
Avibactam, a non-β-lactam β-lactamase inhibitor with activity against extended-spectrum β-lactamases (ESBLs), KPC, AmpC, and some OXA enzymes, extends the antibacterial activity of ceftazidime against most ceftazidime-resistant organisms producing these enzymes. In this study, the bactericidal activity of ceftazidime-avibactam against 18 Pseudomonas aeruginosa isolates and 15 Enterobacteriaceae isolates, including wild-type isolates and ESBL, KPC, and/or AmpC producers, was evaluated. Ceftazidime-avibactam MICs (0.016 to 32 μg/ml) were lower than those for ceftazidime alone (0.06 to ≥256 μg/ml) against all isolates except for 2 P. aeruginosa isolates (1 blaVIM-positive isolate and 1 blaOXA-23-positive isolate). The minimum bactericidal concentration/MIC ratios of ceftazidime-avibactam were ≤4 for all isolates, indicating bactericidal activity. Human serum and human serum albumin had a minimal effect on ceftazidime-avibactam MICs. Ceftazidime-avibactam time-kill kinetics were evaluated at low MIC multiples and showed time-dependent reductions in the number of CFU/ml from 0 to 6 h for all strains tested. A ≥3-log10 decrease in the number of CFU/ml was observed at 6 h for all Enterobacteriaceae, and a 2-log10 reduction in the number of CFU/ml was observed at 6 h for 3 of the 6 P. aeruginosa isolates. Regrowth was noted at 24 h for some of the isolates tested in time-kill assays. These data demonstrate the potent bactericidal activity of ceftazidime-avibactam and support the continued clinical development of ceftazidime-avibactam as a new treatment option for infections caused by Enterobacteriaceae and P. aeruginosa, including isolates resistant to ceftazidime by mechanisms dependent on avibactam-sensitive β-lactamases.
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Bailey BL, Griggs TC, Rayburn EB, Krause KM. Beef heifer growth and reproductive performance following two levels of pasture allowance during the fall grazing period. J Anim Sci 2014; 92:3659-69. [PMID: 24948653 DOI: 10.2527/jas.2013-7121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
The objective of this study was to compare heifer growth and reproductive performance following 2 levels of stockpiled fall forage allowance of orchardgrass (30.5%) and tall fescue (14.1%). Spring-born heifers (n = 203 and BW = 246 ± 28.9 kg) of primarily Angus background were allocated to 2 grazing treatments during the fall period (November 12 to December 17 in yr 1, November 7 to January 4 in yr 2, and November 7 to January 14 in yr 3) each replicated 3 times per year for 3 yr. Treatments consisted of daily pasture DM allowance of 3.5% of BW (LO) or daily pasture DM allowance of 7.0% of BW (HI) under strip-grazing management. Throughout the winter feeding period, mixed grass-legume haylage and soybean hulls were fed. Heifers were grazed as 1 group under continuous stocking after the winter period. Heifers in the LO group gained less than heifers in the HI group during the fall grazing period (0.12 vs. 0.40 kg/d; P < 0.0001). For each 1 10 g increase in NDF/kg fall pasture (DM basis), fall ADG decreased 0.14 kg (P = 0.01). During winter feeding, ADG was 0.30 and 0.39 kg/d for LO vs. HI heifers, respectively (P = 0.0008). During the spring grazing period (April 16 to May 24 in yr 1, April 22 to May 26 in yr 2, and April 5 to May 16 in yr 3), LO heifers had numerically greater ADG than HI heifers (1.38 vs. 1.30 kg/d; P = 0.64). Hip height (122.7 vs. 121.4 cm; P = 0.0055), BCS (5.8 vs. 5.6; P = 0.0057), and BW (356 vs. 335 kg; P < 0.0001) at the end of spring grazing was greater for HI than LO heifers. Heifers in the LO group compensated with greater summer ADG than heifers in the HI group (0.74 vs. 0.66 kg/d; P = 0.03). Total ADG from treatment initiation (November) through pregnancy diagnosis (August) was greater for HI than LO heifers (0.61 vs. 0.55 kg/d; P < 0.001) as was BW at pregnancy diagnosis (415 vs. 402 kg; P = 0.0055). Percentage of heifers reaching puberty by the time of AI was 34% for both groups (P = 0.93). Percentage of heifers becoming pregnant to AI tended (P = 0.13) to be greater for HI (44%) than for LO heifers (32%). Fall ADG across treatment groups affected the probability of a heifer becoming pregnant by AI (P = 0.01). Percentage pregnant by natural service (61% for LO vs. 59% for HI; P = 0.80) and final pregnancy rate (74% for LO vs. 77% for HI; P = 0.61) was not different for the 2 groups. These results indicate that altering fall forage allowance may delay the majority of BW gain until late in heifer development without negatively affecting overall pregnancy rates.
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Affiliation(s)
- B L Bailey
- Division of Animal and Nutritional Sciences, West Virginia University, Morgantown 26506
| | - T C Griggs
- Division of Plant and Soil Sciences, West Virginia University, Morgantown 26506
| | - E B Rayburn
- West Virginia University Extension Service, Morgantown 26506
| | - K M Krause
- Division of Animal and Nutritional Sciences, West Virginia University, Morgantown 26506
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Jim SR, Foroughi-Abari A, Krause KM, Li P, Kupsta M, Taschuk MT, Cadien KC, Brett MJ. Ultrathin-layer chromatography nanostructures modified by atomic layer deposition. J Chromatogr A 2013; 1299:118-25. [PMID: 23768654 DOI: 10.1016/j.chroma.2013.05.050] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2013] [Revised: 05/17/2013] [Accepted: 05/21/2013] [Indexed: 10/26/2022]
Abstract
Stationary phase morphology and surface chemistry dictate the properties of ultrathin-layer chromatography (UTLC) media and interactions with analytes in sample mixtures. In this paper, we combined two powerful thin film deposition techniques to create composite chromatography nanomaterials. Glancing angle deposition (GLAD) produces high surface area columnar microstructures with aligned macropores well-suited for UTLC. Atomic layer deposition (ALD) enables precise fabrication of conformal, nanometer-scale coatings that can tune surfaces of these UTLC films. We coated ∼5μm thick GLAD SiO2 UTLC media with <10nm thick ALD metal oxides (Al2O3, ZrO2, and ZnO) to decouple surface chemistry from the underlying GLAD scaffold microstructure. The effects of ALD coatings on GLAD UTLC media were investigated using transmission electron microscopy (TEM), gas adsorption porosimetry, and lipophilic dye separations. The results collectively show that the most significant changes occur over the first few nanometers of ALD coating. They further demonstrate independent control of film microstructure and surface characteristics. ALD coatings can enhance complex GLAD microstructures to engineer new composite nanomaterials potentially useful in analytical chromatography.
