Gut bacteria , gut flora, microbiome. Bacteria inside the small intestine, concept, representation. 3D illustration.
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In a boost for the microbiome field, the U.S. FDA has approved Vowst (fecal microbiota spores, live-brpk). It is the first approved orally-administered microbiota-based therapeutic to prevent recurrence of C. difficile infection (CDI). The drug, from Seres Therapeutics and Nestlé Health Science, is expected to be available in June of this year. It was formerly called SER-109 and is approved in adults following antibacterial treatment for recurrent CDI (rCDI).

This is the second approved microbiome-related product. In November 2022 the agency approved Rebyota, also for prevention of rCDI.  Rebyota is administered rectally as a single dose and is prepared from stool donated by qualified individuals.

“Recurrent C. difficile infection is a highly debilitating and life-threatening disease, and antibiotics alone do not address the underlying cause of rCDI, dysbiosis of the gut microbiome,” said Carl Crawford MD, assistant professor of Clinical Medicine at Weill Cornell Medical College. “The approval of VOWST provides an important new oral treatment option for this disease, and I am pleased to now be able to offer this medicine to recurrent CDI patients.”

Seres is due to receive a $125 million milestone payment from Nestlé Health Science associated with the FDA approval of Vowst. Upon the drug’s commercialization, each company will be entitled to share equally in profits and losses. This morning, Seres also announced a $250M debt financing.

A gastrointestinal infection caused by C. difficile bacteria, rCDI is linked to disruption of the gut microbiome. According to the FDA, C. difficile infection is one of the most common healthcare-associated infections in the U.S. alone, where it is associated with 15,000 to 30,000 deaths annually.

 “With Vowst, we and Nestlé Health Science have the opportunity to prevent recurrence in a broad group of adult rCDI patients, including those who have experienced a first recurrence,” said Eric Shaff, president and CEO at Seres.

In 2015 Vowst was granted Breakthrough Therapy and Orphan Drug Designations by the FDA.

Vowst’s approval was supported by a Phase III development program that included the ECOSPOR III and ECOSPOR IV studies. ECOSPOR III was a multicenter, randomized, placebo-controlled study in individuals with rCDI, the results of which were published in the New England Journal of Medicine. In ECOSPOR III, VOWST was shown to reduce CDI recurrence at eight weeks, with approximately 88% of individuals recurrence-free at eight weeks post-treatment, compared to 60% in participants who received placebo.

In addition, at six months post-treatment, 79% of the Vowst group were demonstrated to be recurrence-free, compared to 53% in the placebo group. No treatment-related serious adverse events were observed in the active arm and the frequency of treatment-related adverse events was similar between the Vowst and placebo arms.

ECOSPOR IV was an open-label, single arm study evaluating Vowst in 263 adult participants with rCDI. Study results were published in the JAMA Network Open.

In July 2021, Seres and Nestlé Health Science entered into an agreement to jointly commercialize Vowst in the U.S. and Canada. Said Greg Behar, CEO, Nestlé Health Science, “Our teams have vast experience in gastrointestinal disorders and are poised to engage with healthcare professionals to start addressing this critical need for patients. We expect VOWST to be available in June and look forward to helping patients.”

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