Historic Phase 3 Microbiota Trial for C Diff Treatment Completes Enrollment

An original version of this article was published on sister publication ContagionLive.

Enrollment for a phase 3 trial involving an investigative Rebiotix therapy for Clostridioides difficile (C diff) has been completed.

The clinical study of RBX2660 will be the first phase 3 trial in the history of the microbiome industry. The randomized, double-blinded study will include 300 patients with the gastrointestinal disease.

The treatment is an investigational microbiota-based therapy. RBX2660 has previously been granted Fast Track, Orphan, and Breakthrough Therapy Status designations from the FDA.

Fast Track designation allows the expedited review of an investigational drug which fulfills an unmet need. Orphan designation applies to a drug which meets a medical need but may not be profitable to produce without development incentives. Breakthrough Therapy Status expedites the review of a drug that preliminary evidence indicates may provide substantially better outcomes than existing therapies.

There are limited options for the treatment of C diff available, and roughly 1 in 5 patients face a recurrence of C diff after taking antibiotics for it.

Additionally, with each recurrent C diff infection, the likelihood of further recurrence increases.

The company intends to use results from the trial to apply for FDA licensure.

Previous results from the phase 2 clinical trial of RBX2260 found the treatment safe and efficacious for preventing C diff recurrence.

Ken Blount, PhD, chief scientific officer at Rebiotix, a Ferring Company, discussed the phase 2 trial results and plans for next steps with Contagion® at IDWeek 2019.

At 8 weeks, RBX2660 efficacy in preventing CDI recurrence (78.9%&#894;112/142) was higher than the CDI-free rate in the historical control group (30.7%, 23/75&#894; P <.0001) in the phase 2 study.

The safety profile of RBX2660 was also consistent with previous reports.

C diff infection can increase hospital length of stay between 3 and 21 days, according to recent research. Recurrence places a substantial burden on patients and the health care system.

If the phase 3 trial shows further promising results, the trial would represent a major step forward for the growing field of microbiome-based interventions.