A Phase 3b, Multicenter, Rollover Study for Participants Previously Enrolled in Clinical Trials of Povorcitinib

Inclusion Criteria: * Ability to comprehend and willingness to sign a written ICF for the study. * Completed the treatment period of a predetermined, Incyte-sponsored, povorcitinib parent study without safety or tolerability concerns, per investigator's assessment. * Received clinical benefit from treatment with study drug during the parent study, as determined by the investigator. * Demonstrated compliance, as assessed by the investigator, with the parent Protocol requirements. * Willingness to avoid pregnancy or fathering children as defined in the protocol. * Willingness and ability to com…