Clostridium Difficile Treatment Did Not Meet Primary Endpoint in Study

The phase 2 study enrolled 89 people with multiply recurrent CDI, defined as 3 or more recent recurrences, in a randomized, double-blind, placebo-controlled 24-week study conducted to evaluate the safety and efficacy of SER-109.

An eight-week study evaluating a microbiome designed to reduce the relative risk of Clostridium difficile recurrence at up to 8 weeks was not achieved, according to a statement from the manufacturer, Seres Therapeutics, Inc. 

The phase 2 study enrolled 89 people with multiply recurrent Clostridium difficile infection (CDI), defined as 3 or more recent recurrences, in a randomized, double-blind, placebo-controlled 24-week study conducted to evaluate the safety and efficacy of SER-109. 

The researchers randomly assigned subjects at a 2:1 ratio with 59 subjects receiving SER-109 and 30 subjects receiving placebo. SER-109 was administered orally as a single dose, of 1 X 108 bacterial spores, following the completion of antibiotic treatment for CDI. The study was conducted at 36 centers across the United States. 

CDI recurrence occurred in 26 of 59 people who received SER-109, compared to 16 of 30 who received placebo, according to the statement. The relative risk of CDI recurrence for the placebo population compared to the SER-109 population was not statistically significant. 

Reference

Seres Therapeutics Announces Interim Results from SER-109 Phase 2 ECOSPOR Study in Multiply RecurrentClostridium Difficile Infection. Press release. 2016.