A Study to Evaluate the Durability of Response of CTP-543 in Adult Patients With Moderate to Severe Alopecia Areata

SALT is a quantitative assessment of scalp hair loss with scores ranging from 0 (no scalp hair loss) to 100 (complete scalp hair loss). LOM is defined as an absolute SALT score >20. The percentage of participants achieving LOM criteria (SALT >20) was compared to the percentage of participants maintaining treatment success (SALT ≤ 20) for each of the following dose reduction conditions. Due to the variable time on study for each participant within Part A Period 2, the primary analysis visit was the end of Part A Period 2, where the last observed non-missing SALT value was selected for each participant.

SALT is a quantitative assessment of scalp hair loss with scores ranging from 0 (no scalp hair loss) to 100 (complete scalp hair loss). LOM is defined as an absolute SALT score >20. The percentage of participants achieving LOM criteria (SALT >20) was compared to the percentage of participants maintaining treatment success (SALT ≤ 20) for each of the following dose discontinuation conditions. Due to the variable time on study for each participant within Part A Period 2, the primary analysis visit was at the end of Part A Period 2, where the last observed non-missing SALT value was selected for each participant.

SALT is a quantitative assessment of scalp hair loss with scores ranging from 0 (no scalp hair loss) to 100 (complete scalp hair loss). ROR is defined as the participant's attainment of an absolute SALT score of ≤20 at Week 24 of re-treatment.

SALT is a quantitative assessment of scalp hair loss with scores ranging from 0 (no scalp hair loss) to 100 (complete scalp hair loss). LOM is defined as an absolute SALT score >20.

SALT is a quantitative assessment of scalp hair loss with scores ranging from 0 (no scalp hair loss) to 100 (complete scalp hair loss). LOM is defined as an absolute SALT score >20.

SPRO is a questionnaire answered by the participant and designed to measure how satisfied alopecia areata participants are with their hair at the time of the assessment. The responses range from 1 to 5: 1= very satisfied, 2= satisfied, 3= neither satisfied nor dissatisfied, 4= dissatisfied, and 5= very dissatisfied. SPRO responder is defined as a post-baseline response of 'very satisfied' or 'satisfied'.

SALT is a quantitative assessment of scalp hair loss with scores ranging from 0 (no scalp hair loss) to 100 (complete scalp hair loss).

SALT is a quantitative assessment of scalp hair loss with scores ranging in severity from 0 (no scalp hair loss) to a maximum of 100 (complete scalp hair loss). Relative change (percent change) to baseline is calculated as: 100 x ([post-baseline SALT score - baseline SALT score]/baseline SALT score). Negative change indicates no hair loss.

The CGI-I is a questionnaire that asks the clinician to evaluate the improvement or worsening of the participant's alopecia areata as compared to the start of the study on a 7-point scale. Responses range from 1 (very much worse) to 7 (very much improved). Responders were defined as participants with responses of 6 (much improved) or 7 (very much improved).

The PGI-I is a self-administered questionnaire that asks the participant to evaluate the improvement or worsening of their alopecia areata as compared to the start of the study on a 7-point scale. Responses range from 1 (very much worse) to 7 (very much improved). Responders were defined as participants with responses of 6 (much improved) or 7 (very much improved). PGI responder is a response of 'very much improved' or 'much improved'.

The CGI-S is a questionnaire that asks the clinician to evaluate the symptom severity of the participant's alopecia areata at the time of assessment. The symptom severity was rated on a scale ranging from 1 to 7, where 1=normal, no hair loss; 2=borderline hair loss; 3=mild hair loss; 4=moderate hair loss; 5=marked hair loss; 6=severe hair loss; 7=among the most extreme hair loss. Higher scores indicate more hair loss. A negative change from baseline indicates less hair loss.

The PGI-S is a self-administered questionnaire that asks the participant to evaluate the symptom severity of their alopecia areata at the time of assessment. Symptom severity was rated on a scale ranging from 1 to 7, where 1=normal, no hair loss; 2=borderline hair loss; 3=mild hair loss; 4=moderate hair loss; 5=marked hair loss; 6=severe hair loss; 7=among the most extreme hair loss. Higher scores indicate more hair loss. A negative change from baseline indicates less hair loss.

The QPRO questionnaire provides additional details on key attributes of hair and helps provide context to the SPRO response. The individual items of QPRO are: Satisfied thickness hair coverage; Satisfied evenness hair coverage; How satisfied with your eyebrows; How satisfied with your eyelashes, scored on a scale ranging from 1 to 5 where 1=very satisfied, 2=satisfied, 3=neither satisfied nor dissatisfied, 4=dissatisfied, 5=very dissatisfied. Higher scores indicates the greater dissatisfaction on hair quality. A negative change from baseline indicate the greater satisfaction on hair quality.

SALT is a quantitative assessment of scalp hair loss with scores ranging from 0 (no scalp hair loss) to 100 (complete scalp hair loss). ROR is defined as the participant's attainment of an absolute SALT score of ≤20 during re-treatment.

SALT is a quantitative assessment of scalp hair loss with scores ranging in severity from 0 (no scalp hair loss) to a maximum of 100 (complete scalp hair loss). Relative change (percent change) to baseline is calculated as: 100 x ([post-baseline SALT score - baseline SALT score]/baseline SALT score).

An adverse event is any untoward medical occurrence that may appear or worsen in a participant during the course of a study. It may be a new intercurrent illness, a worsening concomitant illness, an injury, or any concomitant impairment of the patient's health, including laboratory test values, regardless of etiology. Any worsening (ie, any clinically significant adverse change in the frequency or intensity of a pre-existing condition) should be considered an adverse event. TEAEs were defined as any adverse event that occurs after administration of the first dose of study drug in each Part/Period (ie, on or after the day of the first dose in each Part/Period). TEAEs included both serious and non-serious TEAEs.