Pioneering microbiome upstart Seres Therapeutics targets a $100M IPO

Seres CEO Roger Pomerantz

Microbiome pioneer Seres Therapeutics is taking its promising lead therapy and the high expectations for an emerging field in biotech and heading to Wall Street, where it hopes to raise $100 million in an IPO that is likely to provide another litmus test of investors' appetite for new drug technologies.

Cambridge, MA-based Seres has staked its future on the vast internal ecosystem of trillions of tiny microorganisms that make up the microbiome. Part of a wave of new microbiome adventurers, the biotech has developed its own technology--specializing in the colonic microbiome and dubbed Ecobiotics--for assessing the microbiome of healthy people against a targeted group of people who share the same disease, then coming up with the right mix of spores in a capsule that can correct what's wrong.

Seres stirred considerable attention, and was recognized as a 2014 Fierce 15 company, after its lead therapy SER-109 prevented recurring Clostridium difficile infection, CDI, in 29 out of 30 patients. A Phase II study was launched this month and data are expected in mid-2016, when it expects to move its next CDI candidate into the clinic and start a Phase III study of SER-109. In the meantime, a Phase I for SER-287 in ulcerative colitis is expected to get underway later this year as the biotech builds up its pipeline.

Like a lot of biotechs making the leap to Nasdaq over the last two years, Seres is a young company. Its accumulated deficit was a mere $36 million at the end of March, an economical price for a biotech that was launched three years ago. CEO Roger Pomerantz is a longtime veteran of the Big Pharma R&D industry, with stints at Merck ($MRK) and Johnson & Johnson ($JNJ). And he has some big goals in mind.

"We want to grow out into the white space as the lead company in the microbiome, a lot like Amgen and Centocor did in the 1980s with monoclonal antibodies," Pomerantz told FierceBiotech last year. "We want to become the Amgen of the microbiomic space."

Dreams like that, backed by some solid proof-of-concept data, have helped keep the IPO window open for biotechs around the world. Last year's crop of private Fierce 15 companies has helped illustrate that trend. Since last September, 7 of the 15 biotechs--Adaptimmune ($ADAP), Aduro ($ADRO), Cidara ($CDTX), Juno ($JUNO), Molecular Partners, Spark Therapeutics ($ONCE) and now Seres--have now either filed or completed an IPO, an unprecedented performance. And others like Dimension Therapeutics have openly discussed their interest in following the same path to Wall Street.

Flagship Ventures founded Seres and stands to gain the lion's share of the rewards from a successful IPO. Flagship owns 54.7% of the stock right now, followed by Nestle Health Science at 18.3%, Fidelity Management at 8.1% and Enso Ventures at 5.9%.

The biotech plans to trade under the symbol "MCRB."

- here's the S-1

Special Report: FierceBiotech's 2014 Fierce 15 - Seres Health