The Investigator's Global Assessment (IGA) is a modified global assessment tool to assess the severity of lesions. Grading was based on 0 (clear), 1 (almost clear), 2 (mild), 3 (moderate), and 4 (severe). IGA-TS response was defined as an IGA score of 0 or 1 with a ≥2-grade improvement from Baseline at Week 16.

Intent-to-Treat (ITT) Population: all randomized participants. Treatment groups were defined according to the treatment assignment at the time of randomization regardless of the actual study drug the participant might have taken during their participation in the Double-blind; vehicle-controlled (DBVC) period. Missing post-Baseline values were imputed as nonresponders. Only participants with available data were analyzed.

The IGA is a global assessment tool to assess the severity of lesions. The IGA includes items such as depigmentation/hypopigmentation, lichenification (fine wrinkling/cigarette paper skin), excoriations, petechiae/ecchymosis, telangiectasias, erosions, fissures, or ulcers. Grading was based on 0 (clear), 1 (almost clear), 2 (mild), 3 (moderate), and 4 (severe). IGA-TS response was defined as an IGA score of 0 or 1 with a ≥2-grade improvement from Baseline at each scheduled post-Baseline visit. Participants with a score of 0 have a morphology of: no inflammatory signs (no erythema, no induration/papulation). Postinflammatory hyperpigmentation and/or hypopigmentation may be present. Participants with a score of 1 have a morphology of: barely perceptible erythema, barely perceptible induration/papulation/elevation, and/or minimal scale. Features include palpable, slightly erythematous papules.

ITT Population. Only participants with available data were analyzed.

The IGA is a global assessment tool to assess the severity of lesions. The IGA includes items such as depigmentation/hypopigmentation, lichenification (fine wrinkling/cigarette paper skin), excoriations, petechiae/ecchymosis, telangiectasias, erosions, fissures, or ulcers. Grading was based on 0 (clear), 1 (almost clear), 2 (mild), 3 (moderate), and 4 (severe). IGA-TS response was defined as an IGA score of 0 or 1 with a ≥2-grade improvement from Baseline at each scheduled post-Baseline visit. Participants with a score of 0 have a morphology of: no inflammatory signs (no erythema, no induration/papulation). Postinflammatory hyperpigmentation and/or hypopigmentation may be present. Participants with a score of 1 have a morphology of: barely perceptible erythema, barely perceptible induration/papulation/elevation, and/or minimal scale. Features include palpable, slightly erythematous papules.

ITT Population. Only participants with available data were analyzed.

ITCH4 response was defined as a ≥4-point improvement in the Itch Numeric Rating Scale (NRS) score from Baseline at each scheduled post-Baseline visit, up to and including Week 32. The Itch NRS is a daily participant-reported measure (24-hour recall) of the worst level of itch intensity. Participants were instructed to complete and record their Itch NRS in a diary each evening beginning on the day of screening through Week 32 or treatment discontinuation. Participants rated itch severity of their lichen planus by selecting a number from 0 (no itch) to 10 (worst imaginable itch) that best described the worst level of itch they experienced in the past 24 hours.

ITT Population. Only participants with available data were analyzed.

ITCH4 response was defined as a ≥4-point improvement in the Itch Numeric Rating Scale (NRS) score from Baseline at each scheduled post-Baseline visit, up to and including Week 32. The Itch NRS is a daily participant-reported measure (24-hour recall) of the worst level of itch intensity. Participants were instructed to complete and record their Itch NRS in a diary each evening beginning on the day of screening through Week 32 or treatment discontinuation. Participants rated itch severity of their lichen planus by selecting a number from 0 (no itch) to 10 (worst imaginable itch) that best described the worst level of itch they experienced in the past 24 hours.

ITT Population. Only participants with available data were analyzed.

ITCH4 response was defined as a ≥4-point improvement in the Itch Numeric Rating Scale (NRS) score from Baseline at each scheduled post-Baseline visit, up to and including Week 32. The Itch NRS is a daily participant-reported measure (24-hour recall) of the worst level of itch intensity. Participants were instructed to complete and record their Itch NRS in a diary each evening beginning on the day of screening through Week 32 or treatment discontinuation. Participants rated itch severity of their lichen planus by selecting a number from 0 (no itch) to 10 (worst imaginable itch) that best described the worst level of itch they experienced in the past 24 hours.

