Clostridioides difficile (C. diff) is a contagious bacterium that causes colon infections. People with C. diff infections (CDI) experience various symptoms, such as diarrhea and colonic inflammation, and in some cases, CDI can be fatal. The infection can be treated with specific antibiotics (e.g., vancomycin or fidaxomicin) for at least 10 days, although it may recur in some individuals.

Caitlyn Stulpin reported in Healio on the Phase 3, double-blind, placebo-controlled ECOSPOR III trial, which examined how effectively an oral fecal microbiota product reduced the risk of recurrent CDI. This product, FDA-approved in April 2023, is named Vowst (formerly SER-109). Vowst is used to prevent recurrent CDI but not to treat active CDI infections.

Data published in Clinical Infectious Diseases revealed that the trial included 182 participants aged 18 or older who had experienced three or more CDI episodes within a one-year period. The majority of participants were female, with a mean age of 65.5 years. Unlike other studies, this trial specifically sought to include individuals with comorbidities, such as those using proton pump inhibitors (PPI), the elderly, or those with renal insufficiency. In this case, 13.7% of participants used non-CDI-targeted antibiotics, and 40.7% took acid-suppressing medications.

During the trial, participants were randomly assigned to receive either Vowst or the standard-of-care antibiotics mentioned above. In a post-hoc analysis of the trial data, researchers found that:

• After eight weeks, participants receiving Vowst had a lower risk of recurrent CDI than the placebo group, even when factors such as creatinine clearance, age, sex, prior CDI episodes, antibiotic use, and acid-suppressing medication use were considered.
• Researchers used a comorbidity score to identify recurrence rates/risk. Among those receiving a placebo, the recurrence rate ranged from 20% to 45.7%, while the range was 0% to 20% in those taking Vowst.
• People on the placebo who were taking acid-suppressing medications had recurrence rates of 48.8%, compared to 9.1% in the Vowst-treated group.

About C. difficile Infection (CDI):

Each year, there are approximately 500,000 cases of CDI in the United States alone. This infection often occurs while someone is taking antibiotics or shortly after completing antibiotic treatment. While it predominantly affects older adults and those in care settings, CDI can also affect people outside of these groups. The CDC suggests that 1 in every 6 people with C. diff will experience a recurrence within 2 to 8 weeks following treatment, and this infection is fatal in 1 in every 11 adults over 65 years old.

Typically, symptoms of CDI appear within 5-10 days following the start of antibiotics. Symptoms of a mild infection may include:

• Mild abdominal cramping and tenderness
• Watery diarrhea three or more times a day for more than one day

In severe cases or as the infection worsens, additional symptoms may appear:

• Watery diarrhea as often as 10-15 times a day
• Blood or pus in the stool
• Dehydration
• Fast heart rate
• Severe abdominal pain and cramping
• Nausea and vomiting
• Loss of appetite
• Abdominal distension