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Affiliation(s)
- S R Jim
- Department of Electrical and Computer Engineering, University of Alberta, Edmonton, Alberta T6G 2V4, Canada.
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Krause KM, Blais J, Lewis SR, Lunde CS, Barriere SL, Friedland HD, Kitt MM, Benton BM. In vitro activity of telavancin and occurrence of vancomycin heteroresistance in isolates from patients enrolled in phase 3 clinical trials of hospital-acquired pneumonia. Diagn Microbiol Infect Dis 2012; 74:429-31. [DOI: 10.1016/j.diagmicrobio.2012.08.010] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2012] [Accepted: 08/16/2012] [Indexed: 10/27/2022]
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Farrell DJ, Krause KM, Benton BM. In vitro activity of telavancin and comparator antimicrobial agents against a panel of genetically defined staphylococci. Diagn Microbiol Infect Dis 2011; 69:275-9. [PMID: 21353951 DOI: 10.1016/j.diagmicrobio.2010.09.017] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2010] [Revised: 09/19/2010] [Accepted: 09/23/2010] [Indexed: 11/15/2022]
Abstract
The in vitro activity of telavancin was determined for 94 diverse Staphylococcus spp. Telavancin had MIC(90) values of 0.5 μg/mL for methicillin-susceptible, methicillin-resistant, and vancomycin-susceptible Staphylococcus aureus, and coagulase-negative staphylococci isolates. Telavancin MICs were 0.5-1 μg/mL for vancomycin-intermediate S. aureus isolates and 2-4 μg/mL for vancomycin-resistant S. aureus strains.
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Tager LR, Krause KM. Effects of essential oils on rumen fermentation, milk production, and feeding behavior in lactating dairy cows. J Dairy Sci 2011; 94:2455-64. [PMID: 21524537 DOI: 10.3168/jds.2010-3505] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2010] [Accepted: 01/07/2011] [Indexed: 11/19/2022]
Abstract
Seven ruminally cannulated lactating Holstein dairy cows were used in an incomplete Latin rectangle design to assess the effects of 2 commercial essential oil (EO) products on rumen fermentation, milk production, and feeding behavior. Cows were fed a total mixed ration with a 42:58 forage:concentrate ratio (DM basis). Treatments included addition of 0.5 g/d of CE Lo (85 mg of cinnamaldehyde and 140 mg of eugenol), 10 g/d of CE Hi (1,700 mg of cinnamaldehyde and 2,800 mg of eugenol), 0.25 g/d of CAP (50mg of capsicum), or no oil (CON). Cows were fed ad libitum twice daily for 21 d per period. Dry matter intake, number of meals/d, h eating/d, mean meal length, rumination events/d, h ruminating/d, and mean rumination length were not affected by EO. However, length of the first meal after feeding decreased with addition of CE Hi (47.2 min) and CAP (49.4 min) compared with CON (65.4 min). Total volatile fatty acids, individual volatile fatty acids, acetate:propionate ratio, and ammonia concentration were not affected by EO. Mean rumen pH as well as bouts, total h, mean bout length, total area, and mean bout area under pH 5.6 did not differ among treatments. Total tract digestibility of organic matter, dry matter, neutral detergent fiber, acid detergent fiber, crude protein, and starch were not affected by EO. Milk yield and composition did not change with EO. In situ dry matter disappearance of ground soybean hulls was not affected by EO. However, organic matter disappearance of soybean hulls with CE Hi tended to decrease compared with CON. Compared with CON, neutral detergent fiber disappearance (41.5 vs. 37.6%) and acid detergent fiber disappearance (44.5 vs. 38.8%) decreased with addition of CE Hi. The CE Lo had no effect on rumen fermentation, milk production, or feeding behavior but CAP shortened the length of the first meal without changing rumen fermentation or production, making it a possible additive for altering feeding behavior. The CE Hi negatively affected rumen fermentation and shortened the length of the first meal, suggesting that a dose of 10 g/d is not beneficial to lactating dairy cows.
