US-based microbiome therapeutics developer Seres Therapeutics has begun a Phase III clinical trial of SER-109 for the treatment of patients suffering from multiple recurrent clostridium difficile (C. difficile) infection.

SER-109 is an Ecobiotic microbiome therapeutic currently being developed as an oral capsule.

The product comprises biologically sourced consortium of bacterial spores and is designed to catalyse a shift in a dysbiotic gastrointestinal microbiome to a healthier state.

Estimated to recruit up to 320 patients at more than 100 clinical centres in the US and Canada, the Phase III ECOSPOR III trial is expected to further support an adequate safety database for potential product licensure.

Seres Therapeutics president, chairman and CEO Roger Pomerantz said: “If ECOSPOR III is successful, we believe this study could serve as the basis for SER-109 approval.

"If ECOSPOR III is successful, we believe this study could serve as the basis for SER-109 approval."

“Our goal is to have SER-109 approved as the first microbiome drug in this new field of medicine, and the first for patients with multiple recurrent C. difficile infection, an area of very high unmet need for patients in the US and around the world.”

The primary endpoint of the trial is the comparison in the decrease of C. difficile recurrence rates by SER-109, with that of placebo at approximately eight weeks after dosing.

Under a previously signed development and commercialisation collaboration agreement with Nestlé Health Science, the commencement of the ECOSPOR III trial triggers a $20m milestone payment for Seres.

The firm intends to work with Nestlé Health Science for expediting discussions with European regulatory agencies on the approval of SER-109.

The US Food and Drug Administration (FDA) has granted breakthrough therapy and orphan drug designations for the product.