Results from the compassionate use program for
linezolid (Zyvox), an investigational new antibiotic still under
development, show that the drug is effective in the treatment of
patients with bacteremia associated with significant gram-positive
infections, including those resistant to current therapies. These
data were discussed at a poster session at the 37th annual meeting of
the Infectious Diseases Society of America in Philadelphia.
Data were presented on 254 patients with bacteremia from 165
investigational sites. Of the total bacteremic population enrolled in
the compassionate use program, 120 were clinically evaluable at
short-term follow-up. Of this group, 82.5% were considered to be
cured. A total of 64 patients were considered to be microbiologically
evaluable at short-term follow-up, and linezolid demonstrated an
85.9% microbiologic cure rate in these individuals.
A third group of 50 patients was studied to assess how rapidly
linezolid eradicated the bacteria from patients bloodstream.
Linezolid eradicated organisms from the bloodstream by day 2 of
treatment in approximately 50% of these patients and by day 5 in 75%.
Our data from the Zyvox compassionate use program suggest
that Zyvox is well tolerated and successful in treating patients with
bacteremia, said study coordinator Mary Birmingham PharmD,
program director, The Clinical Pharmacokinetics Laboratory, Millard
Fillmore Hospital, and State University of New York, Buffalo.
Zyvox is an excellent treatment option for these seriously ill
patients with gram-positive bacteremia.
Range of Infections Treated
The infections in the patients studied included documented
intravenous or catheter-line infections, gastrointestinal infections,
skin and soft-tissue infections, urinary tract infections, infected
thrombi, and infected devices. The primary causative organism
isolated from from the group was vancomycin-resistant Enterococcus faecium
(81.4%). Other organisms isolated included methicillin-resistant Staphylococcus
aureus (6.2%), methicillin-resistant S epidermidis
(2.7%), other strains of vanco-mycin-resistant entercocci (2.7%),
vancomycin-susceptible enterococci (2.7%), vancomycin-resistant E faecalis
(2.3%), and methicillin-susceptible S aureus (1.2%).
Nonevaluability in a large number of patients was due to repeat
baseline blood cultures being negative prior to the initiation of
treatment with linezolid or to patients dying from their underlying
illnesses. The overall adverse event rate was 25.2%, with 5.5% of
these events considered to be serious and 9.0% requiring
discontinuation of treatment.