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Affiliation(s)
- L R Tager
- Division of Animal and Nutritional Science, West Virginia University, Morgantown 26506, USA
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Krause KM, Barriere SL, Kitt MM, Benton BM. In vitro activity of telavancin against Gram-positive isolates from complicated skin and skin structure infections: results from 2 phase 3 (ATLAS) clinical studies. Diagn Microbiol Infect Dis 2010; 68:181-5. [DOI: 10.1016/j.diagmicrobio.2010.05.008] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2010] [Revised: 04/23/2010] [Accepted: 05/08/2010] [Indexed: 10/19/2022]
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Tager LR, Krause KM. Effects of cinnamaldehyde, eugenol, and capsicum on fermentation of a corn-based dairy ration in continuous culture. Can J Anim Sci 2010. [DOI: 10.4141/cjas09080] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
A 12-unit continuous culture system was used in a complete randomized design to study the effects of no oil (CON), cinnamaldehyde oil (CIN), eugenol oil (EUG), and capsicum oil (CAP) (500 mg L-1 d -1) with a 45:55 forage:concentrate ratio (dry matter basis) ration on rumen fermentation. Dry matter digestibility did not differ among treatments. Organic matter digestibility tended to decrease with CIN. Digestibility of neutral detergent and acid detergent fiber tended to be highest with CAP. Crude protein digestibility and bacterial nitrogen flow was depressed with CIN and EUG. CIN tended to decrease microbial protein synthesis and increase effluent ammonia nitrogen. Total volatile fatty acid production did not differ among treatments; however, isovalerate production tended to be highest with CAP. CIN and EUG had higher mean pH, spent fewer hours per day and had smaller area under the curve at pH < 5.6 and 5.8. CAP had smaller area under the curve at pH < 5.6. Supplementation with these oils at the current dose had limited effects on rumen fermentation, with the majority of effects observed being mainly attributable to the very high dosage of oil used. Key words: Dairy cow, essential oil, continuous culture, rumen fermentation, rumen pH
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Lemley CO, Vonnahme KA, Tager LR, Krause KM, Wilson ME. Diet-induced alterations in hepatic progesterone (P4) catabolic enzyme activity and P4 clearance rate in lactating dairy cows. J Endocrinol 2010; 205:233-41. [PMID: 20223860 DOI: 10.1677/joe-10-0042] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Elevated rates of steroid clearance may lead to lower reproductive success in several mammalian species. Cytochrome P450 (EC 1.14.14.1) and aldo-keto reductases (AKR; EC 1.1.1.145-151) are involved in the first phase of steroid inactivation, before second phase conjugation and excretion of the steroid metabolite. The current objectives were to determine liver blood flow (LBF), hepatic enzyme activity, and metabolic clearance rate (MCR) of progesterone (P(4)) in dairy cows consuming isoenergetic and isonitrogenous diets formulated to cause divergent insulin secretion. Insulin concentrations increased by 22% in cows fed the high cornstarch diet, and both cytochrome P450 2C and cytochrome P450 3A activities were decreased (P<0.05) by approximately 50%, while AKR1C tended (P<0.10) to be lower in cows fed the high cornstarch diet. LBF was similar between the two diets (1891+/-91 l/h). MCR of P(4) tended (P<0.10) to be lower in cows fed the high cornstarch diet (25+/-5 l/hxBW(0.75)) versus the high fiber diet (40+/-6 l/hxBW(0.75)). The half-life of P(4) was increased (P<0.05) in cows fed the high cornstarch diet (73+/-10 min) versus the high fiber diet (24+/-10 min). In summary, cows with elevated insulin concentrations and lower enzyme activity showed a decrease in P(4) clearance without any changes in LBF. This dietary relationship with hepatic enzyme activity may explain some of the observed alterations in steroid profiles during the estrous cycle or gestation of the high producing dairy cow.
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Affiliation(s)
- C O Lemley
- Division of Animal and Nutritional Sciences, Davis College of Agriculture, Natural Resources and Design, West Virginia University, Morgantown, West Virginia 26506, USA
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Hegde SS, Skinner R, Lewis SR, Krause KM, Blais J, Benton BM. Activity of telavancin against heterogeneous vancomycin-intermediate Staphylococcus aureus (hVISA) in vitro and in an in vivo mouse model of bacteraemia. J Antimicrob Chemother 2010; 65:725-8. [PMID: 20139142 DOI: 10.1093/jac/dkq028] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
OBJECTIVES Infections caused by heterogeneous vancomycin-intermediate Staphylococcus aureus (hVISA) are associated with high rates of vancomycin treatment failure. Telavancin is a bactericidal lipoglycopeptide active in vitro against Gram-positive pathogens including hVISA and vancomycin-intermediate S. aureus (VISA). This study characterizes the microbiological activity of telavancin against vancomycin-susceptible S. aureus (VSSA), hVISA and VISA strains. METHODS Reference strains of VSSA, hVISA and VISA were assessed for potential telavancin heteroresistance by population analysis. In addition, the efficacies of telavancin (40 mg/kg subcutaneously every 12 h for 4 days) and vancomycin (110 mg/kg subcutaneously every 12 h for 8 days) were compared in a neutropenic murine model (immunocompromised female non-Swiss albino mice) of bacteraemia caused by hVISA strain Mu3. Blood and spleen bacterial titres were quantified from cohorts of mice euthanized pre-treatment and at 24 h intervals post-treatment for 8 days. RESULTS Telavancin was active against all strains of S. aureus tested, with MIC values < or =0.5 mg/L. Population analyses revealed no evidence of subpopulations with reduced susceptibility to telavancin. In the murine bacteraemia model of hVISA infection, all animals were bacteraemic pre-treatment and mortality was 100% within 16-24 h post-infection in untreated animals. Treatment with telavancin was associated with lower spleen bacterial titres, lower rates of bacteraemia and lower overall mortality than treatment with vancomycin. CONCLUSIONS These in vitro and pre-clinical in vivo studies demonstrate that telavancin has the potential to be efficacious in infections caused by hVISA.
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Affiliation(s)
- Sharath S Hegde
- Theravance, Inc., 901 Gateway Boulevard, South San Francisco, CA 94080, USA.
