Seres Presents Late Breaking Data at ASM Microbe Conference

At the ongoing ASM Microbe, Seres announced it had presented data from its 2 phase 3 trials for its C diff therapy, Vowst (SER-109), which is indicated for recurrent bouts of the healthcare-associated infection.

The presentation highlighted post-hoc gastrointestinal microbiome analyses of recurrent C diff patients enrolled in the ECOSPOR III and ECOSPOR IV Phase 3 studies, including those with a first recurrence and multiple recurrences.

Results showed that at baseline (pre-treatment), individuals experiencing a first recurrence or multiple recurrences exhibited a similarly low degree of gut microbiome diversity. Following treatment with Vowst both first recurrence and multiple recurrence patient groups had a significant increase in microbiome diversity as well as increased levels of secondary bile acids, a metabolites shown to inhibit growth of C. difficile bacteria

"Results from this post-hoc analysis of the ECOSPOR III and ECOSPOR IV Phase 3 studies show that whether recurrent C. difficile infection patients have experienced either a first recurrence or multiple recurrences, patients exhibit a similar level of loss of microbiome diversity,” Seres CMO Lisa von Moltke, MD, said in a statement. “Following treatment with VOWST, we observed an early robust increase in microbiome diversity in both patient groups within one week.”

Back in April, the FDA approved the oral microbiota treatment to prevent recurrent C diff infection (rCDI) in individuals 18 years of age and older following antibacterial treatment.

In previous reporting by Contagion, the company shared data from the aforementioned trial, ECOSPOR IV, which was a randomized, placebo-controlled study that examined the safety and effectiveness of Vowst in 263 adults with rCDI, including in first recurrence patients. The investigators determined whether Vowst was more effective than placebo in reducing rCDI after 8 weeks.

The data, which was presented at the DDW conference, demonstrated that 91.3% of the study patients who received Vowst achieved a significant clinical response at week 8. Through week 24, 94.6% of these participants maintained the response.

“In the ECOSPOR IV phase 3 open-label single-arm study, high clinical response rates were achieved at week 8 and continued into week 24 following Vowst treatment, regardless of the number of prior CDI infections,” von Moltke, said at that time.