Pharmacokinetic-Pharmacodynamic Target Attainment Analyses Evaluating Omadacycline Dosing Regimens for the Treatment of Patients with Community-Acquired Bacterial Pneumonia Arising from Streptococcus pneumoniae and Haemophilus influenzae

Omadacycline, a novel aminomethylcycline with in vitro activity against Gram-positive and -negative organisms, including Streptococcus pneumoniae and Haemophilus influenzae, is approved in the United States to treat patients with community-acquired bacterial pneumonia (CABP). Using nonclinical pharmacokinetic-pharmacodynamic (PK-PD) targets for efficacy and in vitro surveillance data for omadacycline against S. pneumoniae and H. influenzae, and a population pharmacokinetic model, PK-PD target attainment analyses were undertaken using total-drug epithelial lining fluid (ELF) and free-drug plasma exposures to evaluate omadacycline 100 mg intravenously (i.v.) every 12 h or 200 mg i.v. every 24 h (q24h) on day 1, followed by 100 mg i.v. q24h on day 2 and 300 mg orally q24h on days 3 to 5 for patients with CABP. Percent probabilities of PK-PD target attainment on days 1 and 2 by MIC were assessed using the following four approaches for selecting PK-PD targets: (i) median, (ii) second highest, (iii) highest, and (iv) randomly assigned total-drug ELF and free-drug plasma ratio of the area under the concentration-time curve to the MIC (AUC/MIC ratio) targets associated with a 1-log₁₀ CFU reduction from baseline. Percent probabilities of PK-PD target attainment based on total-drug ELF AUC/MIC ratio targets on days 1 and 2 were ≥91.1% for S. pneumoniae for all approaches but the highest target and ≥99.2% for H. influenzae for all approaches at MIC₉₀s (0.12 and 1 μg/mL for S. pneumoniae and H. influenzae, respectively). Lower percent probabilities of PK-PD target attainment based on free-drug plasma AUC/MIC ratio targets were observed for randomly assigned and the highest free-drug plasma targets for S. pneumoniae and for all targets for H. influenzae. These data provided support for approved omadacycline dosing regimens to treat patients with CABP and decisions for the interpretive criteria for the in vitro susceptibility testing of omadacycline against these pathogens.

LB2306. Population Pharmacokinetic (PPK), Pharmacokinetic/Pharmacodynamic attainment (PTA), and Clinical Pharmacokinetic/Pharmacodynamic (PK/PD) Analyses for Sulbactam-Durlobactam (SUL-DUR) to Support Dose Selection for the Treatment of Acinetobacter baumannii-calcoaceticus Complex (ABC) Infections

Background

SUL-DUR is a β-lactam/β-lactamase inhibitor combination in development for the treatment of ABC infections, which are often severe and associated with substantial mortality. PPK, PTA, and clinical PK/PD analyses were conducted using all available PK and efficacy data to support SUL-DUR dose selection.

Methods

PPK analyses were performed using PK data from 373 subjects, including 110 patients who received SUL-DUR and underwent PK sampling in the pivotal Phase 3 (ATTACK) trial. SUL-DUR concentrations in epithelial lining fluid (ELF) from healthy subjects were utilized to predict SUL-DUR ELF concentrations in Phase 3 patients. Covariate analyses evaluated the impact of demographic factors on PK exposures. The PPK model, non-clinical PK/PD data, and in vitro surveillance data were used to assess the PTA by MIC in simulated patients with ABC infections. Clinical PK/PD relationships were assessed using dichotomous and time-to-event efficacy endpoints from the ATTACK trial.

Results

Two-compartment models with linear kinetics best characterized SUL and DUR PK. Consistent with high renal clearance of SUL-DUR, dose adjustments are needed in patients with renal impairment or augmented renal function. Body weight, site of infection, and East Asian region (which grouped patients from mainland China, Taiwan, and South Korea vs others) were statistically significant covariates in the PPK analysis but were not clinically relevant. No other statistical or clinically relevant covariates were identified. As shown in Figures A and B for plasma and ELF, respectively, the PTA was ≥ 90% for pathogens with an MIC ≤ 4 µg/mL across renal function categories in simulated patients, using PK/PD targets associated with a 1-log kill₁₀. No relationships were observed between PK/PD indices and efficacy endpoints, consistent with most patients achieving SUL and DUR exposures above nonclinical PK/PD targets for efficacy.

Percent PTA by MIC on Day 1 based on the assessment of sulbactam %T>MIC ≥ 50% and durlobactam AUC:MIC ratio ≥ 10 targets and free-drug plasma (A) and total-drug ELF (B) exposures among simulated patients by CLcr group after administration of sulbactam 1 g/ durlobactam 1 g IV q6h and dosing regimens adjusted for renal impairment and augmented renal function Abbreviations: %T>MIC, percentage of time on Day 1 that concentration exceed minimum inhibitory concentration; AUC, area under the concentration-time curve; CLcr, creatinine clearance; ELF, epithelial lining fluid; MIC, minimum inhibitory concentration; q6h, every 6 hours; PK-PD, pharmacokinetic/pharmacodynamic; PTA, probability of PK/PD target attainment

Conclusion

The simulated plasma and ELF exposures yielded a high PTA, which when combined with the favorable efficacy and safety findings from ATTACK (abstract #1266378), support a dose of 1.0 g sulbactam/1.0 g durlobactam via a 3-hour infusion, every 6 hours in patients with normal renal function and renal function-based dose adjustments.

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|ICPD Holdings: Ownership Interest|ICPD Technologies: 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|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|ICPD Holdings: Ownership Interest|ICPD Technologies: 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|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|ICPD Holdings: Ownership Interest|ICPD Technologies: 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|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|ICPD Holdings: Ownership Interest|ICPD Technologies: 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 Anthony P. Cammarata, M.S., 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 Kajal Larson, PhD, Entasis Therapeutics: Employee Kathryn Liolios, MA, 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 Sarah McLeod, PhD, Entasis Therapeutics: Employee Alita Miller, PhD, Entasis Therapeutics: Employee 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|ICPD Holdings: Ownership Interest|ICPD Technologies: Ownership Interest|Insmed Inc.: Grant/Research Support|Iterum Therapeutics Limited: Grant/Research Support|Kaizen Bioscience, Co.: 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 Ruben Tommasi, PhD, Entasis Therapeutics: Employee John O'Donnell, B.S, Entasis Therapeutics: Employee

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

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.

733. Pharmacokinetic–Pharmacodynamic (PK–PD) Analyses for Alanine Aminotransferase (ALT) Using Phase 3 Data From Omadacycline (OMC)-Treated Patients

Background

OMC, an aminomethylcycline structurally related to tetracycline agents, was recently approved by the US FDA for the treatment of adult patients with ABSSSI (IV-to-PO and PO regimens) and CABP (IV-to-PO regimen). To better understand exposure-related concerns for ALT increase, PK-PD relationships for ALT were evaluated using data from OMC-treated patients enrolled in three Phase 3 studies.

Methods

Repeated-measures multiple linear regression was used to evaluate factors predictive of ALT, including different OMC total-drug AUC measures prior to each ALT, with interactions and covariates selected stepwise. Using a final AIC-optimized model, predicted percent probabilities of ALT elevation >1, 1.5, 2, 3, 5, and 10 × upper limit of normal (ULN) at any time post-baseline and up to 2 days after the end of therapy were calculated among analysis patients for fixed post-baseline OMC AUC measures, and among simulated patients after IV-to-PO and PO dosing regimens.

Results

The final model, developed using data from 327 patients with PK, included increased prior cumulative AUC among males, increased baseline gamma-glutamyl transferase, and study (ABSSSI, PO only) as factors predictive of increased ALT (P < 0.0001). However, the model-predicted impact of OMC across fixed average daily AUC values on ALT elevation endpoints of >1, 1.5, 2, 3, 5, and 10 × ULN was minimal (Figure 1), even for males despite the interaction with AUC (Figure 2). Among all patients, the estimated increases in percent probabilities for the 90th percentile of AUC relative to zero AUC were 5.81, 5.20, 1.53, 0.61, 0.31, and 0%, respectively, and ≤11.5, 7.76, 8.33, 1.31, 1.31, and 0%, respectively, across single variable patient subsets. Percent probabilities of ALT elevation endpoints were within 2.84% when comparing simulated and observed patients after administration of OMC IV-to-PO and PO dosing regimens (Figure 3).

Conclusion

A statistically significant relationship between an increase in ALT and increase in OMC AUC for males in the presence of other factors was found. However, increases in model-predicted ALT elevation endpoints across fixed OMC AUC values, or among simulated patients after administration of OMC IV-to-PO and PO dosing regimens relative to observed patients, were minimal.

Disclosures

All authors: No reported disclosures.

Pharmacokinetic/pharmacodynamic target attainment analyses to support intravenous and oral lefamulin dose selection for the treatment of patients with community-acquired bacterial pneumonia

OBJECTIVES

Lefamulin is a semi-synthetic intravenous (iv) and oral pleuromutilin antibiotic active against community-acquired bacterial pneumonia (CABP) pathogens. Pharmacokinetic/pharmacodynamic (PK/PD) target attainment analyses were carried out to evaluate lefamulin 150 mg iv q12h and 600 mg orally q12h under fed and fasted conditions for the treatment of patients with CABP.

