Seres drug for recurrent CDI fails in mid-stage study

Last Updated: 2016-07-29

By Reuters Staff

(Reuters) - Seres Therapeutics Inc said its experimental drug for preventing recurrent clostridium difficile infection (CDI) missed the main goal in a mid-stage study, sending its shares down 74 percent in premarket trading.

In eight weeks, the drug, SER-109, did not reduce the relative risk CDI recurrence, the company said in reporting interim results of the study.

The company said it would continue to develop a drug for the condition, which has limited treatment options.

"Seres continues to gather and analyze study data, and in consultation with the FDA, plans to make appropriate adjustments to its SER-109 development plans," the company said in a statement.

The most common adverse events reported in the SER-109 arm were diarrhea, abdominal pain and flatulence. No drug-related serious adverse events were observed.

SER-109 is an oral microbiome therapeutic developed using the Seres Microbiome Therapeutics platform that provides insight into the ecologies of disease and then identifies microbial compositions that can catalyze a shift to a healthier state, the company explains on their website.

Analysts from HC Wainwright & Co had previously said they expected SER-109 to potentially generate about $500 million in worldwide sales in 2025.