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Long DD, Aggen JB, Christensen BG, Judice JK, Hegde SS, Kaniga K, Krause KM, Linsell MS, Moran EJ, Pace JL. A multivalent approach to drug discovery for novel antibiotics. J Antibiot (Tokyo) 2009; 61:595-602. [PMID: 19168973 DOI: 10.1038/ja.2008.79] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
The design, synthesis and antibacterial activity of novel glycopeptide/beta-lactam heterodimers is reported. Employing a multivalent approach to drug discovery, vancomycin and cephalosporin synthons, A and B respectively, were chemically linked to yield heterodimer antibiotics. These novel compounds were designed to inhibit Gram-positive bacterial cell wall biosynthesis by simultaneously targeting the principal cellular targets of both glycopeptides and beta-lactams. The antibiotics 8a-f displayed remarkable potency against a wide range of Gram-positive organisms including methicillin-resistant Staphylococcus aureus (MRSA). Compound 8e demonstrated excellent bactericidal activity against MRSA (ATCC 33591) and initial evidence supports a multivalent mechanism of action for this important new class of antibiotic.
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Hegde SS, Difuntorum S, Skinner R, Trumbull J, Krause KM. Efficacy of telavancin against glycopeptide-intermediate Staphylococcus aureus in the neutropenic mouse bacteraemia model. J Antimicrob Chemother 2009; 63:763-6. [PMID: 19155225 DOI: 10.1093/jac/dkp001] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
OBJECTIVES The aim of the study was to compare the efficacies of telavancin and vancomycin against glycopeptide-intermediate Staphylococcus aureus (GISA) and heterogeneous vancomycin-intermediate S. aureus (hVISA) in a neutropenic murine bacteraemia model. METHODS Immunocompromised mice (female non-Swiss albino, 18-30 g) were inoculated intraperitoneally with 10(7) cfu/mL of GISA (strain HIP-5836 or Mu50) or hVISA (strain Mu3). Infected mice received a subcutaneous dose of telavancin (40 mg/kg) or vancomycin (110 mg/kg) at 4 and 16 h post-inoculation. Control animals received a subcutaneous dose of vehicle at 4 h post-inoculation only. Blood and spleen bacterial titres were quantified in drug-treated mice at 16, 28 and 52 h post-inoculation. RESULTS Telavancin was 8-fold more potent than vancomycin against HIP-5836 (MIC 1 versus 8 mg/L), 16-fold more potent against Mu50 (MIC 0.5 versus 8 mg/L) and 8-fold more potent against Mu3 (MIC 0.25 versus 2 mg/L). Telavancin produced significant (P < 0.05) and sustained reductions in blood and spleen titres from pre-treatment levels in mice infected with HIP-5836, Mu50 or Mu3. Vancomycin lowered blood and spleen HIP-5836 counts transiently, but did not lower blood or spleen Mu50 or Mu3 counts significantly at any timepoint. Reductions in blood and spleen HIP-5836 and Mu3 titres and in spleen Mu50 titres at 52 h post-inoculation were significantly greater with telavancin than vancomycin (P < 0.05). CONCLUSIONS Telavancin was more efficacious than vancomycin in clearing infections caused by GISA strains HIP-5836 and Mu50 and hVISA strain Mu3 in a neutropenic mouse bacteraemia model. Further evaluation of telavancin for GISA and hVISA bacteraemia is warranted.
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Affiliation(s)
- Sharath S Hegde
- Theravance, Inc., 901 Gateway Boulevard, South San Francisco, CA 94080, USA.
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Reyes N, Skinner R, Benton BM, Krause KM, Shelton J, Obedencio GP, Hegde SS. Efficacy of telavancin in a murine model of bacteraemia induced by methicillin-resistant Staphylococcus aureus. J Antimicrob Chemother 2006; 58:462-5. [PMID: 16735425 DOI: 10.1093/jac/dkl222] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
OBJECTIVES The efficacy of telavancin, a bactericidal lipoglycopeptide, was compared with vancomycin against methicillin-resistant Staphylococcus aureus (MRSA) in an immunocompromised murine model of bacteraemia. METHODS Immunocompromised mice were inoculated intraperitoneally with S. aureus ATCC 33591 and treated with two subcutaneous doses (once every 12 h) of vehicle or test compound. Mouse pharmacokinetic data were generated and used to choose doses of telavancin (40 mg/kg) and vancomycin (110 mg/kg) in order to equate clinical exposures. Reduction in bacterial titre (in blood and spleen) and mortality were the two pharmacodynamic endpoints of the study. RESULTS Mortality was 100% in animals treated with vehicle or vancomycin but was significantly lower (7%) in telavancin-treated animals. Telavancin produced significantly greater reductions in blood and spleen bacterial titres compared with vancomycin. CONCLUSIONS The data described here demonstrate that telavancin's in vivo bactericidal activity is superior to that of vancomycin against a single strain of MRSA and results in successful infection resolution and, consequently, improved survival in the murine bacteraemia model.
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Affiliation(s)
- Noe Reyes
- Theravance, Inc., 901 Gateway Boulevard, South San Francisco CA 94080, USA
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Abstract
Data from experiments in which subacute ruminal acidosis (SARA) was induced in lactating dairy cows (days in milk = 154 +/- 118) were evaluated to investigate the effectiveness of the induction protocol and its effect on production outcomes. For 13 cows in 3 trials, ruminal pH was measured continuously and recorded each minute; dry matter intake and milk yield were recorded daily. Milk composition data were obtained from 9 cows in 2 of these trials. The SARA induction protocol included 4 separate periods: 4 d of baseline [normal total mixed ration (TMR)], 1 d of 50% restricted feeding, 1 or 2 d of challenge feeding [addition of 3.5 or 4.6 kg of wheat-barley pellet (dry matter basis) to normal TMR], and 2 d of recovery measurements when feeding normal TMR. The SARA induction protocol lowered mean ruminal pH from 6.31 during the baseline period to 5.85 during the challenge period; pH remained below baseline level during the recovery period (6.16). Mean ruminal pH was highest (6.59) during the day of restricted feeding. Nadir ruminal pH decreased from baseline to challenge period (5.76 vs. 5.13). Hours below pH 5.6 increased from 1.10 to 8.26/d from baseline to challenge period and area below 5.6 (pH x min/d) increased from 15.0 to 190.3. Dry matter intake was not affected by SARA induction. Milk yield dropped from 35.2 kg/d during baseline to 31.7 k/d during the challenge period and did not return to baseline level during the recovery period (31.3 kg/d). No depression in milk fat percentage was observed when SARA was induced. Yield of fat was highest during the restricted feeding period (1.47 kg/d) and was lower during the recovery period than during the baseline period (1.12 vs. 1.31 kg/d). The protocol successfully induced SARA (low ruminal pH without signs of acute ruminal acidosis) on the challenge day. Milk yield was substantially reduced and did not recover within 2 d after the challenge.
