The Food and Drug Administration on Wednesday approved Ferring Pharmaceuticals’ microbiota-based therapy for a type of debilitating intestinal infection, making it the first drug of its kind to get to market in the U.S.

The treatment, called Reybota, is cleared for use in adults 18 and older who have recurrent infections of Clostridioides difficile, or C. diff, and have completed a round of antibiotics, the FDA said in a statement Wednesday. The drug-resistant bacteria is responsible for an estimated half of a million infections annually that can cause diarrhea and, in some cases, life-threatening colon inflammation.

Ferring did not disclose the price of the treatment in an emailed response to BioPharma Dive’s questions.

“Our goal is to make Rebyota widely accessible to patients and providers who need it,” a spokesperson said, adding that the company will be offering patients assistance programs.

Reybota is a single-dose enema manufactured from donor samples of gut bacteria. After an infection, treatment with Reybota is meant to restore balance to the microbiome, the trillions of microbes that inhabit the human body. It’s a regulated, standardized alternative to the fecal transplants that the agency has allowed under investigational use since 2013.

The approval comes two months after FDA advisers voted 13-4 in support of the treatment. The panel concluded Rebyota’s apparent benefit, while modest, was significant enough for patients who don’t have any approved options after antibiotics fail to clear their infection.

That benefit was observed in two Phase 3 studies that showed the therapy had a 70.6% success rate in preventing recurrent infections compared to 57.5% for placebo recipients after eight weeks.

Committee members also noted a standardized option could be better monitored for efficacy and safety than an unregulated fecal transplant that, as one panelist put it, people could get “from their roommate.”

The approval for Ferring is a milestone for microbiome-based drug research, which has drawn significant interest from large drugmakers and biotech companies in recent years but also met with several setbacks.

“This is the first FDA approval of a live biotherapeutic and the culmination of decades of research and clinical development,” said Ferring president Per Falk, in a statement. Rebyota’s arrival “holds promise that many other diseases might be better understood, diagnosed, prevented and treated using our rapidly evolving insights on the role of the microbiome in human health and disease.”

It could also be the first of multiple microbiome therapies for C. diff to reach market.

Seres Therapeutics is developing an oral pill for C. diff that’s made from spores from a common type of gut bacteria. The FDA began reviewing the treatment, called SER-109, in October and could make a decision by April 26.

Finch Therapeutics is also developing an oral therapy for C. diff, but it is further behind. Finch said last month it began dosing patients in a Phase 3 trial and expects to report data in the first half of 2024.