METHODS

The analyses undertaken used a population PK model based on Phase 1 PK data, non-clinical PK/PD targets for efficacy and in vitro surveillance data for Streptococcus pneumoniae (SP) and Staphylococcus aureus (SA), and Monte Carlo simulation. Percentage probabilities of PK/PD target attainment by MIC on day 1 were determined using median total-drug epithelial lining fluid (ELF) and free-drug plasma AUC:MIC ratio targets associated with 1 and 2 log10 cfu reductions from baseline.

RESULTS

Percentage probabilities of attaining the total-drug ELF AUC:MIC ratio target for a 1 log10 cfu reduction from baseline for SP were ≥99.2% at the MIC90 of 0.12 mg/L and 96.7%, 82.1% and 96.3% for iv and oral dosing regimens under fed and fasted conditions, respectively, at the MIC99 of 0.25 mg/L. Percentage probabilities of attaining the free-drug plasma AUC:MIC target for the same endpoint at the SP MIC99 were 100% for each regimen. For the SA MIC90 of 0.12 mg/L and AUC:MIC ratio targets for the same endpoint, percentage probabilities were 92.7%-100% for iv and oral dosing regimens.

CONCLUSIONS

These data provide support for lefamulin 150 mg iv q12h and 600 mg orally q12h for the treatment of patients with CABP and suggest that doses may not need to be taken under fasted conditions.

1392. Pharmacokinetic-Pharmacodynamic (PK-PD) Target Attainment Analyses to Support Inhaled ME1100 Dose Selection

Background

ME1100 (arbekacin inhalational solution) is an inhaled aminoglycoside being developed to treat patients with hospital-acquired and ventilator-associated bacterial pneumonia (HABP and VABP, respectively). PK-PD target attainment analyses were undertaken to evaluate ME1100 regimens for patients with HABP/VABP arising from Klebsiella pneumoniae (KP), Pseudomonas aeruginosa (PA) and Staphylococcus aureus (SA), including those with renal impairment.

Methods

Data used included a population pharmacokinetic (PPK) model developed using Phase 1 and post-marketing PK data, nonclinical PK-PD targets from one compartment in vitro and/or in vivo infection models, and MIC data. Using parameter estimates from the PPK model (four-compartment model with first-order elimination), total-drug epithelial lining fluid concentration-time profiles were generated for simulated patients with varying creatinine clearance (CLcr; mL/minute/1.73 m²) and by CLcr group. Twice daily (BID) ME1100 regimens ranging from 300 to 900 mg were assessed in simulated patients with CLcr >80 to ≤120 mL/minute/1.73 m². Percent probabilities of PK-PD target attainment by MIC were determined based on total-drug ELF AUC:MIC ratio targets associated with 1- and 2-log₁₀ CFU reductions from baseline for KP, PA and SA using Day 1 AUC. Regimens in simulated patients with renal impairment that best matched the BID regimen in the normal CLcr group with high percent probabilities of PK-PD target attainment and a low percent probability of C_min > 2 mg/L were identified.

Results

ME1100 600 mg BID in simulated patients with CLcr >80 to ≤120 mL/minute/1.73 m², with 600 mg once daily, 450 mg BID and 600 mg BID in simulated patients with CLcr of 0 to ≤30, >30 to ≤50 and >50 to ≤80 mL/minute/1.73 m², respectively, achieved high percent probabilities of PK-PD target attainment based on PK-PD targets for a 1-log₁₀ CFU reduction from baseline at relevant MIC values for KP, PA and SA, and relatively lower C_min values. In simulated patients with varying CLcr who received these regimens, high percent probabilities of PK-PD target attainment were achieved for KP, PA and SA at the upper margins of the MIC distributions (Figures 1–3).

Conclusion

The data provide support for ME1100 dose selection for patients with HABP/VAPB.

Disclosures

S. M. Bhavnani, Meiji Seika Pharma Co. Ltd.: Research Contractor, Research support. J. P. Hammel, Meiji Seika Pharma Co. Ltd.: Research Contractor, Research support. E. A. Lakota, Meiji Seika Pharma Co. Ltd.: Research Contractor, Research support. B. D. VanScoy, Meiji Seika Pharma Co. Ltd.: Research Contractor, Research support. Y. Nagira, Meiji Seika Pharma Co. Ltd.: Employee, Salary. C. M. Rubino, Meiji Seika Pharma Co. Ltd.: Research Contractor, Research support. N. Sato, Meiji Seika Pharma Co. Ltd.: Employee, Salary. T. Koresawa, Meiji Seika Pharma Co. Ltd.: Employee, Salary. K. Kondo, Meiji Seika Pharma Co. Ltd.: Employee, Salary. P. G. Ambrose, Meiji Seika Pharma Co. Ltd.: Research Contractor, Research support.

2562. Re-Appraisal of Aminoglycoside (AG) Susceptibility Testing Breakpoints Based on the Application of Pharmacokinetics–Pharmacodynamics (PK-PD) and Contemporary Microbiology Surveillance Data

Background

Resistance to AGs and numerous other classes continues to emerge. To ensure that susceptibility is accurately characterized and that clinicians have reliable data to select effective agents, appropriate in vitro susceptibility testing interpretive criteria (susceptible breakpoints [BKPTs]) are crucial to ensure optimal patient care. Recently, USCAST, the USA voice to EUCAST/EMA, evaluated the BKPTs for the 3 most commonly used AGs, gentamicin, tobramycin, and amikacin [Bhavnani et al., IDWeek 2016; P-1977]. As a result of consultation from interested parties, which included evaluating AG dosing regimens provided in the US-FDA product package inserts and simulated patients with varying creatinine clearance, these BKPTS were reassessed.

Methods

Data sources considered included longitudinal US reference MIC distributions using in vitro surveillance data collected over 18 years, QC performance (MIC, disk diffusion), population pharmacokinetics (PK), and in vivo PK-PD models. Using population PK models, PK-PD targets for efficacy and Monte Carlo simulation, percent probabilities of PK-PD target attainment by MIC after administration of traditional and extended interval AG dosing regimens were evaluated among simulated patients. Epidemiological cut-off and PK-PD BKPTs were considered when recommending BKPTs for AG–pathogen pairs.

Results

An example of PK-PD target attainment analysis output is provided in Figure 1 and a subset of recommended AG BKPTs for 3 pathogens is shown in Table 1. Updated USCAST BKPTs, which were based on the application of population PK and PK-PD models, simulation techniques, and contemporary MIC distribution statistics, are generally lower than those of EUCAST/EMA, USA-FDA, and CLSI. Adequate PK-PD target attainment was not achieved for some AG-pathogen pairs, even when high-dose AG dosing regimens and PK-PD targets for stasis were evaluated (e.g., gentamicin vs. P. aeruginosa; amikacin vs. S. aureus).

Conclusion

These revised AG BKPT recommendations, which will be made freely available to EUCAST, USA-FDA, and CLSI, will be finalized after considering comments from additional interested stakeholders. This process will be followed in an effort to bring harmonization to global BKPTs for AGs.

Disclosures

All authors: No reported disclosures.

The utility of biomarkers in diagnosis of aspirin exacerbated respiratory disease

Background

Aspirin-exacerbated respiratory disease (AERD) is a distinct eosinophilic phenotype of severe asthma with accompanying chronic rhinosinusitis, nasal polyposis, and hypersensitivity to aspirin. Urinary 3-bromotyrosine (uBrTyr) is a noninvasive marker of eosinophil-catalyzed protein oxidation. The lack of in vitro diagnostic test makes the diagnosis of AERD difficult. We aimed to determine uBrTyr levels in patients with AERD (n = 240) and aspirin-tolerant asthma (ATA) (n = 226) and to assess whether its addition to urinary leukotriene E₄ (uLTE₄) levels and blood eosinophilia can improve the prediction of AERD diagnosis.

Methods

Clinical data, spirometry and blood eosinophilis were evaluated. UBrTyr and uLTE₄ levels were measured in urine by HPLC and ELISA, respectively.

Results

Both groups of asthmatics (AERD, n = 240; ATA, n = 226) had significantly higher uBrTyr, uLTE₄ levels, and blood eosinophils than healthy controls (HC) (n = 71) (p < 0.05). ULTE₄ levels and blood eosinophils were significantly higher in AERD as compared to ATA (p = 0.004, p < 0.0001, respectively). whereas uBrTyr levels were not significantly different between both asthma phenotypes (p = 0.34). Asthmatics with high levels of uBrTyr (> 0.101 ng/mg Cr), uLTE₄ levels (> 800 pg/mg Cr) and blood eosinophils (> 300 cells/ul) were 7 times more likely to have AERD.. However, uBrTyr did not increase the benefit for predicting AERD when uLTE₄ and blood eosinophils were already taken into account (p = 0.57).

