New Drug Targets C. diff Infection
First in New Class of Antibiotics Being Tested Against Diarrhea Bug
WebMD News Archive
Sept.16, 2009 (San Francisco) -- Researchers are developing a novel
antibiotic that they hope can help turn the tide in the epidemic of the nasty
bug Clostridium difficile, or C. diff.
Dubbed NVB302, the drug is the first in a new class of antibiotics called
Type B lantibiotics to undergo testing against C. diff.
NVB302 successfully killed C. diff in test tube studies and prolonged
survival in hamsters infected with the bacterium. Novacta Biosystems, the
company developing the drug, hopes to start human studies within a year, says
Michael J. Dawson, MD, chief scientific officer.
C. Diff: the Epidemic
The potentially dangerous diarrhea bug causes several hundred thousand human
infections and several thousand deaths each year in the United States,
according to the CDC.
In recent years, the number and severity of these infections has been on the
rise, says Curtis Donskey, MD, an infectious diseases specialist at Case
Western Reserve University in Cleveland.
“Cases have tripled in the last few years,” he tells WebMD.
Most cases of C. diff occur in people taking so-called broad spectrum
antibiotics that kill many different types of pathogens.
Spores enter the body through the mouth, which is the entryway for the
gastrointestinal tract. The broad spectrum antibiotics kill “good” bacteria in
the gut that keep C. diff at bay.
The resulting overgrowth of the C. diff bacteria in the colon, or
large intestine, can cause diarrhea, which is often severe and accompanied by
intestinal inflammation known as colitis.
C. Diff: The New Drug
Other more selective antibiotics such as Vancocin and Flagyl are typically
used to treat the infection, but many patients still suffer recurrences, says
Sjoerd Wadman, PhD, director of therapeutic products at Novacta.
These drugs work in about 75% of patients, he says. “But after seemingly
successful initial treatment, symptoms come back in some 20% to 25% of patients
10 to 30 days later,” he tells WebMD.
Researchers don’t fully understand why recurrences occur, but they believe
that even these "selective" antibiotics sometimes kill off the "good" pathogens
in the gut, Wadman says.
“New therapeutic approaches are urgently needed," he says.