INCB054707

Each evening, the participants assessed their worst level of itch during the past 24 hours on a scale of 0 (no itch) to 10 (worst itch imaginable). The Baseline Itch NRS score was determined by averaging the 7 daily Itch NRS scores before Day 1 (i.e., Day -7 to Day -1). If ≥4 of the 7 days of the daily Itch NRS scores were missing prior to Day 1, then the Baseline Itch NRS score was set to "missing." The by-visit Itch NRS score for postbaseline visits was determined by averaging the 7 daily Itch NRS scores before the visit day. If 4 or more daily Itch NRS scores out of the 7 days before the visit day were missing, the Itch NRS score at the visit was set to missing.

The T-VASI was calculated based on values from the whole body, which was split into 6 separate and mutually exclusive regions (possible range: 0-100; higher values=worse outcome). The percentage of vitiligo involvement was estimated in hand units (% body surface area \[BSA\]; investigator assessed), based on the participant's hand size. The degree of depigmentation for each body site was determined and estimated to the nearest percentage: 0%, 10%, 25%, 50%, 75%, 90%, or 100%. The T-VASI was derived by multiplying the values assessed for the vitiligo involvement by the percentage of affected skin for each body site and summing the values of all body sites. Percent change was calculated as (\[post-Baseline value minus the Baseline value\] / Baseline value) x 100.

Change from Baseline was calculated as the post-Baseline value minus the Baseline value. The mixed model repeated measure (MMRM) included the fixed effects of treatment group (placebo and INCB054707 15, 45, and 75 mg), stratification factors (disease severity \[Hurley Stage I, II, and III\] and geographical region \[North America and outside of North America\]), visit (Weeks 2, 4, 6, 8, 12, and 16), treatment by visit interaction, and covariates of Baseline measurement and Baseline measurement by visit interaction. The variance-covariance matrix of the within-participant errors in MMRM are modeled as unstructured.

TEAE is defined as any adverse event either reported for the first time or worsening of a pre-existing event after first dose of study drug. Grading was performed using guidance from the CTCAE v 4.03. A grade 3 and above would constitute as "severe".

A TEAE is any adverse event (AE) either reported for the first time or worsening of a pre-existing event after first dose of study drug.

Defined as maximum observed plasma concentration of INCB054707

Area Under the concentration- time curve up to the last measurable concentration of INCB054707

Defined as under the concentration-time curve up to the last measurable concentration of INCB054707

Defined as maximum observed plasma concentration of INCB054707

Defined as the area under the concentration- time curve up to the last measurable concentration of INCB54707.

Defined as area under the concentration-time curve From 0 to Infinity of INCB054707

Adverse events reported for the first time or worsening of a pre-existing event after first dose of study drug/treatment.

Maximum Observed Plasma Concentration of INCB054707

Minimum Observed Plasma Concentration of INCB054707

Time to reach maximum plasma concentration of INCB054707

Area Under the concentration- time curve up to the last measurable concentration of INCB054707

Area Under the Concentration-time Curve From 0 to Infinity of INCB054707

Area under the single-dose or steady-state plasma concentration-time curve from hour 0 to the end of the dosing period of INCB054707