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Affiliation(s)
- K M Krause
- School of Veterinary Medicine, University of Wisconsin-Madison, Madison 53706, USA
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Reyes N, Skinner R, Kaniga K, Krause KM, Shelton J, Obedencio GP, Gough A, Conner M, Hegde SS. Efficacy of telavancin (TD-6424), a rapidly bactericidal lipoglycopeptide with multiple mechanisms of action, in a murine model of pneumonia induced by methicillin-resistant Staphylococcus aureus. Antimicrob Agents Chemother 2006; 49:4344-6. [PMID: 16189117 PMCID: PMC1251517 DOI: 10.1128/aac.49.10.4344-4346.2005] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The efficacy of telavancin, a bactericidal lipoglycopeptide, was compared to that of vancomycin and linezolid against methicillin-resistant Staphylococcus aureus (MRSA) in a murine pneumonia model. Telavancin produced greater reductions in lung bacterial titer and mortality than did vancomycin and linezolid at human doses equivalent to those described by the area under the concentration-time curve. These results suggest the potential utility of telavancin for treatment of MRSA pneumonia.
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Affiliation(s)
- Noe Reyes
- Theravance, Inc., South San Francisco, CA 94087, USA
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Higgins DL, Chang R, Debabov DV, Leung J, Wu T, Krause KM, Sandvik E, Hubbard JM, Kaniga K, Schmidt DE, Gao Q, Cass RT, Karr DE, Benton BM, Humphrey PP. Telavancin, a multifunctional lipoglycopeptide, disrupts both cell wall synthesis and cell membrane integrity in methicillin-resistant Staphylococcus aureus. Antimicrob Agents Chemother 2005; 49:1127-34. [PMID: 15728913 PMCID: PMC549257 DOI: 10.1128/aac.49.3.1127-1134.2005] [Citation(s) in RCA: 341] [Impact Index Per Article: 17.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The emergence and spread of multidrug-resistant gram-positive bacteria represent a serious clinical problem. Telavancin is a novel lipoglycopeptide antibiotic that possesses rapid in vitro bactericidal activity against a broad spectrum of clinically relevant gram-positive pathogens. Here we demonstrate that telavancin's antibacterial activity derives from at least two mechanisms. As observed with vancomycin, telavancin inhibited late-stage peptidoglycan biosynthesis in a substrate-dependent fashion and bound the cell wall, as it did the lipid II surrogate tripeptide N,N'-diacetyl-L-lysinyl-D-alanyl-D-alanine, with high affinity. Telavancin also perturbed bacterial cell membrane potential and permeability. In methicillin-resistant Staphylococcus aureus, telavancin caused rapid, concentration-dependent depolarization of the plasma membrane, increases in permeability, and leakage of cellular ATP and K(+). The timing of these changes correlated with rapid , concentration-dependent loss of bacterial viability, suggesting that the early bactericidal activity of telavancin results from dissipation of cell membrane potential and an increase in membrane permeability. Binding and cell fractionation studies provided direct evidence for an interaction of telavancin with the bacterial cell membrane; stronger binding interactions were observed with the bacterial cell wall and cell membrane relative to vancomycin. We suggest that this multifunctional mechanism of action confers advantageous antibacterial properties.
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Affiliation(s)
- Deborah L Higgins
- Theravance, Inc., 901 Gateway Blvd., South San Francisco, CA 94080, USA
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Leadbetter MR, Adams SM, Bazzini B, Fatheree PR, Karr DE, Krause KM, Lam BMT, Linsell MS, Nodwell MB, Pace JL, Quast K, Shaw JP, Soriano E, Trapp SG, Villena JD, Wu TX, Christensen BG, Judice JK. Hydrophobic Vancomycin Derivatives with Improved ADME Properties: Discovery of Telavancin (TD-6424). J Antibiot (Tokyo) 2004; 57:326-36. [PMID: 15303493 DOI: 10.7164/antibiotics.57.326] [Citation(s) in RCA: 123] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Novel derivatives of N-decylaminoethylvancomycin (2), containing appended hydrophilic groups were synthesized and their antibacterial activity and ADME properties were evaluated. The compounds were prepared by reacting amines with the C-terminus (C-) of 2 using PyBOP mediated amide formation, or with the resorcinol-like (R-) position of 2 using a Mannich aminomethylation reaction. These analogs retained the antibacterial activity of 2 against methicillin-resistant staphylococci and vancomycin-resistant enterococci. Compounds with a negatively charged auxiliary group also exhibited improved ADME properties relative to 2. In particular, R-phosphonomethylaminomethyl derivative 21 displayed good in vitro antibacterial activity, high urinary recovery and low distribution to liver and kidney tissues. Based on these results, 21 was advanced into development as TD-6424, and is currently in human clinical trials. The generic name telavancin has recently been approved for compound 21.
