Affiliation:
1. Antibacterial Discovery Performance Unit, Infectious Disease Therapeutic Area, GlaxoSmithKline, Collegeville, Pennsylvania, USA
Abstract
ABSTRACT
GSK1322322 is a novel inhibitor of peptide deformylase (PDF) with good
in vitro
activity against bacteria associated with community-acquired pneumonia and skin infections. We have characterized the
in vivo
pharmacodynamics (PD) of GSK1322322 in immunocompetent animal models of infection with
Streptococcus pneumoniae
and
Haemophilus influenzae
(mouse lung model) and with
Staphylococcus aureus
(rat abscess model) and determined the pharmacokinetic (PK)/PD index that best correlates with efficacy and its magnitude. Oral PK studies with both models showed slightly higher-than-dose-proportional exposure, with 3-fold increases in area under the concentration-time curve (AUC) with doubling doses. GSK1322322 exhibited dose-dependent
in vivo
efficacy against multiple isolates of
S. pneumonia
e,
H. influenzae
, and
S. aureus
. Dose fractionation studies with two
S. pneumoniae
and
S. aureus
isolates showed that therapeutic outcome correlated best with the free AUC/MIC (
f
AUC/MIC) index in
S. pneumoniae
(
R
2
, 0.83), whereas
f
AUC/MIC and free maximum drug concentration (
fC
max
)/MIC were the best efficacy predictors for
S. aureus
(
R
2
, 0.9 and 0.91, respectively). Median daily
f
AUC/MIC values required for stasis and for a 1-log
10
reduction in bacterial burden were 8.1 and 14.4 for 11
S. pneumoniae
isolates (
R
2
, 0.62) and 7.2 and 13.0 for five
H. influenzae
isolates (
R
2
, 0.93). The data showed that for eight
S. aureus
isolates,
f
AUC correlated better with efficacy than
f
AUC/MIC (
R
2
, 0.91 and 0.76, respectively), as efficacious AUCs were similar for all isolates, independent of their GSK1322322 MIC (range, 0.5 to 4 μg/ml). Median
f
AUCs of 2.1 and 6.3 μg · h/ml were associated with stasis and 1-log
10
reductions, respectively, for
S. aureus
.
Publisher
American Society for Microbiology
Subject
Infectious Diseases,Pharmacology (medical),Pharmacology
Cited by
14 articles.
订阅此论文施引文献
订阅此论文施引文献,注册后可以免费订阅5篇论文的施引文献,订阅后可以查看论文全部施引文献