Competing with several other firms to bring the first microbiome-derived therapy to market, Seres says the magnitude of its Phase III efficacy compared to placebo may enough for registrational filing.

Preliminary efficacy findings from an ongoing pivotal study of Ferring's RBX2660 showed that the first-in-class microbiota-based therapy helped restore the gut microbiome and break the cycle of recurrence of C diff. infection.

If all goes well, 2020 could see the Swiss firm's Rebiotix subsidiary get a green light from the FDA for its recurrent Clostridioides difficile fecal product.

Pivotal trials are underway for two microbiota restoration therapies, a narrow-spectrum antibiotic and a vaccine; funding from non-profits and new owners have revived stalled projects at Summit, Deinove and MGB Biopharma.