ITT Population. Only those participants achieving a ≥4-point improvement in daily Itch NRS score from Baseline were analyzed.

Participants were instructed to complete and record the Skin Pain NRS in a diary each evening beginning on the day of screening through Week 32 or treatment discontinuation. Participants rated their pain, which included all types of pain (e.g., burning, tearing, pulling, stabbing, etc.) severity of lichen planus by selecting a number from 0 (no pain) to 10 (worst imaginable pain) that best described the worst level of pain they experienced in the past 24 hours. Change from Baseline was calculated as the post-Baseline value minus the Baseline value.

ITT Population. No imputation was performed for missing values. Only participants with available data were analyzed.

Participants were instructed to complete and record the Skin Pain NRS in a diary each evening beginning on the day of screening through Week 32 or treatment discontinuation. Participants rated their pain, which included all types of pain (e.g., burning, tearing, pulling, stabbing, etc.) severity of lichen planus by selecting a number from 0 (no pain) to 10 (worst imaginable pain) that best described the worst level of pain they experienced in the past 24 hours. Change from Baseline was calculated as the post-Baseline value minus the Baseline value.

ITT Population. Only participants with available data were analyzed.

An adverse event (AE) was defined as any untoward medical occurrence associated with the use of a drug in humans, whether or not it is considered drug related. An AE could therefore have been any unfavorable or unintended sign (including an abnormal laboratory finding), symptom, or disease (new or exacerbated) temporally associated with the use of study drug. A TEAE was defined as an AE either reported for the first time or the worsening of a pre-existing event after the first application of study drug.

Safety Population: all participants who applied ruxolitinib 1.5% cream BID or vehicle cream BID at least once. Treatment groups for this population were determined according to the actual treatment the participant applied on Day 1 regardless of assigned study drug treatment.

A TEAE was defined as an AE either reported for the first time or the worsening of a pre-existing event after the first application of study drug. The severity of AEs was assessed using the Common Terminology Criteria for Adverse Events (CTCAE) version 5.0 (v5.0) Grades 1 through 5. The investigator made an assessment of intensity for each AE and SAE reported during the study and assigned it to 1 of the following categories: Grade 1: mild; asymptomatic or mild symptoms; clinical or diagnostic observations only; treatment not indicated. Grade 2: moderate; minimal, local, or noninvasive treatment indicated; limiting age-appropriate activities of daily living. Grade 3: severe or medically significant but not immediately life-threatening; hospitalization or prolongation of hospitalization indicated; disabling; limiting self-care activities of daily living. Grade 4: life-threatening consequences; urgent treatment indicated. Grade 5: fatal.

Safety Population

An AE was defined as any untoward medical occurrence associated with the use of a drug in humans, whether or not it is considered drug related. An AE could therefore have been any unfavorable or unintended sign (including an abnormal laboratory finding), symptom, or disease (new or exacerbated) temporally associated with the use of study drug. A TEAE was defined as an AE either reported for the first time or the worsening of a pre-existing event after the first application of study drug.

Open-label Extension Evaluable Population: all participants who applied ruxolitinib 1.5% cream at least once during the Open-label Extension Period

A TEAE was defined as an AE either reported for the first time or the worsening of a pre-existing event after the first application of study drug. The severity of AEs was assessed using the CTCAE v5.0 Grades 1 through 5. The investigator made an assessment of intensity for each AE and SAE reported during the study and assigned it to 1 of the following categories: Grade 1: mild; asymptomatic or mild symptoms; clinical or diagnostic observations only; treatment not indicated. Grade 2: moderate; minimal, local, or noninvasive treatment indicated; limiting age-appropriate activities of daily living. Grade 3: severe or medically significant but not immediately life-threatening; hospitalization or prolongation of hospitalization indicated; disabling; limiting self-care activities of daily living. Grade 4: life-threatening consequences; urgent treatment indicated. Grade 5: fatal.

Open-label Extension Evaluable Population