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Pilmanis AA, Balldin UI, Webb JT, Krause KM. Staged decompression to 3.5 psi using argon-oxygen and 100% oxygen breathing mixtures. Aviat Space Environ Med 2003; 74:1243-50. [PMID: 14692466] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 04/27/2023]
Abstract
INTRODUCTION The current extravehicular activity (EVA) space suit at 4.3 psia causes hand and arm fatigue and is too heavy for Martian EVA. A 3.5 psia EVA pressure suit requires increased preoxygenation time but would reduce structural complexity, leak rate, and weight while increasing mobility, comfort, and maintainability. On Mars, nitrogen and argon are available to provide the inert gas necessary for a fire-resistant habitat atmosphere, eliminating need for transport. This study investigated breathing argon/oxygen and 100% oxygen gas mixtures during staged decompression prior to exposure to 3.5 psia. METHOD During this study, 40 subjects each completed 3 hypobaric exposures to 3.5 psia for 3 h in a reclined position: (A) a 4-h 25-min 14.7-psia (ground level) denitrogenation (100% oxygen breathing) prior to exposure to 3.5 psia; (B) the same as A, utilizing a 7.3-psia stage denitrogenation; and (C) the same as B, with 62% argon-38% oxygen (ARGOX) during the stage. Venous gas emboli (VGE) were monitored with echocardiography. RESULTS Decompression sickness (DCS) incidence at 3.5 psia with ARGOX at 7.3 psia (C) was significantly higher than with oxygen breathing with or without staged decompression: there was 78% DCS for C compared with 33% and 55% DCS, respectively, for A and B. The corresponding VGE incidences were 73% (C) compared with 33% (A) and 45% (B). CONCLUSION Preoxygenation at a 7.3-psia stage resulted in a higher DCS risk at 3.5 psia than ground level preoxygenation. It is suggested that an 8.0-psia stage pressure could eliminate this difference. Unfavorable results after preoxygenation with ARGOX indicate argon on-gassing was significant.
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Affiliation(s)
- Andrew A Pilmanis
- Biodynamics and Protection Division, Air Force Research Laboratory, Brooks City-Base, San Antonio, TX 78235-5105, USA.
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Griffin JH, Linsell MS, Nodwell MB, Chen Q, Pace JL, Quast KL, Krause KM, Farrington L, Wu TX, Higgins DL, Jenkins TE, Christensen BG, Judice JK. Multivalent drug design. Synthesis and in vitro analysis of an array of vancomycin dimers. J Am Chem Soc 2003; 125:6517-31. [PMID: 12785792 DOI: 10.1021/ja021273s] [Citation(s) in RCA: 60] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The design, synthesis, and in vitro microbiological analysis of an array of forty covalently linked vancomycin dimers are reported. This work was undertaken to systematically probe the impact of linkage orientation and linker length on biological activity against susceptible and drug-resistant Gram-positive pathogens. To prepare the array, monomeric vancomycin synthons were linked through four distinct positions of the glycopeptide (C-terminus (C), N-terminus (N), vancosamine residue (V), and resorcinol ring (R)) in 10 unique pairwise combinations. Amphiphilic, peptide-based linkers of four different lengths (11, 19, 27, and 43 total atoms) were employed. Both linkage orientation and linker length were found to affect in vitro antibacterial potency. The V-V series displayed the greatest potency against vancomycin-susceptible organisms and vancomycin-resistant Enterococcus faecalis (VRE) of VanB phenotype, while the C-C, C-V, and V-R series displayed the most promising broad-spectrum activity that included VRE of VanA phenotype. Dimers bearing the shortest linkers were in all cases preferred for activity against VRE. The effects of linkage orientation and linker length on in vitro potency were not uniform; for example, (1) no single compound displayed activity that was superior against all test organisms to that of vancomycin or the other dimers, (2) linker length effects varied with test organism, and (3) whereas one-half of the dimers were more potent than vancomycin against methicillin-susceptible Staphylococcus aureus (MSSA), only one dimer was more potent against methicillin-resistant S. aureus (MRSA) and glycopeptide-intermediate susceptible S. aureus (GISA). In interpreting the results, we have considered the potential roles of multivalency and of other phenomena.
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Affiliation(s)
- John H Griffin
- Contribution from Theravance, Inc., 901 Gateway Boulevard, South San Francisco, California 94080, USA.
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Abstract
Our study investigated the effects of, and interactions between, forage particle size, level of dietary ruminally fermentable carbohydrate (RFC), and level of dietary starch on performance, chewing activity, and ruminal pH for dairy cows fed one level of dietary NDF. Twelve cows (48 DIM) were assigned to six treatments in a replicated 6 x 6 Latin square. Treatments were arranged in an incomplete 2 x 2 x 2 factorial design. Factors were: dry cracked shelled corn (DC, low RFC) or ground high-moisture corn (HMC; high RFC), finely chopped or coarse silage, and alfalfa silage as the only forage or a 50:50 ratio (DM basis) of alfalfa and corn silage. Diets combining HMC with only alfalfa silage were not included in the experiment. Diets were fed for ad libitum intake as a TMR with a concentrate:forage ratio of 61:39. Diets based on only alfalfa silage and diets based on a mix of alfalfa and corn silage averaged 18.6 and 15.8% CP, 25.8 and 24.7% NDF, 17.7 and 14.8% ADF, and 29.1 and 37.3% starch, respectively. Mean particle sizes were 5.3, 2.7, 5.6, and 2.8 mm for coarse alfalfa, fine alfalfa, coarse corn silage, and fine corn silage, respectively. Decreasing forage particle size decreased DMI (23.3 vs. 21.6 kg) and organic matter intake (22.0 vs. 20.2 kg). Increasing RFC decreased DMI (22.8 vs. 21.0 kg) and organic matter intake (21.5 vs. 20.0 kg). Decreasing forage particle size increased energy-corrected milk for alfalfa based diets (34.9 vs. 37.4 kg). Percentage of milk fat decreased with decreasing forage particle size (3.07 vs. 2.90%) and increased level of RFC (3.04 vs. 2.57%). Percentage of protein increased when corn silage partially replaced alfalfa silage (2.84 vs. 2.90%) but decreased when HMC replaced DC (2.90 vs. 2.84%). Apparent total tract digestibility of DM (66.7 vs. 68.5%), OM (65.9 vs. 70.7%), and starch (88.9 vs. 93.4%) increased when level of RFC was increased. Increasing level of RFC decreased mean ruminal pH from 5.82 to 5.67 and decreased minimum pH. Hours per day at which pH was <5.8, and area <5.8, increased when corn silage partially replaced alfalfa silage (2.6 vs. 4.4 h and 8.9 h x pH vs. 11.4 h x pH) and decreased further when level of RFC was increased (4.4 vs. 6.4 h and 11.4 h x pH vs. 14.3 h x pH). Decreasing forage particle size in HMC diets increased hours and area <5.8, but for DC diets, the effect of forage particle size depended on forage source. Interactions were found between level of physically effective fiber, forage source, and level of RFC on production and pH, complicating the inclusion of these effects in dairy ration formulation and evaluation.
