RBX2660 Reduces Recurrent C difficile Infections in Patients With Comorbid Conditions

clostridium difficile
clostridium difficile
Researchers evaluated the safety and efficacy of the investigational, microbiota-based, live biotherapeutic RBX2660 for treatment of recurrent C difficile infection.

Treatment with investigational, microbiota-based, live biotherapeutic RBX2660 reduced recurrent Clostridioides difficile infection (rCDI) in patients with rCDI and comorbid conditions, according to research presented at the American College of Gastroenterology (ACG) 2021 Annual Meeting, held from October 22 to 27, 2021, in Las Vegas, Nevada and virtually.

The study included a real-world population of 94 adult patients with rCDI who received RBX2660 via a rectal route under Food and Drug Administration (FDA) enforcement discretion. Doses were determined by the investigator.

Using data from electronic health records, researchers assessed the safety and clinical response duration of RBX2660. Additionally, the investigators evaluated treatment success, which was defined as the absence of a CDI recurrence within 8 weeks following RBX2660 treatment.

Patients in the study presented with several comorbid conditions, including gastroesophageal reflux disease (47.9%), irritable bowel syndrome (17%), gastritis (11.7%), constipation (8.5%), microscopic colitis (7.4%), diverticulitis (6.4%), Crohn disease (5.3%), and ulcerative colitis (4.3%). At the time of RBX2660 treatment, approximately 16% of patients were taking concomitant immunosuppressants, including glucocorticoids (7%) and monoclonal antibodies (6%).

The treatment success rate in the 64 patients who were included in the primary safety set was 82.8%. No difference was observed between patients who received 1 vs 2 doses of RBX2660 in regard to the treatment success rate (83.3% vs 82.5%, respectively). Among the patients who experienced an initial response, the sustained clinical response to the 6-month follow-up period was 88.7%.

According to the researchers, the “safety outcomes were comparable to prospective studies for RBX2660,” with 92.2% of the adverse events (AEs) being mild or moderate in their severity. The mild to moderate AEs were also reported in patients who had immune-mediated/autoimmune disorders and nonspecific inflammation conditions.

“The results substantiate the potential safety and efficacy of RBX2660 in ‘real world’ populations with common rCDI comorbidities,” the investigators concluded.

Disclosure: Multiple authors declared affiliations with the pharmaceutical industry. Please refer to the original article for a full list of disclosures.


Feuerstadt P, Harvey A, Bancke L. RBX2660, an investigational live microbiota-based biotherapeutic, improves outcomes of Clostridioides difficile infection in a real-world population: a retrospective study of use under enforcement discretion. Presented at: ACG 2021 Annual Meeting; October 22-27, 2021; Las Vegas, NV and virtual. Abstract P2217.

This article originally appeared on Gastroenterology Advisor