Vedanta Biosciences has dosed the first subject in Phase III RESTORATiVE303 clinical trial of VE303, a live biotherapeutic product candidate aimed at preventing recurrent C difficile infection (rCDI).

The international, double-blind, randomised, placebo-controlled study is designed to assess the safety and efficacy of VE303 in people at increased rCDI risk after completing a course of antibiotics for an infection episode previously.

It will be conducted at approximately 200 sites in 22 countries across four continents.

Comparing the recurrence rates of CDI at eight weeks between patients treated with VE303 and those receiving a placebo is the trial’s primary endpoint.

The dosing regimen and design of the Phase III trial are informed by the results of the previous Phase II study.

VE303 successfully met its primary endpoint in the Phase II trial, demonstrating a significant reduction in CDI recurrence at eight weeks and exhibiting a well-tolerated profile.

It consists of a specifically designed bacterial consortium and has been recognised by the US Food and Drug Administration (FDA) with orphan drug designation in 2017 and fast track designation in 2023 to prevent rCDI.

Following the anticipated success of the RESTORATiVE303 trial, Vedanta plans to submit a biologics licence application to the FDA.

In the Phase II CONSORTIUM trial, VE303 treatment led to a 30.5% adjusted absolute risk reduction in CDI recurrence versus placebo, translating to more than 80% decrease in the likelihood of recurrence.

Vedanta Biosciences chief medical officer Jeffrey Silber said: “Building on the successes of earlier VE303 clinical studies, RESTORATiVE303 is the first pivotal Phase III study of a live biotherapeutic product for prevention of recurrent CDI, a potentially serious infection that affects up to 175,000 patients and results in approximately 20,000 deaths annually in the US.

“Based on the efficacy and safety data we have generated to date for this programme, we believe that an oral, rationally designed, defined consortium candidate has the potential to offer patients with rCDI an attractive alternative to undefined, donor-derived faecal approaches.”

In October 2023, the company dosed the first patient in the Phase II COLLECTiVE202 clinical trial of VE202 to treat ulcerative colitis.