The efficacy of SER-109 was demonstrated in ECOSPOR III, a phase 3, double-blind, placebo-controlled trial. After 8 weeks, SER-109 recipients demonstrated a statistically significant lower incidence of C difficile recurrence than the placebo group (12% and 40%, respectively; RR, 0.32; 95% CI, 0.18–0.58; P<0.001).

Subsequently, the ECOSPOR IV trial, a phase 3, open-label, single-arm study, focused on the safety, efficacy, and durability of the response to SER-109 treatment in 263 adult patients. Participants received SER-109 following the remission of symptoms after antibiotics treatment, along with laxatives to wash out residual antibiotics from the gastrointestinal tract. The mean age was 64 and 68% of participants were female. The overall C difficile recurrence rate was 8.7% at week 8; 95% of participants maintained this response through week 24, regardless of prior recurrences.

More than half of participants (52%) reported adverse events, most of which were mild to moderate and gastrointestinal in nature. There were eight deaths within 8 weeks posttreatment, but none were deemed related to the study drug.

“Recurrent C difficile infection often has a debilitating impact on patients’ lives, and current treatments are often insufficient due to the persistence of microbiome disruption,” Louis Korman, MD, said. “Microbiome restoration, as provided by SER-109, could be a game-changer in treating this condition.”

Copyright ©2023 Medicom Medical Publishers