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Affiliation(s)
- K M Krause
- Department of Dairy Science, University of Wisconsin-Madison, 53706, USA
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Abstract
Our study investigated the effect of a linear increase in level of ruminally fermentable carbohydrate, at a constant level of dietary starch and fiber, on performance, microbial N yield, chewing activity, and ruminal pH of midlactation dairy cows. Eight cows (53 DIM) were assigned to four treatments in a double 4 x 4 Latin square. Diets consisted of increasing levels of refined cornstarch (0, 5.9, 11.9, and 17.9% of diet dry matter) replacing dry cracked, shelled corn so that increasing amounts of dietary starch originated from refined cornstarch. Corn gluten feed was used to balance diets for similar NDF content. The four diets averaged 17.9% CP, 27.2% NDF, 18.7% ADF, and 31.1% starch (dry matter basis). Diets were fed for ad libitum intake and had a forage to concentrate ratio of 40:60. Forage was coarsely chopped (13.7 mm mean particle size) alfalfa silage. Daily dry matter intake averaged 26.0 kg and tended (P = 0.08) to increase quadratically with increasing level of refined cornstarch. Milk production averaged 38.9 kg/d and milk fat percentage tended (P = 0.08) to decrease linearly, whereas percentage of protein increased quadratically, with increasing level of refined cornstarch. Yield of components and energy corrected milk was similar across diets. Total tract digestibility of starch increased linearly from 85.1% to 92.4% with increasing level of refined cornstarch. Microbial yield was unaffected by diet and averaged 371.1 g N/d. Time spent eating decreased linearly from 329 to 308 min/d when level of refined cornstarch was increased, but rumination time was unaffected. Ruminal concentration and proportion of acetate decreased linearly while concentration and proportion of propionate increased linearly with increasing level of refined cornstarch. Mean ruminal pH, time spent below pH 5.8 (h), and area below pH 5.8 (h x pH units/d) were unaffected by level of refined cornstarch and averaged 5.97, 8.4, and 2.9, respectively. Increasing the level of carbohydrates fermented in the rumen by replacing dry cracked corn with refined cornstarch (up to 57% of dietary starch) did not compromise rumen fermentation or affect performance of midlactation dairy cows.
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Affiliation(s)
- K M Krause
- Department of Dairy Science, University of Wisconsin, Madison 53706, USA
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Krause KM, Combs DK, Beauchemin KA. Effects of forage particle size and grain fermentability in midlactation cows. I. Milk production and diet digestibility. J Dairy Sci 2002; 85:1936-46. [PMID: 12214986 DOI: 10.3168/jds.s0022-0302(02)74270-7] [Citation(s) in RCA: 80] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Our study investigated the effects of, and interactions between, level of dietary ruminally fermentable carbohydrate (RFC) and forage particle size on milk production, nutrient digestibility, and microbial protein yield for dairy cows fed one level of dietary NDF. Eight cows (61 days in milk) were assigned to four treatments in a double 4 x 4 Latin square. Treatments were arranged in a 2 x 2 factorial design; finely chopped alfalfa silage (FS) and coarse alfalfa silage (CS) were combined with concentrates based on either dry cracked shelled corn (DC; low RFC) or ground high-moisture corn (HMC; high RFC). Diets were fed ad libitum as a total mixed rations with a concentrate to forage ratio of 61:39. Diets based on DC had a predicted NEL content of 1.73 Mcallkg dry matter (DM), while HMC diets contained 1.80 Mcal/kg DM. Diets averaged 18.7% CP, 24.0% NDF, 18.3% ADF, and 27.4% starch on a DM basis. Mean particle size of the four diets was 6.3, 2.8, 6.0, and 3.0 mm for DCCS, DCFS, HMCCS, and HMCFS, respectively. Increasing level of RFC decreased dry matter intake (DMI) from 25.0 to 23.8 kg/ d and organic matter intake from 22.3 to 21.1 kg/d, but intake was not affected by particle size. Milk production averaged 44.0 and 26.8 kg/d solids corrected milk (SCM) and was not affected by diet, but increasing level of RFC tended to increase milk yield. Efficiency of milk production, expressed as SCM/DMI, increased from 1.06 to 1.14 when level of RFC was increased. Milk composition or yield of milk components was not affected by diet, and averaged 3.53% fat, 3.11% protein, 1.55 kg/d fat, and 1.36 kg/d protein. Total tract digestibility of DM and OM increased from 71.4 to 73.0% and 72.4 to 76.1% for DM and OM, respectively, when level of RFC was increased. Total tract digestibility of fiber was unaffected by diet, but total tract starch digestibility increased from 93.1 to 97.4% when HMC replaced DC. Total urinary excretion of the purine derivatives uric acid and allantoin increased from 415 to 472 mmol/d when level of RFC was increased, and calculated microbial N supply increased from 315 to 365 g/d. When expressed as per kilogram of digestible OMI, increasing level of RFC tended to increase microbial N supply (20.4 vs. 22.2 g/kg). Cow productivity was not affected by forage particle size and ruminally fermentable carbohydrates in this study.
