Seres Therapeutics To Conduct First Clinical Trial Of Synthetic Microbiome Drug

Microbiome therapeutics company Seres has announced it has started a Phase Ib clinical trial of its SER-262 oral microbiome therapy. While most microbiome therapeutics are composed of microorganisms isolated from healthy human fecal matter – a practice which limits production to serve just a few orphan disease patients – Seres has created the first synthetic designer microbiome capsule.

SER-262 contains 12 bacterial strains in a resistant, long-lasting spore form. Based on a number of factors – including data on the human microbiome, efficacy against Clostridium difficile infection in animals, and bacterial strain characterization – each strain present in the microbiome therapeutic was hand-chosen.

“Advancing SER-262 to the clinic is a landmark event for Seres and the microbiome field in general. The SER-262 program has demonstrated our ability to rapidly develop a new class of synthetic microbiome therapeutics comprised of rationally designed bacterial compositions,” said Dr. Roger Pomerantz, President, Chief Executive Officer and Chairman of Seres. “We intend to continue to utilize our platform technology and unique knowledge of bioinformatics, microbiology, manufacturing and regulatory requirements to develop additional rationally designed microbiome therapeutics for serious diseases in each of our three therapeutic franchises: infectious disease, immunology and metabolic disease.”

The Phase Ib clinical trial is a randomized, placebo-controlled trial which will take place over a 24-week period. The study is expected to enroll about 60 patients, some of which will receive escalating doses of the microbiome therapeutic.

The primary endpoint has been set as the recurrence rate of Clostridium difficile infection at up to eight weeks after commencement, between the treatment and placebo arms of the trial. By referring to a library of over 14,000 different strains of bacteria, the developers at Seres were able to choose bacteria outside the strains commonly found in the healthy human microbiome. According to Seres, this library of the microbiome could be the largest of its kind – even larger than that maintained by the National Institutes of Health (NIH).

In addition to its synthetic microbiome candidate, Seres also has two biologically-sourced microbe drugs in its pipeline. SER-109 – the company’s lead candidate in this category – is designed to prevent Clostridium difficile infection in those that have experienced over three incidents within a nine-month period.

It’s estimated that 85,000 to 110,000 US patients experience recurring Clostridium difficile infections, which are caused when antibiotics create an imbalance in the gut microbiome. A Phase II clinical trial for SER-109 is already underway, and Seres has received a coveted Breakthrough Therapy designation for the drug from the US Food and Drug Administration (FDA).

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