Paul Feuerstadt, MD: Years of Work Culminating in an Approval for Vowst

Throughout the last decade plus recurrent Clostridioides difficile infections (rCDI) has been a growing problem.

While primary cases are generally handled with the existing stable of medications, for those patients that do have recurrence, there were very few effective options.

However, that may soon change with the approval of a pair of live microbiota therapeutics earmarked for the prevention of patients at a risk of recurrence.

In November, the US Food and Drug Administration (FDA) approved RBX2660 (Rebyota), which isprepared from stool donated by qualified individuals and administered rectally as a single dose. Joining RBX2660 is Vowst (fecal microbiota spores, live-brpk), which is made from purified firmicutes spores, which are resistant to gastric acid and allows for oral administration.

In an interview with HCPLive®, Paul Feuerstadt, MD, Assistant Clinical Professor of Medicine, Yale School of Medicine, said while both products are donor derived from human stool, they are very different treatments.

“The processes behind these products are remarkably different and the data behind these products is different and the studies that looked at these products is really different,” Feuerstadt said. “SER-109 says look we don’t need to give the entire group of microorganisms, let’s just give the firmicutes spores.”

The approval was largely based on the results of the phase 3 ECOSPOR III and ECOSPOR IV studies, where investigators demonstrated that Vowst was shown to reduce CDI recurrence at week 8, with approximately 88% of individuals recurrence-free at week 8 post-treatment, compared to 60% in participants who were treated with placebo.

The efficacy maintained for at least 6 months, where 79% of the treatment group was recurrence-free, compared to 53% of the placebo group.