Conclusion

UBrTyr levels are elevated both in AERD and ATA as compared to HC, but they could not differentiate between these asthma phenotypes suggesting a similar eosinophilic activation. The addition of uBrTyr to elevated uLTE4 levels and blood eosinophils did not statistically enhance the prediction of AERD diagnosis.

Is hyponatremia associated with mortality in pulmonary arterial hypertension?

Hyponatremia is associated with poor prognosis in left heart failure and liver disease. Its prognostic role in pulmonary arterial hypertension (PAH) is not well defined. We investigated the association between hyponatremia and one-year mortality in two large cohorts of PAH. This study is a secondary analysis evaluating the association between hyponatremia and one-year mortality in patients treated with subcutaneous treprostinil (cohort 1). The results are validated using a PAH registry at a tertiary referral center (cohort 2). Eight-hundred and twenty patients were enrolled in cohort 1 (mean age = 47 ± 14 years) and 791 in cohort 2 (mean age = 55 ± 15 years). Sodium level is negatively correlated with mean right atrial pressure (r = -0.09, P = 0.018; r = -0.089, P = 0.015 in cohorts 1 and 2, respectively). In unadjusted analyses of cohort 1, the sodium level (as a continuous variable) is associated with one-year mortality (hazard ratio = 0.94; P = 0.035). Hyponatremia loses its significance (as a continuous variable and when dichotomized at ≤ 137 mmol/L; P = 0.12) when adjusted for functional class (FC), which is identified as the variable whose presence turns the effect of sodium level into non-significant. Secondary analyses using a cut-off value of < 135 mmol/L showed similar results. These results are validated in cohort 2. Although the sample size for patients with sodium < 130 mmol/L is small (n = 31), severe hyponatremia is associated with higher overall mortality (47% versus 23%; P = 0.01), even when adjusting for age, FC, and baseline 6-min walk distance ( P < 0.001). Although baseline hyponatremia is associated with one-year mortality, it loses its significance when adjusted for FC.

TH1 and TH2 cytokine data in insulin secretagogues users newly diagnosed with breast cancer

Stimulation of insulin production by insulin secretagogue use may impact T helper cells’ cytokine production. This dataset presents the relationship between baseline insulin secretagogues use in women diagnosed with breast cancer and type 2 diabetes mellitus, the T-helper 1 and 2 produced cytokine profiles at the time of breast cancer diagnosis, and subsequent cancer outcomes. A Pearson correlation analysis evaluating the relationship between T-helper cytokines stratified by of insulin secretagogues use and controls is also provided.

Dataset on granulopoiesis- and lymphopoiesis-stimulating cytokine levels in insulin secretagogue users with incident breast cancer

GM-CSF and G-CSF are widely used for their benefit in reducing chemotherapy-associated neutropenia. However, whether GM- or G-CSF administration could have tumorigenic or pro-metastatic effects or whether insulin resistance could negatively impact such effects is not known. Their ability to stimulate monocyte production at the same time with the highly sought after neutrophils’ production, enables an enhanced potential for activation of tumor-associated macrophages. At the same time, IL-7 remains the main driver of B and T cell differentiation and maturation, a process linked to the development of insulin resistance and response to diabetes pharmacotherapy.

Insulin secretagogues have the potential to interfere with the hematopoiesis process, respectively with the formation of lineages that may lead to a tumorigenic or pro-metastatic phenotype, but this relationship has not been yet investigated. The data presented here shows the relationship between pre-existing use of insulin secretagogues in women diagnosed with breast cancer and type 2 diabetes mellitus, the GM-CSF, G-CSF and IL-7 cytokine profiles at the time of breast cancer diagnosis, and subsequent cancer outcomes. A Pearson correlation analysis evaluating the relationship between investigated cytokines stratified by secretagogue use and controls, and interferon is also provided.

Insulin secretagogue use and circulating inflammatory C-C chemokine levels in breast cancer patients

Monocytes’ infiltration into the tumor tissue and their activation to tumor-associated macrophages is an essential step in tumor development, also playing a critical role in an eventual metastasis. Stimulation of endogenous insulin production by oral insulin secretagogue treatment has the potential to interfere with the production and release of C–C chemokines, a group of potent inflammatory cytokines acting as monocyte chemo-attractants and influencing their behavior in the tumor microenvironment.

Studied plasma samples were collected under a previously reported study design involving a population of women diagnosed with breast cancer presenting with or without type 2 diabetes mellitus at the time of breast cancer diagnosis (Wintrob et al., 2017, 2016) [1,2]. The data presented here shows the relationship between pre-existing use of insulin secretagogue, the inflammatory C–C chemokine profiles at the time of breast cancer diagnosis, and subsequent cancer outcomes. A Pearson correlation analysis stratified by secretagogue use and controls was implemented to evaluate the relationship between the investigated biomarkers and respectively each of these biomarkers and the other relevant reported cytokine datasets derived from the same patient population (Wintrob et al., 2017, 2016) [1,2].

TH1 and TH2 cytokines dataset in insulin users with diabetes mellitus and newly diagnosed breast cancer

Exogenous insulin use may interfere with the T helper cells’ cytokine production. This dataset presents the relationship between pre-existing use of injectable insulin in women diagnosed with breast cancer and type 2 diabetes mellitus, the T-helper 1 and 2 produced cytokine profiles at the time of breast cancer diagnosis, and subsequent cancer outcomes. A Pearson correlation analysis evaluating the relationship between T-helper cytokines stratified by of insulin use and controls is also provided.

Circulating adipokines data associated with insulin secretagogue use in breast cancer patients

Oral drugs stimulating endogenous insulin production (insulin secretagogues) may have detrimental effects on breast cancer outcomes. The data presented shows the relationship between pre-existing insulin secretagogues use, adipokine profiles at the time of breast cancer (BC) diagnosis and subsequent cancer outcomes in women diagnosed with BC and type 2 diabetes mellitus (T2DM). The Pearson correlation analysis evaluating the relationship between adipokines stratified by T2DM pharmacotherapy and controls is also provided. This information is the extension of the data presented and discussed in “Insulin use, adipokine profiles and breast cancer prognosis” (Wintrob et al., in press) [1].

Insulin use, adipokine profiles and breast cancer prognosis

BACKGROUND

Type-2 diabetes mellitus (T2DM) and breast cancer (BC) share common cytokine signaling changes resultant from adipose tissue dysfunction. This modified adipokine signaling was shown to be directly associated with changes in the body mass index (BMI) and diet and it is expected to also be influenced by T2DM pharmacotherapy. We evaluated the relationship between pre-existing diabetes treatment, circulating adipokine levels at cancer diagnosis, and long-term outcomes.

METHODS

All incident BC cases were reviewed (01/01/2003-12/31/2009, N=2194). Each of the subjects with baseline T2DM (cases) was matched with two other subjects without T2DM (controls) based on the following criteria: age, BMI, ethnicity, menopausal status and tumor stage. All cases and controls with available baseline plasma and tumor biopsies, and being surgery and BC treatment naïve, were included (N₁=97, N₂=194). Clinical history and vital status were documented. Adipokine levels (adiponectin, leptin, TNF-α, CRP, IL-1β, IL-1Ra, IL-6, and C-peptide) were assessed by either ELISA or Luminex® assays. Cancer outcomes were assessed by Kaplan-Meier analysis; associations between categorical variables were assessed by Fisher's exact test, categorical and continuous variables by Kruskal-Wallis or Wilcoxon Rank-Sum test, where appropriate. Multivariate adjustments (MVP, multivariate p-value) were performed accounting for age, tumor stage, BMI, estrogen receptor (ER) status and cumulative comorbidity. All biomarker correlations were assessed by the Pearson method. Utilization of insulin and insulin secretagogues was associated with ER (-) phenotype (p=0.008, p=0.043) and poorer BC outcomes (p=0.012, p=0.033). Insulin users were found to have lower C-peptide and higher IL-6, TNF-α and CRP levels, of which elevated CRP and TNF-α were associated with poorer BC outcomes (p=0.003, MVP=0.210). Insulin remarked by higher leptin levels as compared to controls (p=0.052), but did not differ significantly from non-users. Although lower adiponectin levels were observed among non-insulin users as compared to controls (p<0.001, MVP=0.006), insulin use seemed to have restored adiponectin production. C-peptide levels were lower among insulin users as compared to non-users (p<0.001, MVP<0.001) and approached levels comparable with those of the controls. In the overall dataset, C-peptide lower than 0.75ng/ml were strongly associated with poorer survival (p=0.007, MVP=0.002). Among insulin users, C-peptide levels were inversely correlated with IL-1β and IL-1Ra levels only after full adjustment (p=0.012, p=0.030); the correlation was unremarkable in other groups.

CONCLUSION

Insulin use is associated with elevated leptin, CRP, TNFα, and lower C-peptide and also linked to poor BC outcomes. More research is needed to verify these findings; however, we are among the first to correlate pharmacotherapy use, measures of adipose tissue dysfunction and cancer outcomes.

