The US Food and Drug Administration (FDA) has granted Vedanta Biosciences’ oral microbiome treatment VE303 a fast track designation for the treatment of recurrent Clostridioides difficile (C.diff) infection, as the company plans to start a Phase III trial later this year, based on a May 8 announcement.

In late April, the Cambridge, Massachusetts-headquartered company announced a $106.5 million financing round that will fuel the upcoming Phase III trial, which is set to begin by Q3 2023. The funding will also be used for a Phase II trial of Vedanta’s ulcerative colitis treatment VE202, which is expected to start in this quarter.

In October 2021, Vedanta reported that the use of a high dose of VE303 in a Phase II study resulted in a 31.7% absolute risk reduction in the rate of recurrence of C.diff infections versus placebo, meeting the trial’s primary endpoint.

Fast track designations are given to treatments, which have the potential to target an unmet need in serious conditions. The  designation gives Vedanta’s VE303 a further boost in a changing microbiome therapeutic landscape that has seen several recent developments. In November 2022, the FDA approved Ferring Pharmaceutical’s enema-based treatment Rebyota for use against recurrent C. diff infections, making it the first FDA-approved faecal microbiota product. Seres Therapeutics’ oral treatment Vowst quickly followed and received a nod from the FDA in April 2023.

However, unlike both Rebyota and Vowst, VE303 does not use donated stool samples. Instead, VE303 is made from eight strains sourced from clonal bacterial cell banks. The use of donated stool samples has previously attracted concerns from the FDA. Most recently, the FDA stated that the use of Vowst, for which samples are screened for pathogens, may carry a risk of transmitting infectious agents. Prior to that, the same agency shared alerts on the potential risks of Covid-19 and mpox transmission through faecal microbiota transplants, requesting further safety protections.

According to Vedanta, roughly 500,000 individuals develop C. diff infections every year in the US. C. diff infections cause symptoms such as diarrhoea, fever, and nausea.