In the effort to contain Clostridium difficile infection in hospitals, a new antibiotic may provide a significant boost.
In a large-scale, phase-3 trial, the use of Fidaxomicin led to a 45% reduction in recurrences of C. difficile when compared with the existing licensed treatment, according to a report in the February edition of the New England Journal of Medicine.
There wasnt much interest in C. difficile for many years, because it wasnt considered a serious disease, said study co-author Dr. Mark A. Miller, head of the Division of Infectious Diseases and chief of microbiology at the Jewish General Hospital in Montreal, and a clinical investigator at the Lady Davis Institute for Medical Research.
However, over the past decade the bacterium has mutated into something much more serious that has caused epidemics worldwide. It is particularly notorious for recurrences. About 20 to 30% of patients suffer relapses. Recurrent C. difficile is very difficult to treat, and this has spurred interest in newer and better treatments.
Fidaxomicin, developed by Optimer Pharmaceuticals of San Diego, is the first in a new class of narrow-spectrum macrocyclic antibiotics. It gets absorbed from the gut to the bloodstream only in minimal amounts. By specifically targeting C. difficile in the intestine, it kills off the bacteria without affecting flora, which stave off recurrences.
In the trial, researchers enrolled 629 patients at multiple centers of treatment between 2006 and 2008. Patients received 200 milligrams of Fidaxomicin twice daily or 125 milligrams of the antibiotic vancomycin four times a day. Vancomycin, first developed in the 1950s, is the only treatment for the CDI that has been approved by the U.S. Food and Drug Administration and Health Canada.
These results showed that recurrence of CDI is significantly less likely to occur following treatment with Fidaxomicin versus vancomycin, said lead author Thomas J. Louie, MD, medical director, Infection Prevention and Control for the Calgary Health Region and professor in the Departments of Medicine and Microbiology-Infectious Diseases, University of Calgary.
Anything that can reduce the recurrence rate, especially as dramatically as Fidaxomicin, is a very important milestone in the treatment of C. difficile.