Right atrial pressure/pulmonary artery wedge pressure ratio: A more specific predictor of survival in pulmonary arterial hypertension

BACKGROUND

Pulmonary arterial hypertension (PAH) is a progressive, fatal disease. Current prognostic models are not ideal, and identifying more accurate prognostic variables is needed. The objective of this study was to evaluate the relative prognostic value of the right atrial pressure/pulmonary artery wedge pressure (RAP/PAWP) ratio in PAH patients. We hypothesized that the RAP/PAWP ratio is more predictive of survival than any of the other measured or calculated hemodynamic variables.

METHODS

We performed a secondary analysis of a PAH cohort (Cohort 1) and validated our results in a separate cohort (Cohort 2). Cohort 1 included primarily patients enrolled in prospective, short-term, randomized clinical trials and subsequently followed long term. Cohort 2 included patients prospectively enrolled in a PAH registry at a tertiary PAH referral center.

RESULTS

Cohort 1 (n = 847) and Cohort 2 (n = 697) had a mean age of 47 and 54 years, respectively. Most were female (78% and 73%, respectively), Caucasian (83% and 82%), with advanced functional class disease status (New York Heart Association Functional Class III/IV 85% and 68%) and with significantly elevated hemodynamics (mean RAP/PAWP ratio: 1.2 and 1.0; pulmonary vascular resistance: 13.5 and 9.4 Wood units). RAP/PAWP ratio indicated a 1-year hazard ratio of 1.44 (p = 0.0001) and 1.35, respectively (p < 0.0001), and was the most consistently predictive hemodynamic variable across the 2 cohorts. These results remain valid even when adjusted for other covariables in multivariable regression models.

CONCLUSIONS

The RAP/PAWP ratio is a more specific predictor of survival than any other hemodynamic variable, and we recommend that it be used in clinical prognostication and PAH predictive models.

Volatile Organic Compounds in Urine for Noninvasive Diagnosis of Malignant Biliary Strictures: A Pilot Study

BACKGROUND

The use of volatile organic compounds (VOCs) in bile was recently studied and appeared promising for diagnosis of malignancy. Noninvasive diagnosis of malignant biliary strictures by using VOCs in urine has not been studied.

AIM

To identify potential VOCs in urine to diagnose malignant biliary strictures.

METHODS

In this prospective cross-sectional study, urine was obtained immediately prior to ERCP from consecutive patients with biliary strictures. Selected-ion flow-tube mass spectrometry was used to analyze the concentration of VOCs in urine samples.

RESULTS

Fifty-four patients with biliary strictures were enrolled. Fifteen patients had malignant stricture [six cholangiocarcinoma (CCA) and nine pancreatic cancer], and 39 patients had benign strictures [10 primary sclerosing cholangitis (PSC) and 29 with benign biliary conditions including chronic pancreatitis and papillary stenosis]. The concentration of several compounds (ethanol and 2-propanol) was significantly different in patients with malignant compared with benign biliary strictures (p < 0.05). Using receiver operating characteristic curve analysis, we developed a model for the diagnosis of malignant biliary strictures adjusted for age and gender based on VOC levels of 2-propranol, carbon disulfide, and trimethyl amine (TMA). The model [-2.4191 * log(2-propanol) + 1.1617 * log(TMA) - 1.2172 * log(carbon disulfide)] ≥ 7.73 identified the patients with malignant biliary stricture [area under the curve (AUC = 0.83)], with 93.3 % sensitivity and 61.5 % specificity (p = 0.009). Comparing patients with CCA and PSC, the model [38.864 * log(ethane) - 3.989 * log(1-octene)] ≤ 169.9 could identify CCA with 80 % sensitivity and 100 % specificity (AUC = 0.9).

CONCLUSIONS

Measurement of VOCs in urine may diagnose malignant biliary strictures noninvasively.

Predictors of poor outcome among older liver transplant recipients

With the increasing age of recipients undergoing orthotopic liver transplant (OLT), there is need for better risk stratification among them. Our study aims to identify predictors of poor outcome among OLT recipients ≥ 60 yr of age. All patients who underwent OLT at Cleveland Clinic from January 2004 to April 2010 were included. Baseline patient characteristics and post-OLT outcomes (mortality, graft failure, length of stay, and major post-OLT cardiovascular events) were obtained from prospectively collected institutional registry. Among patients ≥ 60 yr of age, multivariate regression modeling was performed to identify independent predictors of poor outcome. Of the 738 patients included, 223 (30.2%) were ≥ 60 yr. Hepatic encephalopathy, platelet counts < 45,000/μL, total serum bilirubin > 3.5 mg/dL, and serum albumin < 2.65 mg/dL independently predicted poor short-term outcomes. The presence of pre-OLT coronary artery disease and arrhythmia were independent predictors of poor long-term outcomes. Cardiac causes represented the second most common cause of mortality among the elderly cohort. Despite that, this carefully selected cohort of older OLT recipients had outcomes that were comparable with the younger recipients. Thus, our results show the need for better pre-OLT evaluation and optimization, and for closer post-OLT surveillance, of cardiovascular disease among the elderly.

Pharmacokinetic-pharmacodynamic analysis for efficacy of ceftaroline fosamil in patients with acute bacterial skin and skin structure infections

Ceftaroline is a cephalosporin with broad-spectrum in vitro activity against pathogens commonly associated with acute bacterial skin and skin structure infections (ABSSSI), including methicillin-resistant Staphylococcus aureus. Ceftaroline fosamil, the prodrug of ceftaroline, is approved for the treatment of patients with ABSSSI. Using data from the microbiologically evaluable population from two phase 2 and two phase 3 randomized, multicenter, double-blind studies of patients with ABSSSI, an analysis examining the relationship between drug exposure, as measured by the percentage of time during the dosing interval that free-drug steady-state concentrations remain above the MIC (f%T>MIC), and clinical and microbiological responses was undertaken. The analysis population included 526 patients, of whom 423 had infections associated with S. aureus. Clinical and microbiological success percentages were 94.7 and 94.5%, respectively, among all of the patients and 95.3 and 95.7%, respectively, among those with S. aureus infections. Univariable analysis based on data from all of the patients and those with S. aureus infections demonstrated significant relationships between f%T>MIC and microbiological response (P < 0.001 and P = 0.026, respectively). Multivariable logistic regression analyses demonstrated other patient factors in addition to f%T>MIC to be significant predictors of microbiological response, including age and infection type for all of the patients evaluated and age, infection type, and the presence of diabetes mellitus for patients with S. aureus infections. Results of these analyses confirm that a ceftaroline fosamil dosing regimen of 600 mg every 12 h provides exposures associated with the upper plateau of the pharmacokinetic-pharmacodynamic relationship for efficacy.

Volatile organic compounds in bile can diagnose malignant biliary strictures in the setting of pancreatic cancer: a preliminary observation

BACKGROUND

Ascertaining the nature of biliary strictures is challenging. The role of volatile organic compounds (VOCs) in bile in determining the cause of biliary strictures is not known.

OBJECTIVE

To identify potential VOCs in the headspaces (gas above the sample) of bile in patients with malignant biliary strictures from pancreatic cancer.

DESIGN

Prospective cross-sectional study.

SETTING

Referral center.

PATIENTS

Prospective study in which bile was aspirated in 96 patients undergoing ERCP for benign and malignant conditions.

MAIN OUTCOME MEASUREMENTS

Selected ion flow tube mass spectrometry (VOICE200R SIFT-MS instrument; Syft Technologies Ltd, Christchurch, New Zealand) was used to analyze the headspace and to build a predictive model for pancreatic cancer.

RESULTS

The headspaces from 96 bile samples were analyzed, including 24 from patients with pancreatic cancer and 72 from patients with benign biliary conditions. The concentrations of 6 compounds (acetaldehyde, acetone, benzene, carbon disulfide, pentane, and trimethylamine [TMA]) were increased in patients with pancreatic cancer compared with controls (P < .05). By using receiver-operating characteristic curve analysis, we developed a model for the diagnosis of pancreatic cancer based on the levels of TMA, acetone, isoprene, dimethyl sulfide, and acetaldehyde. The model [10.94 + 1.8229* log (acetaldehyde) + 0.7600* log (acetone) - 1.1746* log (dimethyl sulfide) + 1.0901* log (isoprene) - 2.1401 * log (trimethylamine) ≥ 10] identified the patients with pancreatic cancer (area under the curve = 0.85), with 83.3% sensitivity and 81.9% specificity.

LIMITATIONS

Sample size.

CONCLUSIONS

The measurement of biliary fluid VOCs may help to distinguish malignant from benign biliary strictures. Further studies are warranted to validate these observations. (Clinical Trial Registration Number NCT01565460.).

The impact of mesenteric tension on pouch outcome and quality of life in patients undergoing restorative proctocolectomy

AIM

The study aimed to establish a method for the measurement of mesenteric tension after ileal pouch-anal anastomosis (IPAA) and to evaluate the impact of tension on clinical outcome and quality of life.

