Clinical remission is defined by a CDAI score of ≤ 150 points. The CDAI measures the severity of active disease using 8 disease variables (stool frequency, severity of abdominal pain, degree of general well-being, presence or absence of extra-intestinal manifestations or fistula, use or non-use of antidiarrheal agents, presence or absence of an abdominal mass, hematocrit, and body weight). The CDAI score is calculated by summing weighted scores for each item. CDAI scores range from 0 to 600, with higher scores indicating greater disease activity.

The full analysis set included all randomized participants; missing data were analyzed using the non-responder imputation method.

CDAI response is defined as a reduction from baseline in CDAI score of ≥ 100 points.

The CDAI measures the severity of active disease using 8 disease variables (stool frequency, severity of abdominal pain, degree of general well-being, presence or absence of extra-intestinal manifestations or fistula, use or non-use of antidiarrheal agents, presence or absence of an abdominal mass, hematocrit, and body weight). The CDAI score is calculated by summing weighted scores for each item. CDAI scores range from 0 to 600, with higher scores indicating greater disease activity.

Full analysis set; non-responder imputation was used.

The CDAI measures the severity of active disease using 8 disease variables (stool frequency, severity of abdominal pain, degree of general well-being, presence or absence of extra-intestinal manifestations or fistula, use or non-use of antidiarrheal agents, presence or absence of an abdominal mass, hematocrit, and body weight). The CDAI score is calculated by summing weighted scores for each item. CDAI scores range from 0 to 600, with higher scores indicating greater disease activity.

A negative change from baseline indicates improvement.

Full analysis set; missing CDAI scores were imputed using baseline values.

An adverse event (AE) is any untoward medical occurrence in a clinical trial participant, including worsening of a pre-existing medical condition. The event does not necessarily have a causal relationship with study treatment. A treatment-emergent AE is an event that occurred after the initiation of study drug or was already present prior to the initiation of study drug but worsened in either intensity or frequency after the initiation of study drug.

A serious AE is an adverse event that met at least one of the following criteria:

• fatal,
• life threatening,
• required in-patient hospitalization or prolongation of existing hospitalization,
• resulted in persistent or significant disability/incapacity,
• congenital anomaly/birth defect, and/or
• other significant medical hazard.

The investigator assessed whether each AE was possibly related to the study drug.

The safety analysis set included all participants who were randomized and received at least 1 dose of study drug.

An optional pharmacokinetic (PK) substudy was offered to participants at a subset of sites and required additional informed consent.

Serum concentrations of brodalumab were measured using a validated analytical method, enzyme-linked immusosorbent assay (ELISA). The lower limit of quantification (LLOQ) for the assay was 0.0500 μg/mL.

The PK analysis set includes participants in the PK substudy who received at least one dose of brodalumab and who provided valid drug concentration data at each sampling time point in Weeks 1 to 4, or in Week 5 to 12, and for whom at least one PK parameter or endpoint could be adequately estimated.

An optional pharmacokinetic (PK) substudy was offered to participants at a subset of sites and required additional informed consent.

Serum concentrations of brodalumab were measured using a validated analytical method, enzyme-linked immusosorbent assay (ELISA). The lower limit of quantification (LLOQ) for the assay was 0.0500 μg/mL.

The PK analysis set with available data

An optional pharmacokinetic (PK) substudy was offered to participants at a subset of sites and required additional informed consent.

Serum concentrations of brodalumab were measured using a validated analytical method, enzyme-linked immusosorbent assay (ELISA). The lower limit of quantification (LLOQ) for the assay was 0.0500 μg/mL.

The PK analysis set with available data.

An optional pharmacokinetic (PK) substudy was offered to participants at a subset of sites and required additional informed consent.

Serum concentrations of brodalumab were measured using a validated analytical method, enzyme-linked immusosorbent assay (ELISA). The lower limit of quantification (LLOQ) for the assay was 0.0500 μg/mL.

The PK analysis set with available data.