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Affiliation(s)
- K M Krause
- Department of Dairy Science, University of Wisconsin, Madison 53706, USA
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48
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Abstract
Our study investigated the effects of, and interactions between, level of dietary ruminally fermentable carbohydrate (RFC) and forage particle size on rumen pH and chewing activity for dairy cows fed one level of dietary NDF. Also, correlations between intake, production, chewing, and ruminal pH parameters were investigated. Eight cows (61 days in milk) were assigned to four treatments in a double 4 x 4 Latin square. Treatments were arranged in a 2 x 2 factorial design; finely chopped alfalfa silage (FS) and coarse alfalfa silage (CS) were combined with concentrates based on either dry, cracked-shelled corn (DC; low RFC) or ground, high-moisture corn (HMC; high RFC). Diets were fed ad libitum as a total mixed rations with a concentrate:forage ratio of 60:40. Diets averaged 18.7% crude protein, 24.0% neutral detergent fiber, 18.3% , acid detergent fiber and 27.4% starch on a DM basis. Mean particle size of the four diets were 6.3, 2.8, 6.0, and 3.0 mm for DCCS, DCFS, HMCCS, and HMCFS, respectively. Decreasing forage particle size decreased ruminal pH from 6.02 to 5.81, and increasing level of RFC decreased pH from 5.99 to 5.85. Minimum daily ruminal pH decreased from 5.66 to 5.47 when level of RFC was increased, and decreased from 5.65 to 5.48 when forage particle size decreased. Time below pH 5.8 per day increased from 7.4 h to 10.8 h when level of RFC increased, and increased from 6.4 h to 11.8 h when forage particle size was decreased. Area below 5.8 showed the same relationship with RFC and forage particle size. Also, forage particle size affected the postprandial pH pattern. Cows spent more time eating when fed CS compared with FS (274 vs. 237 min/d), and time spent eating decreased when level of RFC was increased (271 vs. 241 min/d). Decreasing forage particle size decreased time spent ruminating (485 vs. 320 min/d), rumination periods (15.3 vs. 11.7), and duration of rumination periods (29 vs. 26 min). Increasing level of RFC increased time spent ruminating per kg NDF intake (68.5 vs. 79.5 min/kg). Milk fat percentage was correlated to mean ruminal pH (r = 0.41), time spent below pH 5.8 (r = -0.55), and area below 5.8 (r = -0.57), but not to intake or chewing variables. DMI of particles retained on a screen equivalent in size to the top screen of the Penn State particle separator was the intake parameter explaining most of the variation in mean ruminal pH (r = 0.27) and was correlated to time spent ruminating (r = 0.61) and chewing (r = 0.61).
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Affiliation(s)
- K M Krause
- Department of Dairy Science, University of Wisconsin, Madison 53706, USA
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Webb JT, Krause KM, Pilmanis AA, Fischer MD, Kannan N. The effect of exposure to 35,000 ft on incidence of altitude decompression sickness. Aviat Space Environ Med 2001; 72:509-12. [PMID: 11396555] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/20/2023]
Abstract
INTRODUCTION Exposure to 35,000 ft without preoxygenation (breathing 100% oxygen prior to decompression) can result in severe decompression sickness (DCS). Exercise while decompressed increases the incidence and severity of symptoms. Clarification of the level of activity vs. time to symptom onset is needed to refine recommendations for current operations requiring 35,000-ft exposures. Currently, the U.S. Air Force limits these operations to 30 min following 75 min of preoxygenation. The objective of this study was to determine the effect of exercise intensity on DCS incidence and severity at 35,000 ft. METHODS Following 75 or 90 min of ground-level preoxygenation, 54 male and 38 female subjects were exposed to 35,000 ft for 3 h while performing strenuous exercise, mild exercise, or seated rest. The subjects were monitored for venous gas emboli (VGE) with an echo-imaging system and observed for signs and symptoms of DCS. RESULTS Exposures involving strenuous and mild exercise resulted in higher incidence (p < 0.05) and earlier onset of symptoms (p < 0.05) of DCS than exposure at rest. Mild and strenuous exercise during exposure did not differ in incidence or rate of onset. Incidence at 30 min of exposure was 8% at rest and 23% while exercising. CONCLUSION The results showed that current guidelines for 35,000-ft exposures keep DCS risk below 10% at rest. Exercise, even at mild levels, greatly increases the incidence and rate of onset of DCS.
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Affiliation(s)
- J T Webb
- Air Force Research Laboratory, High Altitude Protection Research at Brooks AFB, San Antonio, TX, USA.
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Krause KM, Pilmanis AA. The effectiveness of ground level oxygen treatment for altitude decompression sickness in human research subjects. Aviat Space Environ Med 2000; 71:115-8. [PMID: 10685583] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/15/2023]
Abstract
BACKGROUND Current therapy for altitude decompression sickness (DCS) includes hyperbaric oxygen therapy and ground-level oxygen (GLO). The purpose of this paper is to describe the Air Force Research Laboratory experience in the extensive use of GLO for the treatment of altitude DCS in research subjects. METHODS Data were collected from 2001 altitude chamber subject-exposures. These data, describing DCS symptoms, circulating intracardiac venous gas emboli, and treatment procedures used were collected for each subject exposure and stored in an altitude DCS database. RESULTS In the database of 2001 subject exposures, 801 subjects (40.0%) were diagnosed with altitude DCS. Subjects reporting DCS symptoms were immediately recompressed to ground level. Of the 749 subjects who received 2 h GLO, 739 (98.7%) resolved completely and required no further treatment. CONCLUSIONS Although not an operational study, these data provide indirect support for the current USAF guidelines for the treatment of altitude DCS with GLO.
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Affiliation(s)
- K M Krause
- Air Force Research Laboratory, Brooks Air Force Base, TX, USA
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