METHODS

All consecutive patients undergoing an open IPAA from July 2008 to October 2009 were prospectively enrolled. After the creation of the anastomosis, mesenteric tension was estimated by the surgeon in the operating room on a 10-point scale (1, least tension; 10, most tension). The association was analysed between mesenteric tension defined as low (1-2), medium (3-7) and high (8-10) and postoperative complications and quality of life (Cleveland Clinic Global Scale).

RESULTS

A mesenteric tension score was obtained in 134 patients (71 men, 53.0%). Median age was 38.5 (29.3-47.0) years. Fifty-six patients (41.8%) had a low, 59 (44.0%) a medium and 19 (14.2%) a high degree of mesenteric tension. Patients with a high mesenteric tension had a shorter anal transitional zone, a longer distance from the upper border of the symphysis pubis to the apex of the small bowel loop designated for the ileoanal anastomosis, a thinner abdominal wall at the stoma site and a longer distance from the pouch to the ileostomy. The proportion of patients with high mesenteric tension was less after stapled anastomosis. On long-term follow-up, patients with high mesenteric tension were more likely to suffer from anastomotic stricture and pouch failure. Pouch function was not influenced by mesenteric tension.

CONCLUSION

High mesenteric tension after IPAA is adversely associated with postoperative complications and pouch survival.

Comparison of outcomes for patients with primary sclerosing cholangitis associated with ulcerative colitis and Crohn's disease

Background: The comparative outcomes of ulcerative colitis (UC) and Crohn’s disease (CD) in patients with primary sclerosing cholangitis (PSC) are unclear; the aim of our study was to make an objective comparison.

Methods: A total of 273 patients with PSC and inflammatory bowel disease (223 with UC and 50 with CD) were included. Clinical and demographic variables were obtained.

Results: The PSC risk score was similar for both groups. The median follow-up period in patients with PSC-UC was 12 years (range 0–38) and that for PSC-CD was 14 years (range 1–36). The median number of disease flares per year was higher in PSC-UC patients than in the PSC-CD group [1vs.0 (ranges 0–20 and 0–9, respectively); P < 0.001]. More patients with UC developed colon neoplasia than CD (35.9% vs.18%; P = 0.009). On proportional hazards analysis for the risk of colectomy, UC patients had a 12% higher risk for colectomy [hazard ratio (HR) = 0.88; 95% confidence interval (CI) 0.51–1.51; P = 0.64]. Liver transplantation for PSC was associated with decreased risk (HR = 0.57; 95% CI 0.37–0.89; P = 0.013), while colon neoplasia increased the risk (HR = 3.83; 95% CI 2.63–5.58; P < 0.001) for colectomy. On proportional hazards analysis for the risk of colon neoplasia, UC patients had 56% higher risk of developing colon neoplasia than CD (HR = 0.44; 95% CI 0.16–1.25; P = 0.12).

Conclusions: PSC patients with CD appear to be associated with a lower risk of colon neoplasia and colectomy than PSC patients with UC.

Clinical characterization and survival of patients with borderline elevation in pulmonary artery pressure

Normal resting mean pulmonary artery pressure (PAP) is 8-20 mmHg. Pulmonary hypertension is defined as mean PAP of ≥25 mmHg. Borderline PAP levels of 21-24 mmHg are of unclear significance. We sought to determine the clinical characteristics and survival of subjects with mean PAP of 21-24 mmHg. We examined 1,491 patients enrolled in the Cleveland Clinic Pulmonary Hypertension Registry between February 1990 and May 2012 with baseline right heart catheterization. The relationship between PAP and all-cause mortality was assessed by Cox models and a tree-based analysis. Sixty-three patients had borderline PAP (underlying conditions: 12 left heart disease, 20 respiratory disease, 17 connective-tissue disease, 4 others, and 10 none). We then compared 3 groups: borderline PAP without heart or lung disease ([Formula: see text]), normal PAP without heart or lung disease ([Formula: see text]), and category 1 pulmonary arterial hypertension (PAH; [Formula: see text]). Borderline-PAP patients had levels of hemodynamic and functional compromise between those for normal-PAP patients and those for patients with PAH. Borderline PAP was associated with increased mortality compared to normal PAP (hazard ratio: 4.03 [95% confidence interval: 0.78-20.80], [Formula: see text]). A tree-based analysis demonstrated almost identical cut points in mean PAP (≤20, 21-26, and ≥27 mmHg) associated with differential survival ([Formula: see text]). Connective-tissue disease and an elevated transpulmonary gradient were predictors of worse survival in the borderline-PAP population. Borderline PAP elevation is associated with decreased survival, particularly in the context of connective-tissue disease and an elevated transpulmonary gradient.

Progression of low-grade dysplasia to advanced neoplasia based on the location and morphology of dysplasia in ulcerative colitis patients with extensive colitis under colonoscopic surveillance

BACKGROUND

The management of low-grade dysplasia (LGD) in ulcerative colitis (UC) patients remains unclear.

AIM

The aim of our study was to study the risk of progression of LGD to advanced neoplasia (AN), defined as high-grade dysplasia (HGD) or colorectal cancer (CRC) for UC patients undergoing surveillance based on location and morphology of LGD.

METHODS

997 UC patients underwent 3152 surveillance colonoscopies from 1998 to 2011. Kaplan-Meier estimates and incidence rates calculated.

RESULTS

Of the 102 patients with LGD (65 raised and 37 flat), 5 (4.9%) patients progressed to AN (3 HGD and 2 CRC) after a median follow-up of 36 months (interquartile range 18-71 months). Initial location of dysplasia was in the proximal colon in 47, distal colon in 55 patients. Four of the 5 (80%) patients with AN had initial dysplasia in the distal colon. Distal colonic LGD had an incidence rate for AN of 2.1 cases per 100 person years at risk, while proximal LGD had an incidence of 0.5 cases per 100 person years. Flat LGD in the distal colon was more likely to progress to AN [hazard ratio=3.6; 95% confidence interval, CI (1.3-10.6)]. Twenty of the 102 patients (15 flat and 5 raised) underwent colectomy: 2 (10%) had evidence of AN in colectomy (1 HGD and 1 CRC), 9 had LGD and remaining 9 did not have dysplasia.

CONCLUSIONS

The frequency of progression of LGD to AN is low. Flat dysplasia located in the distal colon is associated with a greater risk of progression to AN.

Pharmacokinetic-pharmacodynamic analyses for efficacy of ceftaroline fosamil in patients with community-acquired bacterial pneumonia

Pharmacokinetic-pharmacodynamic (PK-PD) analyses for efficacy using phase III trial data from patients treated with a ceftaroline fosamil dosing regimen of 600 mg intravenously (i.v.) every 12 h (q12h) for 5 to 7 days for community-acquired bacterial pneumonia (CABP) were conducted. High clinical and microbiological success rates (84.7 and 86.3%, respectively) and percentages of time during the dosing interval that free-drug steady-state concentrations remained above the MIC (f%T>MIC) (98.4% had f%T>MIC values of ≥63.3) were observed among 124 microbiologically evaluable patients. As a result, significant PK-PD relationships could not be identified. These data provide support for the use of a ceftaroline fosamil dosing regimen of 600 mg i.v. q12h to treat patients with CABP.

Morbidity and mortality of the Hartmann procedure for diverticular disease over 18 years in a single institution

AIM

Hartmann's procedure for perforated diverticulitis is associated with substantial morbidity and mortality. This study analyses factors associated with morbidity/mortality and possible changes over time.

METHOD

Patients treated by urgent Hartmann's procedure for perforated diverticulitis between 1992 and 2010 were studied, and information was collected on age, sex, perioperative details, 30-day morbidity and mortality recorded in an institutional review board approved database supplemented by chart review. Patients were divided into four groups based on the year of surgery. Univariate and multivariate logistic regression analysis was performed to identify risk factors associated with morbidity and mortality.

RESULTS

In all, 199 patients (51% female, mean age 65 years, mean body mass index 28 kg/m(2)) were identified. The American Society of Anesthesiologists (ASA) score was 4 in 30% of patients and Hinchey Stage IV in 16%. The mean length of stay was 12.5 ± 10 days. Mortality was 15% and did not change significantly over time. Overall morbidity was 52% and significantly increased over time on univariate analysis (P = 0.007) but not on multivariate analysis (P = 0.11). Independent predictors of morbidity on multivariate analysis were Hinchey IV (P < 0.001) and hypoproteinaemia (P = 0.001). Independent predictors for mortality were ASA > 3 (P = 0.01), abnormal creatinine (P = 0.007), steroid use (P = 0.007), Hinchey IV (P = 0.032), low albumin (P < 0.001) and low body mass index (P = 0.001).

CONCLUSION

Mortality after Hartmann's procedure for perforated diverticulitis has not decreased during the last 18 years. Morbidity has actually increased over time although this is related to increased disease severity and comorbidity. Future efforts should focus on the identification of patient subgroups benefiting from earlier elective surgery and alternative surgical approaches when perforated diverticulitis does occur.

