On the basis of the O’Brien-Fleming method for early stopping,[19] an interim analysis occurred after 174 volunteers (87 on each arm) completed the study. Descriptive summaries were reported as median (minimum and maximum) for continuous variables

and frequency and percentages for categorical variables within each treatment arm. Comparison of continuous variables was performed using the Wilcoxon Rank Sum test and a comparison of categorical variables was performed using either a Chi-square or Fisher’s exact test. Ordered categorical variables were compared using the Cochran Armitage trend test. Kaplan–Meier survival curves for time to onset of diarrhea for AKSB and placebo groups were plotted and compared using a log rank test. All Trichostatin A cell line tests were two-sided and p values < 0.05 were Epigenetic Reader Domain inhibitor considered statistically significant. Analysis was performed using sas version 9.0 (SAS, Inc.). A total of 251 subjects met the

criteria for entry and were subsequently enrolled in the study (Table 1). Fifty-five subjects dropped out after consent but prior to starting the study drug and 196 provided follow-up data. The most common reasons cited for dropping out were trip cancellation, participation was too inconvenient, and the use of an antibiotic within 2 weeks prior to onset of study. The current analysis is based on 196 subjects (94 in the AKSB and 102 in the placebo arm), including data from the interim analysis of 174 subjects. The median travel duration was 22 days (Table 1). Travel locations per each group are outlined in Table 2. The study enrollment was discontinued based on the results of the interim analysis. The adherence to the study drug was poor and less than expected. On the basis of self-reported adherence recorded in the patient diaries, only 58.1% (114/196) were fully adherent to the given

schedule—62.8% Rucaparib (59/94) of AKSB subjects and 53.9% (55/102) of those on placebo (p = 0.25). The median duration of days on the study agents was 20.5 and 21 for AKSB and placebo, respectively, with 97% (91/94) of subjects on AKSB and 97% (99/102) of those on placebo (p = 0.92) staying on drug for at least 15 days. Of the 196 subjects, 107 (54.5%) subjects reported diarrhea. The incidence of diarrhea was 52 (55.3%) in the AKSB study arm compared to 55 (53.9%) in the placebo arm [p = not significant (NS); Table 3]. Of the 114 subjects in full adherence with the protocol, diarrhea incidence was 31 (52.5%) on the AKSB arm and 27 (49.1%) on the placebo arm (p = NS; Table 3). There was also no statistically significant difference between the time of onset of diarrhea between the two groups (p = 0.70; Figure 1). The median time to diarrhea occurrence in the AKSB group was 14 days versus 18 days for the placebo group. In the majority of patients, the diarrhea lasted for three or less days (60% of the patients in AKSB and 80% in placebo arm).