MedicalResearch.com Interview with:
Dr. Elizabeth Rhee MD
Director, Infectious Disease Clinical Research Merck
MedicalResearch.com: What is the background for this study? What are the main findings?
Response: High-risk patients, such as the critically ill, with suspected bacterial infections require prompt treatment with appropriate empiric therapy to improve survival. Given the high prevalence of multidrug-resistant (MDR) Pseudomonas aeruginosa in the ICU setting, new safe and broadly effective treatment options are needed for critically ill patients requiring antipseudomonal agents.
Ceftolozane/tazobactam (C/T) is an antipseudomonal cephalosporin/beta-lactamase inhibitor combination with broad in vitro activity against Gram-negative pathogens, including MDR P. aeruginosa and many extended-spectrum beta-lactamase (ESBL) producers. It is FDA approved for complicated intra-abdominal and urinary tract infections in adults at 1.5g (1g/0.5g) q8h. C/T is currently being studied at 3g (2g/1g) q8h, for the treatment of ventilated nosocomial pneumonia, in the ASPECT-NP Phase 3 trial.
This Phase 1 pharmacokinetic (PK) study investigated the penetration of a 3g dose of C/T in the epithelial lining fluid (ELF) of ventilated patients with proven or suspected pneumonia. This is the dose and patient population being evaluated in ASPECT-NP. ELF lines the alveoli, and investigators took samples in a group of 26 patients to see what amount of C/T was in the lung and what was circulating in the plasma during the dosing intervals.
In mechanically ventilated critically ill patients, the 3g dose of C/T achieved ≥50% lung penetration (relative to free plasma) and sustained levels in ELF above the target concentrations for the entire dosing interval. These findings support the 3g dose that is included in the ASPECT-NP Phase 3 trial. Continue reading