Comparison of baseline predictors of prognosis in pulmonary arterial hypertension in patients surviving ≤2 years and those surviving ≥5 years after baseline right-sided cardiac catheterization

Idiopathic pulmonary arterial hypertension (PAH) is usually associated with a poor outcome but the prognosis with other forms of PAH is not well-described. Advances in therapy have furthered clouded the disease course. We sought to determine the baseline indicators of prognosis in patients with PAH. We reviewed the records of patients with PAH followed up at our institution to identify those who died within 2 years (reduced survival group; n = 21) and those who survived >5 years (long survival group; n = 60). The groups were compared for prognostic significance of the baseline clinical parameters. The reduced survival group were older (p = 0.001) and more likely to have scleroderma-associated PAH (p = 0.01), have pericardial effusion (p = 0.01), have a shorter 6-minute walk test (6MWT) distance (p = 0.001), to require oxygen during 6MWT (p = 0.02), have a worse World Health Organization functional class (p <0.001), and have greater serum brain natriuretic peptide levels (p = 0.01). Regression analysis showed age, World Health Organization functional class, 6MWT distance, the need for oxygen during the 6MWT, and renal disease to be independently associated with a poor prognosis. In conclusion, age, PAH etiology, World Health Organization functional class, pericardial effusion, 6MWT distance, the need for oxygen during the 6MWT, and brain natriuretic peptide are predictors of prognosis in patients PAH receiving specific therapy and might help identify a group that could benefit from aggressive upfront therapy.

Surgery of recurrent parastomal hernia: direct repair or relocation?

PURPOSE

Parastomal hernia is a common late complication after stoma creation. The management options are many; unfortunately, most literature suggests unsatisfactory results. There are few studies comparing the outcomes after repair of parastomal hernias especially in recurrent cases, and the results are controversial. The aim of this study was to compare outcomes after repair of recurrent parastomal hernias between direct repair (DR) and relocation (RL).

METHOD

We performed a retrospective chart review of patients who underwent direct repair or RL for recurrent parastomal hernia during the period between 1990 and 2005. Perioperative data and re-recurrence rates were obtained and analysed with appropriate statistical methods.

RESULTS

With mean follow-up time of 2 years, 50 operations were available for evaluation; 27 (54%) DR and 23 (46%) RL [five same-side RL (SSRL) and 18 opposite-side RL (OSRL)]. There were no deaths and there were similar complication rates between groups. Four of five (80%) SSRL had a re-recurrent parastomal hernia. Considering only DR with OSRL, although OSRL had longer operative time and hospital stay than DR, the re-recurrence rate was lower (38%vs 74%; P = 0.02). However, with Kaplan-Meier calculated and longer predicted follow-up time, re-recurrence rates were similar (Log rank P = 0.09).

CONCLUSION

Recurrent parastomal hernia repair is associated with high re-recurrence rates.OSRL seems to have promising short-term outcomes; however, whether these results hold up long-term remains unclear. Therefore, larger cohorts of patients with longer follow-up or prospective randomized trials are needed.

Combined surgery in pelvic organ prolapse is safe and effective

OBJECTIVE

In women, rectal prolapse is often accompanied by other signs of generalized pelvic floor weakness including uterine and bladder prolapse. The purpose of this study was to compare whether there are differences in outcomes of rectal prolapse surgery between women having combined pelvic organ prolapse (POP) surgery with a urologist or urogynecologist (CS) vs those having abdominal rectal prolapse surgery alone (RP).

METHOD

Charts were reviewed to collect perioperative data on those having surgery from 1995 to 2001. Phone surveys were conducted to obtain Cleveland Clinic Foundation (CCF) Incontinence score, Knowles-Eccersley-Scott-Symptom (KESS) Constipation Score, Short Form 36 (SF-36) quality of life score and recurrence rate. Appropriate statistical analysis was performed.

RESULTS

Ninety-four operations were performed (23 CS and 71 RP). Forty-six (49%) could be contacted by phone. Mean follow-up was similar in both groups (CS 4.1 vs RP 3.6 years; P = 0.796). There were no significant differences between both groups regarding age, American Society of Anesthesiology classification Score, complications, length of hospital stay, CCF Incontinence score, KESS Constipation Score, SF-36 Score and recurrence rate of rectal prolapse. The operative time (CS 226 vs RP 122 min; P < 0.001) and blood loss (CS 377 vs RP 183 ml; P < 0.001) were significantly increased in the CS group.

CONCLUSION

Combined surgery for POP is safe and effective when considering outcomes of rectal prolapse surgery. Therefore surgeons should not hesitate to address all pelvic floor issues during the same operation by working in partnership with the anterior pelvic floor colleagues.

Cost-Effectiveness of daptomycin versus vancomycin and gentamicin for patients with methicillin-resistant Staphylococcus aureus bacteremia and/or endocarditis

BACKGROUND

Methicillin-resistant Staphylococcus aureus (MRSA) is an increasingly common cause of bacteremia and endocarditis. The cost-effectiveness (CE) of daptomycin was compared with that of vancomycin-gentamicin in patients with MRSA bacteremia with or without endocarditis.

METHODS

With use of data from an open-label, randomized study comparing daptomycin with vancomycin-gentamicin in the aforementioned patient population, 3 cost strata were considered: (1) study drug acquisition (daptomycin, $0.37/mg; vancomycin, $7/g; and gentamicin, $0.12/mg); (2) stratum 1 plus the cost of therapy for treatment failures and adverse events, therapeutic drug monitoring, and preparation and administration of all medications; and (3) stratum 2 plus hospital bed costs. Drug costs were based on mean wholesale price, with other costs based on those for a typical community hospital. Cost-effectiveness ratios were calculated as cost divided by proportion of successes. Sensitivity analyses were performed by varying the study drug cost.

RESULTS

Forty-five (20 successes) and 44 (14 successes) patients received daptomycin and vancomycin-gentamicin, respectively. The respective median cost-effectiveness ratios for daptomycin and vancomycin-gentamicin for each cost stratum were as follows: $4082 (range, $1062-$13,893) and $560 (range, $66-$1649) for stratum 1 (P < .001); $4582 (range, $1109-$21,882) and $1635 (range, $163-$33,444) for stratum 2 (P = .026); $23,639 (range, $6225-$141,132) and $26,073 (range, $5349-$187,287) for stratum 3 (P = .82). Sensitivity analyses indicated that if the cost of vancomycin was $0, strata 3 cost-effectiveness ratios did not differ ($23,639 and $25,668, respectively; P = .85). Similar results between groups were seen among patients with bacteremia.

CONCLUSIONS

When all costs of therapy were considered, the cost-effectiveness of daptomycin and vancomycin-gentamicin was similar, even if the cost of vancomycin was $0.

Nonreversal of Hartmann's procedure for diverticulitis: derivation of a scoring system to predict nonreversal

PURPOSE

A Hartmann's procedure is performed in perforated diverticulitis, but in some patients the colostomy is never closed. Identification of patients at risk for Hartmann's nonreversal would be helpful to determine the extent of resection. The aim of this study was to quantify the risk of nonclosure by deriving a predictive score.

METHODS

Patients undergoing a Hartmann's procedure for diverticulitis were identified from database. They were separated into those who underwent Hartmann's reversal within one year of the initial operation, and those who did not. The data were analyzed in univariable and multivariable logistic regression. A predictive scoring system of Hartmann's reversal was created. The predictive power of the multivariable models, the predictive scoring system, and colorectal POSSUM physiology scores were compared.

RESULTS

Eighty of 117 patients (68.4%) had their colostomy reversed. Multivariate analysis identified age, American Society of Anesthesiologists' score, pulmonary comorbidity, preoperative blood transfusion, perforation, and anticoagulants as the factors of failure for stoma reversal. All 36 patients with a predictive score of less than 14 had their stoma reversed. Twenty-two of 25 patients (88%) with scores greater than 18 did not have a reversal. Predictive power was similar when using only colorectal POSSUM physiology scores alone, or with preoperative data.

CONCLUSIONS

More than 30% of patients undergoing a Hartmann's procedure for diverticulitis will not have their stoma reversed within a year. If this scoring system can be validated in an independent group of patients, it will be useful in allowing surgeons to strategize accurately and to counsel patients realistically.

Risk factors for low bone mass in patients with ulcerative colitis following ileal pouch-anal anastomosis

OBJECTIVES

Bone mineral density (BMD) can be adversely affected by the chronic nature of inflammatory bowel disease. Ileal pouch-anal anastomosis (IPAA) is the surgical treatment of choice for patients with ulcerative colitis (UC) who require proctocolectomy. There are few data on BMD in UC patients with IPAA. The aim of the study was to assess the prevalence and risk factors associated with low BMD in UC patients after IPAA.

METHODS

A total of 327 eligible patients with UC and IPAA from the Pouchitis Clinic were enrolled. Dual-energy X-ray absorptiometry was performed. Patients were classified as having normal or low BMD, based on the criteria by the International Society for Clinical Densitometry. A total of 39 demographic and clinical variables were evaluated with logistic regression models.

