FMT efficacy for C. diff does not vary between stool bank donors

NEW ORLEANS — Clinical efficacy of fecal microbiota transplantation for recurrent Clostridium difficile infection is unlikely to vary between donors from a public stool bank, according to an analysis of real-world patient data presented at IDWeek 2016.

“We’ve done a lot of work thinking about what [it takes] to select a safe donor,” and in effect just 2.8% of donors qualify after a rigorous screening protocol, Majdi Osman, MD, MPH, from the nonprofit public stool bank OpenBiome, said during his presentation. However, this study focused on “how [to] select for an effective donor, and there’s some evidence to suggest that in IBD this might be very important.”

For example, in Moayyedi and colleagues’ randomized controlled trial of FMT in 70 patients with ulcerative colitis, just one of the six donors appeared to drive positive clinical outcomes, Osman said.

“This ... hints that the donor might be important not just for safety, but for clinical outcomes. Unfortunately, there’s a paucity of data on this for C. difficile,” he said. “So our aim was to firstly look at the overall efficacy and safety for FMT from this real-world patient data that we have, and then secondly to assess whether there’s any donor effect.”

Osman and colleagues used OpenBiome’s quality assurance system — which tracks its rigorously screened FMT preparations from donor to patient — to evaluate de-identified outcomes data from 482 health care facilities spanning 50 states and seven countries. Ultimately, they identified 28 donors (mean age, 28.5 years, 18 men; mean BMI, 24) who provided FMT material for at least 10 CDI patients each (n = 1,999) between January 2014 and April 2016.

The overall physician-reported clinical cure rate was 83.9%. In terms of safety, there were 42 reported adverse events, three of which were possibly related to FMT, and there were no reports of serious adverse events that were definitively related to FMT.

The investigators identified a single outlier donor linked to a significantly lower clinical cure rate of 70.9% (P = .05). However, after a sensitivity analysis, they found that the lower efficacy was driven by the site of the procedure, where the overall clinical cure rate for multiple donors was 50.7% (P = .05). They did not observe reduced efficacy at other hospitals where the outlier donor’s FMT material was also used.

This site-specific lower efficacy may be due to patients having alternative diagnoses despite testing positive for C. difficile on PCR, Osman said.

“This real-world data seems to replicate what we’ve seen in controlled trials,” he concluded. “FMT appears to be safe,” and the stool bank donor chosen “doesn’t matter for effectiveness.” – by Adam Leitenberger

Reference:

Osman M, et al. Abstract #841. Presented at: IDWeek; Oct. 25-30, 2016; New Orleans.

Disclosures: All but one of the researchers are employed by OpenBiome, and two report financial relationships with Finch Therapeutic.