Analysis adds to the consistent body of efficacy and safety evidence for RBX2660 across prospective and retrospective analyses and varying patient populations

PARSIPPANY, N.J.-- October 26, 2021 -- Ferring Pharmaceuticals and Rebiotix, a Ferring Company, today announced the results of two key retrospective analyses at the American College of Gastroenterology 2021 annual congress. One analysis evaluated the safety and efficacy of investigational RBX2660 among a broad cohort of CDI patients with comorbidities commonly found in patients with CDI, and was recognized with a Presidential Poster Award for high-quality, novel, unique and interesting research.

While the eligibility criteria in prospective clinical trials often are narrowly defined to include patients diagnosed with only CDI, this analysis allowed researchers to evaluate the impact of RBX2660 in a patient population that is more reflective of a real-world setting. In the analysis, 94 participants with comorbid conditions commonly found in people with recurrent CDI (rCDI) were treated with RBX2660 under a U.S. Food and Drug Administration (FDA) Enforcement Discretion policy. The analysis showed a treatment success rate of 82.8%, with no observable difference between participants who received one dose (83.3%) vs. two doses (82.5%). Treatment success was defined as absence of CDI recurrence at 8 weeks post administration of RBX2660. Among participants who responded to treatment after the first dose, 88.7% demonstrated a sustained clinical response to six months. Safety outcomes in this real-world analysis were comparable to prospective studies with most treatment-emergent adverse events being mild to moderate in severity.[1]

“The results of this retrospective study provide critical additional information about RBX2660, as it supports the concept that data observed in well-controlled, prospective clinical trials may be replicable in a real-world setting,” said Paul Feuerstadt, MD, FACG, AGAF, Yale University School of Medicine. “This research shows that even with wide eligibility criteria, RBX2660 performed similarly to the more narrow and limited inclusion for the Phase 2 and 3 trials. This retrospective study included patients across different comorbidities who are more representative of the population living with C. difficile and remain vulnerable to the debilitating cycle of recurrence.”

The comorbid conditions represented in this population included: gastroesophageal reflux disease (47.9%); irritable bowel syndrome (17%); gastritis (11.7%); constipation (8.5%); microscopic colitis (7.4%); diverticulitis (6.4%); Crohn’s disease (5.3%); and ulcerative colitis (4.3%).[1]

In a second abstract, researchers conducted a real-world comparison of outcome rates and healthcare resource utilization among patients ages 65 or older who had at least one CDI episode with or without co-occurring IBD. The analysis, based on Medicare data analyzed between 2009 and 2017, included a total of 497,489 patients with CDI, including 36,059 diagnosed with IBD. Overall, the rate of death among patients with CDI was higher among those without co-occurring IBD, including Crohn’s disease (CD) (42.9% vs. 34.7% with CD; p<0.0001) and ulcerative colitis (UC) (42.9% vs. 40.0% with UC; p<0.0001). Among patients with IBD, mortality was higher among those with primary CDI (CD 37.6%; UC 44.6%) vs. recurrent CDI (CD 28.7%; UC 31.1%; p<0.001).[2]

While all the groups studied had high rates of hospitalization - between 86% and 99% (p<0.0001) - those with CDI and IBD used more healthcare resources, including longer hospital stays and higher 30-day readmission rates. Among patients who died, those with CDI and UC had significantly higher monthly costs versus those with CD. The researchers noted that, given their elevated risk, CDI patients with IBD are likely to be identified more rapidly and require more resources to stabilize both conditions, which may explain the lower death rates but higher healthcare usage.[2]

References:

[1] 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 Scientific Meeting & Postgraduate Course. October 22-27, 2021. Poster #P2217.
[2] Feuerstadt, P, Dahdal, D., Wong, A., et al. A Real-World Comparison of Mortality, Healthcare Resource Utilization, and Cost Among Medicare Beneficiaries with Clostridioides difficile Infection (CDI) With and Without Inflammatory Bowel Disease (IBD). Presented at ACG 2021 Annual Scientific Meeting & Postgraduate Course. October 22-27, 2021. Poster #2611.