The purpose of this observation study is to learn about the safety and effects of the study medicine (called Litfulo) for the potential treatment of Severe Alopecia Areata.

To evaluate the safety of Litfulo Capsule after marketing, with regard to the following clauses in routine clinical practice.

• Adverse Events (AEs)/ Adverse Drug Reactions (ADRs)

• Unexpected Adverse Events (AEs)/ADRs that have not been reflected in the approved drug label

• Serious Adverse Events (SAEs)/Serious Adverse Drug Reaction (SADRs)

• Adverse Event of Special Interest(AESI)

  • Serious Infections, defined as any infection (viral, bacterial, and fungal) requiring parenteral antimicrobial therapy or hospitalization for treatment or meeting other criteria that require the infection to be classified as serious adverse event
  • Opportunistic infections and Herpes Zoster
  • Malignancy

Inclusion Criteria:

Patients with severe alopecia areata who have been determined to start treatment with Litfulo Capsule according to the approved indications of the medicinal product Treatment of severe alopecia areata in adults and adolescents 12 years or older Evidence of a personally signed and dated informed consent document indicating that the patient or their parent(s)/legal guardian, if applicable, have been informed of all pertinent aspects of the study

Patients with severe alopecia areata

Pfizer will provide access to individual de-identified participant data and related study documents (e.g. protocol, Statistical Analysis Plan (SAP), Clinical Study Report (CSR)) upon request from qualified researchers, and subject to certain criteria, conditions, and exceptions. Further details on Pfizer's data sharing criteria and process for requesting access can be found at: https://www.pfizer.com/science/clinical\_trials/trial\_data\_and\_results/data\_requests.