Clinical Cure (CC) is defined as: • Resolution of Diarrhea (≤ 3 unformed bowel movement per day for at least 2 consecutive days) on study treatment and maintained for 2 days after end-of-treatment (EOT), AND • No additional antimicrobial treatment active against Clostridium difficile-associated diarrhea (CDAD) or fecal microbiota transplant between first dose of study drug and 2 days after EOT. CCR is the percentage of subjects with Clinical Cure. Analyses are performed on two analysis sets. Results on the modified intent-to-treat set (mITT) are reported below.

Clinical Cure (CC) is defined as: • Resolution of Diarrhea (≤ 3 unformed bowel movement per day for at least 2 consecutive days) on study treatment and maintained for 2 days after end-of-treatment (EOT), AND • No additional antimicrobial treatment active against Clostridium difficile-associated diarrhea (CDAD) or fecal microbiota transplant between first dose of study drug and 2 days after EOT. CCR is the percentage of subjects with Clinical Cure. Analyses are performed on two analysis sets. Results on the per-protocol set (PPS) are reported below.

Percentages of subjects with clinical cure are calculated, with clinical cure being defined as resolution of diarrhea with no further Clostridium Difficile-associated diarrhea (CDAD) treatment required at test-of-cure (TOC) visit. Resolution of diarrhea was defined as the occurrence of ≤ 2 semi-formed or formed stools during 24 h for at least 2 consecutive 24 h periods.

Blood samples for pharmacokinetic analysis taken immediately prior to dosing with cadazolid, and at 0.5, 1, 2, 4, 6, 8, 12, 24, 36, 48, 72, 96, 120, and 144 hours after dosing. Cmax was calculated on the basis of the blood sampling time points.

Blood samples for pharmacokinetic analysis taken immediately prior to dosing with cadazolid, and at 0.5, 1, 2, 4, 6, 8, 12, 24, 36, 48, 72, 96, 120, and 144 hours after dosing. tmax was calculated on the basis of the blood sampling time points.

Blood samples for pharmacokinetic analysis taken immediately prior to dosing with cadazolid, and at 0.5, 1, 2, 4, 6, 8, 12, 24, 36, 48, 72, 96, 120, and 144 hours after dosing. AUC(0-144) was calculated according to the linear trapezoidal rule using the measured concentration-time values above the limit of quantification.

Urine was collected into standard-weight polyethylene containers over the following time intervals: 0-12 h, 12-24 h, 24-36 h, 36-48 h, 48-72 h, 72-96 h, 96-120 h, and 120-144 h. The concentration of cadazolid was determined using validated liquid chromatography-tandem mass spectrometry assays. The amount of drug excreted in the urine was obtained by multiplying the concentration of drug by the volume of matrix collected.

Faeces were collected in pre-weighed polypropylene boxes. The concentration of cadazolid was determined using validated liquid chromatography-tandem mass spectrometry assays. The amount of drug excreted in the faeces was obtained by multiplying the concentration of drug by the volume of matrix collected.