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

Inclusion Criteria:

* Written informed consent has been obtained.
* Japanese subjects with severe alopecia areata who are between 18 and 65 years of age, inclusive, at the time of informed consent.
* Definitive diagnosis of alopecia areata with a current episode of scalp hair loss lasting at least 6 months.
* SALT score of 50 or more at both Screening and Baseline.

Exclusion Criteria:

* Treatment with systemic immunosuppressive medications or agents, including Janus kinase inhibitors, within 4 months prior to randomization.
* Treatment with biologics within 6 months prior to Screening.
* Positive test results for hepatitis B virus, hepatitis C virus, or human immunodeficiency virus at Screening.
* History of active tuberculosis, a positive interferon gamma release assay at Screening, or evidence of tuberculosis-related lesions on chest radiography.
* Clinically significant hematologic abnormalities, hepatic impairment, or renal impairment at Screening.