Table. Cumulative Recurrent Clostridioides difficile Infection Rates, Rate Differences, and Relative Risks at Weeks 4, 8, 12, and 24^a.

Time pointb	No. (%)		Rate difference (95% CI)c	P value	Relative risk (95% CI)d	P value
	SER-109 (n = 89)	Placebo (n = 93)
4 wk	10 (11.2)	31 (33.3)	−22.1 (−33.4 to −10.1)	<.001	0.35 (0.19 to 0.67)	<.001
8 wk	11 (12.4)	37 (39.8)	−27.4 (−38.9 to −14.8)	<.001	0.32 (0.18 to 0.58)	<.001
12 wk	16 (18.0)	43 (46.2)	−28.3 (−40.3 to −14.8)	<.001	0.40 (0.24 to 0.65)	<.001
24 wk	19 (21.3)	44 (47.3)	−26.0 (−38.4 to −12.2)	<.001	0.46 (0.30 to 0.73)	<.001

^a Patients with recurrence (confirmed and imputed) shown for all time points. Confirmed recurrence was defined as ≥3 unformed stools per day over 2 consecutive days, a positive C difficile stool toxin assay (enzyme immunoassay or cell cytotoxicity neutralization assay), a decision by the investigator to treat, and the requirement that diarrhea continued until antibiotics were initiated. Patients who were lost to follow-up, left the study prematurely, or died were imputed as a recurrence. If a patient had 1 missing criterion (eg, toxin test) but other criteria were documented (eg, diarrhea, decision to treat), recurrence was imputed.

^b Week 8 was the study primary efficacy end point. Weeks 4, 12, and 24 are secondary efficacy end points defined in the statistical analysis plan.

^c SER-109 minus placebo recurrence rate. P value is from a χ² test for differences between treatment groups. 95% CIs are based on the Newcombe-Wilson method. Negative values favor SER-109.

^d SER-109 divided by placebo recurrence rate adjusted for stratification based on Cochran-Mantel-Haenszel method. 95% CI based on Greenland-Robins method. Values less than 1 favor SER-109.