Study to Evaluate the Efficacy and Safety of Deuruxolitinib in Adolescents With Severe Alopecia Areata

Inclusion Criteria: * Clinical presentation compatible with alopecia areata with a current episode lasting at least 6 months and not exceeding 10 years. * Between 12 to \<18 years of age * At least 50% scalp hair loss, as defined by a Severity of Alopecia Tool (SALT) score ≥50. * Willing to comply with the study visits and requirements of the study protocol Exclusion Criteria: * Active scalp inflammation, psoriasis, or seborrheic dermatitis requiring topical treatment to the scalp, significant trauma to the scalp, or other scalp condition that may interfere with the SALT assessment, or untreated actinic keratosis at Screening and/or Baseline * Treatment with other medications or agents within 28 days of Baseline or during the study that may affect hair regrowth or immune response. * Females who are nursing, pregnant, or planning to become pregnant while in the study, and for 30 days after last dose of study drug. * Clinically significant medical condition, psychiatric disease, or social condition, as determined by the Investigator, that may unfavorably alter the risk-benefit of study participation, adversely affect study compliance, or confound interpretation of study results.