RESULTS

Of 327 patients with a median of 4 years after IPAA, 105 (32.1%) had low BMD. Fragility fracture was documented in 11 patients (10.5%) in the low BMD group and in 13 of 222 patients (5.9%) in the normal BMD group (P=0.14). In the multivariable analysis, covariate-adjusted factors associated with a low BMD were advanced age (odds ratio (OR) =1.64 per 5 years; 95% CI, 1.44-1.87), low body mass index (OR=0.43 per 5 kg/m(2); 95% CI, 0.30-0.62), and non-use of daily calcium supplement (OR=0.53; 95% CI, 0.29-0.96). Pouch-associated factors were not found to be significantly associated with the bone loss.

CONCLUSIONS

Low BMD was common in patients with UC, even after colectomy and IPAA. Low BMD in this patient population was associated with certain risk factors, some of which may be modifiable.

Family history of Crohn's disease is associated with an increased risk for Crohn's disease of the pouch

BACKGROUND

Crohn's disease (CD) of the pouch can occur in patients with restorative proctocolectomy and ileal pouch-anal anastomosis originally performed for a preoperative diagnosis of ulcerative colitis (UC). CD of the pouch was often observed in patients with a family history of CD. The purpose was to determine whether the family history of CD increased the risk for CD of the pouch in patients who underwent restorative proctocolectomy.

METHODS

A total of 558 eligible patients seen in the Pouchitis Clinic were enrolled, including 116 patients with CD of the pouch and 442 patients with a normal pouch or other pouch disorders. Demographic and clinical variables were included in the study. Multivariable logistic regression analyses were performed.

RESULTS

The adjusted multivariate logistic analyses revealed that the risk for CD of the pouch was increased in patients with a family history of CD, with an odds ratio (OR) of 3.22 (95% confidence interval [CI] 1.56-6.67), or with a first-degree relative with CD (OR = 4.18, 95% CI, 1.48-11.8), or with a greater number of family members with CD (OR = 2.00 per family member, 95% CI, 1.19-3.37), adjusting for age, gender, smoking status, duration of IBD, duration of having a pouch, and a preoperation diagnosis of indeterminate colitis or CD. In addition, patients of younger age and longer duration of having a pouch had a higher risk for CD of the pouch. A diagnosis of CD of the pouch was associated with a poor outcome, with a greater than 5-fold estimated increased odds of pouch failure (OR = 5.58, 95% CI, 2.74-11.4).

CONCLUSIONS

The presence of a family history of CD is associated with an increased risk for CD of the pouch, which in turn has a high risk for pouch failure.

Effect of small bowel obstruction on functional outcome and quality of life in patients with ileal pouch-anal anastomosis: 10-year follow-up study

BACKGROUND AND AIM

Postoperative abdominal adhesion formation is a troublesome clinical problem and a common cause of intestinal obstruction, chronic pain and infertility. The aim of this study was to evaluate the effect of small bowel obstruction (SBO) on functional outcome and quality of life (QOL) in patients who experienced ileal pouch-anal anastomosis (IPAA).

METHODS

A total of 2418 patients who had undergone IPAA were categorized into three groups: group 1 comprised patients who had no SBO episodes until the last follow-up; group 2 comprised patients who had one or more SBO episodes treated medically; and group 3 comprised patients who had one or more SBO episodes, at least one of which was treated surgically. Functional outcomes and QOL scores for patients in each group were evaluated at 1, 3, 5 and 10 years of follow-up using multivariate analysis.

RESULTS

We found that patients who had SBO episodes which were treated medically were more likely to have a higher number of total bowel movements in a day in the first year of follow-up compared to patients without postoperative SBO (P = 0.03), and more seepage during the day at 10 years follow-up compared to patients with no SBO episodes or surgically treated SBO episodes (P = 0.01). The Cleveland Global Quality of Life (CGQL) scores were comparable between the three groups at 1, 3, 5 and 10 years of follow-up.

CONCLUSION

Medical management of SBO is associated with an increase in two symptoms, but QOL is comparable with surgical management.

Increased prevalence of breast cancer among patients with thyroid and parathyroid disease

BACKGROUND

A breast cancer (BC) history was elicited more frequently than expected among thyroid operation patients, which prompted an investigation of risks for concurrent or subsequent nonendocrine malignancies.

METHODS

Of 94,939 patients at a tertiary referral center with breast, thyroid, or parathyroid disease from 2000 to 2006, those patients with more than one tumor type were identified. Rates of BC, thyroid cancer (TC), hyperparathyroidism (HPT), and multiple diagnoses were compared with matched populations using Surveillance, Epidemiology, and End Results (SEER) data.

RESULTS

Of those patients identified, 1604 patients had TC, 12,440 patients had BC, and 1352 patients had HPT. Sixty patients with TC (3.7%) and 70 patients with HPT (5.2%) also had BC. Of 820 consecutive thyroidectomy patients, 23 patients (2.8%) had TC and BC, compared with 1.6% expected from a Monte Carlo distribution using SEER data (P = .001). BC and TC occurred within 5 years in 90% of patients, who tended to be older than those with a single cancer. HPT affected 0.6% of patients with BC, 6% of patients with TC, and 7% of patients with both malignancies.

CONCLUSION

Patients found initially to have TC or BC may be predisposed to develop the other malignancy within a short timeframe. HPT is also more prevalent among these patients. Vigilant screening for associated disorders should accompany initial diagnosis of either cancer.

Tubal anastomosis by robotic compared with outpatient minilaparotomy

OBJECTIVE

To compare tubal anastomosis by robotic system compared with outpatient minilaparotomy.

METHODS

In this retrospective case-control study, women were identified by current procedural terminology code for tubal anastomosis. We included all cases of tubal anastomosis for reversal of a prior tubal ligation by either outpatient minilaparotomy or robotic system technique. Cases performed by laparoscopy without aid of the robot were excluded. Comparisons were based on Fisher's exact, chi(2), and Wilcoxon rank sum tests.

RESULTS

There were 26 cases of tubal anastomosis performed with the robot and 41 cases performed by outpatient minilaparotomy. The two groups were comparable in age, body mass index, and parity. Anesthesia time for the robotic technique (median with interquartile range) was 283 (267-290) minutes compared with 205 (170-230) minutes with outpatient minilaparotomy (P<.001). Surgical times for the robot and minilaparotomy were 229 (205-252) minutes and 181 (154-202) minutes respectively (P=.001). Hospitalization times, pregnancy, and ectopic pregnancy rates were not significantly different. The robotic technique was more costly. The median difference in costs of the procedures was $1,446 (95% confidence interval $1,112-1,812) (P<.001). The time to return to work was significantly shorter in the robotic system group by approximately 1 week (P=.013).

CONCLUSION

Robotic surgery for tubal anastomosis was successfully accomplished without conversion to laparotomy. The robotic technique for tubal anastomosis required significantly prolonged surgical and anesthesia times over outpatient minilaparotomy (P<or=.001). Costs were higher with the robotic technique. Return to normal activity was shorter with the robotic technique.

Clinical outcomes and cost analysis of a "fast track" postoperative care pathway for ileal pouch-anal anastomosis: a case control study

PURPOSE

Traditional length of hospital stay after ileal pouch-anal anastomosis is 8 to 15 days. Fast track rehabilitation programs reduce stay, but there are concerns that readmission and complication rates may be increased. This study evaluated a fast track pathway after ileoanal pouch surgery.

METHODS

One hundred three consecutive patients underwent ileal pouch-anal anastomosis on two colorectal services using a fast track protocol with early ambulation, diet, and defined discharge criteria. Direct hospital costs and 30-day and long-term complication data were collected. Patients were matched to controls managed with traditional care pathways by other colorectal staff.

RESULTS

Matching was established for 97 patients. Fast track patients had shorter hospital stay than controls (median 4 vs. 5 days; mean 5.0 vs. 5.9, P = 0.012). Readmission and recurrent operation rates were similar (24 vs. 20 percent, P = 0.49, and 9 vs. 10 percent, P = 0.8, fast track vs. control, respectively). Median direct costs per patient (US$) within 30 days were lower with fast track (5692 vs. 6672, P = 0.001), primarily because of reductions in postoperative management expenses. Complication rates, including pouch failure, bowel obstruction, pouchitis, and anastomotic stricture were comparable. Early discharge (< or = 5 days from surgery) occurred in 79 (77 percent) fast track patients. Failure with early discharge was associated with male gender, reoperations, and anastomotic complications.

CONCLUSIONS

Fast track protocol after ileoanal pouch surgery reduces length of stay and hospital costs without increasing complication rates. Successful early discharge usually signals a benign postoperative course.

Factors associated with failure in managing pelvic sepsis after ileal pouch-anal anastomosis (IPAA)--a multivariate analysis

BACKGROUND

Pelvic sepsis is known to cause a detrimental outcome after ileal pouch-anal anastomosis (IPAA). The aim of this study was to examine potential factors associated with failure in managing pelvic sepsis after IPAA.

