Rebyota Trial Subgroup Analysis: Why Look at Patients With Renal Disease? | IDWeek 2023

First of two parts

Although research into microbiota and the microbiome has understandably focused on the gut, there are microorganisms populating other parts of the body.

“The microbiome is an incredibly complex entity — and it ain’t just in your bowel. It’s everywhere,” Glenn Tillotson, Ph.D., M.Sc., a Virginia-based consultant to the pharmaceutical industry, said in an interview with Managed Healthcare Executive.

Tillotson is one of the co-investigators of findings presented in a poster at the IDWeek 2023 that focuses on a subgroup of 98 people (out of 402) with renal comorbidities in the PUNCH CD3-OLS trial of Rebyota (fecal microbiota live) as a treatment for Clostridioides difficile (C. diff.) infection.

Tillotson and his co-investigators reported that a smaller proportion of the study participants with renal comorbidities experienced “treatment success” — defined as an absence of C. diff-related diarrhea through eight weeks after Rebyota was administered — than those without renal comorbidities (66.3% vs. 77.3%), although Tillotson said the difference was not statistically significant.

The results they reported also show that a greater proportion of study participants with renal comorbidities had severe treatment-emergent adverse events than those without renal comorbidities (20 of 98, or 20.4% vs. 33 of 304, or 10.9%). Tillotson said none of those adverse events were related to administration of Rebyota and the majority were related to pre-existing conditions.

Tillotson said part of the interest in looking at patients with renal comorbidities lies in the fact that outcomes of C. diff infections are more complex for those patients. “Overall patients with renal complications are more at risk of severe disease and more at risk of mortality,” he noted.

Tillotson said the microbiome in the GI tract has been recognized as the “big player” but that researchers have identified microbiomes in the renal system, the liver and other parts of the body. “I was surprised to learn recently that there is actually a microbiome in the brain, principally viruses … there are bugs in virtually every part of the body," he said

Metabolites produced by the renal system affect the bowel, Tillotson told MHE, and in people with chronic kidney disease there is a decrease in “friendly bugs” in the bowel that allow C. diff infections to gain a foothold.