Placebo to match ritlecitinib 50 mg

B7981027 - A PHASE 3 RANDOMIZED, DOUBLE-BLIND, PLACEBO-CONTROLLED STUDY TO INVESTIGATE THE EFFICACY AND SAFETY OF RITLECITINIB IN PEDIATRIC PARTICIPANTS 6 TO LESS THAN 12 YEARS OF AGE WITH SEVERE ALOPECIA AREATA

B7981028 - A LONG-TERM, DOUBLE-BLIND EXTENSION STUDY TO INVESTIGATE THE SAFETY AND EFFICACY OF RITLECITINIB IN PARTICIPANTS WITH SEVERE ALOPECIA AREATA WHO PREVIOUSLY COMPLETED STUDIES B7981027 OR B7981031