Relapses in C. diff Infections Reduced
Antibody Treatment Cuts Relapses That Plague C. diff Patients
Jan. 20, 2010 -- New monoclonal antibodies can break the cycle of recurrent
infections in patients plagued by C. diff, a clinical trial
C. diff -- Clostridium difficile -- is the most common cause
colitis. A particularly nasty strain of the bug, dubbed toxinotype III
BI/NAP1/027, is linked to several large outbreaks.
It's a nasty bug, but what makes it worse is that about 25% of patients
suffer recurrent bouts of infection. Some of these patients get into a spiral
of multiple relapses despite treatment with powerful antibiotics.
Animal studies suggest that C. diff is vulnerable to lab-grown
antibodies that attack the bacterium's A and B toxins. Now researchers at the
University of Massachusetts MassBiologics research facility report that it
greatly lowered C. diff recurrence in a medium-size clinical trial.
"The combined administration of [the] human monoclonal antibodies
significantly reduced the recurrence of C. difficile infection," report
Israel Lowy, MD, PhD, of Medarex Inc., and colleagues. Medarex is a wholly
owned subsidiary of Bristol-Myers Squibb. Merdarex and MassBiologics have
licensed the antibodies to Merck.
The antibodies are given in a single, two-hour infusion. The study,
conducted at 30 sites in the U.S. and Canada, enrolled 200 patients receiving
antibiotic treatment for lab-confirmed C. diff diarrhea. Half the
patients received the monoclonal antibodies, and half got an inactive
C. diff recurred in 25% of patients receiving placebo, but in only 7%
of those receiving the antibodies: a 72% reduction in C. diff
The treatment worked even better -- reducing C. diff recurrence by
82% -- in patients who already had suffered multiple relapses.
The treatment did not make the patients' initial C. diff disease any
better or worse and did not shorten their hospitalization.
"The trial results are impressive," Lorraine Kyne, MD, MPH, of University
College, Dublin, writes in an editorial accompanying the Lowy report. "This
novel non-antibiotic approach is likely to offer hope to physicians and
patients battling C. difficile infection."
The Kyne editorial, and the Lowy report, appear in the Jan. 21 issue of the
New England Journal of Medicine.