METHODS

We performed univariate and multivariate logistic regression analysis on 2518 IPAA patients between 1983 and 2005. Failure was defined as pouch failure, the need for a permanent ileostomy, or mortality as a result of sepsis. There were 157 patients (6.2%) with pelvic sepsis after IPAA. These involved anastomotic leak 34% (54/157) and fistula 25% (40/157). There were 5 mortalities related to sepsis. Mean age at surgery was 38.1 +/- 14.4 years and mean follow-up was 5.5 +/- 4.7 years.

RESULTS

Pouches were saved in 75.8% patients. Univariate analysis identified early sepsis (P = .040), preoperative steroid use (P = .007), and need for percutaneous drainage (P = .004) as significant factors associated with treatment success. Factors associated with failure were hypertension (P = .026), hand-sewn anastomosis (P = .038), associated fistula (P = .0003), need for transanal drainage (P = .0002), need for laparotomy to control septic complications (P < .0001), delayed ileostomy closure (P = .0003), and need for a new diverting ileostomy (P < .0001). By using multivariate analysis with selected covariates, significant factors associated with failure were associated fistula (P = .0013), need for transanal drainage (P = .003), delayed ileostomy closure (P = .022), need for a new ileostomy diversion (P = .004), and hypertension (P = .039). We developed a predictive scoring system for failure to use in management plans and decision-making for the treatment of septic complications of IPAA.

CONCLUSIONS

Pelvic sepsis after IPAA has a significant impact on pouch failure. This predictive model for failure may play an important role in providing risk estimates for successful outcomes.

Differential effectiveness of etanercept and infliximab in the treatment of ocular inflammation

PURPOSE

Anti-tumor necrosis factor alpha (anti-TNF-alpha) agents are being used increasingly in refractory inflammatory eye diseases. We reviewed our patients on etanercept and infliximab to determine whether these medications are equally efficacious in controlling ocular inflammation.

DESIGN

Exploratory retrospective analysis.

PARTICIPANTS

Patients with ocular inflammatory disease on an anti-TNF-alpha agent (etanercept, infliximab).

METHODS

Case records of 22 patients treated with anti-TNF-alpha therapy were reviewed for demographic information, ocular and systemic diagnosis, duration and dose of anti-TNF-alpha treatment, concomitant ocular and systemic immunosuppressive medications, and treatment response.

MAIN OUTCOME MEASURES

Uveitis recurrence rate, initial treatment response, treatment response, and medication use at 6 months, 1 year, and last visit.

RESULTS

Patients treated with infliximab had a significant decrease in uveitis recurrences after starting therapy compared with those treated with etanercept (59% vs. 0%, P = 0.004). One year after treatment initiation and at final visit, more infliximab-treated patients had an improvement in their ocular inflammation (100% vs. 33%, P = 0.002, and 94% vs. 0%, P<0.001, respectively) and a decreased requirement for topical prednisolone acetate 1% (94% vs. 33%, P = 0.009, and 89% vs. 29%, P = 0.007, respectively) compared with those treated with etanercept. No significant differences in the use of oral corticosteroids and immunosuppressive agents were noted between the 2 groups at 6 months, 1 year, and final visit.

CONCLUSIONS

Infliximab was more effective than etanercept in the treatment of recalcitrant uveitis and decreased the use of topical steroids.

Comparison of censored regression and standard regression analyses for modeling relationships between antimicrobial susceptibility and patient- and institution-specific variables

In order to identify patients likely to be infected with resistant bacterial pathogens, analytic methods such as standard regression (SR) may be applied to surveillance data to determine patient- and institution-specific factors predictive of an increased MIC. However, the censored nature of MIC data (e.g., MIC < or = 0.5 mg/liter or MIC > 8 mg/liter) imposes certain limitations on the use of SR. In order to investigate the nature of these limitations, simulations were performed to compare a regression tailored for censored data (censored regression [CR]) and one tailored for an SR. By using a model relating piperacillin-tazobactam MICs against Enterobacter spp. to patient age and hospital bed capacity, 200 simulations of 500 isolates were performed. Various MIC censoring patterns were imposed by using 26 left- or right-censored (L,R) pairs (i.e., MICs < or = 2 mg/liter(L) [2L] or MICs > 2 mg/liter(R) [2R], respectively). Data were fit by CR and SR for which censored MICs were either (i) excluded, (ii) replaced by 2L or 2R, or (iii) replaced by 2(L - 1) or 2(R + 1). Total censoring for the 26 pairs ranged from 7 to 86%. By CR, deviations of average parameter estimates from the true parameter values were <0.10 log2 (mg/liter) for all parameters for each of the 26 pairs. By SR, these deviations were >0.10 log2 (mg/liter) for at least 18 of the 26 pairs for all but one parameter. Two-standard-error confidence intervals for individual parameters contained as little as 0% of cases for all SR approaches but > or = 91.5% of cases for the CR approach. When censored MIC data are modeled, CR may reduce or eliminate biased parameter estimates obtained by SR.

Multivariable analysis of factors associated with hospital readmission after intestinal surgery

BACKGROUND

Readmission rates after major abdominal surgery have a significant impact on hospital costs and quality of care. Identification of risk factors for readmission may improve postoperative care and discharge plans.

METHODS

One hundred fifty consecutive patients readmitted within 30 days of discharge after intestinal surgery (RD) were compared with matched nonreadmitted patients. Patient-related (demographic, comorbidity, medications), disease-related (diagnosis, type of surgery), and perioperative course variables were collected for logistic regression analysis.

RESULTS

RD was associated with chronic obstructive pulmonary disease (odds ratio [OR] 7.12 and 95% confidence interval [CI] 1.4-37.6), worse functional capacity class (OR 2.02 and CI 1.15-3.56), previous anticoagulant therapy (OR 4.85 and CI 1.2-19.7), steroid treatment, and discharge to a facility other than home (OR 4.35 and CI 0.97-20.0, P = .055). In patients with intestinal perforation, RD rate was decreased (OR 0.3 and CI 0.1-0.9), but this was associated with a longer primary hospital stay (median 8 vs. 6 days, P = .12). RD causes included surgical site septic complications (33%), ileus and/or small-bowel obstruction (23%), medical complications (24%), and others (20%).

CONCLUSIONS

Functional capacity, chronic obstructive pulmonary disease, previous anticoagulant therapy, perioperative steroids, and discharge destination are independent predictors of RD. Disease-related factors have minor impact on RD rates. Improving functional status before surgery, decreasing the adverse impact of steroids, and/or stratifying perioperative anticoagulant use may decrease unexpected readmissions in this patient population.

Risk factors for diseases of ileal pouch-anal anastomosis after restorative proctocolectomy for ulcerative colitis

BACKGROUND & AIMS

Although pouchitis is considered the most common adverse sequela of ileal pouch-anal anastomosis (IPAA), inflammatory and noninflammatory conditions other than pouchitis are increasingly being recognized. The risk factors for these non-pouchitis conditions, including Crohn's disease (CD) of the pouch, cuffitis, and irritable pouch syndrome (IPS), have not been studied. The aim of this study was to assess risk factors for inflammatory and noninflammatory diseases of IPAA in a tertiary care setting.

METHODS

The study consisted of 240 consecutive patients who were classified as having healthy pouches (N = 49), pouchitis (N = 61), CD of the pouch (N = 39), cuffitis (N = 41), or IPS (N =50). Demographic and clinical features were assessed to determine risk factors for each of these conditions by using logistic regression analysis.

RESULTS

Risk factors remaining in the final logistic regression models were for pouchitis: IPAA indication for dysplasia (odds ratio [OR], 3.89; 95% confidence interval [CI], 1.69-8.98), never having smoked (OR, 5.09; 95% CI, 1.01-25.69), no use of anti-anxiety agents (OR, 5.19; 95% CI, 1.45-18.59), or use of NSAIDs (OR, 3.24; 95% CI, 1.71-6.13); for CD of the pouch: a long duration of IPAA (OR, 1.20; 95% CI, 1.12-1.30) and current smoking (OR, 4.77; 95% CI, 1.39-16.25); for cuffitis: arthralgias (OR, 4.13; 95% CI, 1.91-8.94) and younger age (OR, 1.16; 95% CI, 1.01-1.33); and for IPS: use of antidepressants (OR, 4.17, 95% CI, 1.95-8.92) or anti-anxiety agents (OR, 3.21; 95% CI, 1.34-7.47).

CONCLUSIONS

The majority of risk factors for the 4 inflammatory and noninflammatory conditions of IPAA are different, suggesting that each of these diseases has a different etiology and pathogenesis. The identification and modification of these risk factors might help patients and clinicians to make a preoperative decision for IPAA, reduce IPAA-related morbidity, and improve response to treatment.

Use of pharmacokinetic-pharmacodynamic target attainment analyses to support phase 2 and 3 dosing strategies for doripenem

A doripenem population pharmacokinetic model and Monte Carlo simulations were utilized for dose regimen decision support for future clinical development. Simulation results predict that 500 mg of doripenem administered over 1 h every 8 h would be effective against bacterial strains with MICs less than 2 microg/ml and that less susceptible strains could be treated with prolonged infusions.