Clostridium difficile recurrence reduced by Merck drug, study confirms

Clostridium difficile is defined by the Mayo Clinic as "a bacterium that can cause symptoms ranging from diarrhea to life-threatening inflammation of the colon," and has caused 500,000 infections in the U.S. in 2011, 29,000 of which resulted in death within a month of initial diagnosis, the CDC reports. Older adults who take antibiotics and get medical care are at higher risk for this illness, because antibiotics also eliminate bacteria that helps fight C. difficile.

Pharmaceutical company Merck is developing an experimental antibody to fight C. difficile, Reuters reports. Merck said that they completed 2 Phase 3 studies, which were presented at Interscience Conference of Antimicrobial Agents and Chemotherapy (ICAAC) and International Congress of Chemotherapy and Infection (ICC) joint medical meeting in San Diego. Results showed that following 12 weeks of treatment with the antibody and a single infusion of bezlotoxumab, which was designed to block the ability of a toxin to attach itself to a cell, the risk of C. difficle recurrence was decreased by 15%. Results also showed that the infection recurred in 25% of patients who were treated with antibiotics and placebo.

Reuters reports that according to Nick Kartsonis, associate vice president in clinical research, infectious diseases at Merck, "We have therapies to treat the initial episode, but this infection comes back frequently - there is a 25 percent risk of recurrence after the first time, and that rises to 40 percent or even 60 percent after the second infection."

The drug's side effects include nausea, diarrhea and urinary tract infection, which occurred at similar rates for patients in the study's placebo group. Merck said they are currently planning for the regulatory approval of bezlotoxumab before the end of the year. They licensed the drug from Massachusetts Biologic Laboratories and Medarex, which is now owned by Bristol-Myers Squibb.

According to Businesswire, Dr. Eliav Barr, vice president infectious diseases at Merck Research Laboratories said, "Today, with increasing concerns about the rise of antimicrobial resistance, we continue to advocate for appropriate and responsible use of these important medicines."

She added: "At Merck we continue to advance a broad portfolio of investigational infectious disease medicines."

Dr. Julie Gerberding, executive vice president, strategic communications, global public policy and population health also said, "Merck is one of a few large pharmaceutical companies that have remained deeply committed to developing novel anti-infective therapies. Today, with increasing concerns about the rise of antimicrobial resistance, we continue to advocate for appropriate and responsible use of these important medicines."